Colorectal Cancer

Colorectal cancer is the third most common cancer in men and women. These malignant tumors arise from polyps which grow in the lining of the colon. Not all polyps will become cancerous, but those which will, generally take 5 to 10 years to do so. The risk of developing colorectal cancer is approximately 6% over a person’s lifetime. The majority of these cancers develop after the age of fifty. There are certain factors which increase a person’s risk of colorectal cancer. For example, a person with a brother, sister, mother or father with colorectal cancer, will have a three-fold increase in risk of developing this cancer also. A person with inflammatory bowel disease such as Crohn’s Disease or Ulcerative Colitis, will also have an increased risk. A person with polyps in the colon has an eight-fold increase risk of developing cancer. It is important to remember however, that the vast majority of colorectal cancers occur in people who have no specific personal risk factors, and no family members with the disease.

Colorectal cancer is unique in that we are able to dramatically decrease it’s occurrence by effective screening programs. By identifying and removing polyps, we can prevent them from progressing to cancer. The recommended screening protocol for people without special risk factors, begins with annual fecal occult blood tests (testing for blood in the stool) and digital rectal exams starting at age forty. At the age of fifty, a person should undergo colonoscopy. This test will allow your physician to directly examine the inside of the colon and rectum, and to remove polyps if they are encountered. Another option for examining the colon is a sigmoidoscopy. This test is similar to a colonoscopy, but only examines the lower left side of the colon. The sigmoidoscopy must be accompanied by a complimentary test, such as a barium enema, in order to evaluate the remainder of the colon. Unfortunately, if a suspicious lesion or polyp is identified on this radiographic study, a colonoscopy will be required to examine, biopsy or remove the area in question. For this reason, most physicians consider colonoscopy to be the screening test of choice, as it can evaluate the entire colon and remove polyps at the same time. In the near future, other options for screening, such as CT virtual colonosocopy will be perfected. These tests will still require colonoscopy for tissue sampling. Complete colon screening should be carried out every five years after the age of fifty. The presence of polyps, or the development of symptoms such as bleeding , abdominal or rectal pain or changes in bowel habits, may necessitate more frequent examinations. The goal of screening is to prevent cancer by removing polyps, and to identify cancers early, giving the greatest opportunity for cure.

After a diagnosis of colorectal cancer is made, additional studies are usually ordered such as a CT scan, chest x-ray and blood tests. When the workup has been completed, the next step is the surgical resection of the cancer. The exception to this is rectal cancer, which is often treated first with a combination of chemotherapy and radiation. This treatment, which produces shrinkage of the tumor, is then followed by surgical resection. Colon cancers are treated first by surgical resection, and then followed by chemotherapy, if indicated. Resection of a colorectal cancer involves the removal of the segment of the bowel that contains the cancer along with margins of normal bowel to reduce the possibility of local recurrence. The segment of the colon or rectum to be removed is generally dictated by the blood supply to that segment of colon. The entire blood supply and the associated lymphatic vessels and lymph nodes are removed along with the segment of bowel. This not only helps prevent recurrence, but allows for accurate staging of the cancer, and therefore helps to direct further treatment decisions. Colostomies, in which the bowel is brought out through the abdominal wall and opened into a bag, is not part of the usual surgical treatment of colorectal cancer. However, there are situations which my require the formation of a colostomy. Your surgeon will discuss this possibility as it relates to your condition. Minimally invasive surgical techniques have changed the operative experience dramatically for most patients. Using very small incisions, a camera and specialized surgical instruments are introduced into the abdomen. The resection of the diseased bowel is carried out with significantly less surgical trauma to the patient when compared to traditional operations. The same excellent cancer resection can be accomplished utilizing these minimally invasive techniques, but with less blood loss, less pain, faster return of bowel function, shorter hospital stay and faster return to normal activity.

The staging of colorectal cancer is based on the depth of the tumor invasion in the bowel, whether lymph nodes have become involved, and whether the cancer has metastasized (spread) to other organs. This information will help determine the need for chemotherapy. Follow up after cancer therapy will include periodic physical examination, blood tests, CT scans, chest xrays and colonoscopy. In every case, the patient is followed by a team of specialists (surgeon, medical oncologist, radiation oncologist, nurses, nutritionists, etc.) to assure that they receive the latest and most complete cancer care available.

All content copyright 2010, Alan F. Jacks, MD, PA