What is colon cancer?. How common is colon cancer?. What are the risk factors for colon cancer?.

What is Colon Cancer?

Colon cancer forms in the tissues of the colon, which is part of the large intestine. The colon is part of the body’s digestive system, which is made up of the esophagus, stomach, and the small and large intestines. The first six feet of the large intestine are called the colon, and the remaining several inches form the rectum.

Different types of cancer can develop in the colon, but most colon cancers are adenocarcinomas, which are cancers from glandular tissue. Other cancer types that can occur in the colon include carcinoid tumors, small cell carcinomas, and gastrointestinal stromal tumors (GIST). The focus of this information is on colon cancers that are adenocarcinomas.

How Common is Colon Cancer?

Colon and rectal cancers are the fourth most common cancers diagnosed in the United States. Survival after diagnosis has been gradually increasing in the past decade. This is due to several reasons, including screening programs that can catch the disease in its pre-cancerous or early stages, which are more curable, and better treatments, both surgical techniques and chemotherapies, including targeted therapies.

Most colon cancers start as polyps, or growths in the colon. Over time, some, but not all polyps change into cancers. Polyps that have a higher risk of becoming cancer are known as adenomas. The reason screening is so important is that finding polyps before they become cancer reduces the risk of developing colon cancer by at least 90 percent.

What are the Risk Factors for Colon Cancer?

Risk factors for colon cancer include increasing age, with most people who develop colon cancer being 50 or older, a family history of cancer of the colon or rectum, certain hereditary conditions such as familial adenomatous polyposis and hereditary nonpolyposis colon cancer (Lynch syndrome), a history of inflammatory bowel disease (IBD) such as ulcerative colitis and Crohn’s disease, and a personal history of cancer of the colon, rectum, ovary, endometrium, or breast.

A personal or family history of adenomas (polyps) in the colon or rectum can also increase the risk of developing colon cancer, as these growths can be pre-cancerous. Regular screening to remove them reduces the risk of developing colon cancer.

What are the Symptoms of Colon Cancer?

What are the symptoms of colon cancer? Colon cancer can cause a variety of symptoms, including changes in bowel habits, such as diarrhea, constipation, or narrowing of the stool, rectal bleeding or blood in the stool, abdominal discomfort, such as cramps, gas, or pain, a feeling of not being able to fully empty the bowel, and unexplained weight loss.

These symptoms can be caused by conditions other than colon cancer, so it’s important to see a healthcare provider if you experience any of them. Early detection is key, as colon cancer is highly treatable when caught early.

How is Colon Cancer Diagnosed?

How is colon cancer diagnosed? Colon cancer is typically diagnosed through a combination of tests, including a physical exam, blood tests, imaging tests such as a colonoscopy or CT scan, and biopsy. A colonoscopy is the gold standard for detecting and diagnosing colon cancer, as it allows the healthcare provider to visually inspect the entire colon and rectum and take samples of any suspicious areas for further testing.

If colon cancer is detected, additional tests may be performed to determine the stage of the cancer and develop a treatment plan. Early detection is crucial, as colon cancer is highly treatable when caught in its early stages.

How is Colon Cancer Treated?

How is colon cancer treated? The treatment for colon cancer depends on the stage of the cancer, the location of the tumor, and the overall health of the patient. Common treatment options include surgery to remove the tumor, chemotherapy, radiation therapy, and targeted therapies.

Surgery is often the first line of treatment for colon cancer, and may involve removing the tumor and a portion of the healthy tissue surrounding it. Chemotherapy may be used before or after surgery to help shrink the tumor or kill any remaining cancer cells. Radiation therapy may also be used, particularly for rectal cancers. Targeted therapies, which target specific genetic or molecular changes in cancer cells, are also being increasingly used to treat colon cancer.

What is the Prognosis for Colon Cancer?

What is the prognosis for colon cancer? The prognosis for colon cancer depends on the stage of the cancer at the time of diagnosis. When caught early, colon cancer is highly treatable, with a 5-year survival rate of over 90% for stage I cancers. However, as the cancer becomes more advanced, the prognosis declines, with the 5-year survival rate dropping to around 14% for stage IV cancers.

That said, even for more advanced cases, new treatments are constantly being developed and the overall prognosis for colon cancer has been improving in recent years. With early detection and comprehensive treatment, many patients with colon cancer can go on to live long, healthy lives.

About Colon Cancer – Dana-Farber Cancer Institute

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  Signs and Symptoms of Colon and Rectal Cancer
  Dana-Farber’s Jeffrey Meyerhardt, MD, talks about symptoms, screening, and what you can do to prevent colon and rectal cancer.

  
  
  
  
  




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  What is colon cancer?

  Colon cancer forms in the tissues of the colon, which is part of the large intestine.

  The colon is part of the body’s digestive system, which is made up of the esophagus, stomach, and the small and large intestines. The first six feet of the large intestine are called the colon. The remaining several inches of the large intestine form
  the rectum.

  Different types of cancer can develop in the colon. Most colon cancers are adenocarcinomas, which are cancers from glandular tissue. Other cancer types that can occur in the colon include
  carcinoid tumors, small cell carcinomas, and
  gastrointestinal stromal tumors (GIST).

  The focus of this information is on colon cancers that are adenocarcinomas.

