Although giving radiation before rectal cancer surgery reduces the risk that cancer will return in the rectum and nearby tissues, it does so at a cost. Quality-of-life studies that accompanied a trial of a short course of radiation therapy before surgery found more sexual and bowel problems with presurgical radiation.
During the Medical Research Council CR07 clinical trial, patients with rectal cancer were randomized to receive a short, five-day course of radiation before their surgery or surgery with chemoradiation afterwards only for those with cancer cells remaining in tissues outside the tumor . Three years later only 4 percent of the presurgical radiation group had cancer return locally compared to 11 percent of those treated with surgery and selective postsurgical chemoradiation. Presurgical radiation patients were also more likely to be alive five years later — 78 percent of them survived compared to 72 percent of the patients who didn’t have radiotherapy before their surgery.
Three months after surgery both groups of men had issues with sexual functioning, which researchers attributed to the surgery. Those difficulties returned to normal as patients recovered. However, additional problems with sexual function developed later for men who had presurgical radiation. They declined over time, but some men still reported difficulties three years later.
Men had no less interest or enjoyment in sexual activities, but did have problems with function. For both groups, men who had colostomies had worse function three months after surgery than men who had surgery that preserved anal sphincters.
Overall, bowel problems weren’t different between the two groups, but in one area radiation made a difference. Eighteen months after surgery, patients who had radiation were more than twice as likely to have stool leakage and bowel incontinence (16.4 percent versus 6.5 percent).
Results of local recurrence at three and five years during the trial were first presented at ASCO in 2006.That report found that with the best surgery, which removed the rectum and its entire surrounding tissue, along with short-course preoperative radiotherapy, almost completely eliminated local recurrence. Only one percent of the 1,350 patients in the study had cancer return in the rectum or local area around it when they received excellent surgery and presurgical radiation.
Without preoperative radiotherapy, 6 percent of patients had local recurrence. When surgery was not optimal, 9 percent of patients with preoperative radiation and 19 percent of those who did not have radiotherapy had local recurrence three years later.
Discussing the results of the quality of life analysis at ASTRO, David Sebag-Montefiore, MD, a leader of the study and a radiation oncologist in Leeds, UK, said,
We know that this and other trials have consistently shown that radiation before surgery reduces the risk of local cancer returning. However, this has to be balanced against any negative side effects. The results of our quality of life study should help doctors and patients to discuss both the benefits and risks of pre-operative radiation before surgical removal of rectal cancer.
You can hear an interview with Dr. Sebag-Montefiore recorded at ASTRO on Medpage Today.