Skin cancer in skin of colour

Dr Paul Yesudian is not your typical Consultant Dermatologist.

This doc is outspoken and keen to uncover the facts within a sub-segment of medical science he believes is under-represented and needs much better training and education of the professionals themselves: treating people with skin of colour.

Dr Yesudian has over 60 publications in peer-reviewed journals and has co-authored chapters in two major textbooks. He was given the title of Honorary Professor by the University of Madras in 2009 and is a medical advisor to Melanoma UK, our official partner, as their expert on skin of colour.

So, you could say, he’s well-qualified.

We recently listened to a Melanoma UK seminar presented by Dr Paul where some of what he said really took us by surprise. In our pursuit to make products, educate and inspire all men to take care of their long-term skin health, we felt compelled to share his knowledge with our community.

How is skin of colour defined?

This is the starting point: defining skin types.

In the 1970s, two photo-biologists called Fitzpatrick and Pathak classified skin into six groups.

The Fitzpatrick-Pathak scale
The Fitzpatrick-Pathak classification. Where are you?

In a nutshell, Fitzpatrick and Pathak classified groups 1-4 as types of white skin (think red head through to Mediterranean), type 5 as Asian skin and type 6 as African and Afro-Caribbean skin. They came up with this classification by asking people how their skin responded to the sun.

In reality, there’s often overlap and people don’t always fit within one ‘type’ i.e. you can often bridge or overlap two types. But to this day, the classification is used as a reference point by dermatologists, understanding that it may have its limitations.

For the purpose of this article, ‘skin of colour’ can be considered to be people with skin types 5 and 6 (and maybe some darker type 4s).

Quick recap of skin cancer incidence (for context)

According to Dr Yesudian, skin cancer is the most common malignancy in the UK and US.

30% of all cancers in white people can be attributed to skin cancer.

In stark contrast, skin cancer accounts for 2-4% of cancers in people with Asian skin and 1% in people with African skin. On the face of it, Caucasians are 70x more likely to get skin cancer than people with skin of colour.

But….

Dr Paul was quick to point out that medical and dermatological textbooks and medical training almost exclusively document white skin. Images in books always show diseased white skin and in a science that’s as visual as dermatology, that’s not good enough in 2021. The point is incidence rates are clearly lower in skin of colour but statistically, that could be because it isn’t always picked up.

What gives skin its tone?

A natural pigment called melanin is what gives humans such an amazingly broad and rich range of skin tones.

Melanocytes are cells in the skin that produce this melanin. We all have very similar numbers of melanocytes regardless of skin type but in people with skin of colour, melanocytes are more reactive causing them to produce more melanin, that gets distributed equally, giving the skin a darker pigment.

Melanin is the body’s natural defence mechanism against UV light. It’s the truest definition of ‘natural sunscreen’ (unlike the BS you see on Instagram!). The amount of melanin within Afro or Afro-Caribbean skin gives an equivalent SPF of 10-13, providing quite a decent foundational level of UV protection.

Is this the largest ever skin cancer study on skin of colour?

It’s estimated that 90% of skin cancers in skin types 1-4 are caused by ultraviolet light. Typically, they occur on parts of the body that are sun-exposed. You’ve heard us bang on this drum forever.

However, this is where things get interesting…

In December 2020, research was released in JAMA Dermatology, a monthly peer-reviewed medical journal published by the American Medical Association.

This research put forward some interesting findings following one of the largest ever studies conducted into UV exposure and the risk of melanoma in skin of colour.

If you’re interested, you can read how the study was put together, how it was reviewed and its flaws but the conclusion was that the association between UV exposure and melanoma in skin of colour is weak (as compared with the 90% causal effect in caucasian skin).

So, when it comes to skin cancer in skin of colour, what are the risk factors?

The three most common types of skin cancer in skin of colour

We explain the different forms of skin cancer in a separate journal so to avoid repetition, I’ll jump straight into it. But do check out this post if you need more info.

Squamous Cell Carcinoma (SCC)

This is the most common skin cancer in people with skin types 5 and 6.

SCC does NOT present in areas of the body that are sun exposed further suggesting that sun or UV exposure doesn’t play a role in causing SCC. This is contrary to white skin where UV light is the main cause for SCC.

The causes or triggers for SCC in people with skin of colour are (1) chronic scarring and (2) chronic inflammation. If you have either of these, you should pay close attention to changes in the skin at these sites.