  Colon and rectal cancers are the fourth most common cancers diagnosed in the United States. Survival after diagnosis has been gradually increasing in the past decade. There are several reasons for this. First, screening programs can catch the disease
  in its pre-cancerous or early stages, which are more curable. Second, there are better treatments, both surgical techniques and chemotherapies, including targeted therapies.

  Our team has been a leader in
  clinical trials for various treatments for colon cancer to improve outcomes for patients and survivors.

  When detected early, colon cancer is a very treatable form of cancer. The earlier it is found, the more likely it is that the cancer will be cured. As the cancer becomes more advanced, the cure rate declines, but it may still be treatable for long periods
  of time.

  Most colon cancers start as polyps, or growths in the colon. Over time, some, but not all polyps change into cancers. Polyps that have a higher risk becoming cancer are known as adenomas.

  • The reason screening is so important is that finding polyps before they become cancer reduces the risk of developing colon cancer by at least 90 percent.
  • Finding ways to prevent polyps from forming is an important area of ongoing research at Dana-Farber Brigham Cancer Center.

  Incidence

  • Together, colon and rectal cancer are the fourth most common type of cancers in the United States.
  • Colon cancer is mainly a disease of developed countries with a Western culture.
  • The disease is most often diagnosed in people 50 and older. However, it can affect those younger and appears to be increasing among younger people, though the reason for this is not known.
  • Colon cancer affects men and women about equally.

  Risk factors

  Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors does not mean that you will not get cancer. Risk factors for colon cancer include:

  • Increasing age: Most people who develop colon cancer are 50 or older.
  • A family history of cancer of the colon or rectum.
  • Certain hereditary conditions, such as
    familial adenomatous polyposis, and hereditary nonpolyposis colon cancer, called
    Lynch syndrome.
    • Dana-Farber Brigham Cancer Center’s team of international leaders in the genetics of cancer has a well-established
      program focused on colorectal cancer.
  • A history of inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn’s disease
  • A personal history of cancer of the colon, rectum, ovary, endometrium, or breast.
  • A personal or family history of adenomas (polyps) in the colon or rectum. These growths can be pre-cancerous. Most adenomas will not turn into cancer. However, regular screening to remove them reduces the risk of developing colon cancer.
  • Environmental and lifestyle-related factors, such as lack of exercise, obesity, smoking, and alcohol consumption.
    • Our team works on research with the Harvard T.H. Chan School of Public Health and has published many landmark papers on diet, lifestyle, and the risk of colon cancer.
  • A diet high in red and processed meat.
  • Low vitamin D levels.
    • Our team has published many studies on – and is currently conducting several trials testing –
      the role of vitamin D in the treatment of colon cancer.

  According to research conducted at Dana-Farber Brigham Cancer Center, 70 to 80 percent of colon cancer cases may be prevented through exercise, weight control, limiting alcohol consumption, and taking aspirin and vitamin D.

  People with a family history of colon cancer and/or other cancers in several close relatives across generations – especially if these cancers occur at a young age – may benefit from genetic counseling and testing.

  Learn more about the importance of
  exercise and
  good nutrition in cancer prevention for cancer patients and survivors.

  Learn more about having a family history of cancer and genetic risk factors through our
  Center for Cancer Genetics and Prevention.

  Symptoms and signs

  Potential symptoms and signs of colon cancer include:

  • A change in bowel habits.
  • Blood (either bright red or very dark) in the stool.
  • Diarrhea, constipation, or feeling that the bowel does not empty all the way.
  • Stools that are narrower than usual.
  • Frequent gas pains, bloating, fullness, or cramps.
  • Weight loss for no known reason.
  • Feeling very tired.
  • Vomiting.
  • Anemia (low red blood cell count).

  It is important to know that these symptoms and signs can have many causes, and may not be due to cancer. However, it is important that you discuss these symptoms or signs with your doctor.

  Further, many people, particularly those with polyps or early stages of colon cancer, may not have any symptoms or show any signs, making it difficult to detect without regular screening. Several screening methods make it possible to find some cancers
  before symptoms appear.

  Screening and prevention

  Screening for colon cancer helps prevent the disease and decrease the number of deaths from it. Some tests to find polyps can actually prevent the development of cancer because doctors can remove the growths before they become problems.

  There are several ways to screen for colon cancer. Each type of test has advantages and disadvantages, due to risks from the test and the sensitivity/accuracy of the test. You should talk to your doctor about when to begin screening for colon cancer,
  what test to have, the benefits and drawbacks of each test, how often to undergo screening, and when to stop screening.

  Options for screening include:

  • Fecal occult blood testing: A test to check stool (solid waste) for blood that can be seen only with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.
  • Sigmoidoscopy: A procedure to look inside the rectum and sigmoid (lower) colon for polyps (small areas of bulging tissue), other abnormal areas, or cancer. A sigmoidoscope is inserted through the rectum into the sigmoid colon. A sigmoidoscope
    is a thin, tube-like instrument with a light and a lens for viewing. It also has a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
  • Colonoscopy: A procedure to look inside the rectum and entire colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and
    a lens for viewing. It will also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.

