Neoadjuvant Short-Course Radiotherapy Followed By Chemotherapy And Delayed Surgery For Locally Advanced Rectal Adenocarcinoma A Retrospective Analysis

Abstract

Introduction

Neoadjuvant concurrent chemoradiotherapy is an established treatment for locally advanced rectal adenocarcinoma. With the emerging adaptation of short-course radiotherapy as neoadjuvant regimen, the Polish Colorectal Study Group has provided a protocol with comparable outcomes.

Objectives

To compare short-term outcomes of patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant adapted Polish II protocol versus standard long-course chemoradiotherapy, both followed by definitive surgery.

Methods

A chart review and analysis of patients with rectal adenocarcinoma between January 2016 to December 2017 with short-course radiotherapy followed by chemotherapy (adapted Polish II Protocol) were compared to patients who underwent long-course concurrent chemoradiotherapy. Acute toxicities were graded based on NCI/CTCAE and RTOG acute radiation scoring. Pathologic complete response (pCR) and resection margin status were used to assess pathologic outcomes. Overall survival and disease-free survival rates were assessed for short-term oncologic outcomes.

Results

Seven out of 16 (44%) underwent adapted Polish II protocol and the rest (9, 56%) underwent long-course protocol. Acute toxicities were comparable between groups, however, patients who underwent long-course treatment had higher grades of acute skin toxicity (p-value =0.004). Pathologic findings were comparable: one patient (14.3%) achieved pCR in short-course group, while none (0%) in long-course group; all patients (100%) had adequate resection margins in both groups. Long-course protocol group showed better short-term overall survival (34 months versus 26 months) and disease-free survival (p-value =0.509).

Conclusion

Achievement of pathologic complete response (pCR) and adequacy of resection margins as pathologic outcomes were comparable between neoadjuvant short-course and long-course chemoradiotherapy. Hence, adapting Polish II protocol as an alternative neoadjuvant treatment for locally advanced rectal adenocarcinoma has potential use in the local setting.