Hormone therapy was associated with improved overall survival in women with non–small-cell lung carcinoma, reported investigators in the March issue of the Journal of Thoracic Oncology.
Long-term hormone use and combinations of estrogen and progesterone predicted the most significant survival benefit, reported Dr. Ann G. Schwartz of the Karmanos Cancer Institute and Wayne State University, both in Detroit, and her associates.
Women with lung cancer usually live longer than do men with the disease. But few prior studies have examined associations between reproductive factors, hormone therapy, and lung cancer outcomes, and results have been inconsistent, investigators said (J. Thorac. Oncol. 2014;9:355-61).
Researchers interviewed 485 women who were diagnosed with non–small-cell lung carcinoma between 2001 and 2005, about their reproductive histories and type, dose, and duration of hormone therapy.
Only hormone therapy predicted overall survival (hazard ratio, 0.69; 95% confidence interval, 0.54-0.89) after accounting for stage at diagnosis, surgery, radiation, education level, cigarette smoke exposure, age, and race, the investigators reported.
Women who received hormone therapy prior to lung cancer diagnosis survived a median of 80 months, compared with 37.5 months for women who did not.
The survival benefit was most significant when hormone therapy lasted 11 years or longer, particularly for combinations of estrogen and progesterone (HR, 0.50; 95% CI, 0.30-0.83). Taking estrogen alone for less than 11 years had no significant effect.
Because patients had to be healthy enough to participate in the survey, results might not apply to all women with non–small-cell lung cancer, Dr. Schwartz and associates noted.
"These findings suggest a complex relationship between exposure to exogenous hormones and lung cancer outcomes," added the researchers. They recommended research to explore the biological reasons for their findings.
This study was supported by the National Institutes of Health. The authors disclosed no relevant financial conflicts of interest.