Can people of dark skin colour get melanoma?

“Can people of dark skin colour get melanoma?’’

More than often this question reflects inherent disbelief and skepticism since people of dark skin colour do report much less incidence of melanomas, for example melanomas only account for 1-8% skin malignancies in people of black complexion[1-3] whereas for Asian Indians it is around 12%[3, 4]. However, their melanomas often show poorer prognosis than their Caucasian counterparts. For example, melanoma tumours that African-Americans get are generally deeper in nature and are of more advanced stage of the disease[5]. The 5-year mortality for people of black skin colour in melanoma is in the range of 37.5% to 85%, as reported in multiple studies[2, 3, 6].

The difference in terms of prognosis of the disease doesn’t only come from the nature of tumours but also from the type of melanoma as well. People of black complexion and Asian origin usually get non-sun induced melanomas. Now, the term might sound odd, but not all melanomas are caused by sun-exposure. Non-sun induced melanomas are often found in parts of the body which are usually not exposed to sunlight or even if exposed such exposure is not attributed to the formation of melanomas. These types of melanomas are quite rare than their sun-induced counterpart, and are usually difficult to diagnose at an early stage, attributing to further problems in treating the patients.

One of the major non-sun induced melanomas that dark skinned people get is acral melanoma or ALM. This type of melanoma arises in the palm, soles or beneath fingernails and can appear without a pre-existing mole.Like other non-sun induced melanomas, ALMs are quite rare among all melanoma types, however there is no major difference in incidence in terms of ethnicity. But ALMs do represent a major fraction of all types of melanomas that people of dark complexion get.

 

Acral melanoma
Picture of an acral melanoma on the sole of feet. Source: www.diseasespictures.com[7]

ALM tumours are generally not more lethal than other melanomas but higher mortality arises due to the challenges with the detection of the tumours. Many such tumours appear in the feet or sole which is more than often an overlooked part of the body. Also, sometimes they are misdiagnosed as skin problems related to diabetes or a wart. Considering these facts, it is advisable to seek professional opinion of an experienced dermatologist as soon as one finds a mole, which fits the malignant type according to the standard ABCDE of melanoma.

 

ABCDE Melanoma
ABCDE of melanoma. Source: SKINCAREAUS[8]
Treatment for ALM in early stage is usually surgery but for progressing metastatic diseases other options such as immunotherapy is also being considered.

Major obstacles for prevention and treatment of acral melanoma are rarity and lack of information about what causes it. Therefore, continuous and methodical vigilance of such moles and seeking experienced dermatologist’s opinion in time, are probably the best options for avoiding an aggressive disease and an unfavourable outcome.

 

References: 

  1. Giraud, R.M.A., E. Rippey, and J.J. Rippey, Malignant melanoma of the skin in Black Africans. South African Medical Journal, 1975. 49(16): p. 665-668.
  2. Halder, R.M. and K.M. Bang, Skin cancer in blacks in the United States. Dermatologic Clinics, 1988. 6(3): p. 397-405.
  3. Gloster, H.M. and K. Neal, Skin cancer in skin of color. Journal of the American Academy of Dermatology, 2006. 55(5): p. 741-760.
  4. Dhir, A., et al., Basal cell carcinoma on the scalp of an indian patient. Dermatologic Surgery, 1995. 21(3): p. 247-250.
  5. Mahendraraj, K., et al., Malignant Melanoma in African–Americans: A Population-Based Clinical Outcomes Study Involving 1106 African–American Patients from the Surveillance, Epidemiology, and End Result (SEER) Database (1988–2011). Medicine, 2017. 96(15): p. e6258.
  6. Fleming, I.D., et al., Skin cancer in black patients. Cancer, 1975. 35(3): p. 600-605.
  7. SUREKHA. Acral Lentiginous Melanoma – Causes, Symptoms, Treatment. [Blog] January 30,2017; Available from: https://diseasespictures.com/acral-lentiginous-melanoma-causes-symptoms-treatment/.
  8. SKINCAREAUS. Know your ABCDEs. 2018; Available from: http://skincareaus.com.au/know-your-abcdes/.