A systematic review and meta-analysis published in Oncology Letters found that using hormone replacement therapy (HRT) before a breast cancer diagnosis may decrease mortality rates.
“The observed association with better survival appears to be influenced by factors such as treatment duration, timing of discontinuing HRT use, and the year of participant recruitment,” the authors said, highlighting the complicated relationship between HRT and survival.
Physicians commonly prescribe HRT to alleviate premenopausal symptoms. However, its use declined significantly following a 2002 Women’s Health Initiative study linking HRT with various health risks.
The effect of HRT use prior to breast cancer diagnosis on survival outcomes remains unclear, with mixed findings across studies. In their review, the authors evaluated 33 previous studies investigating this association.
Read more about breast cancer therapies
Compared with individuals not using HRT, those taking the therapy experienced 14% lower odds of breast cancer mortality. However, the authors reported moderate heterogeneity among the studies.
Next, the study assessed duration of HRT use. Those receiving treatment for fewer than five years or for five to 10 years showed lower breast cancer mortality. Individuals taking HRT for more than 10 years, though, showed no difference in survival.
In addition, current HRT users experienced a lower breast cancer mortality risk, while those not taking HRT at the time of diagnosis had the same survival rate as those who never took HRT.
The researchers also found that the association between HRT use and reduced mortality was strongest among studies that recruited participants after the year 2000. Before this point, study findings were more mixed.
The authors note that the small number of included studies limited their analysis of subgroups. Therefore, results should be evaluated with caution.
“Further research is warranted to clarify the underlying mechanisms and potential
clinical implications of these observed associations,” they concluded. “Importantly, these observational data do not support the use of HRT as a therapeutic strategy to enhance breast cancer prognosis.”
Sign up here to get the latest news, perspectives, and information about breast cancer sent directly to your inbox. Registration is free and only takes a minute.
