The Use of Re-irradiation in Locally Recurrent, Non-metastatic Rectal Cancer.

Abstract

The optimal approach to patients with locally recurrent, non-metastatic rectal cancer is unclear. This study evaluates the outcomes and toxicity associated with pelvic re-irradiation. Patients undergoing re-irradiation for locally recurrent, non-metastatic, rectal cancer between 2000 and 2014 were identified. Acute and late toxicities were assessed using common terminology criteria for adverse events version 4.0. Disease-related endpoints included palliation of local symptoms, surgical outcomes, and local progression-free survival (PFS), distant PFS and overall survival (OS) using the Kaplan-Meier method. Thirty-three patients met the criteria for inclusion in this study. Two (6%) experienced early grade 3+ toxicity and seven (21%) experienced late grade 3+ toxicity. Twenty-three patients presented with symptomatic local recurrence and 18 (78%) reported symptomatic relief. Median local PFS was 8.7 (95% CI 3.8-15.2) months, with a 2-year rate of 15.7% (4.1-34.2), and median time to distant progression was 4.4 (2.2-33.3) months, with a 2-year distant PFS rate of 38.9% (20.1-57.3). Median OS time for patients was 23.1 (11.1-33.0) months. Of the 14 patients who underwent surgery, median survival was 32.3 (13.8-48.0) months compared with 13.3 (2.2-33.0) months in patients not undergoing surgery (p=0.10). A margin-negative (R0) resection was achieved in 10 (71%) of the surgeries. Radiation treatment modality (intensity-modulated radiation therapy, three-dimensional conformal radiotherapy, intraoperative radiation therapy) did not influence local or distant PFS or OS. Re-irradiation is a beneficial treatment modality for the management of locally recurrent, non-metastatic rectal cancer. It is associated with symptom improvement, low rates of toxicity, and similar benefits among radiation modalities.