A Prognostic Nomogram Combining Postoperative SII and PIV Improves Long-Term Survival Prediction in NSCLC

Systemic inflammation plays a crucial role in the progression and prognosis of non-small cell lung cancer (NSCLC), yet the prognostic value of perioperative inflammatory markers remains underexplored.

We retrospectively analyzed 243 patients who underwent resection (2015-2019) at The Second Xiangya Hospital. Five inflammatory indices-neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and pan-immune-inflammation value (PIV)-were calculated from pre- and postoperative blood counts, and their changes (Δ values) were derived. Prognostic markers were identified using receiver operating characteristic (ROC) curve analysis, Cox regression, least absolute shrinkage and selection operator (LASSO), and stepwise selection. A nomogram was developed in a training cohort and internally validated using a 70/30 hold-out split from the same center.

Postoperative SII and PIV, along with their perioperative changes (ΔSII and ΔPIV), showed superior prognostic performance compared to preoperative values. The final nomogram (POST_SII, POST_PIV, clinical tumor-node-metastasis stage, smoking history, preoperative albumin, age, and gender) achieved a concordance index (C-index) of 0.85 in the training cohort, with area under the curve (AUCs) of 0.86, 0.89, and 0.94 at 1-, 3-, and 5-year, and a C-index of 0.80 with AUCs of 0.74, 0.85, and 0.90 in the validation cohort. The model surpassed TNM and clinical models and showed greater net clinical benefit in decision-curve analysis.

Postoperative SII and PIV are strong inflammatory predictors of survival after NSCLC resection. A nomogram integrating these markers with clinical variables provides accurate, individualized risk stratification.