Evaluating Prognostic Factors for Sex Differences in Lung Cancer Survival: A Retrospective Analysis of Real-World...

Lung cancer survival rates are higher among women than men across many populations globally. We examined real-world data on prognostic factors for lung cancer in Australia and assessed their contribution to the sex survival disparity.

This was a retrospective analysis of data from the Victorian Lung Cancer Registry. People diagnosed with lung cancer during 2016 to 2022 were included with follow-up to August 2023. One-year overall survival was estimated by sex and stratified by 4 domain prognostic factors. The contribution of 4 domains of factors (patients' characteristics, smoking history, tumor-related and treatment-related factors) to sex-based survival differences (alone and jointly) was assessed with multiple Cox proportional hazard regressions.

A total of 5313 women and 6540 men were diagnosed with lung cancer, with median 1-year survival 76.5% and 69.4%, respectively. The unadjusted hazard of all-cause death was significantly higher for men than women 1-year post-diagnosis (HR = 1.38, 99% CI, 1.28-1.49, P < .0001). The survival disparity remained statistically significant when each domain of prognostic factors was evaluated individually. Multivariable analysis revealed that treatment-related factors explained about 77% of the overall survival difference, followed by smoking history and tumor-related factors (explaining 26% and 24% respectively). After adjusting for all 4 domains of prognostic factors together, the excess risk of death among men was reduced by about 82% (HR = 1.05, 99% CI, 1.00-1.11, P = .02).

The sex-related lung cancer survival disparity in Australia is largely accounted for by treatment disparities, indicating an opportunity to explore sex differences in treatment preferences, options, and access.