Timing of surgery following neoadjuvant chemoradiation in rectal cancer: A retrospective analysis from an academic medical center.

Abstract

702 Background: Neoadjuvant chemoradiotherapy has been proven to achieve decreased local recurrence in rectal cancer with lower toxicity but data confirming the optimal timing of surgery following neoadjuvant cares is less robust. Methods: The University of Iowa Cancer Registry was queried to identify all patients with rectal cancer between 2000-2012. Individual records were reviewed for all patients with Stage II-III disease who received neoadjuvant chemoradiation. Primary endpoints were time interval from last day of chemoradiation to surgery (TI) and overall survival (OS). Secondary endpoints included hospital length of stay following surgery (LOS), intraoperative blood loss (BL), and major postoperative complication including infection, anastomotic failure, and thromboembolic event. Patient characteristics such as personal and family history of malignancy were studied, and treatment regimens including chemotherapy type, radiation technique and quality of resection were also compared. All postoperative pathology slides were reviewed for completeness of resection by a single pathologist. Univariate logistic regression analyses were used to study the association between TI and OS to help define the optimal interval. Results: 88 patients were identified with Stage II and III rectal cancer after imaging and endoscopic study. There was no significant association between OS and TI when comparing less than 8 weeks to greater than 8 weeks (p = 0.14) or when considering TI as a continuous variable (p = 0.99). There was no significant association between TI and surgical complications including BL (p = 0.60) or LOS (median = 7.00 days, p = 0.06), though patients undergoing pelvic exenteration experienced notably longer LOS (n = 4, mean 24.25 days, max 60 days). Conclusions: Our findings indicate that overall survival is not significantly impacted by longer intervals between chemoradiation and surgery. The incidence of major postoperative complication was rare but cost patients and the healthcare provider significant resources; thus, our results implicate potential benefits to treating some Stage II and III rectal cancers solely with chemoradiotherapy.