Crystal Gao, Editorials and Publications Team PMSA
Melanoma, a cancer of the pigmented cells (melanocytes) in our skin, is widely regarded as one of the most aggressive forms of skin cancer (Figure 1). Currently, more than 100,000 melanomas are diagnosed worldwide every year, although its incidence is more prevalent in countries with fair skin and high levels of sun exposure (1).
Figure 1. Diagram of melanoma in the layers of the skin
Traditionally, the incidence of melanoma was particularly high in Australia, a Pacific country with high levels of UV radiation due to ozone depletion. However, more recently, the number of cases in New Zealand have soared, overtaking Australia as the country with the highest rate of melanoma skin cancer in the world (2).
Research has shown that New Zealand now has 50 new cases of melanoma diagnosed per 100,000 of the population per year, compared to Australia’s previous figure of 48 new cases per 100,000 per year. Melanoma type skin cancer is now the fourth most common cancer in New Zealand, and is responsible for nearly 80% of all skin cancer-related deaths in the population (3). At the same time, Australia’s rate of melanoma has begun to decrease in recent years owing to a strong push from the government, which has successfully raised awareness about the dangers of excess UV exposure and the importance of adequate sun protection through national programs such as the “Slip Slop Slap” campaign in schools (2).
Moving forward, it is hoped that the New Zealand government will follow Australia’s example in introducing stricter sun protection policies in schools and funding programs to raise awareness of the dangers of melanoma type skin cancers, in order to prevent this currently superficial problem from growing into a deeper, more invasive burden on their healthcare system.
Given that one of the risk factors for melanoma is a fair skin type, it was noted that New Zealanders of European background were more prone to developing this type of skin cancer compared to those with darker skin types, such as those of Maori, Pacific and Asian heritage (58.3 cases/100,000 population vs 0.8 – 3.1 cases/100,000 population respectively)(4). However, it can be easier to miss pigmented lesions such as melanoma in those with darker skin-type, so from a clinical perspective, a patient’s skin type should never preclude the physician from conducting a thorough examination of all patients who present with a lesion of concern.
ABCDEs of diagnosing a melanoma
1. WHO. Skin Cancers. 2018.
2. Roy EA. New Zealand now has world's highest rate of melanoma skin cancer. 2016.
3. Melanoma NZ. Understanding Melanoma. About Melanoma. 2018.
4. Sneyd MJ, Cox B. Melanoma in Maori, Asian, and Pacific Peoples in New Zealand. Cancer Epidemiology Biomarkers & Prevention. 2009;18(6):1706-1713.