SINGAPORE — Can the prolonged use of skin-lightening products, such as hydroquinone, lead to skin cancer?
This question was posed by Ousmane Faye, MD, PhD, director general of Mali’s Bamako Dermatology Hospital, at the 25th World Congress of Dermatology (WCD).
Dr Ousmane Faye
Faye explored the issue during a hot topics session at the meeting, tacrolimus ointment risks prefacing that it was an important question to ask because “in West Africa, skin bleaching is very common.”
“There are many local names” for skin bleaching, he said. “For example, in Senegal, it’s called xessal; in Mali and Ivory Coast, its name is caco; in South Africa, there are many names, like ukutsheyisa.“
Skin bleaching refers to the cosmetic misuse of topical agents to change one’s natural skin color. It’s a centuries-old practice that people, mainly women, adopt “to increase attractiveness and self-esteem,” explained Faye.
To demonstrate how pervasive skin bleaching is on the continent, he presented a slide that summarized figures from six studies spanning the past two decades. Prevalence ranged from 25% in Mali (based on a 1993 survey of 210 women) to a high of 79.25% in Benin (from a sample size of 511 women in 2019). In other studies of women in Burkina Faso and Togo, the figures were 44.3% and 58.9%, respectively. The most recently conducted study, which involved 2689 Senegalese women and was published in 2022, found that nearly 6 in 10 (59.2%) respondents used skin-lightening products.
But skin bleaching isn’t just limited to Africa, said session moderator Omar Lupi, MD, PhD, associate professor of dermatology at the Federal University of the State of Rio de Janeiro in Brazil, when approached for an independent comment. “It’s a traditional practice around the world. Maybe not in the developed countries, but it’s quite common in Africa, in South America, and in Asia.”
His sentiments are echoed in a meta-analysis that was published in the International Journal of Dermatology in 2019. The work examined 68 studies involving more than 67,000 people across Africa, Asia, Europe, the Middle East, and North America. It found that the pooled lifetime prevalence of skin bleaching was 27.7% (95% CI, 19.6-37.5; P < .01).
“This is an important and interesting topic because our world is shrinking,” Lupi told Medscape Medical News. “Even in countries that don’t have bleaching as a common situation, we now have patients who are migrating from one part [of the world] to another, so bleaching is something that can knock on your door and you need to be prepared.”
Misuse Leads to Complications
The issue is pertinent to dermatologists because skin bleaching is associated with a wide range of complications. Take, for example, topical steroids, which is the most common products used for bleaching, said Faye in his talk.
“Clobetasol can suppress the hypothalamic-pituitary-adrenal (HPA) function,” he said, referring to the body’s main stress response system. “It can also foster skin infection, including bacterial, fungal, viral, and parasitic infection.”
In addition, topical steroids that are misused as skin lighteners have been reported to cause stretch marks, skin atrophy, inflammatory acne, and even metabolic disorders such as diabetes and hypertension, said Faye.
To further his point, he cited a 2021 prospective case-control study conducted across five sub-Saharan countries, which found that the use of “voluntary cosmetic depigmentation” significantly increased a person’s risk for necrotizing fasciitis of the lower limbs (odds ratio [OR], 2.29; 95% CI, 1.19-3.73; P = .0226).
Similarly, mercury, another substance found in products commonly used to bleach skin, has been associated with problems ranging from rashes to renal toxicity. And because it’s so incredibly harmful, mercury is also known to cause neurologic abnormalities.
Apart from causing certain conditions, prolonged use of skin-lightening products can change the way existing diseases present themselves as well as their severity, added Faye.
An Increased Risk
But what about skin bleaching’s link with cancer? “Skin cancer on Black skin is uncommon, yet it occurs in skin-bleaching women,” said Faye.
“Since 2000, we have had some cases of skin cancer associated with skin bleaching,” he continued, adding that squamous cell carcinoma (SCC) is the most frequent type of cancer observed.
If you look at what’s been published on the topic so far, you’ll see that “all the cases of skin cancer are located over the neck or some exposed area when skin bleaching products are used for more than 10 years,” said Faye. “And most of the time, the age of the patient ranges from 30 to 60 years.”
The first known case in Africa was reported in a 58-year-old woman from Ghana, who had been using skin bleaching products for close to 30 years. The patient presented with tumors on her face, neck, and arms.
Faye then proceeded to share more than 10 such carcinoma cases. “These previous reports strongly suggest a relationship between skin bleaching and skin cancers,” said Faye.
Indeed, there have been reports and publications in the literature that support his observation, including one last year, which found that use of the tyrosinase inhibitor hydroquinone was associated with approximately a threefold increased risk for skin cancer.
For some, including Brazil’s Lupi, Faye’s talk was enlightening: “I didn’t know about this relationship [of bleaching] with skin cancer, it was something new for me.”
But the prevalence of SCC is very low compared with that of skin bleaching, Faye acknowledged. Moreover, the cancer observed in the cases reported could have resulted from a number of reasons, including exposure to harmful ultraviolet rays from the sun and genetic predisposition in addition to the use of bleaching products such as hydroquinone. “Other causes of skin cancer are not excluded,” he said.
To further explore the link between skin bleaching and cancer, “we need case-control studies to provide more evidence,” he added. Until then, dermatologists “should keep on promoting messages” to prevent SCC from occurring. This includes encouraging the use of proper sun protection in addition to discouraging the practice of skin bleaching, which still persists despite more than 10 African nations banning the use of toxic skin-lightening products.
Faye and Lupi report no relevant financial relationships.
25th World Congress of Dermatology (WCD). Presented July 5, 2023.
Sandy Ong is a freelance health and science journalist based in Singapore. @sandyong_yx.
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