Preoperative prognostic nutritional index, opioid-sparing anesthesia, and outcomes after gynecologic cancer surgery: a retrospective cohort study

Background Preoperative prognostic nutritional index (PNI) may identify patients at increased perioperative risk, but whether PNI is associated with differences in outcomes across anesthetic strategies remains uncertain. Methods This retrospective cohort included 342 women undergoing surgery for ovarian, endometrial, or cervical cancer from 2019 to 2024. PNI was calculated as serum albumin (g/L) + 5 × absolute lymphocyte count (10 9 /L); PNI < 45 was used as a prespecified pragmatic cutoff. A propofol-based total intravenous, opioid-sparing multimodal strategy, with regional or neuraxial analgesia when feasible, was compared with volatile-based anesthesia and opioid-centered analgesia. Outcomes included postoperative biomarkers, 30-day complications, return to intended oncologic therapy (RIOT) within 42 days, recurrence-free survival (RFS), and overall survival (OS). Regression models examined PNI-by-strategy interactions. Results PNI < 45 was present in 156/342 patients (45.6%). Within this stratum, median postoperative day 3 CRP was 79.1 vs. 92.6 mg/L, major complications occurred in 18.8% vs. 43.3%, and timely RIOT occurred in 79.1% vs. 55.4% with opioid-sparing vs. conventional anesthesia, respectively. Reported 36-month RFS estimates were 72.8% vs. 36.5%. In the cancer-type-stratified adjusted Cox model, the low-PNI term in the conventional-anesthesia reference stratum was associated with RFS (adjusted HR 2.14, 95% CI 1.31–3.48), with a nominal PNI-by-strategy interaction for RFS (interaction HR 0.46, 95% CI 0.22–0.94; p = 0.033). The interaction was not significant for OS ( p = 0.837) or after changing the PNI cutoff to 44 or 46. Conclusions Lower PNI was associated with greater perioperative and oncologic risk. The observed RFS interaction is exploratory and sensitive to PNI dichotomization; residual oncologic, procedural, and calendar-era confounding precludes causal interpretation. Prospective confirmation with continuous PNI modeling and detailed cancer-specific adjustment is required.