Lung cancer among never-smokers (LCNS) ranks as the 11th most common cancer among men and the 8th most common among women, according to research published in Lung Cancer.
For this study, researchers evaluated individual-level data from 77,641 patients in Florida’s cancer registry who were diagnosed with lung cancer during 2014-2018.
The researchers combined the registry data with population denominators adjusted with National Health Interview Survey data on smoking prevalence to calculate population-based LCNS incidence.
The researchers found that LCNS accounted for 12.7% of lung cancer cases, including 15.9% of lung cancer cases among women and 9.6% of lung cancer cases among men.
When compared with lung cancer in ever-smokers, LCNS was more common among women (P <.001), non-White patients (P <.001), and patients aged 15-44 years or 75 and older (P <.001). LCNS cases were more likely to be adenocarcinoma (P <.001), and to be localized at diagnosis (P <.001).
The overall incidence rate (IR) of LCNS among women was 11.7 (95% CI, 11.4-12.0). LCNS was most common among Asian/Pacific Islander women (IR, 13.5; 95% CI, 11.7-15.3), followed by Black women (IR, 12.9; 95% CI, 11.9-13.9), White women (IR, 11.8; 95% CI, 11.4-12.2), and Hispanic women (IR, 10.6; 95% CI, 10.0-11.3).
Among men, the overall IR was 13.1 (95% CI, 12.7-13.6). The differences in LCNS incidence were similar among men, with the highest incidence among Asian/Pacific Islander men (IR, 15.3; 95% CI, 12.4-18.2), followed by Black men (IR, 14.6; 95% CI, 13.0-16.2), White men (IR, 13.2; 95% CI, 12.7-13.7), and Hispanic men (IR, 12.1; 95% CI, 11.0-13.2).
The proportion of cancer deaths, as measured by proportionality mortality rank, was highest among White and Hispanic individuals for both women (9 and 10, respectively) and men (14 for both).
The researchers concluded that additional studies are needed to help explain these findings and improve our understanding of risk factors for LCNS.
Pinheiro PS, Callahan KE, Medina HN, et al. Lung cancer in never smokers: Distinct population-based patterns by age, sex, and race/ethnicity. Lung Cancer. Published online October 29, 2022. doi:10.1016/j.lungcan.2022.10.009