Sex differences in the characteristics and survival of patients with non-small-cell lung cancer: A retrospective analytical study based on real-world clinical data of the Korean population.

Purpose: This study aimed to investigate the differences in characteristics, clinical stages, treatment modalities, and survival outcomes in patients with non-small-cell lung cancer (NSCLC) based on sex differences using Korean nationwide registry data.

Methods: We analyzed the data of 8650 patients diagnosed with NSCLC between 2014 and 2017, obtained from the Korean Association for Lung Cancer Registry (KALC-R). The Cox proportional hazard model was used to define the differences in survival based on sex. Propensity score matching was used to adjust for differences between men and women.

Results: Of a total of 10 943 patients, 8650 (79.1%) were diagnosed with NSCLC, of whom 68.7% were men and 31.3% were women. For NSCLC, the median age was higher (69.0 vs. 67.0, p < 0.001) and the proportion of ever-smokers (84.5% vs. 10.8%, p < 0.001) was higher in men. Adenocarcinoma (55.5% vs. 90.4%, p < 0.001) and stage I NSCLC (26.3% vs. 41.3%, p < 0.001) were more common in women. Survival was significantly lower in men with NSCLC (hazard ratio [HR] 1.493 [95% confidence interval, CI 1.238-1.800], p < 0.001) even after adjusting for meaningful clinical variables, and in the matched cohort (HR 1.339 [1.075-1.667], p = 0.009). Similarly, survival was significantly lower in men with stage IV adenocarcinoma after adjusting for other clinical variables (HR 1.493 [1.238-1.800], p < 0.001) and in the matched cohort (HR 1.339 [1.075-1.667]; p = 0.009).

Conclusions: Male patients with NSCLC had poorer prognosis, not only after variable adjustments for prognostic factors, but also in the matched cohort.