Prevention: Skin cancer does not stop with dark skin

People with dark skin are generally considered to be less at risk for skin cancer. In fact, they are diagnosed less often, but it is important to keep in mind that cases do occur.

What you should know about skin cancer on dark skin:

While basal cell carcinoma is the most common form of skin cancer overall, squamous cell carcinoma is the most common in dark-skinned people in the African continent.
The localisation of skin cancer may differ in dark-skinned people compared to light-skinned people.
Risk factors may also differ among different ethnic groups. However, cumulative UV exposure plays a role in all skin types.
Lack of knowledge and awareness means that skin cancer on dark skin is often diagnosed late.

Sparse data

Data on skin cancer in dark-skinned people are scarce. According to some international surveys, the incidence in people from Africa is estimated at 0.9/100,000, in black US Americans at 7.9/100,000, in Asian and Pacific Islanders at 1.2/100,000 and in Hispanics at 4.5/100,000. In contrast, the incidence in light-skinned people stands out significantly at 29.4/100,000.

Sun and other risks

Contrary to popular belief, sun exposure is also a risk factor for dark skin, although not to the same extent as for light skin. For basal cell carcinoma, UV radiation remains the main risk factor for all ethnicities.

By contrast, for squamous cell carcinoma (the most common type of skin cancer among black US Americans), chronic ulceration, skin irritation and scarring often also play a role. This in turn means that skin cancer in this group often forms on other parts of the body, such as the lower extremities or the anogenital region. Here it can easily be overlooked.

Pay attention to the feet when it comes to melanoma

There are also differences between population groups when it comes to melanoma. While superficial spreading melanoma is most common in this country, the acral lentiginous subtype dominates among people from Africa and Asia.

Most melanomas occur on the plantar surface, but also on other areas that are not exposed to the sun, such as the mucous membrane. Thus, risk factors other than sun exposure seem to be decisive here. The problem is also here: Melanomas are often detected late at atypical sites.

Sun increases cancer risk in all skins

In people with darker pigmented skin, skin cancer is often misdiagnosed and diagnosed late. This can lead to more severe courses and limit therapeutic options. Although dark skin offers some protection from UV radiation, cumulative sun exposure remains a significant risk factor for all ethnicities. Therefore, it is important to also educate dark-skinned people about this and to motivate them to have regular skin cancer screening.

Source:

In German only: Shencoru E, Schlaak M. Klinische und diagnostische Besonderheiten bei Hautkrebs auf dunklerer Haut. (Clinical and diagnostic features of skin cancer on darker skin). Die Dermatologie 2023; 74: 90-94.