An analysis of lung cancer incidence rates showed wide variations among the racial and ethnic subgroups in Florida’s Black and Hispanic population, according to data presented by Cranford et al at the American Association for Cancer Research (AACR) Annual Meeting 2023 (Abstract 1902/8). Study results indicated that disaggregating statistics revealed distinctions among subgroups that could help inform prevention efforts.
Lung cancer is the leading cause of cancer death in the United States, and the second most common cancer type in both U.S. men and women. While overall incidence and mortality rates have declined in recent decades, progress has not been uniform across all racial and ethnic groups. Furthermore, most research on lung cancer is presented in aggregate groups, providing little data on ethnic subgroups, explained the study’s first author, Hannah M. Cranford, MPH. Ms. Cranford is a PhD candidate in epidemiology in the Department of Public Health Sciences at the University of Miami School of Medicine.
“As the United States is becoming increasingly diverse, the characterization of lung cancer incidence rates by detailed race and ethnicity is critical for furthering public health advances in cancer diagnosis, treatment, and prevention tailored to distinct groups,” Ms. Cranford said.
To assess incidence patterns in Florida’s highly diverse population, Ms. Cranford and colleagues examined data from the Florida state cancer registry from 2012 to 2018, comprising 120,550 cases. They computed specific age-adjusted incidence rates for U.S.-born Black, Caribbean-born Black, U.S.-born Mexican, foreign-born Mexican, Puerto Rican, Cuban, Dominican, Central American, and South American populations.
Variations in Incidence
In the aggregated groups, lung cancer incidence rates per 100,000 were 71.4 for White men and 61.0 for White women; 63.5 for non-Hispanic Black men and 36.0 for non-Hispanic Black women; 25.5 for Asian/Pacific Islander men and 18.8 for Asian/Pacific Islander women; and 49.8 for Hispanic men and 26.4 for Hispanic women.
When the study population was disaggregated into various subgroups, striking differences emerged. For example, among the non-Hispanic Black population, lung cancer incidence rates per 100,000 were 81.7 for U.S.-born men and 26.2 for Caribbean-born men; and 46.4 for U.S.-born women and 14.9 for Caribbean-born women.
Among Mexicans, U.S.-born men and women had lung cancer incidence rates of 59.8 and 23.5 per 100,000, respectively. That compared with 22.3 and 12.2 per 100,000 for foreign-born Mexicans.
“Significant racial-ethnic disparities by place of birth are masked among both the Florida Black and Mexican populations when studied at the aggregate level,” Ms. Cranford said. As suggested by previous research, this disparity may be due to behavioral risk factors in U.S.-born populations, such as higher rates of smoking.
Within the Hispanic population, Cuban men had a lung cancer incidence rate of 65.6 per 100,000—a statistic that can be obscured if one looks only at the lower overall rate for Hispanics, Ms. Cranford said. Persistently higher smoking rates in this group are the root of this disparity, she added.
The lowest lung cancer incidence rates were in Central American (16.3 per 100,000) and Caribbean-born Black women (14.9 per 100,000). However, the Caribbean-born Black women had the largest proportion of patients who had never smoked, accounting for 66.7% of the lung cancer cases in that group. The proportions of lung cancer in never-smokers varied significantly, as noted by senior author Paulo S. Pinheiro, MD, PhD, Research Associate Professor at the University of Miami Health System Sylvester Comprehensive Cancer Center.
“The variability of never-smoker proportions among lung cancer cases across racial-ethnic groups derives from the higher or lower prevalence of smoking among certain groups,” Dr. Pinheiro said, adding that a deeper understanding of these patterns could help guide public awareness. A study led by Dr. Pinheiro, published in the journal Lung Cancer in 2022, suggested that exposure to secondhand smoke and environmental hazards are among the risk factors for lung cancer in never-smokers.
Ms. Cranford said that while she expected to see variation in lung cancer incidence rates, “the magnitude of such heterogeneity within groups is surprising and is important for public health surveillance and clinical practice.” Understanding such differences could allow public health experts to develop information campaigns, including culturally tailored antitobacco efforts aimed at younger populations, she added.
“Aggregation of non-Hispanic Blacks or Hispanics obscures inherent disparities within groups. The implications of these findings are significant for research, public health surveillance, and for clinical professionals working with diverse U.S. populations,” Ms. Cranford said. “These results indicate the need for a more refined approach to the fight against lung cancer.”
A limitation of the study is that some data were derived from multiple imputation due to missing information.
Disclosure: This study was funded by the Bankhead Coley Research Program of the State of Florida, Grant Number 20B16. For full disclosures of the study authors, visit abstractsonline.com.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.