  • Virtual colonoscopy: A procedure that uses a series of x-rays called computed tomography (CT) to make a series of pictures of the colon. A computer puts the pictures together to create detailed images that may show polyps and anything
    else that seems unusual on the inside surface of the colon. This test is also called colonography, or CT colonography.
  • DNA test: A test of the stool for small pieces of DNA that come from cells lining the colon and rectum. It looks for abnormal DNA that may be due to a cancer.
  • Double-contrast barium enema: A series of x-rays of the lower gastrointestinal tract. A liquid that contains barium (a silver-white metallic compound) is put into the rectum. The barium coats the lower gastrointestinal tract and x-rays
    are taken. This procedure is also called a lower GI series. It is rarely used anymore.

  The
  National Cancer Institute website describes these tests in more detail.

  Related links

  • Researchers find a possible link between bacterium and colon cancer
  • Should I get a colonoscopy?
  • Study reinforces the value of colonoscopy screening for prevention
  • Colorectal cancer screening recommendations

Most Common and Rare Forms

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science.

This page was updated on August 11, 2022.

Colorectal cancer develops in the colon or in the rectum. If it starts in the colon, it may be referred to as colon cancer. If it starts in the rectum, it may be called rectal cancer. Regardless of where they start, however, these cancers share a lot in common, which is why they’re together known as colorectal cancer.

The most common type of colorectal cancer is adenocarcinoma. Adenocarcinomas of the colon and rectum make up 95 percent of all colorectal cancer cases. In the gastrointestinal tract, rectal and colon adenocarcinomas develop in the cells of the lining inside the large intestine. These adenocarcinomas typically start as a growth of tissue called a polyp. A particular type of polyp called an adenoma may develop into cancer. Colorectal polyps are often removed during a routine colonoscopy before they may turn cancerous.

While other types of tumors may develop in the colon or rectum, they’re much more rare. Less common types of colorectal cancer include:

• Primary colorectal lymphomas
• Gastrointestinal stromal tumors
• Leiomyosarcomas
• Carcinoid tumors
• Melanomas

This article will cover:

• Types of colorectal cancer
• Rare types of colorectal cancer
• Genetic risks

Types of colorectal cancer

Colorectal adenocarcinoma

“Adeno” is a prefix meaning gland. “Carcinoma” is a type of cancer that grows in epithelial cells, which line the surfaces inside and outside the body. Adenocarcinomas develop in the lining of the large intestine (colon) or the end of the colon (rectum). They often start in the inner lining and spread to other layers.

There are two less common subtypes of adenocarcinomas:

• Mucinous adenocarcinoma is made up of about 60 percent mucus. The mucus may cause cancer cells to spread more quickly and become more aggressive than typical adenocarcinomas. Mucinous adenocarcinomas account for 10 percent to 15 percent of all rectal and colon adenocarcinomas.
• Signet ring cell adenocarcinoma accounts for fewer than 1 percent of all colon cancers. Named for its appearance under a microscope, signet ring cell adenocarcinoma is typically aggressive and may be more difficult to treat.

Most information about colorectal cancer refers to colorectal adenocarcinoma, the most common type. Estimates suggest that 4. 1 percent of people may develop colorectal cancer during their life, according to the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program.

Colorectal adenocarcinoma symptoms generally include:

• Abdominal pain and tenderness
• Blood in stool
• Changes in bowel habits, such as diarrhea or constipation
• Thin stools
• Unexplained weight loss

Getting screened for colon cancer may detect the disease before it starts causing symptoms. The American Cancer Society (ACS) and the U.S. Preventive Services Task Force both recommend adults start colon cancer screening at age 45.

Diagnosing colorectal cancer starts with a colonoscopy, which lets doctors see inside the rectum and colon. If signs of colorectal cancer are discovered during a colonoscopy, other tests will follow. A biopsy may be performed, which involves removing a small piece of potentially cancerous tissue (sometimes during a colonoscopy) and analyzing the sample for the presence of cancer. Once a diagnosis is confirmed by a colonoscopy and a biopsy, blood tests and imaging tests, such as computed tomography (CT) scans and magnetic resonance imaging (MRI) scans, may be used to help learn more about the cancer and whether it’s spread.

Common treatment options for colorectal adenocarcinomas include:

• Surgery
• Chemotherapy
• Radiation therapy
• Targeted therapy

Gastrointestinal carcinoid tumors

Carcinoid tumors develop in nerve cells called neuroendocrine cells, which help regulate hormone production. These tumors are among a group of cancers called neuroendocrine tumors (NETs). Carcinoid tumor cells are slow-growing and may develop in the lungs and/or gastrointestinal tract. They account for about 1 percent of all colorectal cancers and half of all cancers found in the small intestine.

Potential symptoms differ depending on where the tumor grows. A carcinoid tumor in the appendix typically doesn’t cause symptoms, unless it begins to block the pathway from the appendix to the intestine, leading to appendicitis symptoms such as fever, nausea and vomiting.

Tumors in the small intestine or colon may cause stomach cramps and pain, weight loss, tiredness, bloating and other stomach problems. Carcinoid tumors in the rectum may cause pain, bleeding and constipation. In the stomach, carcinoid tumors typically don’t cause symptoms.

Carcinoid tumors also sometimes produce hormones that may lead to various symptoms, depending on the type of hormone. For example, 10 percent of people with these tumors may experience flushing in the face, diarrhea, wheezing and rapid heartbeat due to certain hormone-like substances that are released by the tumor, according to the ACS.

