Abstract:
Background: This study aimed to investigate the predictive value of the Comprehensive Nutritional Index (CNI) for pathological complete response and perioperative safety in patients with localized rectal cancer receiving total neoadjuvant therapy (TNT) combined with delayed surgery.
Methods: A retrospective analysis was conducted on 73 patients with localized rectal cancer who received TNT combined with delayed surgery at our institution from January 2025 to June 2026. Anthropometric and laboratory parameters were collected, and the CNI was calculated and dichotomized by the mean into the CNI ≥ mean group (n=36) and the CNI < mean group (n=37). All patients received the TNT regimen (25 Gy/5 fractions or 45 Gy/25 fractions), followed by three cycles of chemotherapy combined with immunotherapy as induction therapy, and subsequently underwent radical surgery. The chi-square test was used to compare categorical variables between groups, and the independent samples t-test was used for continuous variables. P < 0.05 was considered statistically significant.
Results: The pathological complete response (pCR) rate was significantly higher in the CNI ≥ mean group than in the CNI < mean group [61% (22/36) vs 34% (13/37), χ²=4.227, P=0.040]. No significant difference was found in the R0 resection rate between the two groups [98% (35/36) vs 90% (33/37), χ²=1.848, P=0.174]. The incidence of Clavien-Dindo grade ≥ II postoperative complications was significantly lower in the CNI ≥ mean group [14% (5/36) vs 32% (13/37), χ²=3.684, P=0.037]. Postoperative weight loss was smaller in the CNI ≥ mean group than in the CNI < mean group [(-1.5±0.3) kg vs (-2.1±0.3) kg, t=8.547, P<0.001].
Conclusion: The CNI can effectively predict the pathological complete response rate and the risk of postoperative complications in patients with localized rectal cancer after TNT combined with delayed surgery, helping to identify patients who may benefit from TNT and providing a basis for precise perioperative nutritional intervention.
Keywords: Comprehensive Nutritional Index; total neoadjuvant therapy; localized rectal cancer; pathological complete response; perioperative complications
