Men with melanomas at greater risk of prostate cancer says study
A new study published in the British Journal of Cancer on 1 November 2022 has linked the instance of melanoma in men with an increased risk of prostate cancer.
The study found that men with a history of melanoma had a 32% increased risk of later being diagnosed with prostate cancer, compared to men with no melanoma history.
For men with multiple melanomas the risk of a prostate cancer diagnosis was at least double.
The Sax Institute’s 45 and Up Australian study looked at data from nearly 100,000 males.
Lead author Dr Visalini Nair-Shalliker said the main risk factors for prostate cancer were “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.”
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.
One explanation for the positive association between melanoma and subsequent prostate cancer risk might lie with male sex hormones (androgens), reported the researchers. For example, elevated levels of serum free-testosterone levels have been found in studies of participants who were later diagnosed with melanoma.
The researchers said:
"Androgen status may explain some of the gender bias in melanoma survival where male melanoma cases are reported to have poorer survival than female cases, even after adjusting for various lifestyle and behavioural factors.
“We hypothesise that androgen status in melanoma survivors may have changed in a way that could affect tumour microenvironment and increase cancer susceptibility to androgen-dependent cancers such as prostate cancer, where risk is greater in men with multiple melanomas than only one melanoma."
Prostate Cancer was the most diagnosed cancer among Australian men in 2020, comprising about 25% of all newly diagnosed cancers in men. In the same year, melanoma was the third most diagnosed cancer among Australian men.
Australia has the highest rates of melanoma in the world, and 95% of melanoma cases Down Under are thought to be attributable to solar ultra violet radiation (UVR), compared to approximately 75% worldwide. Australia has the 15th highest incidence rates of prostate cancer in the world.
The researchers note that few studies have investigated the association between melanoma and subsequent risk of various internal cancers such as prostate cancer.
They said:
“A recent systematic review of 17 studies, found that men diagnosed with melanoma were at subsequent higher risk of PC diagnosis than men in general. Its findings, however, do not make clear whether melanoma is a true risk factor for PC or whether detection bias due to increased medical surveillance following a melanoma diagnosis is responsible. As a result of increased interaction with the health system it is possible that more asymptomatic PC is being detected due to more prostate-specific antigen (PSA) testing.”
The Sax Institute’s 45 and Up Study is an ongoing study of health and ageing drawn from the population of NSW.
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