Hormone replacement therapy doesn't lead to breast cancer recurrence

The study included longitudinal data from a national cohort of postmenopausal women, diagnosed between 1997 and 2004 with early-stage breast cancer who received no treatment or five years of hormone therapy, as ascertained from Denmark's national prescription registry.

Among 8461 women who had not received vaginal estrogen therapy or menopausal hormone therapy before a breast cancer diagnosis, 1957 and 133 used vaginal estrogen therapy or menopausal hormone therapy, respectively, after diagnosis. The researchers here found no increase in the risk of recurrence or mortality for those who received either vaginal estrogen therapy or menopausal hormone therapy.

"This large cohort study helps to inform the nuanced discussions between clinicians and breast cancer survivors about the safety of vaginal estrogen therapy," said Elizabeth Cathcart-Rake, who wrote an editorial to accompany the article.

"These results suggest that breast cancer survivors on tamoxifen with severe genitourinary symptoms can take vaginal estrogen therapy without experiencing an increase in their risk for breast cancer recurrence. However, caution is still advised when considering vaginal estrogen for breast cancer survivors on aromatase inhibitors, or when considering menopausal hormonal therapy."

Reference:

Søren Cold, MD, Frederik Cold, MD, Maj-Britt Jensen, MSc, Deirdre Cronin-Fenton, PhD, Peer Christiansen, MD, Bent Ejlertsen, MD, Systemic or Vaginal Hormone Therapy After Early Breast Cancer: A Danish Observational Cohort Study, JNCI: Journal of the National Cancer Institute, 2022;, djac112, https://doi.org/10.1093/jnci/djac112