Melanoma is not associated with either reproductive factors or menopausal hormone therapy use, according to study data published in the British Journal of Dermatology.
Investigators sought to assess the relationship between hormonal and reproductive factors and subsequent risk for melanoma in a large population-based cohort of Australian women. All women of European ancestry from the QSkin Sun and Health Study with no past history of melanoma were eligible (n=21,068).
The study authors obtained data on all melanoma diagnoses from 2011 through December 31, 2016, from the Queensland Cancer Registry. The 2 study end points were invasive cutaneous melanomas and all cutaneous melanomas (invasive and in situ).
During a median 5.4 years of follow-up, 392 women developed an incident melanoma (162 invasive, 250 in situ, 20 both invasive and in situ). At baseline, 88.5% of women were parous and 87.2% reported using oral contraceptives for 6 months or more. More than two-thirds of the women (n=14,248; 70.6%) were postmenopausal at baseline, and of these women, 43% had used menopausal hormone therapy for 6 months or more.
Researchers found no association between age at menarche, parity, menopausal status at baseline, age at menopause, or menopausal hormone therapy use and incidence of invasive melanoma. Additionally, investigators found no association between ever use of oral contraceptives and invasive melanoma; however, 20 or more years of oral contraceptive use was significantly associated with invasive melanoma (hazard ratio, 2.12; 95% CI, 1.11- 4.04), with a significant trend with increasing duration of use (P =.01).”
One of the study limitations is that information about oral contraceptives and menopausal hormone therapy was self-reported, and the researchers did not collect information on specific doses or formulations. In addition, the women may have experienced menopause or commenced or ceased menopausal hormone therapy during follow-up, which could have led to potential misclassification of exposure.
“Our findings do not support an association between either reproductive factors or [menopausal hormone therapy] use and melanoma,” the study authors concluded.
Olsen CM, Pandeya N, Dusingize JC, et al. Reproductive factors, hormone use and melanoma risk: an Australian prospective cohort study. Published online August 27, 2020. Br J Dermatol. doi: https://doi.org/10.1111/bjd.19498