Quantification of Histologic Regression of Rectal Cancer After Irradiation

Abstract

Significant tumor regression was seen in 86 percent of cases after chemoradiotherapy, with 19 patients showing a "good" responsiveness. We propose a modified pathologic staging system for irradiated rectal cancer, the Rectal Cancer Regression Grade, which includes a measurement of tumor regression. The utility of the proposed Rectal Cancer Regression Grade must be tested against long-term outcomes before its value in predicting prognosis and survival can be determined.