Small-cell lung cancer (SCLC) is one of the most prognostically unfavorable malignant tumors for which an effective targeted inhibitor has not yet been found. Cytotoxic therapy for SCLC has not changed in the last thirty years. Immunotherapy is a fundamentally new method of treatment of malignant tumors, which has proven its effectiveness in various solid tumors. Fundamental prerequisites for the efficacy of immunotherapy in SCLC include a high level of mutational load and paraneoplastic syndromes typical for SCLC (Lambert - Eaton syndrome, etc.), leading to immunization against the tumor; factors that may adversely affect the efficacy of immunotherapy are low levels of PD-L1 expression, low content of T-lymphocytes infiltrating the tumor, and loss of histocompatibility of SCLC antigens by tumor cells. The first studies that studied the efficacy of CTLA-4 inhibitors in the first line of therapy of SCLC and PD-L1/PD-1 inhibitors during progression after the first line showed ambiguous results. However, the study to evaluate the efficacy of athezolizumab (antibody to PD-L1 receptor) in combination with chemotherapy in the first line of SCLC, where for the first time in 30 years in the studies of phase 3 at disseminated SCLC a significant increase in the total survival rate was shown. The study of immune control point inhibitors in SCLC, both localized and disseminated, continues, the prospects of immunotherapy in SCLC are already clearly defined, and further development and improvement in one of the most adverse forms of cancer is expected.

.

Aim of the study: to evaluate prognostic value of baseline lung immune prognostic index (LIPI) and its modification (mLIPI) for metastatic non-small cell lung cancer (mNSCLC) patients treated with immune checkpoint inhibitors (ICI).Material and methods. Baseline neutrophil-to-lymphocyte ratio, lactate dehydrogenase, hemoglobin, platelets, and fibrinogen level were collected from 133 patients treated with ICI in monotherapy or combination between July 2015 and July 2022 in N.N. Blokhin NMRCO. According to evaluating factors patients were divided into three groups of “good” (LIPI 0/mLIPI 0–1), “intermediate” (LIPI 1/mLIPI 2–3) and “poor” prognosis (LIPI 2/mLIPI 4–5). The primary endpoint was progression free survival (PFS).Results. The median PFS for the LIPI groups were 9.7 months (1.4–17.9; 95 % CI), 7.9 months (5.9–9.9; CI 95 %) and 6.0 months (4.07–7.93; 95 % CI) in the “good”, “intermediate” and “poor” prognosis groups, respectively; the hazard ratio (HR) for patients in the “poor” prognosis group (17 patients) was 2.02 (1.06–3.84; 95 % CI) compared with the “good” LIPI group (p=0.03). The median PFS for mLIPI groups were 9.0 months (4.53–13.47; 95 % CI), 8.0 months (5.4–10.6; CI 95 %) and 2.0 months. (1.33–2.67; 95 % CI) in the “good”, “intermediate” and “poor” prognosis groups, respectively. The HR for patients in the “poor” prognosis group (n=12) was 3.12 (1.51–6.46; 95 % CI) compared with the “good” mLIPI group (p=0.002).Conclusion. Baseline LIPI and mLIPI predicts potential resistance to ICI treatment in mNSCLC patients.