Exploratory analysis of serial pan-immune-inflammation value and its early dynamics during neoadjuvant chemotherapy as a predictor of complete cytoreduction at interval debulking surgery in advanced ovarian cancer: a retrospective cohort study

Complete cytoreduction at interval debulking surgery (IDS) is the most critical prognostic determinant for advanced ovarian cancer patients receiving neoadjuvant chemotherapy (NACT), yet accurate preoperative prediction remains challenging. Pan-immune-inflammation value (PIV) has emerged as a superior predictor in multiple malignancies compared to simple inflammatory ratios, yet its predictive value for surgical outcomes after NACT in ovarian cancer remains uninvestigated. This study aimed to explore the predictive value of PIV at multiple timepoints and its early dynamics during NACT for complete cytoreduction at IDS in patients with advanced ovarian cancer. PIV was calculated at three timepoints in 231 enrolled patients: before NACT (PIV-0), after one cycle of NACT (PIV-1), and before IDS (PIV-2). Early PIV difference was defined as the percentage change between PIV-0 and PIV-1. Receiver operating characteristic analysis and logistic regression were performed to assess the predictive value for cytoreduction status. Associations with chemotherapy response indicators and survival outcomes were also evaluated. Patients with incomplete cytoreduction had significantly higher PIV levels at all timepoints and less favorable early PIV dynamics (all P < 0.001). The area under the curve for PIV-0, PIV-1, PIV-2, and early PIV difference were 0.762, 0.850, 0.754, and 0.787, with optimal cut-off values of 660.6, 404.9, 219.4, and − 19.4%, respectively. Multivariate analysis identified elevated PIV-0 (OR = 4.06), PIV-1 (OR = 5.31), and unfavorable early PIV difference (OR = 9.93) as independent predictors, while PIV-2 lost significance. High PIV levels at all timepoints and unfavorable early dynamics were associated with lower KELIM score, higher intraoperative peritoneal cancer index, lower chemotherapy response score, and worse survival. PIV and its early dynamics during NACT are potential predictive biomarkers for surgical outcomes in advanced ovarian cancer. Early PIV assessments may help identify patients at risk of incomplete cytoreduction and guide personalized treatment strategies.