The optimal timing for surgery following neoadjuvant chemoradiotherapy (nCRT) in rectal cancer patients and its impact on perioperative and postoperative complications remain subjects of debate. This retrospective study aimed to investigate the association between the interval between nCRT and surgery and postoperative complications.

Data from 279 patients who underwent nCRT were analyzed. The relationship between interval length and peri- and postoperative complications was assessed using the Mann–Whitney test and Spearman’s rank correlation. Logistic regression was employed to evaluate the predictive value of the interval length for outcomes, adjusting for clinicopathological characteristics. Receiver operating characteristic (ROC) analysis determined the optimal cut-off value.

The median interval between nCRT and surgery was 14 weeks (range 4 to 63 weeks). The length of the interval was associated with mean operative time and length of hospital stay (β = −0.86 and 0.03; p = 0.008 and 0.047; respectively). However, no significant associations were found between the interval length and peri- or postoperative complications in uni- or multivariate analyses. ROC analysis demonstrated significant results for total complications, ileus/bowel obstruction, and stomal necrosis (area under the curve [AUC] = 0.58, 0.71, and 0.67; p = 0.045, 0.002, and 0.001; respectively) and identified cut-off values of less than 12, 15, and 12 weeks, respectively, for minimizing these complications.

A longer interval between nCRT and surgery in rectal cancer patients was associated with shorter operative times but longer hospital stays. No significant association was found between time intervals and complications, except for total complications, ileus/bowel obstruction, and stomal necrosis. Timely surgical intervention is crucial for optimizing outcomes.