BackgroundImmunocheckpoint inhibitor(ICI) is a major breakthrough in tumor treatment. It can activate the patient’s own immune system and play an anti-tumor role, but not all patients can benefit from it. At present, there is still a lack of effective biomarkers to guide clinical application. The systemic immune inflammation(SII) index reflects the systemic inflammatory state and immune state of patients. Prognostic nutrition index(PNI) can be used to evaluate immune status of patients. Therefore, SII and PNI indexes may have some value in predicting the efficacy and prognosis of immunotherapy, but there is still a lack of relevant research. The purpose of our study was to explore the influence of SII and PNI index on the efficacy and prognosis of immunotherapy.MethodsA total of 1935 patients treated with ICIs treatment in the Fourth Hospital of Hebei Medical University from November 2016 to October 2021 were retrospectively collected. 435 patients who met the inclusion criteria and did not meet the exclusion criteria. The imaging data, blood results of each patient were collected within 1 week before ICIs treatment. The neutrophil lymphocyte ratio(NLR), platelet lymphocyte ratio(PLR), monocyte lymphocyte ratio(MLR), PNI,systemic inflammatory response index(SIRI),neutrophil-eosinophil ratio(NER) was calculated. The patients were followed up by in-patient, out-patient reexamination and telephone contact, and the efficacy evaluation and survival status were recorded. The deadline of follow-up: January 2021. SPSS-24.0 software was employed for statistical analysis.ResultsAmong the 435 patients receiving ICI treatment, 61,236 and 138 patients were evaluated respectively as partial response (PR), stable disease (SD) and progressive disease (PD). The overall response rate(ORR) and disease control rate (DCR) of this cohort were 14.0% and 68.3%, respectively. Median progression-free survival (mPFS) is 4.0 months, The overall survival (mOS) of this cohort is 6.8 months. Multivariate analysis showed that SIRI(Hazard Ratio, HR = 1.304,P= 0.014), PNI (HR = 0.771,P= 0.019), prealbumin (PAB) (HR = 0.596,P= 0.001), and PNI(HR = 0.657,P= 0.008) were independent risk factors for PFS and OS, respectively.ConclusionsPatients with high SIRI value and low PNI value before ICI treatment have shorter PFS. Patients with higher PNI value have better prognosis. Therefore, hematological indicators may become predictors of immunotherapy.