Colorectal Cancer
Colorectal cancer, also known as colon cancer, develops in either the large intestine or the rectum. According to the Centers for Disease Control and Prevention (CDC), colorectal cancer is the second leading cause of cancer deaths in the United States.
Cancer occurs when healthy cells become altered, growing and dividing in a way that keeps the body from functioning normally. Most cases of colorectal cancer begin as small, benign clusters of cells (polyps) on the lining of the colon or rectum. Certain types of polyps, called adenomas, can become malignant.
Risk Factors for Colorectal Cancer
There are several risk factors for colorectal cancer, some of which are under the patient's control. They include the following:
- Being age 50 years or older
- Smoking
- Lack of exercise
- Excessive alcohol consumption
- Eating red or processed meats
- Obesity
- Certain hereditary syndromes
- Family history of colorectal cancer
- Patient history of inflammatory bowel disease
- Patient history of adenomas
- Patient history of other cancer
- Type 2 diabetes
Symptoms of Colorectal Cancer
While patients with colorectal 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
- Unexplained weight loss
- Nausea or vomiting
Diagnosis of Colorectal Cancer
After performing a thorough physical examination and taking a full patient and family history, the doctor may administer other diagnostic tests, which may include the following:
- Blood tests (including a CBC), and tests for liver enzymes and tumor markers
- Digital rectal examination
- Fecal occult blood test
- Barium enema
- Colonoscopy
- Sigmoidoscopy
- Ultrasound
- MRI
- CT scans
As part of a colonoscopy or sigmoidoscopy, a biopsy may be taken.
Treatment of Colorectal Cancer
Depending on the stage of progression of the colorectal cancer, treatment may include one or more of the following:
- Surgical removal of diseased and immediately adjacent tissue
- Radiation therapy
- Chemotherapy
- Targeted or biological therapy
Prevention of Colorectal Cancer
There are many steps that may be taken to lower the risk of developing colorectal cancer. Individuals may decrease their chances of developing this disease by eating a healthy low fat diet, high in fiber and antioxidants, drinking alcohol only in moderation, exercising regularly, maintaining a healthy weight and refraining from smoking. For individuals at high risk for developing colorectal cancer, medications and surgery may be recommended. Everyone at high risk or 50 years of age and older, and African-Americans 45 years of age and older, should undergo a regularly scheduled colonoscopy, both to screen for cancer and to remove suspicious colorectal polyps at the earliest stage possible.