Asked by
in Maryland, US

With rectal cancer, do you have to remove the colon? Or anus?


Thanks for your question. I am sorry to hear about your situation.

If you have rectal cancer, the doctor may need to remove part of your rectum and anus during surgery. The type of surgery depends on where the cancer is located and how advanced it is. Some surgeries remove just a small part of the rectum and anus, while others remove more, including a part of the lower colon. The goal of the surgery is to remove the cancer while keeping your bowel function as normal as possible. After surgery, you may need to do exercises and take medicine to help with bowel movements. Recovery can take a few months and some people may have long-term changes in bowel function. It’s important to talk with your doctor about what to expect before the surgery.

The extent of surgical resection for rectal cancer depends on the location, the stage of the tumor, and to some extent, the surgeon and patient preferences. For tumors located in the upper or middle third of the rectum, a low anterior resection (LAR) or an anterior resection (AR) may be performed, which involves removing the affected portion of the rectum along with a small portion of the anus. For tumors located in the lower third of the rectum, a proctectomy with coloanal anastomosis (CAA) may be performed, which involves removing the affected portion of the rectum and the anus and creating a new connection between the colon and the remaining part of the rectum. In some cases, where the tumor is very low in the rectum and anus, an abdominoperineal resection (APR) may be performed, which involves removing the anus, rectum, and part of the sigmoid colon.  Please let us know which procedure is being considered and we can guide you more specifically.

Importantly, receiving chemotherapy ahead of surgery may make the tumor smaller and easier to remove, and as has been reviewed in the New York Times, this NEJM demonstrates 16 rectal cancer patients who had complete remissions when they had a tumor sequencing (genomic tumor analysis) with an MSI-H result.  For these reasons, I recommend requesting a consultation with a medical oncologist for any rectal cancer patient who has concerns about the surgery ahead of time.  Unless there is imminent bowel obstruction, there should be time to consider these options.

Finally, you should know that the goal of the surgery is to minimize the disruption to the patient's bowel function. One way to minimize the effect of anus disruption is to preserve as much of the sphincter muscle as possible during surgery. The sphincter muscle is responsible for controlling bowel movements, and preserving as much of it as possible can help maintain the ability to control bowel movements.  Another way to minimize the effect of anus disruption is to use a technique called "stapled transanal rectal resection (STARR)" which is where the surgeon uses a special surgical stapler to remove the affected portion of the rectum while preserving the sphincter muscle.  After surgery, a patient will typically go through a period of rehabilitation to help them regain control over their bowel movements. This may include exercises to strengthen the pelvic muscles, and the use of stool softeners and/or laxatives to help make bowel movements easier.

It's important to note that the recovery process when the sphincter is disrupted can take several weeks to months and some patients may experience some long-term changes in bowel function, such as incontinence or difficulty controlling bowel movements. However, with proper rehabilitation, most patients are able to regain good bowel function and resume their normal activities.  It is difficult to provide a specific percentage of patients who are able to regain good bowel function, as it can vary depending on several factors such as the stage of the cancer, the patient's overall health, and how well the patient adheres to the post-operative rehabilitation.  It's important to have realistic expectations and discuss the potential outcomes with your surgeon prior to the surgery.  I recommend having the surgery with a dedicated rectal cancer surgeon, preferably at an NCI-accredited cancer center, and would be happy to provide a recommendation for getting an opinion from 1 (or 2) if you'd like.

Best Wishes,
Jason Sager, MD