Increased risk of basal cell carcinoma (BCC) in women who use menopausal hormone therapy (MHT) has been confirmed in a new study. Furthermore, this risk may be higher for women who have used MHT for longer periods and for women who experience menopause at a late age; these factors, however, warrant further investigation. These results were presented in a study published in the Journal of Clinical Oncology.1
The relationship between reproductive factors or exogenous estrogen use and BCC is not well studied, despite the known photosensitizing properties of estrogen. In this study, the researchers used data from the US Radiologic Technologists Study to assess the association between reproductive factors, exogenous estrogen use, and first primary BCC.
After accounting for sun exposure, personal sun sensitivity, and lifestyle factors related to geographic location and a wide range of ambient UV radiation exposure, risk of BCC was found to be higher in association with MHT use.
The researchers found that increased risk of BCC was associated with older age at natural menopause (55 years and older) and any use of MHT. Increase in risk of BCC was the highest among women who reported natural age at menopause and MHT use for 10 years or more vs women who never used MHT.
Factors not associated with BCC risk were age at menarche, parity, age at first birth, infertility, diethylstilbestrol use by participant’s mother, age at hysterectomy, or oral contraceptive use.
The researchers conclude that MHT users may be a high-risk group who should undergo more frequent skin cancer screening.
1. J Clin Oncol. doi:10.1200/JCO.2015.62.0625.