Depending on where they develop, gastrointestinal carcinoid tumors may be discovered in various ways. For example, a tumor in the appendix may be found after it causes appendicitis, and the appendix is removed. Rectal tumors may be detected during routine checkups.

Several tests are used to diagnose carcinoid tumors in the abdominal tract, including blood tests, urine tests, imaging scans, endoscopy and colonoscopy.

Gastrointestinal carcinoid tumor treatment options include:

• Surgery
• Radiation therapy
• Chemotherapy
• Hormone therapy

Rare types of colorectal cancer

Other types of rare colorectal cancers combined account for less than 5 percent of all cases:

Primary colorectal lymphomas

A type of non-Hodgkin lymphoma, this cancer type develops in the lymphatic system, specifically in cells called lymphocytes. Lymphocytes are a type of white blood cell that helps the body fight infections. Lymphoma may develop in many parts of the body, including the lymph nodes, bone marrow, spleen, thymus and the digestive tract. Primary colorectal lymphomas account for 0.5 percent of all colorectal cancers and about 5 percent of lymphomas. This colorectal cancer type usually develops later in life and is more common in men.

Symptoms may include indigestion, bloating, unexplained weight loss, stomach pain, vomiting, diarrhea and other stomach issues. Diagnosis may involve biopsy and endoscopy.

Treatment options vary but may include:

• Chemotherapy
• Radiation therapy
• Surgery

Gastrointestinal stromal tumors

Gastrointestinal stromal tumors are a rare type of colorectal cancer that forms in special cells found in the lining of the gastrointestinal (GI) tract called interstitial cells of Cajal (ICCs). More than 50 percent of GISTs develop in the stomach. While most other GISTs form in the small intestine, the rectum is the third most common location. GISTs are classified as sarcomas, or cancers that begin in the connective tissues, which include fat, muscle, blood vessels, deep skin tissues, nerves, bones and cartilage.

While estimates are uncertain, about 4,000 to 6,000 cases of GIST are diagnosed in the United States every year, according to the ACS. These tumors tend to take a while to grow large enough to start causing symptoms. However, they may cause bleeding in the gastrointestinal tract. Depending on the location of the tumor, blood may show up in vomit or bowel movements. Over time, slow bleeding may lead to a decrease in the amount of red blood cells, a condition called anemia, which causes fatigue and weakness.

Other potential symptoms include:

• Abdominal pain
• Abdominal mass or lump
• Nausea
• Vomiting
• Poor appetite
• Weight loss
• Swallowing problems

The diagnostic process may involve an endoscopy, colonoscopy, biopsy and various imaging tests.

Some smaller GISTs may not need to be treated right away, while others are typically treated with surgery and targeted therapy.

 Colon and rectal leimyosarcomas

Another form of sarcoma, leiomyosarcoma essentially means “cancer of smooth muscle.” The colon and rectum have three layers of the type of muscle affected by leiomyosarcoma, and all three work together to guide waste through the digestive tract. This rare type of colorectal cancer accounts for about 0.1 percent of all colorectal cases.

In the early stages, leiomyosarcomas in the colon or rectum may not cause symptoms. As the cancer progresses, symptoms may include fatigue, weight loss, vomiting blood, changes in stools and other stomach problems. Diagnosis generally includes standard measures, such as a biopsy, blood tests and imaging tests. Treatment typically starts with surgery to remove the tumor. Other treatment options include radiation therapy and chemotherapy.

Colon and rectal melanomas

Most commonly associated with skin cancer, these may start to develop anywhere, including in the colon or rectum, or may spread to the GI tract from the primary melanoma site. Melanomas account for 1 percent to 3 percent of all cancers that develop in the digestive system, according to research published in BMJ Case Reports. How melanomas develop in the colon isn’t well understood, as it’s extremely rare. Diagnosis may involve a biopsy and other tests to determine whether the cancer spread from elsewhere in the body or started in the colon or rectum.

Colorectal melanoma treatment may include:

• Surgery
• Immunotherapy
• Chemotherapy
• Radiation therapy

Colorectal squamous cell carcinoma

This cancer, also known as SCC, is extremely rare in the colon, with fewer than 100 cases reported in the literature as of a 2017 case report in the Journal of Community Hospital Internal Medicine Perspectives. Squamous cell carcinoma is typically associated with skin cancer—it’s the second most common type of skin cancer. Squamous cells are a particular type of cell present in many areas of the body. Squamous cell carcinoma occurs when these cells start growing uncontrollably and become cancerous. The reason why this rarely occurs in the colon and rectum isn’t well understood.

Symptoms may resemble colorectal adenocarcinoma, including stomach issues and changes in stool or bowel habits. Colonoscopy and other tests are used to diagnose this cancer. It’s important to determine whether the cancer started in the colon or rectum, or whether it spread to this region from another area of the body. Treatment isn’t standardized but may include surgery, chemotherapy and radiation therapy.

Familial adenomatous polyposis (FAP)

This accounts for about 1 percent of all cancers in the colon or rectum, according to the ACS. People with this syndrome may develop hundreds or even thousands of colon or rectal polyps. These polyps tend to occur when people with this syndrome are 10 to 12 years old. Nearly all people with FAP develop colorectal cancer during their lifetime, and as a result, some people have their colon removed as a preventative measure.

