Over time, the normal cells that line the colon may develop abnormalities that lead to the formation of polyps and if left long enough may turn into cancers. The average lifetime risk for developing a colorectal cancer in a person who has no increased risk factors is 6%. Factors that make the likelihood of polyps and cancers increase are a family history of polyps and cancers, specifically in first degree relatives (parents, siblings, children), known hereditary conditions (hereditary nonpolyposis colorectal cancer syndrome, familial adenomatous polyposis) or a history of inflammatory bowel disease such as Crohn’s disease or ulcerative colitis. People at average risk should be screened beginning at the age of 50 with colonoscopy.

If a polyp that is too large to be removed with the colonoscopy is found or if biopsies show that there is a cancer either within a polyp or a mass is found that is a colon or rectal cancer, this usually will lead to surgical removal of the area of colon involved with all the lymph nodes that drain that area.

Rectal cancer is not the same as colon cancer. A rectal cancer often needs treatment with chemotherapy and radiation prior to surgery in order to shrink the tumor and possibly sterilize lymph nodes. A multispecialty approach which includes a medical oncologist, a radiation oncologist and a colorectal surgeon or surgical oncologist will give the best long term results and chance for cure. In order to determine if radiation and chemotherapy are necessary prior to surgery in the treatment of a rectal cancer, the tumor needs to be staged to see if it has grown all the way through the bowel wall or if there are lymph nodes positive. The best procedure for this is termed “endorectal ultrasound” and this is usually performed by the operating surgeon.

Colon cancers usually require surgery first and, if the tumor is found to invade nearby organs or to have positive lymph nodes or if it is obstructing, will usually need chemotherapy after surgery to give the best chance for cure. Should chemotherapy be needed following surgery, we will discuss with you the possibility of placement of a port which would minimize the need for blood draws while safely giving the chemotherapy with the least toxicity.

Sometimes colon and rectal cancer presents with obstruction. This means that the tumor has narrowed the bowel to such an extent that stool cannot move forward and, therefore, will back up. Symptoms of obstruction will include progressive narrowing of the stool or ribbon-like stools. Nausea and vomiting may be present as well as abdominal distention and abdominal pain. The treatment for colonic obstruction may require an emergency operation and a temporary colostomy (bag). Another option if not emergent or if the obstruction is not complete would be colonic stenting or the placement of a metallic stent similar to that used in the heart to relieve blockage in the arteries.

Surgery for colon cancer often times can be performed safely laparoscopically. This means that small incisions are used to perform the same operation inside the abdomen with good visualization, less postoperative pain and a quicker recovery overall. Laparoscopy has been shown to be as safe and effective as open surgery without risk to the possibility of a cure. Rectal surgery can also be performed laparoscopically safely even if the patient has had radiation prior to surgery.

The best way to treat a colon or rectal cancer is to find it first as a benign polyp and remove it safely before it ever becomes a cancer. The only way to do this is to regularly undergo screening colonoscopy as recommended by your physicians.