No one knows the exact causes of colorectal cancer—which is cancer of the colon or rectum—but we do know that there are certain risk factors. Some of the these risk factors are:
- Age: The older we are, the greater chance of developing colorectal cancer; more than 90 percent of people with colorectal cancer are over age 50.
- Colorectal polyps: Polyps are common over age 50 and most are not cancerous; having them removed reduces the cancer risk.
- Family history of colorectal cancer: If any close relatives have a history of colorectal cancer, the risk is greater.
- Genetic alterations: Changes in genes increase risk; hereditary nonpolyposis colon cancer is the most common gene that may increase risk.
- Chronic inflammation of the colon, as in ulcerative colitis.
- Diet: some studies suggest that diets high in fat, especially animal fat, and low in calcium, folate and fiber increase risk. Also, diets low in fruits and vegetables may increase risk.
- A personal history of colorectal cancer.
- Cigarette smoking and high alcohol consumption.
What is the treatment for colorectal cancer?
Treatment for colorectal cancers usually involves a combination of surgery, radiation therapy and chemotherapy. The treatments may be given at the same time or one after the other. Before starting treatment, it is important to know the stage of the cancer; suggested treatment; benefits, risks and side effects of that treatment; how the treatment will affect normal activities; cost; and if there is a clinical trial that may be appropriate.
Surgery is the most common treatment and is considered local therapy because it treats the tumor and the area close to it. The surgery may be a simple removal of a polyp through a colonoscope. Or if the tumor is larger, an incision may be made in the abdomen so a portion of the colon and/or rectum can be removed, along with the nearby lymph nodes.
The surgeon can usually reconnect (anastomose) the healthy parts of the intestine. Infrequently, this is not possible and the surgeon makes a new route for the waste by creating a stoma (colostomy) in the wall of the abdomen. A disposable pouch is placed over the stoma to contain the waste.
The colostomy is often temporary until the tissues heal and then another surgery is performed to reconnect the intestines and close the stoma. For people with cancer in the lower rectum, a permanent colostomy may be necessary because the sphincter may be involved and need to be removed.
Chemotherapy is the use of anticancer drugs/medications to kill the cancer cells. This is considered systemic therapy because it enters the bloodstream and can affect cancer cells throughout the entire body.
When chemotherapy is given before surgery, the purpose is to reduce the size of the tumor and is called 'neoadjuvant therapy.' When it is given after surgery, it is given to kill any remaining cancer cells and is called 'adjuvant therapy.' Chemotherapy may also be given for advanced disease to shrink the tumor relieving some of the symptoms.
Radiation therapy uses high-energy rays to destroy cancer cells and is considered local therapy because it only affects the cells in the treated area. It may be given to kill any cancer cells after surgery, prevent the cancer from returning or to reduce symptoms, such as pain.
Thus, if you think you may be at risk for colorectal cancer, talk to your doctor and have periodic screenings. If cancer is discovered, know that treatment is available and that there are many resources to support you.
Linda Lochbaum, MS, RN, CWOCN, is a clinical nurse specialist at Mount Nittany Medical Center.