Genetic risks

If an inherited syndrome associated with colorectal cancer is suspected, the patient may consider undergoing genetic testing. Genetic testing involves taking a sample of blood, hair or other bodily fluids to analyze for DNA mutations linked to cancer or a genetic syndrome. The patient also may be advised to get regular colonoscopies to look for colorectal cancer and to begin screening early.

Peutz-Jeghers syndrome (PJS): This condition causes a particular type of polyp to develop in the gastrointestinal tract, called a hamartoma. This syndrome is inherited from one’s parents and is caused by mutations in a particular gene (STK11). It comes with an increased risk of colorectal cancer and others including breast cancer, ovarian cancer and pancreatic cancer. If colorectal cancer does occur in individuals with PJS, it tends to develop at a younger than average age.

Familial colorectal cancer: Some people inherit genetic syndromes from their parents that increase their risk of getting colorectal cancer. These syndromes come with mutations—in particular, genes that make it more likely that cancer will develop. Examples include Lynch syndrome, familial adenomatous polyposis and other rarer syndromes. Lynch syndrome is associated with about 2 percent to 4 percent of all cancers in the colon or rectum, according to the ACS. People with Lynch syndrome have a high risk of getting colorectal cancer at some point in their lifetime—up to 50 percent. Those who have Lynch syndrome and go on to develop colorectal cancer tend to get the cancer at an earlier than average age.

symptoms, stages, prognosis, survival, diagnosis, treatment of sigmoid colon cancer

Contents

• Causes and risk factors
• Signs of cancer of the sigmoid colon
• Types of sigmoid colon cancer
  • Histological classification
  • Growth classification
  • TNM classification and stages
  • ICD-10 code
• Diagnosis of oncology of the sigmoid colon
• Treatment of sigmoid colon cancer
• Prognosis in cancer of the sigmoid colon
• Prophylaxis

Sigmoid colon cancer is a malignant tumor of the intestine that grows from mucosal epithelial cells. Among all oncological diseases of the intestine, it ranks third, and is diagnosed in 34% of patients. The predominant number of cases is in the age group of 40-60 years, men get sick 1.5 times more often than women. At the initial stage, cancer does not give symptoms, so early diagnosis is possible only with the help of regular screening. The progression of the disease is accompanied by metastasis of the tumor to other parts of the intestine, liver, lungs. Given the small number of early diagnosed cases, cure for sigmoid colon cancer is possible only in 50-60% of patients. The median five-year survival rate is 65%. Treatment of sigmoid colon cancer is carried out by surgical methods, radiation and targeted therapy, chemotherapy.

Causes and risk factors for the development of sigmoid colon cancer

The cause of atypical degeneration of epithelial cells of the intestinal mucosa is the negative influence of external and internal factors. The anatomical features of the sigmoid colon increase the risk of malignancy. The intestine has an S-shape, which is why feces move more slowly through it. This leads to a longer contact with the mucosa of carcinogenic food products. The longer this contact, the higher the likelihood of malignancy of epithelial cells.

Causes and risk factors for the development of sigmoid colon cancer:

• sedentary work, low physical activity;
• predominance in the diet of fried, spicy foods, products of animal origin;
• chronic bowel disease;
• anomalies of intestinal development;
• chronic constipation;
• alcohol abuse, smoking;

90,005 cases of colorectal cancer in the family;

• colon polyps;
• unfavorable ecological situation;
• harmful production factors.

Symptoms of sigmoid colon cancer

The initial stage of sigmoid colon cancer, until the tumor has reached a large size, proceeds without obvious symptoms. As the neoplasm grows, the patient complains of:

• weakness, excessive fatigue;
• rumbling, bloating;
• alternating diarrhea and constipation;
• pain in the lower abdomen;
• mucus in stool, discoloration;
• nausea, loss of appetite.

When the first signs of sigmoid colon cancer appear, you should contact your general practitioner or proctologist. Laboratory and instrumental examination reveals the disease at an early stage, when the most sparing surgical treatment can be dispensed with.

When the tumor reaches a large size, begins to disintegrate, signs of intestinal obstruction appear. Constipation begins to predominate in the patient up to the complete absence of stool, feces acquire a ribbon-like or pea-like shape. Blood and pus appear in the feces. Pain in the abdomen bothers a person more and more often, they have a cramping character.

Advanced cancer leads to severe intoxication. Cancer patients have a characteristic appearance:

• gray-earthy skin color;
• weight loss up to cachexia;
• large belly and thin limbs.

When metastases spread to other organs, symptoms appear that indicate a violation of their function. Metastasis of a malignant neoplasm occurs in three ways:

• lymphogenous – through the lymphatic vessels and nodes;
• hematogenous – with the blood flow, atypical cells are carried to different organs, most often to the lungs, liver, bones;
• implantation – a tumor that has sprouted into the intestinal wall passes to the mesentery, fiber, and peritoneum located nearby.

Classification of cancer of the sigmoid colon

Tumors of the sigmoid colon are classified by cellular origin:

• adenocarcinoma is the most common variant, it is formed from cells of the glandular epithelium, the severity of the course depends on the degree of differentiation of atypical cells;
• cricoid cell carcinoma is a rare form, formed by mucinous cells, characterized by an unfavorable course;
• mucoid cancer – formed by mucinous cells, characterized by low differentiation, rapid growth and metastasis.

