Preoperative concomitant boost intensity-modulated radiotherapy with oral capecitabine in locally advanced mid-low rectal cancer: A phase II trial

Purpose

We aimed to assess the safety and efficacy of preoperative intensity-modulated radiotherapy (IMRT) with oral capecitabine in patients with locally advanced mid-low rectal cancer using a concomitant boost technique.

Materials and methods

Patients with resectable locally advanced mid-low rectal cancer (node-negative ?T3 or any node-positive tumor) were eligible. The eligible patients received IMRT to 2 dose levels simultaneously (50.6 and 41.8 Gy in 22 fractions) with concurrent capecitabine 825 mg/m² twice daily 5 days/week. The primary end point included toxicity, postoperative complication, and pathological complete response rate (ypCR). The secondary endpoints included local recurrence rate, progression-free survival (PFS), and overall survival (OS).

Results

Sixty-three eligible patients were enrolled; five patients did not undergo surgery. Of the 58 patients evaluable for pathologic response, the ypCR rate was 31.0% (95% CI 19.1-42.9). Grade 3 toxicities included diarrhea (9.5%), radiation dermatitis (3.2%), and neutropenia (1.6%). There was no Grade 4 toxicity reported. Four (6.9%) patients developed postoperative complications. Two-year local recurrence rate, PFS, and OS were 5.7%, 90.5%, and 96.0%, respectively.

Conclusions

The design of preoperative concurrent boost IMRT with oral capecitabine could achieve high rate of ypCR with an acceptable toxicity profile.