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

Background: 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. Methods: 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. Results: 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. Conclusion: 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.