Personal History of Cancer

Personal history of cancer: A person who has already had colorectal cancer may develop colorectal cancer a second time. Also, women with a history of cancer of the ovary, uterus (endometrium), or breast are at a somewhat higher risk of developing colorectal cancer.

Ulcerative colitis or Crohn's disease: A person who has had a condition that causes inflammation of the colon (such as ulcerative colitis or Crohn's disease) for many years is at increased risk of developing colorectal cancer.

Diet: Studies suggest that diets high in fat (especially animal fat) and low in calcium, folate, and fiber may increase the risk of colorectal cancer. Also, some studies suggest that people who eat a diet very low in fruits and vegetables may have a higher risk of colorectal cancer. However, results from diet studies do not always agree, and more research is needed to better understand how diet affects the risk of colorectal cancer.

Cigarette smoking: A person who smokes cigarettes may be at increased risk of developing polyps and colorectal cancer.

Because people who have colorectal cancer may develop colorectal cancer a second time, it is important to have checkups. If you have colorectal cancer, you also may be concerned that your family members may develop the disease. People who think they may be at risk should talk to their doctor. The doctor may be able to suggest ways to reduce the risk and can plan an appropriate schedule for checkups. See the "Screening" section to learn more about tests that can find polyps or colorectal cancer.

Screening

Screening tests help your doctor find polyps or cancer before you have symptoms. Finding and removing polyps may prevent colorectal cancer. Also, treatment for colorectal cancer is more likely to be effective when the disease is found early.

To find polyps or early colorectal cancer:

People in their 50s and older should be screened.

People who are at higher-than-average risk of colorectal cancer should talk with their doctor about whether to have screening tests before age 50, what tests to have, the benefits and risks of each test, and how often to schedule appointments.

The following screening tests can be used to detect polyps, cancer, or other abnormal areas.
Your doctor can explain more about each test:

Fecal occult blood test (FOBT): Sometimes cancers or polyps bleed, and the FOBT can detect tiny amounts of blood in the stool. If this test detects blood, other tests are needed to find the source of the blood. Benign conditions (such as hemorrhoids) also can cause blood in the stool.

Sigmoidoscopy: Your doctor checks inside your rectum and the lower part of the colon with a lighted tube called a sigmoidoscope. If polyps are found, the doctor removes them. The procedure to remove polyps is called a polypectomy.

Colonoscopy: Your doctor examines inside the rectum and entire colon using a long, lighted tube called a colonoscope. Your doctor removes polyps that may be found.

Double-contrast barium enema: You are given an enema with a barium solution, and air is pumped into your rectum. Several x-ray pictures are taken of your colon and rectum. The barium and air help your colon and rectum show up on the pictures. Polyps or tumors may show up.

Digital rectal exam: A rectal exam is often part of a routine physical examination. Your doctor inserts a lubricated, gloved finger into your rectum to feel for abnormal areas.

Virtual colonoscopy: This method is under study. See "The Promise of Cancer Research."