Lung cancer among postmenopausal women treated with estrogen alone in the women's health initiative randomized trial. J Natl Cancer Inst 2010 Sep 22;102(18):1413-21
Date
08/17/2010Pubmed ID
20709992Pubmed Central ID
PMC2943522DOI
10.1093/jnci/djq285Scopus ID
2-s2.0-77957257347 (requires institutional sign-in at Scopus site) 111 CitationsAbstract
BACKGROUND: In the Women's Health Initiative (WHI) randomized controlled trial, use of estrogen plus progestin increased lung cancer mortality. We conducted post hoc analyses in the WHI trial evaluating estrogen alone to determine whether use of conjugated equine estrogen without progestin had a similar adverse influence on lung cancer.
METHODS: The WHI study is a randomized, double-blind, placebo-controlled trial conducted in 40 centers in the United States. A total of 10 739 postmenopausal women aged 50-79 years who had a previous hysterectomy were randomly assigned to receive a once-daily 0.625-mg tablet of conjugated equine estrogen (n = 5310) or matching placebo (n = 5429). Incidence and mortality rates for all lung cancers, small cell lung cancers, and non-small cell lung cancers in the two randomization groups were compared by use of hazard ratios (HRs) and 95% confidence intervals (CIs) that were estimated from Cox proportional hazards regression analyses. Analyses were by intention to treat, and all statistical tests were two-sided.
RESULTS: After a mean of 7.9 years (standard deviation = 1.8 years) of follow-up, 61 women in the hormone therapy group were diagnosed with lung cancer compared with 54 in the placebo group (incidence of lung cancer per year = 0.15% vs 0.13%, respectively; HR of incidence = 1.17, 95% CI = 0.81 to 1.69, P = .39). Non-small cell lung cancers were of comparable number, stage, and grade in both groups. Deaths from lung cancer did not differ between the two groups (34 vs 33 deaths in estrogen and placebo groups, respectively; HR of death = 1.07, 95% CI = 0.66 to 1.72, P = .79).
CONCLUSION: Unlike use of estrogen plus progestin, which increased deaths from lung cancer, use of conjugated equine estrogen alone did not increase incidence or death from lung cancer.
Author List
Chlebowski RT, Anderson GL, Manson JE, Schwartz AG, Wakelee H, Gass M, Rodabough RJ, Johnson KC, Wactawski-Wende J, Kotchen JM, Ockene JK, O'Sullivan MJ, Hubbell FA, Chien JW, Chen C, Stefanick MLMESH terms used to index this publication - Major topics in bold
AgedCarcinoma, Non-Small-Cell Lung
Carcinoma, Small Cell
Double-Blind Method
Estrogen Replacement Therapy
Estrogens, Conjugated (USP)
Female
Humans
Incidence
Lung Neoplasms
Middle Aged
Postmenopause
Progestins
United States
Women's Health