Classification according to the nature of tumor growth includes two options – exophytic and endophytic. An exophytic tumor is similar to a polyp with a stalk, growing into the intestinal lumen. Endophytic cancer spreads inside the intestinal wall, has an annular shape.

Classification by TNM and stage

The TNM classification of sigmoid colon cancer generally accepted in oncology takes into account the size of the primary tumor, metastases of lymph nodes and other organs:

• Tis – the beginning of the formation of a malignant process, damage to the mucosal lamina propria;
• T0 – defeat of the entire submucosal layer;
• T2 – damage to the muscle layer;
• T3 – germination of the tumor throughout the intestinal wall, spreading into the fiber;
• T4 – tumor invasion of surrounding tissues;
• N0 – no damage to the lymph nodes;
• N1 – metastasis to 1-3 nearest lymph nodes;
• N2 – defeat of more than 3 regional lymph nodes;
• M0 – no metastases;
• M1a – metastases in one organ;
• M1b – metastases in several organs;
• M1c – metastasis in the peritoneum.

The following stages of sigmoid colon cancer are distinguished:

• 1 – the tumor is not more than 2 cm, does not extend beyond the mucosa, does not give metastases;
• 2A – formation up to 5 cm, germinates the intestinal wall, does not give metastases;
• 2B – the same as in 2A, but with metastases to the nearest lymph nodes;
• 3A – mass more than 5 cm, metastases to the nearest lymph nodes;
• 3B – widespread tumor with metastases to distant lymph nodes;
• 4A – the tumor blocks the intestinal lumen, metastasizes with blood flow to other organs;
• 4B – spread of cancer to nearby organs with the formation of fistulas, multiple metastasis.

Disease stages according to TNM classification:

• 0 — Tis, N0, M0;
• 1 – T1-2, N0, M0;
• 2 – T3-4, N0, M0;
• 3 – T1-4, N1-2, M0;
• 4 – T any, N any, M0.

ICD-10 code

ICD 10 code for sigmoid colon cancer (International Classification of Diseases) – C18. 7.

Diagnosis of oncology of the sigmoid colon

Diagnosis of cancer of the sigmoid colon is carried out by a coloproctologist. When communicating with the patient, the doctor specifies the nature of health complaints, the conditions for their occurrence and the duration of their existence. With a digital examination of the rectum, the proctologist cannot detect the tumor itself, since it is located much higher. However, traces of blood and pus remain on the glove, which indicates a pathological process in the intestines.

Instrumental and laboratory methods are used to clarify the diagnosis of sigmoid colon cancer. Blood and urine tests indirectly indicate oncopathology:

• moderate or severe anemia;
• increase in ESR and CRP;
• increased liver enzymes;
• vitamin B deficiency;
• bleeding disorder;
• blood in feces.

Imaging methods allow determining the exact position of the tumor, its size and metastasis:

• sigmoidoscopy, colonoscopy allow the doctor to visually assess the condition of the sigmoid colon mucosa, the size and nature of tumor growth, and also take a tissue sample for histological examination;
• computed tomography provides more accurate information about the prevalence of neoplasm in the intestine;
• radiography, ultrasound and magnetic resonance imaging help to identify immediate and distant metastases.

Histological examination provides information about the cellular origin of the tumor, helps to plan treatment and predict the chances of recovery.

Treatment of sigmoid colon carcinoma

An effective and reliable method of cancer treatment is surgery. Removal of part of the intestine with a tumor and adjacent tissues gives a high chance of a full recovery. However, this method works only at stages 1 and 2A of the disease, until the tumor has metastasized. It is extremely rare to detect cancer at these stages, therefore, in most cases, the patient must be treated in combination. Surgical intervention is combined with radiation and targeted therapy, chemotherapy.

During the operation, the surgeon removes the cancerous part of the sigmoid colon, mesentery and adjacent tissue with lymph nodes. The volume of intervention depends on the prevalence and localization of the pathological process. A prerequisite is the removal of 5 cm of apparently unchanged tissue on both sides of the tumor. This is the prevention of the preservation of atypical cells and the recurrence of the disease in the future.

It is important not only to remove the tumor, but also to restore the anatomical structure of the intestine for its full functioning. With a small size of the neoplasm, the surgeon forms an intestinal anastomosis immediately. Such an operation is called a single-stage operation. In severe cases with a large amount of tissue removed, the surgeon first brings the colostomy to the anterior abdominal wall. Anastomosis is formed after a few months, such an operation is called a two-stage operation.

Before and after surgery, the patient receives radiation therapy and chemotherapy. The purpose of their appointment before the operation is to reduce the size of the neoplasm, to suppress the reproduction of atypical cells. After surgery, radiation therapy and chemotherapy destroy the remaining cancer cells and affect distant metastases.

Chemotherapy is used as an independent method of treatment in patients with inoperable tumors, as well as in patients with contraindications to surgery.

Inoperable patients with sigmoid colon cancer undergo palliative therapy, which increases life expectancy and improves its quality:

• irradiation;
• operations to restore bowel function;
• analgesics;
• treatment of concomitant diseases.

Sigmoid colon cancer: prognosis

The prognosis for life and recovery in sigmoid colon cancer depends on the histological type of neoplasm, stage, timely diagnosis and treatment. The median five-year survival rate after combined treatment is 65%. Sigmoid colon carcinoma has a better prognosis than cricoid and mucosal carcinoma.

