Sex-specific trends in lung cancer incidence and survival: A population study of 40 118 cases

Abstract

Background and aim: Lung cancer is increasingly affecting women. The aim of this study was to identify sex-specific trends in lung cancer incidence and survival. Methods: Complete national data on 40 118 cases from the Cancer Registry of Norway sampled from 1988 to 2007 are presented, with incidence rates, 1- and 5-year relative survival in 5 year intervals and multivariate HRs adjusted for covariates, each with 95% CIs. Results: Lung cancer incidence increased by 64%, with an age-adjusted annual average increase of 4.9% in women and 1.4% in men in this period. Relative survival was lower in men than in women in all time periods, and men had an increased risk of dying within 5 years of diagnosis compared with women (HR 1.14, 95% CI 1.11 to 1.17), adjusted for covariates. Adenocarcinoma is now the most frequent histological group in men and women, yet the risk of dying was higher in men in all histological subtypes except squamous cell carcinoma. A higher proportion of women than men were diagnosed with localised disease, and the risk of dying was significantly higher in men among all stages, most apparent in localised disease (HR 1.25, 95% CI 1.18 to 1.33). Conclusion: The findings highlight important characteristics of the lung cancer epidemic; despite a rising incidence of female lung cancer cases, women are diagnosed with less advanced disease than men; when adjusted for covariates, men have an increased risk of excess death at 5 years compared with women, irrespective of stage, age, period of diagnosis and selected histological subgroups.