SAN ANTONIO--Three studies reported at the San Antonio Breast
Cancer Symposium show no apparent adverse effects of hormone replacement
therapy (HRT) on breast cancer and, in fact, suggest that breast
cancers in patients with a history of HRT may have a more favorable
prognosis in terms of histologic grade and estrogen-receptor (ER)
The largest study focused on 432 postmenopausal women diagnosed
with invasive breast cancer at University Hospital of South Manchester,
England--109 with a history of HRT (mean duration, 48 months)
and 323 who had never received hormones. To qualify as HRT users,
patients must have used HRT for at least 3 months and within 3
months of the cancer diagnosis, said surgical oncologist Claudia
Tumors in the two patient groups were similar with respect to
nodal involvement, tumor size, and ER status. However, women who
received HRT had significantly more grade 1 tumors (42% vs 24%).
A subanalysis showed that women who had taken hormones for more
than 2 years were significantly more likely to have ER-positive
"HRT is associated with better grade, and better grade is
associated with improved prognosis," Dr. Harding said. "Thus,
HRT does not appear to have an adverse effect on mortality."
She added that the similarity with respect to tumor size and node
status reflected that the women all had asymptomatic disease that
was detected by screening.
Higher ER Levels
A Cincinnati study showed that hormone users develop tumors with
significantly higher ER levels. Researchers evaluated the history
of hormone use (contraceptives, fertility drugs, and conjugated
estrogens) in 128 premenopausal and 197 postmenopausal women with
breast cancer. Overall, 102 patients had never used hormones for
any purpose. Their breast tumors had a mean ER level of 51 fm/mg
and a progesterone receptor (PR) level of 92.9 fm/mg.
By comparison, the 223 patients with a history of hormone use
had tumors with a significantly higher ER level, averaging 79.2
fm/mg, and similar average PR level (107.9 fm/mg), reported Elyse
Lower, MD, associate professor of medicine, University of Cincinnati.
Separate analyses of pre- and post-menopausal women showed no
significant correlations between hormone use and receptor levels
of tumors. Dr. Lower suggested that higher ER content might account
for previous reports that post-menopausal hormone users develop
tumors with a more favorable prognosis.