Rectal cancer is cancer that develops in the tissues of the rectum. The rectum is the final six inches of the colon that leads to the anus. Cancer occurs when healthy cells become altered, growing and dividing in a way that keeps the body from functioning normally. Most cases of rectal cancer begin as small, benign clusters of cells, or polyps, on the lining of the rectum. Certain types of these polyps, called adenomas, can become malignant. Screening to locate and remove precancerous polyps can prevent rectal cancer from developing. Individuals are advised to have these polyps removed at an early stage when they have not yet become cancerous.
Risk Factors for Rectal Cancer
Rectal cancer occurs more often in people over the age of 40. Additional risk factors for rectal cancer include:
- Family history of colorectal cancer
- Patient history of polyps
- Patient history of other cancer
Hereditary conditions such as familial adenomatous polyposis (FAP) or hereditary nonpolyposis colon cancer may also put people at a higher risk for rectal cancer.
Symptoms of Rectal Cancer
Initially, people with rectal cancer are often asymptomatic. As the disease progresses, they may experience one or more of the following symptoms:
- A change in bowel habits or a change in consistency of the stool
- Rectal bleeding or blood in the stool
- Persistent abdominal discomfort, such as cramps, gas or pain
- A feeling that the bowel does not empty completely
- Weakness or fatigue
Symptoms may also include unexplained weight loss or a change in appetite.
Diagnosis of Rectal Cancer
Rectal cancer is diagnosed through a physical examination, a review of symptoms and a review of the medical history of the patent and family. Additional diagnostic tests may include:
- Digital rectal examination
- Barium enema
- Fecal occult blood test
- Carcinoembryonic antigen assay
A biopsy may also be taken of rectal tissue and sent to a lab for analysis. If rectal cancer is diagnosed, an X-ray, CT scan or MRI scan may also be performed to determine if cancer cells have spread within the rectum or to other parts of the body.
Treatment of Rectal Cancer
Surgery is the most common form of treatment for cases of rectal cancer at any stage of progression. There are several types of surgery used to excise or destroy the diseased tissue and a surrounding margin. For some patients, radiation therapy, chemotherapy or biological therapy may be performed instead of, or in addition to surgery.
Prevention of Rectal Cancer
There are many steps that may be taken to lower the risk of developing rectal cancer. Individuals may decrease their chances of developing this disease by eating a healthy low-fat diet that is high in fiber and antioxidants, drinking alcohol only in moderation, refraining from smoking, exercising, and maintaining a healthy weight. Regular colonoscopies are recommended for:
- People over the age of 50
- African-Americans over the age of 45
- High risk individuals
Colonoscopies are important because they are used to screen for cancer and to remove suspicious rectal polyps at the earliest stage possible.