Concurrent chemotherapy and preoperative radiation therapy for patients with advanced rectal cancer leads to improved sphincter preservation, according to an article in the September issue of the International Journal of Radiation Oncology Biology Physics.

To better understand the contributions of concurrent chemotherapy to the effect of preoperative radiation therapy, American researchers compared outcomes of patients treated at 2 university cancer centers. They analyzed hospital and radiation records of 403 patients with clinically staged T3 or T4 adenocarcinoma of the rectum treated between 1978 and 1995 with preoperative radiation therapy followed by surgery. Of the 403 patients, 215 received concurrent chemotherapy in addition to radiation and surgery. Senior attending surgeons with a focused practice in colorectal cancer performed the surgery at both institutions and the staging workup was similar at both locations.

The findings of the study suggest that the addition of chemotherapy to preoperative radiation therapy in a standard fractionation scheme improves tumor response to radiation therapy. The additional finding that the tumor response rate increased at 1 center after a policy change in which concurrent chemotherapy was added to radiation therapy also supports the notion that chemotherapy increases the objective tumor response to radiation therapy. These results allow for increased sphincter preservation in locally advanced rectal cancer patients.

“The use of concurrent chemotherapy with preoperative radiation therapy for patients with stage T3 and T4 rectal cancer independently increases the tumor response and may contribute to increase sphincter preservation for patients with low rectal cancer,” said Christopher H. Crane, MD, the lead author of the study.