Use of Neoadjuvant Short-Course Radiotherapy for Rectal Adenocarcinoma in the United States: Insights into Patterns of Practice and Outcomes

Mohamed A Adam, Megan C Turner, Hanna R Kemeny BS, Harvey G Moore, Christopher R Mantyh and John Migaly

Department of Surgery, Duke University, NC, USA

^*Correspondance to: Mohamed A. Adam 

 PDF  Full Text DOI: 10.25107/2474-1647.2234

Abstract

Aim: European data demonstrated the safety of short-course radiation (SC-RT) for Locally Advanced Rectal Adenocarcinoma (LARC); however, use of SC-RT in the US remains unknown. This study characterized patterns of use of SC-RT in the US and its short-term and oncologic outcomes compared to long-course radiation (LC-RT).Methods: Patients with clinical stage II and III rectal adenocarcinoma undergoing neoadjuvant therapy followed by resection were included. Descriptive statistics, propensity matching, and survival analysis used to compare SC-RT vs. LC-RT.Results: Of 28,968 patients identified: 326 received SC-RT and 28,642 LC-RT. SC-RT slightly increased in use from 0.3% of cases in 2004 to 2.3% in 2015. Patients undergoing the SC-RT were older, had more comorbidities, and had Medicare (all p<0.0001). SC-RT was offered more at academic centers, and with regional variation (p<0.05). After propensity matching, rate of complete pathologic response was less in the SC-RT vs. LC-RT cohort (12% vs. 21%, p<0.0001). Hospital lengths of stay and readmission rates were similar. Sphincter preservation, completeness of surgical resection, and circumferential margins were similar between groups. Among all patients, 5-year overall survival was significantly less for SC-RT (51% vs. 47%, p=0.005); however, survival tended towards significance when the cohort limited to patients <80 years without significant comorbidities (65% vs. 73%, p=0.058).Conclusion: Use of short-course radiotherapy for LARC in the US is slowly increasing but remains significantly low. While surgical and short-term oncologic outcomes appear to be comparable to LC-RT, this study argues for level 1 evidence from the US examining long-term survival.

Keywords

Cite the article

Adam MA, Turner MC, Hanna R Kemeny BS, Moore HG, Mantyh CR, Migaly J. Use of Neoadjuvant Short-Course Radiotherapy for Rectal Adenocarcinoma in the United States: Insights into Patterns of Practice and Outcomes. Clin Surg. 2018; 3: 2234.