If treatment for sigmoid colon cancer was started at stage 1, then 5 years or more live 95% of patients. The prognosis for stage 2-3 sigmoid colon cancer is a five-year survival period in 30-50% of patients. At stage 4, five-year survival is possible only in 8%. This is why regular check-ups with colonoscopy are so important. People at risk for developing cancer should be screened annually.

Cancer of the sigmoid colon is completely curable at the first stage; for this, surgical removal of the neoplasm with part of the intestine is used. Starting from the second stage, the effectiveness of treatment decreases, a complete cure cannot be achieved already at stages 3B-4.

Prevention of cancer of the sigmoid colon

Prevention consists in timely detection and removal of risk factors:

• obligatory removal of all intestinal polyps, as they are absolutely precancerous conditions;
• annual examination of people over 40 for fecal occult blood, colonoscopy;
• rational, healthy diet with restriction of carcinogenic products;
• daily intake of fiber in the form of fresh fruits and vegetables;
• prevention of constipation;
• adequate exercise;
• cessation of smoking, alcohol.

Sources:

1. Zakharenko A.A. Staged surgical treatment of a patient with complicated locally advanced cancer of the sigmoid colon / A. A. Zakharenko [et al.] // Bulletin of Surgery. – 2015. – No. 1. – S. 67-70.
2. Demidov S.M. Colorectal cancer and rectal cancer / S.M. Demidov // Textbook. – 2016. – S. 6-36.
3. Davydov M.I. Oncology / M.I. Davydov, Sh.Kh. Gantsev // Textbook. – 2010. -S. 920.
4. Burtsev D.V. The effectiveness of screening for colon tumors on the basis of the regional consultative and diagnostic center / D.V. Burtsev // PM. – 2012. – No. 2. – S. 214-217.

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The information in this article is provided for reference purposes and does not replace the advice of a qualified professional. Do not self-medicate! At the first sign of the disease, you should consult a doctor.

Tumor of the sigmoid colon: cancer of the sigmoid colon, treatment, prognosis, symptoms of oncology of the sigmoid colon In oncology, malignant neoplasms of this localization are called cancer of the rectosigmoid junction.

Together with colon cancer, they are united under the general name of colorectal cancer.

In the vast majority of cases, a malignant tumor of the sigmoid colon is represented by adenocarcinoma. It accounts for 90-95% of all identified malignant neoplasms. The rest of the tumors are represented by the following variants:

• Signet cell.
• Small cell.
• Squamous.
• Medullary.
• Undifferentiated.

Risk group

Currently, several risk factors have been identified, the presence of which increases the likelihood of developing cancer of malignant neoplasms in the sigmoid colon. These include:

Dietary habits

The following dietary habits increase the risk of developing colorectal cancer:

• Excessive consumption of animal fats and red meat.
• Insufficient content of vegetable fiber in the diet.
• Regular consumption of alcohol.
• Excess power.

Vegetarians have been shown to be an order of magnitude less likely to be diagnosed with colorectal cancer than people with a standard diet. For some time, it was even considered that meat is the main carcinogen for the intestines and leads to the formation of malignant tumors. The modern theory is based on the fact that vegetable fibers, which are rich in the diet of vegetarians, cleanse the intestines and do not allow its contents to stagnate. This reduces the contact of the intestinal epithelium with carcinogens and prevents its malignant transformation.

The second risk factor is the presence of polyps . In the vast majority of cases, bowel cancer develops as a result of malignancy of adenomatous polyps. Moreover, the longer it exists and the larger its size, the more likely its malignant degeneration.

Heredity . The role of hereditary predisposition has been proven in relation to two syndromes: familial adenomatous polyposis (FAP) and Lynch syndrome – hereditary non-polyposis colon cancer. The share of hereditary cancer accounts for 5-7% of cases of malignant tumors of cancer of this localization.

Other risk factors:

• Inflammatory bowel disease – ulcerative colitis, Crohn’s disease.
• History of breast and ovarian cancer.
• Immunodeficiency diseases.

Symptoms

The insidiousness of malignant tumors of the sigmoid colon lies in the fact that in the initial stages there are no signs of the disease. The clinical picture unfolds when the process goes into stage 3-4.

At the same time, general and local symptoms are distinguished. Of the general ones, weight loss, chronic fatigue, increased fatigue, pallor and pastosity of the skin (against the background of chronic iron deficiency anemia) are noted.

Local symptoms include:

• Abdominal pain. Pain can have various causes, from impaired intestinal motility to tumor growth into adjacent tissues and organs.
• Violation of the regularity of the chair. Patients are concerned about chronic constipation, which are replaced by fetid diarrhea. This is due to the fact that feces accumulate above the location of the tumor, which, in turn, leads to an increase in the processes of fermentation and putrefaction, the intestinal contents liquefy, and constipation is replaced by diarrhea. Due to inflammation of the intestinal wall and injury to the tumor, there may be blood streaks in the stool. When obturation (blockage) of the intestinal lumen by a tumor develops intestinal obstruction, which is accompanied by cramping pain, bloating, an increase in symptoms of intoxication, nausea and vomiting. This condition requires emergency hospitalization from a surgical hospital for immediate medical care.

