Colon Cancer

Cancer of the large intestine or colon is among the most common cancers in the world, occurring in about one in every 2,000 people.

It is most common in people over the age of 50 and does not differentiate between genders. These cancers develop by the inappropriate (anarchic) proliferation of certain cells. These tumors can be benign (often polyps) and malignant (cancer). The small intestine is about 4-6 meters long, while the large intestine is about 1.5 meters long. The large intestine is the organ where water and beneficial nutrients are absorbed. In the last 15 years, with the increase in screening tests, colon cancers are detected at an early stage and mortality rates are decreasing. 70% of colon cancers are located in the left half of the large intestine, 25% in the right half and 5% in both halves (synchronous tumors). According to the statistics of the American Cancer Institute in 2006, colon cancer; It is the third type of cancer after prostate cancer and lung cancer in men, and the third after breast cancer and lung cancer in women, and the lifetime risk of developing colon and rectum cancer is 5% on average. According to the statistics of the World Health Organization, more than 1 million new cases of bowel cancer were detected worldwide in 2008.

What Does Synchronous and Metachronous Colon Cancer Mean?

The detection of cancer in two different regions of the large intestine simultaneously is called “synchronous bowel cancer” and such tumors are encountered at a rate of 2-12%. A typical example of this is simultaneous cancer in both the right half of the large intestine and the rectum region. Cancer in the large intestine, at different times and in different regions, is called “metachronous bowel cancer”. An appropriate example is the detection of cancer in the right half of the large intestine five years later in a patient undergoing treatment for rectal cancer. It is a different situation if bowel cancer spreads or metastasizes to the liver.

What is Rectal Cancer?

Cancers that occur in the colon, which is the longest part of the large intestine, are called colon cancer, and cancers that occur in the last part of the large intestine, close to the anus, are called ‘rectal cancer’. The behavior and treatment methods of rectum and colon cancers are different.

Does Colon Cancer Develop in a Short Time?

The development of large intestine or colon cancers often takes 3-5 years, and 60% of them develop from benign tumors called polyps in the intestine or from some inflammatory large intestine diseases such as Crohn’s disease or ulcerative colitis. Regular colonoscopy examinations have a great role in preventing bowel (colon) cancer cases that develop on the basis of polyps. These tumors can spread or spread to nearby lymphatic vessels, veins, adjacent organs such as liver, bone, prostate, bladder or uterus. 95% of colon cancers are in the adenocarcinoma group.

Who is in the Risk Group for Colon Cancer?

Age: People over 50

Familial: The risk of colon cancer increases 1.8 times in first degree relatives in the family, people with colon cancer

Familial polyposis disease: familial adenomatosis polyposis – FAP, Lynch syndrome (HNPCC or hereditary nonpolyposis colorectal cancer) cases have uterine cancer or ovarian cancer in addition to bowel cancer.

Patients with Peutz-Jeghers syndrome have a 20% lifetime risk of developing bowel cancer.

People on a high-fat and calorie (especially animal fat) diet

Nutrition with a low fiber diet: 20-35 grams of fiber should be consumed per day in a healthy diet. Bingham et al. In the study, it was determined that the risk of bowel cancer increased in those who consumed less than 17 g of fiber per day.

Red meat: The risk of colon cancer increases 1.5 times with regular consumption of red meat every day.

People with large bowel polyps or cancer

Women with a history of ovarian, uterine, or breast cancer

Inflammatory bowel disease: In the presence of ulcerative colitis and Crohn’s disease, the risk of large bowel cancer increases 2-3 times in the presence of inflammatory bowel disease for more than 10 years. Eaden et al. In the meta-analysis they examined 114 scientific studies on ulcerative colitis involving 54,478 patients; It has been reported that the risk of bowel cancer develops at the rate of 2% at the end of 10 years, 8% at the end of 20 years and 18% at the end of 30 years. In contrast, Bernstein et al. When they examined 2,672 ulcerative colitis patients, they determined the risk of developing bowel cancer as 0.16% and the risk of developing rectal cancer as 0.06%.

Obesity: Being overweight and not doing sports increases the risk of colon cancer 1.5-2 times. It has been determined that obesity, which is a disease of our age, has increased from 20% to 30% in the 60-65 age group in the last 10 years in European countries.

Diabetes: It increases the risk by 40%, in the same way, insulin resistance increases the risk.

Cigarette consumption

Alcohol: Vogel et al. In the study, it was determined that the risk of colon cancer increased 1.5 times with regular consumption of 10 grams of alcohol per day.

Working the night shift for a long time

Despite all these data, no risk factors have been identified in 75% of people who develop bowel (colon) cancer and rectal cancer.

Who is in the Low-Risk Group for Colon Cancer?

• No personal or family history of bowel cancer
• No history of bowel cancer in first-degree relatives
• Having a history of bowel cancer in one of the first-degree relatives after the age of 45
• This group has twice the risk of people who are not at risk.
• Stool occult blood test and colonoscopy are recommended for people in this group.

Who is in the Moderate Risk Group for Colon Cancer?

• History of bowel cancer in one of the first-degree relatives before the age of 45
• History of bowel cancer in two of the first-degree relatives, regardless of age
• This group has six times the risk compared to people who are not at risk.
• Colonoscopy is recommended for people in this group around the age of 35-40 and is repeated around the age of 55.

Who is in the High-Risk Group for Colon Cancer?

• Having familial polyposis disease in one of the family members (familial adenomatosis polyposis – FAP)
• HNPCC (hereditary nonpolyposis colorectal cancer or Lynch syndrome) in a family member
• Hereditary bowel cancer in three or more first- and second-degree relatives

People in this group are at risk of 50%.