Survival analysis of patients with non-small cell lung cancer in Novosibirsk region from 2015 to 2019

Rationale: Lung cancer is the leader in high mortality rates among other malignancies. This is largely due to the asymptomatic course of the disease and, as a consequence, to its late diagnosis. To optimize the oncology service of the Novosibirsk region in terms of diagnosis, treatment, follow-up and management of this patient category, it seems prudent to study the epidemiological characteristics of non-small cell lung cancer (NSCLC) with consideration of its histologic types. Aim: To perform the survival analysis in patients with squamous cell lung cancer (SCLC) and adenocarcinoma of the lung (ACL) depending on their age, sex and disease stage. Materials and methods: We analyzed medical files of patients diagnosed with SCLC (n = 3007) and ACL (n = 3049) who were treated in the Novosibirsk Regional Oncologic Dispensary from 2015 to 2019. The study included 4758 men and 1298 women (mean age, 68 years; men 66.8 years, women 69.1 years). Results: The majority (96%) of the NSCLC patients were above 50 years of age. The 5-year survival rate of the patients with SCLC and ACL was below 20%. Median survival of the SCLC patients was 443 days (interquartile range [IQR] 138; 1241), of those with ACL, 552 (IQR 107; 1511) days. At the diagnosis of NSCLC, 67% of the patients had stage III/IV of the disease. Maximal survival (10 to 15 years) was found in the NSCLC patients aged 61 years who had been diagnosed at stage III of the disease. Testing of the hypothesis on the impact of histological type of NSCLC on survival at a particular disease stage (Wilcoxon-Gehan test for unpaired samples) showed an association between the survival and histological type only for stage IV (p = 0.000001); median survival in ACL IV was 80 days and in SCLC IV, 104 days. Men comprised 87% of the SCLC group and 73% of the ACL one. In SCLC, there was no gender difference in the median survival rates (log rank test, p = 0.48). The median survival of the female patients with ACL was longer than that of the male ones (329 vs 169 days, log rank test, p = 0.000001). The major proportion of the SCLC and ACL patients was in the age range of 61 to 75 years (59% and 50%, respectively). The least favorable outcomes were seen in the patients below 50 years of age, and the most favorable, in those above 75 years. In SCLC, the median survival was 156 days in the patients below 50 years of age, 238.5 days in those aged from 51 to 60 years, 300 days in the age of 61 to 75 years, and 487 days in the patients above 75 years of age (chi-square test 98.77097; df = 3; p = 0.000001). In ACL, the respective values were 143, 201, 210.5, and 230 days (chi-square test 23.93492; df = 3; p = 0.00003). Conclusion: The analysis of survival of the patients with SCLC and ACL in the Novosibirsk region has shown that the disease stage and age significantly impact the median survival. These are the characteristic features of the general morbidity and mortality from NSCLC.