Hormone replacement therapy may increase lung cancer risk

Last Updated: 2006-01-26 12:51:47 -0400 (Reuters Health)

By Clementine Wallace

NEW YORK (Reuters Health) - A history of hormone replacement therapy (HRT) appears to decrease survival rates among women diagnosed with lung cancer, according to a new study published in the January 1st issue of the Journal of Clinical Oncology.

While previous epidemiological studies have resulted in contradictory findings, some demonstrating that estrogens increase the risk of lung cancer, others finding the hormone to be beneficial, "none of them had addressed the impact of HRT on the outcomes of lung cancer," said Dr. Apar Kishor Ganti, from the University of Nebraska Medical Center in Omaha.

Dr. Ganti and colleagues conducted a retrospective chart review of 498 women diagnosed with lung cancer between January 1994 and December 1999. Eight-six percent had a history of smoking and 17% had taken HRT for at least 6 consecutive weeks anytime before lung cancer diagnosis.

The researchers report that overall survival was significantly higher in women without a history of HRT, at a median of 79 months, compared with HRT-experienced women, at a median of 39 months. The survival rates decreased even further when a history of HRT was combined with a smoking history.

Their analysis also showed that HRT-experienced women tended to be younger when diagnosed with lung cancer. The median age was 63, compared with 68 years old for women with no previous experience with HRT (p < 0.0001).

Because of the retrospective nature of the study, the researchers could not establish a dose-response relationship, editorialist Dr. Jill M. Siegfried, of the University of Pittsburgh, commented. Several other areas need to be investigated, such as the effects of administering estrogen alone or in combination with progesterone, or if agents known to block hormones affect lung cancer outcome.

"Here is another possible negative effect of estrogens," she continued. "So unless post-menopausal symptoms are severe, and can't be treated by other medications, HRT should be avoided.

J Clin Oncol 2006;24:59-63.