Investigating the link between melanoma and prostate cancer

Background

In Australia, rates of melanoma and prostate cancer are among the highest in the world. For Australian men, prostate cancer is the most common cancer, and melanoma is the third. Sun exposure is the leading environmental cause of melanoma causing over 95% of cases. However, the few established risk factors for prostate cancer are generally considered non-modifiable, including family history and advanced age. Several studies have suggested that sun exposure may also be a potential risk factor for prostate cancer, but the link is not well understood.

The research

The researchers looked at all prostate cancer and melanoma diagnoses in NSW between 1972 and 2008. During this period, nearly 144,000 men were diagnosed with either cancer. Significantly, of the men first diagnosed with melanoma, 2,114 were subsequently diagnosed with prostate cancer.

These findings show that compared to men with no previous diagnosis of melanoma men with a previous diagnosis are at a 25% increased risk of being diagnosed with prostate cancer later. The results suggest that sun exposure may also play a role in prostate cancer, and that protecting yourself from the sun is therefore all the more important. The team also observed the risk of prostate cancer was highest in Australian born men, and in men’s first year of melanoma diagnosis.

The impact

This study has reinforced the importance of sun protection, as results suggest that sun exposure may
play a role in the development of both melanoma and prostate cancer. Further investigations of the relationship between melanoma and prostate cancer are needed, but these results suggest GPs discuss future prostate cancer risk with men newly diagnosed with melanoma.

Men with a previous melanoma diagnosis are more likely to have more regular interactions with their GP and therefore may be more vigilant about their health – this may consequently increase the likelihood of detecting other diseases, including prostate cancer.