Colorectal Cancer Takes Its Time and Takes Its Toll
Edition: June 2002 - Vol 10 Number 06
Following on the heels of lung cancer, the deadliest of all cancer diseases, colorectal cancer claims over 56,600 lives each year, according to Palo Alto, CA-based Beckman Coulter. Over 148,000 Americans are diagnosed with this disease annually, and an estimated one of every 18 individuals is expected to develop colorectal cancer at some point in his or her life.
How Does It Start?
Colorectal cancer usually begins as a polyp a growth tissue that forms on the inner lining of the colon or rectum. While not all polyps are cancerous, they can increase the risk of developing colorectal cancer. The two most common types of polyps are:
Hyperplastic. Usually smaller than _ inch in diameter and rarely become malignant.
Adenomas. Tend to become cancerous as they grow, especially as they exceed 5 millimeters in diameter.
An adenomatous polyp can take between seven and 10 years to metastasize. In high risk patients or those with a pervasive family history of cancer, however, the cancer can develop much more rapidly, according to the Mayo Clinic.
The National Cancer Institute cites a number of factors associated with a higher risk of colorectal cancer. These include:
Age. While this disease can strike young adults and, on rare occasions, even teenagers, about 90 percent of colorectal cancer patients are 50 years or older.
Diet. High fat, low fiber diets appear to be linked with colorectal cancer.
Familial polyposis. A rare, inherited condition that causes hundreds of polyps to grow in the colon and rectum. If left untreated, it probably will lead to colorectal cancer.
Medical history. Women who have had ovarian, uterine or breast cancer are predisposed to colorectal cancer. Also, individuals who have had colorectal cancer at some point are at higher risk for developing it a second time.
Ulcerative colitis. A condition in which the lining of the colon becomes inflamed. Ulcerative colitis places one at higher risk for colorectal cancer.
While researchers have yet to determine surefire ways to avoid colorectal cancer, they have arrived at some theories for reducing one's risk. For one, patients whose polyps are detected early and removed may be less prone to develop this disease. Some studies have explored whether the use of dietary supplements or aspirin (or similar medicine) can help prevent colorectal cancer. Abstaining from smoking is another possible key to avoiding colorectal cancer. Similarly, increased physical exercise and a low fat, high fiber diet may also help people steer clear of it.
Some researchers believe that individuals with certain changing gene patterns might be more prone to colorectal cancer. A genetic counselor might be able to recommend a special blood test to screen for such changes.
Symptoms that might alert individuals to the possibility of colorectal cancer include the following, according to the National Cancer Institute:
Change in bowel habits.
Diarrhea, constipation, or a sensation that the bowel does not empty completely.
Bright red or very dark blood in the stool.
Stool narrower than usual.
Abdominal discomfort (pain, bloating, fullness, cramps).
Unexplained weight loss.
To gauge the extent to which the cancer has spread throughout the body, physicians employ a staging system. There are five stages of colorectal cancer:
Stage 0. The cancer is detected very early and is limited to the innermost lining of the colon or rectum.
Stage I. The cancer has spread to a greater portion of the inner wall of the colon or rectum.
Stage II. The cancer has spread beyond the colon and rectum, but has not yet invaded the lymph nodes.
Stage III. The cancer has spread to the lymph nodes, but not to other parts of the body.
Stage IV. The cancer has spread to other areas of the body. In the case of colorectal cancer, this stage generally involves the liver and/or the lungs.
When colorectal cancer is recurrent after treatment, it may invade the colon or rectum, or any other body part.
A gastroenterologist and a medical or radiation oncologist all may treat colorectal cancer. Treatment methods vary, depending on the location, size and extent of the tumor, as well as the patient's overall health. Treatment methods include:
Surgery. Surgically removing the tumor and nearby colon or rectum and lymph nodes is the most common solution for treating colorectal cancer, according to the National Cancer Institute. When the surgeon is unable to reconnect healthy portions of the colon or rectum, a colostomy is necessary.
Biological therapy. Also called immunotherapy, this treatment relies on the body's immune system to destroy cancer cells.
Clinical trials. Patients who participate in new studies often receive a new treatment under evaluation.
It is important for physicians to keep their patients informed in order that the best treatment is selected. Patients should be kept aware of the stage of their cancer, treatment options and available clinical trials, anticipated hospital stay and recovery time. ¦
For more information on colorectal disease, visit the National Cancer Institute's website at www.cancer.gov.