In the UK, one in 36 males and one in 47 females will be diagnosed with melanoma skin cancer in their lifetime, making it the fifth most common UK cancer. 86% of UK melanoma cases are caused by UV exposure, but other factors also influence risk, such as age and genetics. A recent study published in the International Journal of Cancer led by Dr Eleanor Watts at the Nuffield Department of Population Health has now found that higher testosterone levels in men are associated with a greater risk of melanoma.
The team studied data from 182,600 men and 122,100 postmenopausal women aged 40 to 69 from the UK Biobank, a large national prospective cohort recruited between 2006-2010. All participants had a blood sample taken at the start of the study and their levels of testosterone were measured. Most of the testosterone in the circulation is bound to the proteins sex hormone-binding globulin (SHBG) and albumin and only ~2% of total testosterone circulates unbound or “free” and is postulated to be biologically active.
The total and freely circulating levels of testosterone were analysed for each participant and linked to records of cancer incidence or death via national registries and health records. During an average follow-up of 7 years, 9,519 (5.2%) men and 5,632 (4.6%) postmenopausal women were diagnosed with a malignant cancer. After accounting for other factors that affect cancer risk, they found that men with higher total or free testosterone concentrations had an increased risk of malignant melanoma.
Further research is still needed, but large studies like this could shift our fundamental understanding of skin cancer and help identify people who are at increased riskMichelle Mitchell, Cancer Research UK’s chief executive
The team also confirmed their previous findings associating testosterone and prostate cancer risk in men and the known association between testosterone and endometrial and breast cancer in post-menopausal women.
This is the first time a link between testosterone and skin cancer has been seen. We already knew men diagnosed with melanoma have a higher risk of developing prostate cancer and vice versa, which was a clue that there may be a common biological or behavioural cause. And it looks like this link might be the hormone, testosterone. The next step will be to see whether this link is seen in other studies, and if it is, to look more closely at why testosterone might be related to the risk of melanoma developing in men. - Dr Eleanor Watts (Nuffield Department of Population Health), lead author of the research
Image source: National Cancer Institute via Wikimedia Commons