Colon cancer is a type of cancer that begins in the large intestine (colon). The colon is the final part of the digestive tract.
Colon cancer most commonly affects older adults, although it can appear at any age. It usually begins as small, noncancerous (benign) clumps of cells called polyps that form inside the colon. Over time, some of these polyps may become colon cancers.
Polyps may be small and produce few, if any, symptoms. For this reason, doctors recommend regular screenings to help prevent colon cancer by identifying and removing polyps before they turn into cancer.
In the case of colon cancer, there are many treatments available to help control it, including surgery, radiation therapy and drug therapies, such as chemotherapy, targeted therapy and immunotherapy.
Colon cancer is sometimes called colorectal cancer, which is a combination of colon cancer and rectal cancer, and it begins in the rectum.
Signs and symptoms of colon cancer include:
A persistent change in bowel movement, whether diarrhea or constipation, or a change in the consistency of stool
•Anal bleeding, or blood in the stool
•Persistent abdominal disturbances, such as painful cramps, gas, or pain
•A feeling that the intestines are not completely empty
•Weakness or exhaustion
•Unexplained weight loss
Many people with colon cancer have no symptoms in the early stages of the disease. If symptoms do appear, they are likely to vary according to the size of the cancer and its location within the large intestine.
When do you visit the doctor?
If you notice any persistent symptoms that worry you, see your doctor.
Doctors aren’t sure what causes colon cancer.
•In general, colon cancer occurs when changes (mutations) arise in the DNA of healthy colon cells. A cell’s DNA contains a set of instructions that direct the cell as to what to do.
•Healthy cells grow and divide in an orderly manner to maintain normal body functions. But when DNA becomes damaged and cancer develops, cells continue to divide — even when new cells are no longer needed. The cells accumulate to form a tumor.
•Over time, cancer cells can grow to invade and destroy nearby normal tissue. Cancer cells can spread to and lodge in other parts of the body (metastasis).
Factors that may increase your risk of colon cancer include:
•the elderly. Colon cancer can be diagnosed at any age, while the majority of people affected are over 50 years old. While we will find an increase in colon cancer rates in people younger than 50 years, although doctors are not sure of the cause.
•African Americans. African Americans have a higher risk of colon cancer than other races.
•A personal history of colorectal cancer or polyps. If you’ve already had colon cancer or noncancerous colon polyps, you have a higher risk of developing colon cancer in the future.
•Inflammatory intestinal diseases. Chronic inflammatory diseases of the colon, such as ulcerative colitis and Crohn’s disease, can increase the risk of colon cancer.
•Inherited syndromes that increase the risk of colon cancer. Certain genetic mutations passed through generations of your family can greatly increase your risk of colon cancer. But only a small percentage of colon cancers are linked to inherited genes. The most common inherited syndromes that increase the risk of colon cancer are familial adenomatous polyposis (FAP) and Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC).
•Having a family history of colon cancer. You are at greater risk of developing colon cancer if a blood relative has the disease. The risk is higher if one or more family members have had colon or rectal cancer.
•Low-fiber, high-fat diet. Colon and rectal cancer may be associated with a traditional Western diet that is low in fiber and high in fat and calories. Research in this field has yielded mixed results. Some studies have found an increased risk of colon cancer in people who eat diets high in red and processed meats.
•A sedentary lifestyle. Sedentary people are more likely to develop colon cancer. Regular physical activity may help reduce your risk of colon cancer.