In addition, signs of sigmoid colon cancer can be:

• Increased gas formation.
• Nausea and bloating.
• Discharge from the anus of mucus, blood or pus.

Staging and classification of sigmoid colon cancer

According to the type of tumor growth, exophytic and endophytic cancer are distinguished. Exophytic tumors grow into the intestinal lumen and look like nodules or outgrowths. If they grow excessively, they can obstruct the intestinal lumen, causing intestinal obstruction.

Endophytic or infiltrative form of cancer is characterized by the fact that it grows in the thickness of the intestinal wall. The tumor can cover the intestinal wall circularly, narrowing its lumen, which also causes intestinal obstruction.

Staging of the disease is carried out on the basis of data on the degree of spread of the tumor:

• cancer in situ – malignant cells are found only in the surface layer of the intestinal mucosa.
• Stage 1 – the tumor invades the intestinal mucosa and reaches the submucosa and muscle layer.
• stage 2 – cancer infiltrates the entire intestinal wall and can go beyond it, but does not yet give metastases.
• stage 3 – metastases appear in regional lymph nodes. The tumor can be of any size.
• Stage 4 – there are distant metastases, or the tumor spreads along the peritoneum (peritoneal carcinomatosis).

Metastasis

The following methods of metastasis are typical for malignant tumors of the sigmoid colon:

• Lymphogenic – through the lymphatic vessels, malignant cells first reach the regional lymph nodes, and then spread further, to more distant groups. For example, supraclavicular nodes may be affected.
• Hematogenous route – malignant cells spread through the blood vessels. The liver and lungs are the first to be affected. If the patient has undifferentiated cancer, metastases to the bone marrow may occur.
• Implantation metastasis – when the tumor goes beyond the intestinal wall, nearby organs and tissues can be affected. In this way, multiple peritoneal metastases, or peritoneal carcinomatosis, are formed.

Diagnosis of sigmoid colon cancer

The most informative method for diagnosing sigmoid colon cancer is colonoscopy with biopsy. The procedure involves a complete examination of the entire surface of the colon using a special endoscopic technique.

A shortened version of colonoscopy is rectosigmoidoscopy, which only looks at the final stage of the colon, the rectum and sigmoid colon.

Both diagnostic methods make it possible to detect a tumor of the sigmoid colon, assess its size, the likelihood of complications, and take a piece of tissue for subsequent histological examination. To obtain enough material to verify the tumor, a biopsy is taken from several points. The results obtained are necessary for treatment planning.

If it is impossible to perform a total colonoscopy at the diagnostic stage, it must be done within 3-6 months after the operation, since there is a risk of synchronous malignant neoplasms that are localized in areas inaccessible during rectosigmoscopy. If even after the operation a total colonoscopy is not possible, CT colonography or barium enema is performed.

As part of a clarifying diagnosis, a CT scan of the abdominal cavity and chest is performed. This study will allow to differentiate the stage of the disease and detect regional and / or distant metastases. CT can be partially replaced by ultrasound of the pelvic organs, abdominal cavity and retroperitoneal space.

Treatment

The key treatment for malignant tumors of the sigmoid colon is radical surgical removal. In the early stages (stages 1-2), it is recommended to give preference to sparing, minimally invasive endoscopic operations. In other cases, resection of the sigmoid colon is indicated within healthy tissues, departing from the edge of the tumor by at least 5 cm. Also, tumor-affected tissues, in particular, regional lymph nodes, are removed as a single block. The radical nature of the operation must be confirmed by an urgent histological examination for the presence of tumor cells in the cut-off edges.

Radical surgical treatment can be carried out in 1 or 2 stages. In a one-stage operation, the tumor is removed with the restoration of the integrity of the intestine by applying an anastomosis.

If this is not possible, two-stage operations are carried out. After removal of the tumor, the adducting section of the intestine is removed to the anterior abdominal wall (a colostomy is formed through which the bowel will be emptied), and a few months later, after the end of treatment, reconstructive operations are performed and the colostomy is removed.

If radical tumor resection is not possible, consider perioperative chemotherapy to shrink the tumor and make it resectable. If this does not happen, palliative operations are performed, and the main treatment of the patient is carried out through chemotherapy.

If there are distant metastases, they are also recommended to be removed surgically. Preference is given to simultaneous operations, when the primary focus and metastases are removed during one operation. If the metastases are unresectable, chemotherapy is performed and then the option of their surgical removal is re-considered.

Chemotherapy for sigmoid colon cancer

Chemotherapy for sigmoid colon cancer can be used as part of combination therapy. In addition, it can be used as an independent method of therapy for unresectable tumors or when it is impossible to perform an operation due to the presence of general contraindications.

Combination treatment includes adjuvant chemotherapy. The expediency of its appointment is determined based on the stage of the tumor and the results of an urgent intraoperative study of the removed fragment of the intestine for the presence of malignant cells.

As part of adjuvant chemotherapy, fluoropyrimidine therapy (5-fluorouracil, then 5 FU) is used together with 3rd generation platinum drugs (oxaliplatin). If the patient develops severe complications on two-component regimens, therapy is continued with fluoropyrimidines in mono mode. The goal of adjuvant chemotherapy is to destroy the remaining tumor cells and prevent the development of relapses of the disease.

Self-administered chemotherapy is palliative in nature and is aimed at containing the tumor process, prolonging the patient’s life and improving its quality.