Comparative Effectiveness of Neoadjuvant Chemoradiation Versus Upfront Surgery in the Management of Recto-Sigmoid Junction Cancer

Abstract

Introduction: The optimal management of locally advanced recto-sigmoid cancer is unclear. Although some experts advocate for upfront surgery, others recommend neoadjuvant chemoradiation followed by surgery. We used the National Cancer Database to characterize patterns-of-care and overall survival (OS) associated with these treatment strategies.

Patients and methods: Patients with clinical stage II or III recto-sigmoid cancer who underwent surgery with or without adjunctive chemotherapy and/or radiotherapy from 2006 to 2014 were identified, and dichotomized into: (1) upfront surgery, and (2) neoadjuvant chemoradiation cohorts. Patterns-of-care were assessed using multivariable logistic regression. The association between neoadjuvant chemoradiation use and OS was assessed using Cox proportional hazards analysis with propensity score-matching.

Results: Of 9313 identified patients, 6756 (73%) underwent upfront surgery and 2557 (27%) received neoadjuvant chemoradiation. Treatment at academic facilities and higher clinical T stage were predictors of neoadjuvant chemoradiation use. Compared with upfront surgery, neoadjuvant chemoradiation resulted in fewer positive circumferential resection margins (384 [11%] patients vs. 108 [8%] patients; P = .001), and 478 [18.7%] patients achieved a pathologic complete response at surgery. In propensity score-matched analysis, neoadjuvant chemoradiation use was associated with improved OS (hazard ratio, 0.79; 95% confidence interval, 0.69-0.90) compared with upfront surgery; 5-year estimated OS was 77.0% versus 72.0%, respectively. The improvement in OS persisted in landmark analysis of patients who survived at least 12 months.

Conclusion: Only a small percentage of patients with locally advanced recto-sigmoid cancer receive neoadjuvant chemoradiation even though its use might result in improved OS relative to upfront surgery. Prospective research is warranted to validate and standardize therapeutic strategies in patients with recto-sigmoid cancer.

Keywords: Chemoradiotherapy; Colorectal cancer; Neoadjuvant therapy; Retrospective studies; Surgery.