Information on Rectal Cancer

Rectal cancer develops in the cells and tissue in the last few inches of the large intestine, nearest the anus. The National Cancer Institute estimates that nearly 41,000 new cases of rectal cancer will be diagnosed in the United States in 2009. Symptoms are generally confined to the gastrointestinal tract, such as changes in bowel habits, bloody stools and abdominal discomfort. When detected and treated early, rectal cancer is highly curable. Treatment depends on the stage of the cancer, and may include a combination of surgery, radiation, chemotherapy and biological therapy.

Risk Factors

• While rectal cancer can develop in someone with no known risk factors, certain considerations may increase the risk of rectal cancer. Some hereditary conditions, such as hereditary nonpolyposis colon cancer and familial adenomatous polyposis, increase the likelihood of developing rectal cancer, and the risk is also greater in those with a personal history of ulcerative colitis or Crohn's disease, rectal polyps, colorectal cancer, and cancer of the breast, endometrium or ovary. A family history of colorectal polyps or cancer and being over the age of 40 are other risk factors. While these risk factors cannot be prevented, they indicate the need for more frequent checkups and screening tests.

Symptoms

• Blood in the stool and a change in bowel habits are often the first two signs of rectal cancer. Diarrhea or constipation may develop, and stools may be narrower than usual. Blood in the stools may appear bright red or nearly black. Other symptoms of rectal cancer may include general abdominal cramping, bloating or discomfort, appetite changes, fatigue, nausea and weight loss. Because early stages of rectal cancer do not typically cause pain, it is important to see a doctor for evaluation if any new gastrointestinal symptoms develop that cannot be explained by a virus or other infection.

Diagnosis

• A number of tests are performed to diagnose rectal cancer. Following a complete physical examination and medical history, a digital rectal exam is performed. A digital rectal exam involves the insertion of a gloved finger into the rectum to check for lumps or other signs of cancer. If rectal cancer is suspected, a proctoscopy usually follows. This test uses a tube-like instrument with a lens and light on one end to look inside the rectum. A colonoscopy may also be performed to check for polyps, abnormal tissue or other signs of cancer. A colonoscope usually has a biopsy tool attached to one end to collect polyps or tissue samples for testing. A blood test called a carcinoembryonic antigen assay measures the level of a substance in the blood that is higher in those with rectal cancer than in those who are cancer free. If rectal cancer is diagnosed, X-rays, CT scans, ultrasounds and other testing is ordered to determine whether the cancer has spread to other areas of the body.

Stages

• Staging of rectal cancer is based on test results. When rectal cancer is located only in the innermost lining of the rectum, a diagnosis of stage 0, or carcinoma in situ, is given. Stage 1 cancer has grown into the wall of the rectum, but not through the wall, while stage 2 cancer extends through the rectal wall or into nearby tissues. If the cancer spreads to nearby lymph nodes, but is not yet detected in distant regions of the body, a stage 3 diagnosis is warranted. Stage 4 rectal cancer has metastasized to distant areas of the body or to other organs, such as the lungs.

Treatment

• Treatment of rectal cancer depends on the stage of the illness upon diagnosis and the overall health of the patient. Early stages may be treated with a combination of surgery and radiation. Later stages require treatment with chemotherapy and biological therapy in addition to radiation and surgery. Chemotherapy works to target and kill cancer cells that are circulating through the body or have spread to other organs. According to the National Cancer Institute, surgery is the most common treatment for all stages of rectal cancer.