Background Immunocheckpoint inhibitors (ICIs) can improve the survival time of patients with non-small cell lung cancer (NSCLC), but there is still a lack of related bioindicator that affect the therapeutic effect and prognosis of immunocheckpoint inhibitors.

Objective To explore the predictive value of the clinical effect and prognosis of the new index system immuno-inflammatory nutrition index (SIINI) on NSCLC patients treated with ICIs.

Methods Clinical data about 126 NSCLC patients in Hefei BOE Hospital from January 2020 to May 2022 were collected, and all patients were treated with immunopharmaceuticals. Multivariate logistic regression analysis was used to analyze the influencing factors of disease control rate (DCR) of NSCLC patients treated with ICIs, and Cox regression analysis was applied to analyze the influencing factors of disease progression free survival (PFS) in NSCLC patients receiving ICIs treatment.

Results A total of 126 NSCLC patients were included, with 88 males and 38 females; 81 patients were aged 60 or older, and 45 patients were younger than 60. The objective response rate (ORR) and DCR of these patients after treatment were 27.78% and 73.02%, respectively. Logistic regression results showed that NSCLC patients with TNM stage at ⅢB - ⅢC (OR=0.449, 95% CI: 0.224-0.898), the number of metastatic sites less than 3 (OR=0.345, 95% CI: 0.122-0.970), NLR ≤ 2.61 (OR=0.244, 95% CI: 0.089-0.670), and SIINI ≤ 95.34 (OR=0.284, 95% CI: 0.107-0.751) had better efficacy (P＜0.05). Cox regression results showed that age ≥ 60 years old (HR=1.811, 95% CI: 1.073-3.059), TNM stage Ⅳ (HR=2.364, 95% CI: 1.253-4.458), and SIINI>95.34 (HR=1.543, 95% CI: 1.037-3.407) were risk factors for PFS in NSCLC patients receiving ICIs treatment (P＜0.05).

Conclusion SIINI may be an independent influencing factor for DCR in patients with NSCLC treated with ICIs, and may be used as a predictor of the efficacy and prognosis of immunotherapy for patients with NSCLC.