Predictors of survival in recurrent rectal cancer after resection and intraoperative radiotherapy

PURPOSE: This study was designed to determine predictors of survival after surgery and intraoperative radiotherapy for recurrent rectal cancer. METHODS: From a prospective database, 634 patients undergoing resection for recurrent rectal cancer between January 1990 and June 2000 were identified. Of these, 111 received intraoperative radiotherapy with curative intent, and 100 were available for follow-up. Clinicopathologic variables from both the primary and recurrent operations were evaluated as predictors of disease-free and disease-specific survival by multivariate Cox regression and log-rank test. RESULTS: There were 54 males and 46 females, with a median age of 57 (range, 37-83) years. With a median follow-up of 23.2 months, 60 patients (60 percent) recurred: 20 (33 percent) locally, 27 (45 percent) distantly, and 13 (22 percent) at both sites. Of all variables analyzed, only complete resection with microscopically negative margins and the absence of vascular invasion in the recurrent specimen predicted improved disease-free and disease-specific survival (P < 0.01 for all). Median disease-free survival and median disease-specific survival were 31.2 and 66.1 months, respectively, for complete resection compared with 7.9 and 22.8 months for resection with microscopic or grossly positive margins (P < 0.01 for both). Median disease-free survival and median disease-specific survival were 6.4 and 16.1 months, respectively, in the presence of vascular invasion in the recurrent specimen compared with 23.3 and 57.3 months in the absence of vascular invasion (P < 0.01 and P < 0.05, respectively). Complete resection and the absence of vascular invasion were the only predictors of improved local control as well (P < 0.05 and P < 0.01, respectively). CONCLUSION: Resection with negative microscopic margins and absence of vascular invasion are independent predictors of local control and improved survival after resection and intraoperative radiotherapy for recurrent rectal cancer.