Early C-reactive protein as a predictive biomarker for postoperative complications following robot-assisted surgery for rectal cancer

This retrospective cohort study aimed to assess the predictive value of early postoperative C-reactive protein (CRP) levels for complications following robot-assisted rectal surgery (RARS) for rectal cancer. We analyzed data from 117 consecutive patients who underwent elective RARS at Okayama University Hospital between September 2020 and January 2025. Serum CRP levels were routinely measured preoperatively and on postoperative days (POD) 1 and 4. The primary outcome was the occurrence of any postoperative complication within 30 days, classified according to the Clavien-Dindo grading system. Postoperative complications were observed in 26 patients, representing 22.2% of the cohort. Univariate analysis revealed that several factors were significantly associated with complications, including older age, higher ASA score, neoadjuvant therapy, stoma creation, prolonged operative time, and elevated CRP levels on POD1 and POD4. Notably, multivariate logistic regression analysis identified POD1 CRP as a robust independent predictor of overall postoperative complications (adjusted odds ratio 0.77, 95% confidence interval (CI) [0.63-0.93], p < 0.01). In the ROC analysis, the AUC was 0.735 (bootstrap bias-corrected 95% CI 0.544-0.848). The optimal cutoff value of POD1 CRP was 5.63 mg/dl, at which Youden's index, yielding a sensitivity of 0.615 and specificity of 0.868. In conclusion, early postoperative measurement of CRP on POD1 serves as a valuable and independent biomarker for predicting complications following RARS for rectal cancer. Incorporating POD1 CRP into postoperative surveillance may facilitate the early identification of high-risk patients, thereby facilitating timely interventions and ultimately improving surgical outcomes in this patient population.