Colorectal cancer is a disease in which normal cells in the lining of the colon or rectum begin to change, grow without control, and no longer die. The cell growth may begin as a noncancerous polyp that can become a cancerous tumor over time. Colorectal cancer often begins in the tissue lining the inside of the colon or rectum, forming a type of tumor called an adenocarcinoma.
WHAT IS THE FUNCTION OF THE COLON AND RECTUM?
The colon and rectum make up the large intestine, which plays an important role in the body’s ability to process waste. The large intestine turns food digested by the stomach and small intestine into fecal matter (stool) that leaves the body by the anus.
RISK FACTORS AND PREVENTION:
The cause of colorectal cancer is not known, but certain factors appear to increase the risk of developing the disease. The following factors may raise a person’s risk of developing colorectal cancer:
AGE: The risk of colorectal cancer increases as people get older. Colorectal cancer can occur in young adults and teenagers, but more than 90% of colorectal cancers occur in people over 50. The average age of diagnosis in the United States is 72.
FAMILY HISTORY OF CANCER:INFLAMMATORY BOWEL DISEASE (IBD): People with IBD, such as ulcerative colitis or Crohn’s disease, may develop chronic inflammation of the large intestine, which increases the risk of colon cancer. IBD is not the same as irritable bowel syndrome.
ADENOMATOUS POLYPS (ADENOMAS): Polyps are not cancer, but some types of polyps called adenomas are most likely to develop into colorectal cancer. Polyps can often be completely removed using a tool during a colonoscopy. Polyp removal can prevent colon cancer
PERSONAL HISTORY OF CERTAIN TYPES OF CANCER: People with a personal history of colon cancer and women who have had cancer of the ovary or uterus are more likely to develop colon cancer.
PHYSICAL INACTIVITY AND OBESITY: People who lead an inactive lifestyle (no regular exercise and a lot of sitting) and people who are overweight may have an increased risk of colorectal cancer.
SMOKING: Recent studies have shown that smokers are more likely to die from colorectal cancer than nonsmokers.
The following may lower a person’s risk of colorectal cancer:
NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS): Some studies suggest that aspirin and other NSAIDs may reduce the development of polyps in people with a history of colorectal cancer or polyps. People should talk with their doctor about the risks and benefits of taking aspirin on a regular basis.
DIET AND SUPPLEMENTS: A diet rich in fruits and vegetables and low in red meat may help reduce the risk of colon cancer. Some studies have also found that people who take calcium and vitamin D supplements have a lower risk of colorectal cancer.
Colorectal cancer can often be prevented through regular screening, which can identify precancerous polyps. Talk with your doctor about when screening should begin based on your age and family history of the disease. Although some people should be screened earlier, people of average risk should begin screening at age 50, and black people should start at age 45 (because they are more commonly diagnosed at a younger age
WHAT DOES STAGE MEAN?
The stage is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. There are five stages for colorectal cancer: stage 0 (zero) and stages I through IV (one though four). Illustrations for these stages are available at www.cancer.net/colorectal.
HOW IS COLORECTAL CANCER TREATED?
The treatment of colorectal cancer depends on the size and location of the tumor, whether the cancer has spread, and the person’s overall health. For cancer that is not advanced, surgery to remove the tumor usually is the first treatment. Additional treatment may be given to lower the risk of cancer returning and/or treat metastatic cancer. This may include chemotherapy, radiation therapy, targeted therapy (treatment that targets specific genes or proteins that contribute to cancer growth and development), and surgery to remove metastases (cancer that has spread past the colon and rectum). When making treatment decisions, people may also consider a clinical trial; talk with your doctor about all treatment options. The side effects of colorectal cancer treatment can often be prevented or managed with the help of your health care team.