Wednesday 8 July 2009 3:29pm
Research points to need for greater awareness of melanoma risk for Māori.
Research conducted at the University of Otago's Hugh Adam Cancer Epidemiology Unit has found rapidly increasing trends in melanoma among New Zealand Māori.
The study of data from the New Zealand Cancer Registry found a near doubling (90%) of malignant melanoma rates over an 11-year period among people of Māori ethnicity.
This compares to a 12% increase over the same period among New Zealand Europeans.
Researchers Dr Mary Jane Sneyd and Dr Brian Cox also found that Māori present with a higher proportion of thick tumours (melanoma with a depth greater than 1mm) than New Zealand Europeans or Asians.
Tumour thickness or depth at time of diagnosis is a major factor in determining the risk of death from melanoma. The rate of nodular melanoma (which tend to be thick melanomas) in Māori (15.9%) is second only to the rate of nodular melanoma found in New Zealand's Pacific people (17.1%).
However, overall melanoma incidence rates in New Zealand's Pacific population are much lower than those in the Māori.
The findings, recently published in the international journal Cancer Epidemiology, Biomarkers and Prevention and accompanied by an editorial, are similar to those from research conducted in the United States that also point to increasing rates of melanoma among non-white populations there.
The University of Otago investigation suggests that, while cutaneous melanoma predominantly remains a disease of people with fair skin and fair hair (the current Māori incidence rate being about 1/10th of the incident rate of European New Zealanders), the rate of increase among Māori is increasing significantly.
The Otago researchers suggest that this dramatic increase may in part be attributable to changing skin phenotypes.
"There is considerable heterogeneity in skin pigmentation within any ethnic group," the researchers say. "For example, there are fair-haired, fair-skinned people who identify as Māori."
Other contributing factors could be the development of different types of melanoma in different ethnic groups, or increased UV radiation due to increased sun exposure over time.
While there remains overall a substantially lower risk of melanoma for Māori, Pacific and Asian people than for fairer-skinned Europeans, this research suggests the need for Māori to be more aware of their potential risk, protect themselves from sunburn and to take any new or changing skin lesions to their doctor.
Dr Mary Jane Sneyd and Dr Brian Cox's research, undertaken at the University of Otago's Hugh Adam Cancer Epidemiology Unit, is funded by the Director's Cancer Research Trust.
Paper details: Mary Jane Sneyd and Brian Cox. Melanoma in Māori, Asian, and Pacific Peoples in New Zealand. Cancer Epidemiology, Biomarkers and Prevention 2009; 18 (6), 1706-1713. Accompanying editorial: Dee W. West and Christina A. Clarke. Rapidly Increasing Trends of Melanoma in Nonwhite Populations: New Data from New Zealand. Cancer Epidemiology, Biomarkers and Prevention 2009; 18 (6): 1674-1675.
For further information contact
Dr Mary Jane Sneyd
Research Fellow
Hugh Adam Cancer Epidemiology Unit
Department of Preventive and Social Medicine
University of Otago
Tel 03 3 479 7226
Email mary-jane.sneyd@otago.ac.nz
Associate Professor Brian Cox
Director
Hugh Adam Cancer Epidemiology Unit
Department of Preventive and Social Medicine
University of Otago
Tel: 03 479 7213
Email brian.cox@otago.ac.nz
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