Abstract
New Zealand Maori, Pacific, and Asian people develop melanoma less frequently than New Zealand Europeans, but little is known about melanomas that develop in these people. We examined the characteristics of melanoma in these minority ethnic groups in New Zealand. In 2007, all first primary melanomas diagnosed from January 1996 to December 2006 were extracted from the New Zealand Cancer Registry database. Melanoma was more commonly diagnosed in Maori than Asian or Pacific peoples. Age-adjusted incidence rates increased annually from 1996 to 2006 by 0.37 per 100,000 in the total population and 0.20 per 100,000 in Maori, a 12% (from 30.9 to 34.6) and 90% (from 2.3 to 4.3) increase, respectively, over the 11 years. Nodular melanoma occurred more often in Maori (15.9%) and Pacific peoples (17.1%) compared with Asians (8.7%) and New Zealand Europeans (10.5%). In Pacific peoples, acral lentiginous melanoma (22.9%) was the most common subtype. The median thickness of melanoma was 0.78 mm in New Zealand Europeans, 1.2 mm in Maori, 2.5 mm in Pacific peoples, and 0.73 mm in Asians (P < 0.001, difference in medians). Thirty-seven percent of melanomas in Pacific peoples were >4 mm thick compared with 7.9% in New Zealand Europeans. About 13% of Asians and 11% of Pacific peoples, compared with 4% of New Zealand Europeans with melanoma, were diagnosed by histology of metastases rather than the primary lesion. Minority ethnicities in New Zealand have a higher than expected risk of thick and more advanced melanoma, with poorer prognosis. Melanoma campaigns should include messages that incorporate the unique features of melanoma in minorities.