Colorectal cancer is the fourth most common cause of cancer in the United States. The lifetime risk of developing colorectal cancer in the general population is approximately 5% however people with a personal or family history of colorectal cancer or a personal history of colon polyps are at increased risk of developing colon cancer. People with a personal history of having other cancers or who have chronic medical conditions including Ulcerative Colitis or Crohn's disease are at increased risk compared to the general population. Smoking also increases your risk of developing colorectal cancer. It is not clear why some people develop rectal cancer and some people do not.
Rectal cancer occurs when the lining of the rectum develops abnormal growth and develops the ability to invade or spread to other parts of the body. In most cases, polyps are the first sign of abnormal growth. Rectal cancer is a preventable disease. Detection and removal of colon polyps at the time of colonoscopy can remove potential cancer before it ever starts, emphasizing the importance of undergoing routine colon screening.
In most cases, rectal cancer does not cause symptoms. Timely colonoscopy helps to identify cancers in early stages. When identified and treated early, up to 90% of patients can be cured of cancer. When cancer has progressed enough to cause symptoms like GI bleeding, pelvic pain, or a change in bowel habits including constipation of lack of bowel control it is usually advanced with a lower chance of cure. When rectal cancer is identified, it is important to know certain characteristic of cancer and if cancer has invaded the wall of the colon or has spread to other organs. Your doctor will determine the best test to evaluate this. Typically a colonoscopy with biopsy, CT scans, pelvic MRI, and blood tests are needed.
In most cases, surgery is required to achieve a complete cure. Rectal cancer surgery involves removing the portion of rectum containing the cancer along with its associated lymph nodes. The colon is then connected to the rectum. If the rectal cancer is very low in the rectum or is attached to the anal sphincter it may not be possible to connect the intestine together and a permanent colostomy is needed. A colostomy is an opening of the intestine into a bag on the skin.
A number of different techniques can be used to perform rectal cancer surgery. North Texas Colon and Rectal associates specialize in minimally invasive techniques including laparoscopy and robotic surgery. Minimally invasive techniques that result in less pain and shorter recovery time.
Occasionally the rectal cancer is caught very early and can be removed through the anus and without an incision in the abdomen. This is called a transanal local excision. North Texas Colon and Rectal associates also specialize in minimally invasive techniques of transanal local excision.
Depending on the stage of colon cancer additional treatments with radiation and/or chemotherapy may be needed either before or after surgery. Your surgeon will work with oncologists, doctors who specialize in the medical treatment of cancer, to tailor a treatment plan that works best for you. It is of utmost importance that you continue a regularly scheduled follow-up with your surgeon and oncologist to monitor the possibility of recurrence.
It is possible that your bowel function may change after rectal cancer surgery. The rectum works normally to store bowel movements until it is time to pass them, so to do this it has the ability to stretch and store a larger volume than other parts of the large intestine.
When part of the rectum is removed, the left colon is used to replace the rectum. However, the left colon has a thick muscular wall that does not stretch to store stool. Instead, stool is stored in a long column in the colon, as a result, people may find that they cannot completely evacuate a bowel movement in one sitting. People can have the sensation of incomplete evacuation and may have to have multiple smaller bowel movements throughout a short period of time to empty the column of stool. This syndrome is called Low Anterior Resection Syndrome. In most cases, the body adapts after surgery to improve storage and evacuation. In rare cases, this can be a severe problem.