What Is Colon Cancer?
According to the National Cancer Institute, there were 108,070 new cases of colon cancer and 40,070 cases of rectal cancer in the U.S. in 2008. There were 49,960 deaths of colon and rectal cancer combined throughout the country during the same year.
Colon cancer forms in the tissues of the colon, which is the lengthiest part of the long intestine. The majority of colon cancers are adenocarcinomas, which are cancers that begin in mucous- and other fluid-manufacturing cells. Rectal cancer forms in the tissues of the rectum, which consists of the last several inches of the large intestine closest to the anus.
Video: Colon Cancer
These symptoms may suggest colon cancer, as listed by the Medline Plus Medical Encyclopedia:
- Abdominal pain and tenderness in the lower abdomen
- Blood in your stool
- Diarrhea, constipation, or other change in bowel habits
- Intestinal obstruction
- Narrow stools
- Unexplained anemia
- Unexplained weight loss
The Memorial Sloan-Kettering Cancer Center has comprehensive information on hereditary links to colon cancer. According to the Center, 5 to 10 percent of all cases have genetic origins. Someone with a family history of colorectal cancers is at greater risk than another person with no family history of the disease.
Warning Signs and Detection
In addition to the symptoms above, you may be at risk for colon cancer if you notice any of the following warning signs:
- Frequent or constant cramps lasting more than a few days
- Narrower-than-normal stools
- A feeling of needing to move the bowels, but with little stool
- Frequent gas pains
- Consistent lack of energy
When it comes to colon cancer, early detection is key to a higher chance of survival. Since the disease is largely asymptomatic until it has progressed beyond the point of a cure, it’s essential to undergo regular screening. For those with no family history, screenings should begin at age 50.
These screenings include:
- Fecal occult blood tests. Small stool samples transferred to a collection card with a narrow stick are screened for the presence of blood.
- Flexible sigmoidoscopy. A small fiber-optic tube is inserted to inspect the rectum and some of the colon.
- Barium x-ray. Contrast material is infused through the rectum, allowing radiologists to see large polyps or cancers in the colon.
- Colonoscopy. Considered the most effective screening tool for both polyps and cancers, this process requires sedation of the patient. A scope with a video chip is inserted into the colon, an image of which is projected onto a video screen for analysis.
Video: Colorectal Cancer Symptoms
Treatment and Survival Rate
Treatment options will depend on three factors:
- The stage of the cancer
- Whether the cancer has recurred
- The patient’s general health
Some treatment options are standard, meaning the treatment currently in use, while others are being tested in clinical trials, or research studies. The three types of standard treatment are surgery, chemotherapy, and radiation therapy. Treatment types currently in clinical trials include biologic therapy, which uses the patient’s immune system to fight cancer.
In the United States, the five-year survival rate for tumors in the ascending colon (closest to the small intestine) is about 63 percent, according to the European Journal of Cancer. Survival rates for cancer in the transverse and descending colon are 59 percent and 66 percent, respectively. Remember, prevention is the best cure.