Improved Metastasis- and Disease-Free Survival with Preoperative Sequential Short Course Radiotherapy and FOLFOX Chemotherapy for Rectal Cancer Compared to Neoadjuvant Long Course Chemoradiotherapy; Results of a Matched Pair Analysis

• Published in: International journal of radiation oncology, biology, physics
• Main Authors: Markovina, Stephanie, MD, Youssef, Fady, MD, Roy, Amit, Aggarwal, Sonya, BS, Khwaja, Shariq, MD, DeWees, Todd, PhD, Hunt, Steven, MD, Tan, Benjamin, MD, Myerson, Robert J., MD, Chang, Daniel T., MD, Parikh, Parag J., MD, Olsen, Jeffrey R., MD
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: Hematology, Oncology and Palliative Medicine; Radiology
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2017.05.048

Abstract Purpose A prospective Phase II trial completed at YYY evaluated near-total neoadjuvant therapy (nTNT) for locally advanced rectal cancer using short course radiotherapy (SCRT, 25 Gy in 5 fractions) followed by four cycles of FOLFOX prior to total mesorectal excision (TME). We present an institutional matched pair analysis of nTNT and conventional neoadjuvant chemoradiotherapy (NCRT) and comparison to patients treated with NCRT at a second institution (XXX). Methods and Materials Sixty-nine patients with cT3-4N0-2M0 rectal adenocarcinoma enrolled on the Phase II study of nTNT were included for analysis. Patients treated at YYY with conventional NCRT and adjuvant FOLFOX were matched for exact cTNM stage. Forty-one patients treated with NCRT at XXX were included in a second analysis. Kaplan-Meier with log-rank analysis was used to compare local control (LC), distant metastasis free survival (DMFS), disease free survival (DFS), and overall survival (OS). Results Median follow-up was 49 and 54 months for nTNT and NCRT, respectively. Pathologic complete response and T-downstaging rates were 28% vs 16% (p = 0.21) and 75% vs 41% (p <0.001) in the nTNT and NCRT cohort, respectively. Three-year DFS (85% vs 68%, p = 0.032) was significantly better in the nTNT group. Actuarial three-year LC (92% vs 96%, p = 0.36) and OS (96% vs 88%, p = 0.67) were similar. The XXX cohort had significantly lower clinical stage. After controlling for clinical stage, age, tumor location, institution and number of chemotherapy cycles, nTNT treatment remained significantly associated with lower risk of recurrence (p = 0.006). Conclusions Patients treated with nTNT had higher T-downstaging, and superior DMFS and DFS compared to conventional NCRT when matched for tumor location and exact cTNM stage. nTNT remained a significant multivariate predictor for improved outcome when including patients treated with NCRT at another institution.