In a nationwide population-based study, Ahmedin Jemal (American Cancer Society, Atlanta, GA, USA) and colleagues examined data from the North American Association of Central Cancer Registries for cases of invasive lung cancer in patients aged 30–54 years who were diagnosed between 1995 and 2014 across 46 US states and the District of Columbia.
The incidence of lung cancer was analyzed according to patients' sex, race, ethnic group, age group, year of birth, and year of diagnosis. Female-to-male incidence rate ratios were calculated, and the prevalence of cigarette smoking was also examined by use of data from the National Health Interview Survey (1970–2016).
The results showed that age-specific incidence of lung cancer decreased overall in women and men aged 30–54 years across all races and ethnic groups over the past 20 years, but that the decline has been more rapid in men. The female-to-male incidence of lung cancer in non-Hispanic white individuals increased and was higher than 1·0 in the 30–34, 35–39, 40–44, and 45–49 years age groups. For example, in non-Hispanic white people aged 40–44 years, the female-to-male incidence rate ratio increased from 0·88 (95% CI 0·84–0·92) during 1995–99 to 1·17 (1·11–1·23) in 2010–14. Similar results were recorded in the Hispanic population, but not in other ethnic groups.
The prevalence of smoking in women born since 1965 approached—but did not exceed—that in men, suggesting that these findings cannot be explained by sex differences in smoking behaviors.
“Our findings portend higher overall lung cancer incidence rates in women than in men as younger cohorts age, underscoring the need for strengthening existing tobacco control programmes to reduce smoking among young women”, explained Jemal. “These results also call for aetiologic studies to understand the reasons for the higher lung cancer incidence rates in young women.”
“That women, at the same dose of cigarette exposure as men, may have higher susceptibility to lung cancer, has been argued for 25 years, and is an appropriate possible explanation for these interesting new findings”, commented Harvey Risch (Yale University School of Medicine, New Haven, CT, USA).
Source: Published originally on pewresearch.org, Lung cancer incidence higher in US women than men, by Elizabeth Gourd, June 1st, 2018.