Racial/Ethnic Variations in Lung Cancer Incidence and Mortality in the Women’s Health Initiative Study Cohort
As reported by Patel et al in the Journal of Clinical Oncology, analysis of lung cancer incidence and mortality in the Women’s Health Initiative Study cohort of postmenopausal women showed a marginally significant lower risk of cancer in Hispanic women vs white women and no difference in mortality risk among all racial/ethnic groups in fully adjusted risk models.
Study Details
The study included data on 129,951 women, including 108,487 (83%) white, 10,892 (8%) black, 4,882 (4%) Hispanic, 3,696 (3%) Asian/Pacific Islander, 534 (< 1%) American Indian/Alaskan Native, and 1,994 (1%) other women. In fully adjusted models, risk estimates were adjusted for age, education, calcium/vitamin D, body mass index, smoking (status, age at start, duration, and pack-years), alcohol, family history of cancer, oral contraceptive use, hormone therapy, physical activity, and diet.
Asian/Pacific Islander (73.8%) and Hispanic (66.3%) women had a higher percentage of never smokers vs white women (52.5%). Black (11.9%) and American Indian/Alaskan Native women (11.2%) had the highest proportion of current smokers. Pack-year smoking history was greatest in white women (21.8 years), followed by American Indian/Alaskan Native women (18.79 years). Black women (26.27 years) had the longest duration of smoking, followed by white women (24.03 years). White women had the highest smoking cessation rate (85.88%), followed by Asian/Pacific Islander women (84.69%).
Overall, 1,044 women developed lung cancer, including 947 white, 71 black, 14 Asian/Pacific Islander, 14 Hispanic, 4 American Indian/Alaskan Native, and 8 other women. A total of 613 died at median follow-up of 10.5 years (550 white, 42 black, 7 Asian/Pacific Islander, 4 Hispanic, and 4 American Indian/Alaskan Native women).
Incidence Risk
In unadjusted models, compared with risk in white women, risk of lung cancer was significantly lower in Hispanic (odds ratio [OR] = 0.34, 95% confidence interval [CI] = 0.20–0.57), Asian/Pacific Islander (OR = 0.45, 95% CI = 0.27–0.75), and black women (OR = 0.75, 95% CI = 0.59–0.95). In age-adjusted models, risk was significantly lower in Hispanic (OR = 0.40, 95% CI = 0.24–0.68) and Asian/Pacific Islander women (OR = 0.46, 95% CI = 0.27–0.77). In age- and smoking-adjusted models, risk was significantly lower in Hispanic (OR = 0.47, 95% CI = 0.28–0.79) and black women (OR = 0.71, 95% CI = 0.56–0.91). In fully adjusted models, risk was lower in Hispanic women (OR = 0.59, 95% CI = 0.35–0.99). There were no significant racial/ethnic differences in incidence by histologic subtypes in adjusted models.
Factors significantly associated with lung cancer risk in fully adjusted models consisted of age 55–59 (OR = 1.58, 95% CI = 1.13–2.20), 60–69 (OR = 2.65, 95% CI = 1.96–3.60), and 70–79 years (OR = 3.18, 95% CI = 2.29–4.42) vs < 55 years; current vs never smoker status (OR = 2.26, 95% CI = 1.55–3.29); family history of cancer (OR = 1.15, 95% CI = 1.01–1.32); body mass index < 25 vs 25–30 (OR = 0.77, 95% CI = 0.66–0.89) and ≥ 30 kg/m2 (OR = 0.78, 95% CI = 0.66–0.92); greater fruit portions consumed (OR = 0.94, 95% CI = 0.88–0.99); longer smoking duration in years (OR = 1.03, 95% CI = 1.03–1.04); and heavy smoker vs nonsmoker status (OR = 2.52, 95% CI = 1.17–5.44).
Mortality Risk
In unadjusted models, Hispanic (OR = 0.30, 95% CI = 0.15–0.62) and Asian/Pacific Islander women (OR = 0.34, 95% CI = 0.16–0.75) had a lower risk of lung cancer mortality vs white women. No significant differences in risk among racial/ethnic groups were observed in fully adjusted analyses.
The investigators concluded: “Differences in lung cancer incidence and mortality are associated with sociodemographic, clinical, and behavioral factors. These findings suggest modifiable exposures and behaviors may contribute to differences in incidence of and mortality by race/ethnicity for postmenopausal women. Interventions focused on these factors may reduce racial/ethnic differences in lung cancer incidence and mortality.”
The study was supported by the National Institutes of Health.
Manali I. Patel, MD, of Stanford University School of Medicine, is the corresponding author of the Journal of Clinical Oncology article.
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®.
