Sep 20, 2016
A new study in the Journal of Clinical Oncology (JCO), “Racial and Ethnic Variations in Lung Cancer Incidence and Mortality: Results from the Women’s Health Initiative,” assessed whether women from various racial and ethnic groups have differing risks of developing and dying (incidence and mortality) from lung cancer. The investigators looked at data from 129,951 women, age 50-79 years, who were part of the Women’s Health Initiative Study (WHI), and carried out three types of analyses. In the first analysis, the researchers looked at the association between incidence and mortality and one factor alone: race and ethnicity. The second analysis adjusted for smoking. In the third analysis, the researchers made further adjustments for additional demographic, clinical, and behavioral factors that might independently explain differing rates of lung cancer incidence and mortality. These factors include, age, education, calcium/vitamin D, body mass index, alcohol, family medical history, oral contraceptives, hormones, physical activity, and diet.
The study, published online ahead of print, December 23, 2015, found that when health and lifestyle variables were factored into the analysis, there were no differences between racial and ethnic groups in terms of lung cancer incidence and mortality, although Hispanic women had a trend towards lower incidence (read about the “Hispanic Paradox” in this 2013 study in JCO, penned by three coauthors of the current study). In the unadjusted model, which factored in race/ethnicity alone into the analysis, differences between groups emerged: Hispanic women had 66% lower odds of developing lung cancer compared with non-Hispanic Whites, and 25% lower odds compared with non-Hispanic Black women. In terms of mortality, the unadjusted model found that Hispanic and Asian/Pacific Islander women had a decreased risk of death from lung cancer, compared with non-Hispanic White women.
The study also found no association between racial and ethnic groups and the risk of developing non-small cell lung cancer versus small cell.
Risk more strongly associated with behavioral factors
Commenting on these findings, the study’s first author, Manali I. Patel, MD, MPH, said, “The findings suggest that disparities in this disease may be due, in part, to behavioral-level differences. We know the risks of smoking but other modifiable behaviors, such as vegetable consumption, may also play a role in reducing disparities in lung cancer incidence and mortality among our patient population, nationally.”
The importance of gender
Dr. Patel said the study addresses a need for more research that focuses specifically on women and lung cancer disparities.
“Many of the previous studies have largely focused on men,” said Dr. Patel. “But there have been few studies looking specifically at women, and these were very inconsistent, with some demonstrating increased incidence and mortality among non-Hispanic White women and others showing increased incidence among non-Hispanic Black women.”
In addition, previous studies that focused on women and disparities in lung cancer had small sample sizes and did not adjust for the behavioral factors associated with incidence and mortality.
“This is the first study that used data from a large, prospective population-based cohort,” said Dr. Patel. “The Women’s Health Initiative Study has impressive granularity in terms of detailed patient-level factors that allowed us to evaluate many specific factors. For example, the data not only looks at dietary factors, but at how many vegetable and fruit products were consumed, and smoking and alcohol intensity and duration of consumption.”
Manali I. Patel, MD, MPH, is a Medical Oncologist and an Instructor in Medicine-Oncology at Stanford School of Medicine. An ASCO member since 2010, she serves on the Health Disparities Committee.
Abstract of the original JCO article.
PDF of the original JCO article.
Patel MI, Wang A, Kapphahn K, et al. Racial and ethnic variations in lung cancer incidence and mortality: results from the Women’s Health Initiative. J Clin Oncol. Epub 2015 Dec 23.
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@ 2015 American Society of Clinical Oncology