Common baldness or androgenic alopecia is characterized by progressive hair loss that is not replaced by the birth of new hair follicles, so the area of the head where there is no hair expands and the individual can go completely bald. Initially, the problem is cosmetic, but hair loss has also been associated with higher rates of skin cancer.
To discover the reasons for this association, a group of scientists from the QIMR Berghofer Medical Research Institute has conducted a new study on the relationship between male pattern baldness and skin cancer that has found reliable evidence indicating why people with hair loss may be more susceptible to developing deadly skin cancers. Their findings have been published in the journal Nature Communications.
“Testosterone levels are an important factor in male pattern baldness and some studies suggest that they may also contribute to this increased risk of skin cancer in people with hair loss,” said lead researcher Dr. Jue. Sheng Ong. The work can also be seen on the QIMR Berghofer YouTube channel.
“We found no evidence that testosterone levels play a significant role in the relationship between baldness and skin cancer.”
“The most obvious explanation would be that people with hair loss receive more sun exposure on their head and neck.” “It seems like the most sensible explanation is the right one: Bald men are more susceptible to sun damage and skin cancer because they have less protection for their hair,” he adds.
Genes related to hair loss and skin color
Although this explanation may seem obvious, researchers conducted extensive genetic analyzes to provide evidence-based information on the relationship between baldness and skin cancer. “It is important that we investigate and demonstrate causality to inform the best evidence-based prevention for deadly skin cancers, even if the answers seem obvious,” said lead researcher Associate Professor Matthew Law, adding that “the programs and health interventions cannot be guided by assumptions. “They need to be backed by evidence to work.”
The researchers analyzed genetic data from more than 29,000 patients with melanoma and keratinocyte cancer, collected in the landmark QSkin study and the Melanoma Institute Australia. Additionally, they incorporated large-scale genetic findings on testosterone and hair loss to determine whether genes that predispose people to high testosterone levels or baldness influence skin cancer risk.
The analysis confirmed a strong link between baldness and skin cancer, and found that this was mainly due to increased sun exposure. However, genes related to hair loss and skin color also seem to play a role. “We found no evidence that testosterone levels play a significant role in the relationship between baldness and skin cancer,” Dr. Ong said.
“Interestingly, we found an overlap between genes that cause hair loss and genes that affect skin color or pigmentation. Skin color is a known risk factor for skin cancer and these results suggest that pigmentation may also contribute to this increased risk in people with hair loss. However, most of this relationship between baldness and skin cancer is still explained by increased sun exposure.”
The genetic findings were supported by additional analysis of skin cancers in people with hair loss, and this led to the discovery that baldness is associated with a high risk of developing skin cancers in the head and neck area, as it is Sun exposure for people with hair loss is likely to be greater around these parts of the body.
Melanoma Institute Australia medical co-directors Professor Richard Scolyer AO and Professor Georgina Long AO said research into the genetic drivers of skin cancer was essential. “Australia has the highest rates of melanoma in the world, with one person diagnosed every 30 minutes, so a greater understanding of which population groups are most at risk helps us address them with preventive and early detection strategies,” said the Professor Long.
“Regardless of individual risk, sun protection is paramount for all Australians, as protecting against excessive UV exposure is the most important preventative measure against melanoma and other skin cancers,” Professor Scolyer concludes.