If you see any of the following symptoms around scarred of inflamed sites, consult a doctor:

  • Starts as a small spot
  • Tender
  • Grows rapidly
  • Forms an ulcer in the centre as gets larger

If you have an insect bite, for example, that isn’t healing and has some or all of the symptoms above, it’s worth checking out. Don’t treat these symptoms as trivial and make sure your doctor takes care. SCC in skin of colour is often missed and caught too late explaining why SCC metastasis rates are 20-40% in skin of colour vs. 1-2% in skin types 1-4.

Treatment is simple: cut it out and perhaps radiotherapy if the site is hard to reach.

Basal Cell Carcinoma (BCC)

This is the most common skin cancer in the world. However, in type 6 skin, SCC is most common.

Regardless of skin type, BCC is caused by ultraviolet light exposure (despite the JAMA research), it’s just that BCC is rare in skin of colour. But that’s not to say we should write it off because it still exists.

In skin of colour, BCC is commonly seen on areas of the body that get sun exposed. If you see any of the following symptoms, consult a doctor:

  • Starts as a transluscent lesion
  • Grows slowly (3-4mm per year)
  • More than 50% can be pigmented which is very different to how it presents in white skin (often causing mis-diagnosis)
  • Sits on the surface of the skin

Again, treatment is simple: cut it out (95% cure rate), a cream can be used on superficial lesions and/or perhaps radiotherapy.

Melanoma

This is the most important skin cancer because it’s so lethal and early diagnosis can save lives.

While incidence of melanoma in skin of colour is lower than in caucasian skin, it does occur. The fact that it’s rare means it can be missed, mis-diagnosed or, quite commonly, diagnosed too late explaining why death rates are so high for people of colour with melanoma.

There are some very specific risk factors to be aware of when it comes to melanoma in skin of colour:

  • Anything that causes scarring of the skin (trauma, radiation, immunosuppression)
  • Pre-existing pigmented lesions

Make note that UV light and genetic factors are NOT melanoma risks in skin of colour (again, contrary to in white skin).

Typically, melanoma in skin of colour presents differently, precisely because of these reasons. For example, it doesn’t necessarily show up on sun-exposed parts of the body. It’s more common to see melanoma on skin of colour in sun-covered, acral or mucosal areas (under nails, bottom of feet or hands, inside the mouth). More than 90% of people with skin of colour have at least one mole and they’re most commonly positioned in the these areas. These pre-existing moles can form dark patches that lead to melanoma.

Again, surgery is the gold standard when it comes to treatment. Melanomas should be excised as early as possible.

What does all this tell us about prevention?

Firstly, skin cancer in skin of colour is rare but it does exist so preventative measures are paramount.

Starting at grass roots, medical textbooks and training needs to be updated. The next generation of doctors must be better-equipped to diagnose all skin diseases in all skin types.

In the meantime, people with skin of colour need to be provided with very specific pamphlets and information on identifying possible skin cancers on their skin. Governments, health services and medical professionals have a responsibility here. As we’ve seen, skin cancer in skin of colour manifests in very specific ways.

Dentists, opticians, gynaecologists, plastic and orthopaedic surgeons (amongst others) should all be considering melanoma (and other skin cancers) when examining patients with skin of colour. That needs to start today.

The mantra of protection and detection still holds true for the individual:

  • Apart from basal cell carcinoma (which is rare in skin of colour), UV light is not a significant risk factor in the same way it is for caucasian skin. But, it is still a risk factor for BCC. And going back to the Fitzpatrick-Pathak classification, if you bridge skin types and have lower levels of melanin than, say, type 6 people, your skin can still burn. For these reasons, year round protection from UV is a good idea.
  • In terms of detection, routine self-examination is important. But it’s different. The usual ABCDE mole check should be used alongside an examination of hands, feet, nails, the mouth etc.

We were blown away by the nuances and differences between skin cancer in different skin types. I’m almost certain 99.9% of people would feel the same. Further research needs to be carried out to understand more. But – for now – Dr Yesudian is doing what he can to educate the 99.9% of us and we hope that sharing his knowledge here is helpful.

p.s. Want to learn more? To see Dr Yesudian in action together with his father and esteemed dermatologist, Professor Patrick Yesudian, you can visit their shared YouTube channel, Discovery Dermatology Lectures.