Estrogen therapy and estrogen-progestin therapy were not associated with an increased risk for cutaneous melanoma, according to results from a nationwide cohort study presented in a research letter published in the British Journal of Dermatology. Recent research has shown conflicting results as to whether menopausal hormone therapy increases the risk for cutaneous melanoma, the researchers noted.
From 1991 to 2007, investigators sent 3 questionnaires to a random sample of women aged 30 to 75 years from the population-based Norwegian Women and Cancer (NOWAC) cohort. The first questionnaire was referred to as baseline, and if it was answered, respondents received 2 follow-up questionnaires. If an age was not recorded for the start of menopause, investigators substituted it with age 53.
Investigators retrieved data on patients’ cancer diagnosis, vital status, and emigration from the Cancer Registry of Norway (CRN), which was linked to NOWAC. Women were excluded if they reported menopause more than 5 years before baseline, had a non-melanoma skin cancer diagnosis, were tibolone users, died, or moved out of the country before baseline. Investigators categorized women as either never, ever (before baseline), or current (at baseline) estrogen therapy (ET) or estrogen-progestin therapy (EPT) users. They further categorized EPT as continuous or sequential. The end of follow-up was December 31, 2018.
There were 70,733 women included in the study who answered the baseline questionnaire and were sent 2 follow-up questionnaires.
The median duration of follow-up was 12.6 years. During this time, 688 women were diagnosed with first primary invasive cutaneous melanoma. At baseline, 3.2% and 26.7% of women were ever users of ET and EPT, respectively. Investigators did not find an association between cutaneous melanoma risk and current ET (HR 1.36, 95% CI 0.96-1.94) or EPT (HR 1.11, 95% CI 0.91-1.36) users. Among women with nevi, there was a significantly higher association of melanoma risk for ET users (HR 1.63, 95% CI 0.84-3.17) than EPT users (HR 0.64, 95% CI 0.37-1.13, P =.023).
Among ET and EPT users, solarium use and living in areas with the highest ambient UV exposure was more common than never HT users. There were no significant differences in estimates of health care utilization between ET and EPT users.
Limitations included self-reported exposure information and covariates.
“The indication of a higher [cutaneous melanoma] risk in women with nevi using ET,” is consistent with the study’s results, the study authors wrote, noting that their research was the first to report associations between ET, EPT, and melanoma risk stratified by nevi.
Støer N, Botteri E, Busund M, et al. Menopausal hormone therapy and risk of melanoma: a population-based cohort study. Br J of Dermatol. Published online July 13, 2021. doi:10.1111/bjd.20640