Men who have had multiple melanomas are at least twice as likely to be diagnosed with prostate cancer than men who have never had melanomas, according to new research from the Daffodil Centre using data from the Sax Institute’s 45 and Up Study.
The study, published in the British Journal of Cancer, is the first to show that the link between melanoma and subsequent risk of prostate cancer is real, and not just a result of increased medical monitoring after a melanoma diagnosis.
Looking at data of nearly 100,000 men from the 45 and Up Study, researchers found that men with any history of melanoma had a 32% increased risk of later being diagnosed with prostate cancer, compared to men with no melanoma history.
Lead author Dr Visalini Nair-Shalliker says that up until now, all established risk factors for prostate cancer were unable to be changed by modifying behaviours. “The main risk factors are family history, advancing age and African ancestry, so to identify and establish a role for melanoma in respect to prostate cancer would be very useful.”
Associate Professor David Smith, leader of the Daffodil Centre’s Prostate Cancer stream, said the study’s findings were very valuable to men’s health.
“Melanoma and prostate cancer are the two most common cancers in Australian men. As part of an overall approach to health, men aged 50 and over who have a history of melanoma should discuss their risk of prostate cancer with their doctor.”
It’s predicted that 24,000 men will receive a prostate cancer diagnosis in 2022, while around 10,000 men will be diagnosed with melanoma.
No more doubt about medical monitoring affecting link
Previous studies have shown a link between the two cancers, but there was always the doubt that increased medical surveillance simply led to more diagnoses, Dr Nair-Shalliker says.
“That’s where the 45 and Up Study and its linkages really helped us,” she says. “We could derive information around men having a PSA (prostate-specific antigen) blood test, as well as information on GP visits and monitoring for abnormal prostate activity, and then adjust for all those factors.”
There is currently no evidence on what the biological link between melanoma and the risk prostate cancer is, however, the authors say that the link “suggests a paradigm of common risk factors”.