Sex-specific Difference for Small Cell Lung Cancer from Immunotherapy Advancement

The treatment of lung cancer has witnessed significant progress, leading to improved survival rates among patients. It is important to assess the individual contributions of non-small cell lung cancer (NSCLC) and small-cell lung cancer (SCLC) to overall lung-cancer incidence and mortality trends based population, especially sex difference.

We analyzed lung cancer mortality based on subtype, gender, and calendar year. The Joinpoint software was used to identify any changes in incidence and trends in mortality.

Incidence and incidence-based mortality declined from 2001 to 2019 both NSCLC and SCLC annually. The most significant decrease occurred between 2016 and 2019 with annual percent change of 5.71%. From 2012 to 2016, the incidence-based mortality of SCLC in women changed by 2.7% in tandem with incidence decreased 2.84%. Remarkably, the incidence-based mortality for women declined notably by 5.23% between 2016 and 2019, even as the incidence showed a less extent of decreasing (-2.59%). The survival rate for women was 15.2% in 2001, 19.3% in 2016, it had increased to 21.3% in 2018 but similar trends not in men. The survival curve showed the change in survival outcomes over time among men and women (median overall survival: 13 vs 23months) receiving immunotherapy for SCLC.

Population-level mortality from NSCLC and SCLC in the United States fell sharply from 2016 to 2019 as incidence deceased, and survival improved substantially. Our analysis suggests that approval for and use of immunotherapy may explain the mortality reduction observed during this period, with significant benefits especially for SCLC patient in women.