TORONTO -- More should be done to make young men aware of the danger a common skin cancer poses to them, a new study suggests.

Researchers at Saint Louis University have found a 51 per cent increase in the rate of head and neck melanoma diagnoses among patients under the age of 40 in the U.S. and Canada between 1995 and 2014.

The highest increase was seen in boys and men aged 15 to 39.

While the study was not designed to offer any insight into why the melanoma incidence rate is rising faster in that group, the researchers suspect that the answer can be found in hair.

They hypothesize that because women typically have longer hair than men, they have more natural protection against the harmful effects of UV rays and indoor tanning beds that can contribute to melanoma.

This also helps explains why they found a higher increase in the melanoma rate of white men than non-white men: Male pattern baldness occurs more often in white men, and previous studies have linked severe baldness to a significant increase in the risk of scalp-related melanoma.

"There is therefore a need to increase head and neck melanoma awareness, especially among young white males at a greater risk for baldness," the researchers said in their study, which was published Thursday in the Journal of the American Medical Association for Otolaryngology.

Melanoma awareness has generally been more targeted toward young women, as campaigns often focus on the risks of tanning beds and UV ray exposure.

Those efforts appear to have been successful, the Saint Louis research suggests, as the increases in the U.S. under-40 melanoma rate fell sharply after 2000, which the study says lines up with significant changes to tanning practices and more widespread use of sunscreen and sunglasses.

The findings were based on a review that incorporated nearly 12,500 head and neck melanoma cases from 26 states and six provinces.

Melanoma is the seventh-most-diagnosed cancer in Canada, with 7,200 new cases reported in 2017. Approximately 20 per cent of melanoma cases affect the head and/or neck.