Detecting, Diagnosing and Treating Colorectal Cancer
Colorectal cancer is a disease that can affect anyone, although the risk increases with age. Colorectal cancer is the third most common type of cancer in men and women in the United States, according to the Centers for Disease Control and Prevention.
It is known as a "silent" disease because it often does not produce symptoms, until the cancer is difficult to cure. However, if the cancer is found and treated at an early stage, before symptoms develop, the cure rate can be quite high.
Avoiding colorectal cancer is always better than treating it once it develops. Unfortunately, there are no reliable methods for completely eliminating the risk. However, there are many things you can do to decrease your risk.
Following healthy living and regular screening guidelines from the American Cancer Society and the American College of Colon and Rectal Surgeons will help you reduce your risk of getting this disease. Remember, colorectal cancer is often preventable and frequently treatable when detected early enough.
Risk factors of developing colon cancer include:
- Increasing age (it is most common in people over age 50)
- High-fat, high-calorie and low-fiber diets
- Having certain types of polyps develop in the colon or rectum
- Ulcerative colitis
- Inherited genes that increase your risk
- Women with a history of ovarian, uterine or breast cancer
- First-degree relatives who have had colorectal cancer
- Large alcohol consumption
- Lack of physical activity
Common signs and symptoms of colon cancer may include:
- A change in bowel habits including the diarrhea, constipation or feeling that the bowel does not empty completely
- Blood in the stool
- Stools that are narrower than usual
- General abdominal discomfort
- Weight loss with no apparent reason
- Constant fatigue
- Certain blood conditions, including anemia
The three principal forms of treatment for cancer of the colon are surgery, radiation therapy and chemotherapy. Depending on the stage of the cancer and the patient's overall health condition, these treatments may be used alone or in combination.
Surgery is the most common treatment for all stages of colon cancer and the only treatment that can be curative when used alone.
If the cancer is detected at an early stage, the primary tumor and a zone of surrounding normal tissue can be removed without cutting into the abdomen, using an endoscope or colonoscope or through a skin incision. The edges of healthy tissue are then sewn together, usually with no permanent effect on the digestive system. If the cancer is contained within a polyp, this procedure is known as a polypectomy.
Segmental Colon Resection (Colectomy)
Surgeons remove the cancer and a length of healthy tissue on either side of the abnormal area, as well as the nearby lymph nodes and blood vessels. Usually about one-fourth to one-third of the colon is removed, depending on the location of the cancer. In most cases, the remaining sections of the colon are reattached, and regular bowel function is restored.
Colon resections may be performed using the following approaches:
- Standard open approach through one large incision in the abdominal wall
- Laparoscopic techniques using four to five small incisions.
- Single incision laparoscopic surgery — abnormal portions of the colon are removed through one small incision in the belly button.
Although laparoscopic surgery often results in a slightly shorter hospital stay and more rapid recovery, it is not always the best approach for all patients.
If the tumor is too advanced to be removed, is blocking the bowel or the surgeon is unable to reconnect remaining areas of the colon after resection, a colostomy may be needed. A colostomy is an opening from the bowel to the abdominal wall. A special plastic bag with an adhesive faceplate is placed over the colostomy to collect the waste.
A colostomy may be temporary or permanent, depending on the situation. Many may be closed in a subsequent operation, after the situation has improved.
Radiation therapy uses high-energy rays to kill cancer cells and shrink tumors. After surgery, radiation can destroy small remaining deposits of cancer, which may not have been visible during the surgery. Also, if the size or location of the cancer makes surgery difficult, this treatment may be used to decrease tumor size.
External Beam Radiation
The radiation comes from a machine outside of the patient's body (similar to an x-ray). This is the most commonly recommended type of radiation for colorectal cancer treatment. A regimen of daily radiation, five days a week for several weeks, is most commonly administered. This often is combined with chemotherapy.
Chemotherapy involves the use of anticancer drugs, either taken orally or injected into a vein or artery, to kill cancer cells. It can increase the chance of survival by destroying cancer cells that cannot be removed by surgery.
Chemotherapy also may help shrink tumors or relieve the symptoms of advanced colon cancer. Chemotherapy primarily is used to treat cancer that has metastasized, or spread, to other body organs, commonly the liver and lungs.
The anticancer drugs are given intravenously or by mouth so that they enter the bloodstream and reach all areas of the body. Because of this, both cancer cells and normal cells may be affected, which leads to side effects. This method is especially useful for cancer that may have spread beyond the colon.
The medication is injected through a catheter into a vein, artery or muscle leading directly to the area where the tumor is located. This approach concentrates the dosage of chemotherapy reaching the cancer cells and limits the amount reaching other body parts, thereby reducing side effects. Hepatic Artery Infusion is an example of regional chemotherapy and is used for colon cancer that has spread to the liver.