Determining the Optimal Interval Between Neoadjuvant Radiochemotherapy and Surgery in Rectal Cancer: a Retrospective Cohort Study.

In locally advanced rectal cancer, the optimal interval between completion of neoadjuvant radiochemotherapy (RT-ChT) and surgical resection remains unclear due to contradictory data on the benefits of extending this interval. Therefore, the aim of this retrospective study was to determine the impact of this interval on outcomes in patients treated for rectal cancer at our center. We retrospectively reviewed 382 consecutive patients treated for stage II/III rectal cancer between October 1, 2012, and December 31, 2017. We evaluated four different cut-off points (56, 63, 70, and 77 days) to determine which had the greatest impact on treatment outcomes. The median time between completion of RT-ChT and surgery was 67.2 days (range, 28–294). Intervals > 8 weeks (56 days) were associated with worse therapeutic outcomes. Specifically, an interval ≥ 77 days was associated with a significant decrease in overall survival (OS; 84