Diagnosis of colorectal cancer
If a person has symptoms, some of these investigations may be performed:
* The doctor may perform a digital examination, that is an internal examination of the rectum for which the doctor uses a gloved finger.
* A more thorough examination can be made by performing a sigmoidoscopy.
* If the symptoms suggest that investigation is required further up the colon, a colonoscopy may be performed, which is the most accurate investigation. This procedure requires careful preparation. The doctor will probably refer the patient to a specialist for this test.
* A barium enema may be an alternative investigation where facilities for a colonoscopy are not readily available. It is not as accurate as a colonoscopy and does not enable the removal of pre-cancer polyps.
Treatment of colorectal cancer
Currently surgical excision is the primary treatment for colorectal cancer. The surgeon removes both the portion of the intestine which contains the cancer and the nearby lymph glands. In most cases the bowel is simply rejoined and there is minimal disfigurement (only the abdominal scar).
In some cases chemotherapy or radiotherapy may be used in addition to curative surgery; this is called adjuvant therapy. In a minority of cases the bowel is brought to an opening in the abdominal wall to permit direct elimination of bowel wastes into a bag. This is called a colostomy.
Modern colostomy appliances and methods of care have greatly simplified colostomy management and enable patients to lead a normal life. Nurses called stomal therapists see the patient before surgery, assist the surgeon in deciding the placement of the opening (stoma), and teach the patient how to change the colostomy appliance both in hospital and after discharge from hospital. The therapist also encourages the patient to regain their confidence to continue with normal life.
Radiation therapy is sometimes used with cancer of the rectum before surgery to reduce the size of the cancer or following surgery to kill any malignant cells which were not removed in the operation. Chemotherapy may also be used to treat some cancers, either alone or in combination with surgery or radiation therapy. When radiation therapy or chemotherapy is combined with surgery it should not be assumed that the disease is necessarily any worse than it is for patients who have surgery alone. Each patient is different and requires individual treatment.
There are a number of practical strategies available for preventing colorectal cancer. These relate to diet as well as clinical procedures. Such a broad approach is not available for any of the other cancers.
Much research effort is being directed towards improving methods of detecting colorectal cancer early before it produces symptoms. Sometimes blood may be present in the bowel motion without being obvious to the naked eye.
Research into causes of colorectal cancer has also focused recently on diet. Population studies have shown that cancer of the colon and rectum is associated with diets high in fats, high in alcohol, low in fibre and low in vegetables.
Diagnosis of colorectal cancer