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Preserving the Anal Sphincter in Rectal Cancer
One aspect of the treatment of rectal cancer that is on the minds of most patients with the disease is: WILL I HAVE TO HAVE A PERMANENT COLOSTOMY? There are a number of factors that play into the decision-making for a permanent colostomy.DISTANCE OF THE CANCER FROM THE ANAL SPHINCTER
The rectum is approximately 8 inches long and at the distal end is connected to the anus which is surrounded by the anal sphincter muscles. The sphincter muscles serve to allow control of the bowel movements and damage or removal of the sphincters precludes hooking the colon back to the anus. Cancers in the lower 1/3 of the rectum are of most concern because if they are close to or invading the sphincter muscles, the sphincters may also have to be removed by a procedure known as an abdominoperineal resection. Surgical techniques to preserve the anal sphincter muscles can often be used even in very distal rectal cancers and are performed by colon & rectal surgeons who are highly specialized in the treatment of these cancers. These techniques are often combined with chemoradiation therapy to shrink the tumor and increase the likelihood of sphincter preservation.ABILITY TO REMOVE THE WHOLE TUMOR
If the tumor is of an advanced stage, such that it has invaded adjacent organs or the pelvic bones, the likelihood of it being completely removed decreases considerably. If the tumor could not be removed or only partially removed, the risk of the tumor growing and obstructing the rectum exists. In these circumstances, the surgeon may elect to perform a colostomy to prevent this from happening.THE PATIENT'S BOWEL CONTROL BEFORE SURGERY
Surgery on the rectum can often affect bowel control in a negative way. The rectum acts as a reservoir for stool, and removal of a part of this reservoir can cause incontinence or very urgent bowel movements in some patients. In patients with poor bowel control before surgery, the surgical treatment of the cancer could leave them with little to no control, and in these cirumstances a permanent stoma would be beneficial.
1 comment:
This doesn't help me but may help newly diagnosed rectal cancer
patients:
http://www.mdanderson.org/diseases/colorectal/
October 2003
Chemotherapy, Radiation and Rectal Cancer
Pre-surgical Treatment Improves Sphincter Preservation
Having chemotherapy and radiation therapy before advanced rectal cancer surgery results in an increased likelihood of preserving the anal sphincter, according to a new study published last month.
“If you shrink the tumor before surgery with chemoradiation (chemotherapy and radiation treatments) there will be a better chance that the person will not have to have a permanent colostomy,” says the study’s lead author Christopher Crane, M.D., an associate professor in the M. D. Anderson Department of Radiation Oncology.
A colostomy involves cutting part of the colon and attaching a bag outside that collects waste material. The device may become necessary when a large portion of the colon must be removed in order to get cancerous tumors that are large or difficult-to-reach by a surgeon.
In the study, Crane and his colleagues reviewed 403 treatment records for advanced rectal cancer patients treated between 1978 and 1995. The patients were cared for at M. D. Anderson and Washington University School of Medicine in St. Louis. Findings of the review were published in the September 2003 issue of the International Journal of Radiation Oncology*Biology*Physics.
The Results
Among the patients with low rectal tumors (6 centimeters or less from the anus) sphincter preservation was more common when chemotherapy was given:
39% at M. D. Anderson where 207 patients were treated with preoperative chemoradiation
13% at Washington University in the group where186 patients were treated with radiation alone
36% at Washington University in the group where 61 patients were treated with chemoradiation between 1998-2000. (After 1995, the institution changed its standard treatment from radiation alone to include preoperative chemotherapy)
Patient Breakdown
The study included patients diagnosed with T3 rectal cancer (369 people) and T4 rectal cancer (34 people).
T3 rectal cancer is diagnosed if palpation (physical exam) reveals the tumor is tethered or if a computer tomographic (CT) scan or ultrasonography shows tumor extension into only the fat surrounding the rectum.
T4 rectal cancer is diagnosed if there is evidence that neighboring organs have been invaded.
Treatment Standards
The hope of the study is to encourage more oncologists to use pre-operative chemotherapy with radiation to improve sphincter preservation, Crane says.
In the United States, radiation therapy and concurrent chemotherapy before surgery already is the treatment of choice for many, he explains. In Europe, however, the treatment is not used as often. Many doctors instead use radiation alone before surgery.
“This should be considered a standard treatment, but not everybody does it,” Crane says, adding that a prospective clinical trial recently presented in Europe shows improvement in sphincter preservation with preoperative chemotherapy and radiation compared to surgery first, consistent with his study.
“There is a randomized trial in Germany that confirms that preoperative chemoradiation is better than postoperative radiation in increasing sphincter preservation and also in local control as well as in having fewer side effects,” he says. “That study will probably be published within the next year.”
Another study from Eurpoe is comparing preoperative radiation with or without chemotherapy and will be reported in the near future.
In the meantime, he adds, investigations are ongoing to evaluate newer chemotherapy treatments that may further improve the study results.
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