Efficacy and safety of neoadjuvant intensity-modulated radiotherapy with concurrent capecitabine for locally advanced rectal cancer.

Abstract

We previously conducted a prospective phase II clinical trial studying a unique 22-fraction neoadjuvant intensity-modulated radiotherapy with concurrent capecitabine treatment followed by total mesorectal excision for locally advanced rectal cancer. The objective of this study was to retrospectively review the efficacy, toxicity, and surgical complications following intensity-modulated radiotherapy in patients who have rectal cancer. This was a retrospective study. Data were gathered from a surgical database. This study included patients who underwent intensity-modulated radiotherapy with gross tumor volume/clinical target volume of 50.6/41.8 Gy in 22 fractions with concurrent capecitabine treatment over a period of 30 days, after which the patients underwent surgery for rectal cancer in Peking University Cancer Hospital (2007-2013). The primary end points were acute toxicity, postoperative complications, and complete response rate. A total of 260 patients were included in our analysis. The median age was 55 years (range, 21-87 years), and 68.5% of the patients were male. The yield complete response rate was 18.5% (48/260). There were no grade 4 toxicity and perioperative mortality. The grade 3 toxicity rate was 5.8%, which included diarrhea (4.2%), neutropenia (1.2%), and radiation dermatitis (0.4%). The 30-day postoperative and severe complication (≥grade 3) rates were 23.1% and 2.7%. The anastomotic leakage rate was 3.3% (5/152). Perineal wound complications (29.2%, 28/96) represented the most common problem following abdominoperineal resection. The estimated 3-year local recurrence-free survival, cancer-specific survival, and disease-free survival rates were 94.2% (95% CI, 90.1%-98.3%), 92.2% (95% CI, 87.5%-97.0%), and 81.4% (95% CI, 75.4%-87.4%). The retrospective nature and the single-arm design was the limitation of the study. The 22-fraction neoadjuvant intensity-modulated radiotherapy regimen used to treat rectal cancer in this study has a high efficacy rate and a low toxicity rate. Further studies are needed to better define the role of intensity-modulated radiotherapy for rectal cancer treatment in a neoadjuvant setting.