There appears to be no link between hormonal and reproductive factors and risk of melanoma, a prospective Australian study has found.

Factors such as age at menarche, menopausal status, age at menopause, parity, and use of menopausal hormone therapy (MHT) showed no association with risk of first incident melanoma, according to findings from the QSkin Sun and Health Study.

In a five year follow up of more than 21,000 women between 2011 and 2016, researchers from the QIMR Berghofer Medical Research Institute found no link between most reproductive and hormonal factors and occurrence of invasive or in situ melanoma.

There was also no significant association seen between ever-use of oral contraception and melanoma, though there was a modest link with long duration of use (more than 20 years) of OCs, with a hazard ratio of 2.12.

The researchers noted there was also a significant trend with increasing duration of OC use and melanoma risk, but they cautioned against making any firm interpretation of this “until further studies, with information on dose and formulation of OCs, have explored these associations”.

Writing in British Journal of Dermatology, they said the question of whether melanoma risk was influenced by hormonal and reproductive factors had remained unresolved for two decades because of a paucity of prospective studies.

The QSkin study had enlisted 21,068 women, of whom 88.5% of women were parous, and 87% reported having used OCs for six months or more. More than two thirds of the women (n=14,248; 70.6%) reporting being post-menopausal at baseline, and of those 43% had used MHT for 6 months or more.

During a median 5.4 years follow-up, 392 women developed an incident melanoma: 162 invasive, 250 in situ and 20 had both.

“In summary, our findings do not support an association between either reproductive factors or MHT use and melanoma,” they concluded.