Cancer that occurs in the large intestine or colon is called colon cancer with adenocarcinoma (tumor arising in glands in the lining cells) as the most common type.
In most cases adenocarcinoma arises in precancerous polyps or adenomas. These polyps begin as small growths and over a long period of time transition into large cancerous tumors. These polyps are easily detected and removed at colonoscopy before they become cancers.
- Older age.
- African-American race.
- A personal history of colorectal cancer or polyps.
- Inflammatory intestinal conditions such as ulcerative colitis or crohn’s disease.
- Inherited syndromes that increase colon cancer risk. The most common are familial adenomatous polyposis (FAP) and lynch syndrome, which is also known as hereditary nonpolyposis colorectal cancer (HNPCC).
- Family history of colon cancer.
- Low-fiber, high-fat diet.
- A sedentary lifestyle.
- Obesity and diabetes (insulin resistance).
- Habits such as smoking and heavy alcohol consumptions.
- Previous radiation therapy.
We would recommend that you stop smoking, reduce or stop alcohol consumption, follow a low fat, high fiber diet, and dedicate some time daily for exercise to maintain a healthy weight.
Symptoms of colon cancer range from no symptoms to rectal bleeding and partial or complete blockage of the intestine. Most commonly, slow blood loss detected by labs as anemia is seen.
Other symptoms include a change in your bowel habit, weakness or fatigue, weight loss, or even abdominal pain. Polyps most commonly do not cause any symptoms making screening tests very important to detect precancerous polyps and colon cancer.
Once a tumor is detected at colonoscopy, biopsies are obtained and the site of the tumor marked by injecting a specialized ink to guide the surgeon. After confirmation of colo-rectal cancer by the pathologist, a specialized test is performed on cancer tissue to look for genetic abnormalities. This may have a bearing on treatment of cancer and determination of future risk to you and your family members. Management of cancers requires determination of stage of the cancer prior to definitive therapy. A CT scan may be ordered to look for spread of the cancer along with referral to a surgeon and cancer specialist. A variety of treatments including surgery, chemotherapy, radiation and immunotherapy are available to treat the cancer.
After recovery from cancer treatments it is important to remember that risk of developing a second cancer is high and close follow-up with colonoscopies at specific intervals is necessary to detect early changes.
Colon cancer is a type of cancer that affects the large intestine (colon) and rectum. It is the third most common cancer in both men and women in the United States.
Symptoms of colon cancer may include:
- Changes in bowel habits, such as diarrhea, constipation, or a change in the consistency of your stool.
- Rectal bleeding or blood in your stool.
- Persistent abdominal discomfort, such as cramping, gas, or pain.
- A feeling that your bowel doesn’t empty completely.
- Weakness or fatigue.
- Unexplained weight loss.
The exact cause of colon cancer is unknown, but certain factors can increase your risk of developing the disease, such as:
- Age: Your risk of colon cancer increases as you get older.
- Family history: If you have a family history of colon cancer or polyps, you may have an increased risk.
- Personal history: If you have had colon cancer or polyps before, you have an increased risk of developing the disease again.
- Chronic inflammatory conditions: Conditions such as inflammatory bowel disease (IBD) can increase your risk of colon cancer.
- Diet: A diet high in red and processed meats and low in fruits, vegetables, and whole grains has been linked to an increased risk of colon cancer.
Colon cancer is usually diagnosed with a colonoscopy, during which a doctor inserts a long, flexible tube with a camera into the rectum to examine the inside of the colon. Other tests that may be used to diagnose colon cancer include a sigmoidoscopy, CT scan, or stool sample test.
Treatment for colon cancer usually involves surgery to remove the cancerous growth, as well as chemotherapy or radiation therapy to kill any remaining cancer cells. The specific treatment plan will depend on the stage of the cancer and the individual patient.
There is no sure way to prevent colon cancer, but there are things you can do to reduce your risk. These include:
- Get screened: Getting screened for colon cancer can help catch the disease early, when it is most treatable. The American Cancer Society recommends that people at average risk for colon cancer start getting screened at age 45.
- Eat a healthy diet: A diet high in fruits, vegetables, and whole grains and low in red and processed meats may help reduce your risk of colon cancer.
- Exercise regularly: Regular physical activity has been shown to reduce the risk of colon cancer.
- Don’t smoke: Smoking increases the risk of colon cancer and many other types of cancer.
- Limit alcohol consumption: Drinking alcohol in excess has been linked to an increased risk of colon cancer.
The survival rate for colon cancer depends on the stage of the cancer at the time of diagnosis. Overall, the 5-year survival rate for people with colon cancer is about 65%. However, the survival rate is much higher for people whose cancer is caught at an early stage (over 90%) compared to those whose cancer has spread to other parts of the body (about 10%).
Yes, it is possible for colon cancer to come back (recur) after treatment. The risk of recurrence is higher for people with more advanced stages of the disease. Regular follow-up care, including colonoscopies and other tests, is important for people who have had colon cancer to help detect any recurrence as early as possible.
Certain inherited genetic conditions can increase the risk of colon cancer. These include familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). These conditions are rare and account for only a small percentage of colon cancer cases.
The chances of a cure for colon cancer depend on the stage of the cancer at the time of diagnosis. In general, the earlier the cancer is caught, the better the chances of a cure. For people with early-stage colon cancer (stage I or II), the 5-year survival rate is over 90%. For people with more advanced stages of the disease (stage III or IV), the survival rate is lower, but it is still possible to achieve long-term survival with treatment.