Mandard tumor regression grade as a prognostic factor following preoperative chemotherapy/radiotherapy for locally advanced rectal cancer.

Abstract

e14024 Background: To assess the prognostic value of the Mandard tumour regression score (TRG) following preoperative chemo/radiotherapy in patients with locally advanced rectal cancer. Methods: The study involved 94 patients with locally advanced rectal cancer treated with preoperative chemo/radiotherapy at Nottingham University Hospital between April 2001 and December 2005. Patients were treated with CT planned radiotherapy to a dose of 50 Gy in 25 fractions over 5 weeks with or without concurrent capecitabine chemotherapy at a dose of 1,650 mg/m2/day. Surgery was performed after an interval of 6-10 weeks. The response to preoperative treatment was carefully graded by a single pathologist using the five point Mandard tumour regression grade (TRG). The median follow-up was 40 months (range 3-90 months). Results: Of the 94 patients 11% were TRG1, 39% were TRG2, 33% were TRG3, 16% were TRG4 and 1% were TRG5. In view of the small numbers in TRG4 and TRG5, the groups were combined into TRG1, TRG2 and TRG3-5 to simplify further analysis. The Mandard score was clearly related to both disease free (p = 0.001) and overall survival (p = 0.023) on Kaplan Meier analysis. The 5 year disease free and overall survival rate for patients with a complete response (TRG1) was 100%. Conclusions: The Mandard tumour regression score is a strong prognostic factor and predicts for long-term outcome following preoperative chemoradiotherapy in rectal cancer. The agreement of a reliable consistent method to evaluate tumour regression remains a clinical priority. No significant financial relationships to disclose.