(HealthDay News) — In postmenopausal women treated for early-stage estrogen receptor-positive breast cancer, neither vaginal estrogen therapy (VET) nor menopausal hormone therapy (MHT) is associated with an increased risk for recurrence or mortality, according to a study published online July 20 in the Journal of the National Cancer Institute.

Søren Cold, MD, from Odense University in Denmark, and colleagues used longitudinal data from a national cohort of postmenopausal women, diagnosed in 1997 to 2004 with early-stage invasive estrogen receptor-positive nonmetastatic breast cancer. The analysis compared mortality and the risk for recurrence in 8,461 women (1,957 used VET and 133 used MHT after diagnosis) over 9.8 years and 15.2 years, respectively.

The researchers found that the adjusted relative risk for recurrence was 1.08 (95% CI, 0.89-1.32) for VET and 1.05 (95% CI, 0.62-1.78) for MHT. In the subgroup receiving adjuvant aromatase inhibitors, the adjusted relative risk for recurrence was 1.39 (95% CI, 1.04-1.85). For overall mortality, the adjusted hazard ratios were 0.78 (95% CI, 0.71-0.87) and 0.94 (95% CI, 0.70-1.26) for VET and MHT, respectively.

“These results suggest that breast cancer survivors on tamoxifen with severe genitourinary symptoms can take VET without experiencing an increase in their risk for breast cancer recurrence,” write the authors of an accompanying editorial. “However, caution is still advised when considering vaginal estrogen for breast cancer survivors on aromatase inhibitors, or when considering MHT.”

Abstract/Full Text