New Zealand (NZ) Pacific Peoples and Maori Have a Higher Risk of Developing Multiple Myeloma Than Other New Zealanders.

Abstract

The incidence of multiple myeloma shows ethnic variation, myeloma age-standardized incidence being higher in African Americans at 11.3 per 100,000 than White Americans in whom the incidence is 5.1 per 100,000 (standardized to US 2000 census population)[Ries et al (2007) http://seer.cancer.gov/csr/1975_2004/]. NZ has a number of ethnic minorities, which includes Maori and Pacific peoples. New diagnoses of multiple myeloma in NZ are reported to a national cancer registry. Since 1994 this has been a legal requirement. We examined data from the cancer registry for 1996 to 2004 to establish the relative incidence of multiple myeloma in NZ ethnic groups. During this period ICD-9 (multiple myeloma and immunoproliferative neoplasms) was used for coding until 2000 when it was replaced by ICD-10 (multiple myeloma and malignant plasma cell neoplasms). Between 1996 and 2004 there were 2101 myeloma registrations. Median age was between 70 and 75yrs. M:F ratio was 1.3. Maori accounted for 160 patients (7.6%), Pacific peoples 81 (3.8%). Mean age-standardized annual incidence rates per 100,000 and 95% confidence intervals (WHO world standard population (WSP)) for the 9 year period were as follows:-AllMaleFemaleMaori6.4 (5.4–7.6)7.9 (6.3–9.8)4.9 (3.8–6.3)Pacific Peoples8.4 (6.6–10.8)10.9 (7.8–15.2)6.0 (4.3–8.4)Non-Maori, non-Pacific4.4 (4.2–4.6)5.4 (5.1–5.7)3.4 (3.1–3.6)All ethnicities4.6 (4.4–4.8)5.7 (5.4–6.0)3.6 (3.3–3.8)The population adjusted incidence of multiple myeloma was significantly higher in Pacific peoples (ratio 1.93 (95% CI 1.50–2.48)) and Maori (ratio 1.46 (95% CI 1.23–1.74)) than in the non Maori, non Pacific population.Conclusion: The overall incidence of myeloma in NZ (4.6 per 100,000, 95%CI 4.4–4.8 WSP) is higher than that reported for a UK population (3.3 per 100,000 WSP) [Phekoo et al (2004) Brit J Haem 127:299]. The incidence of myeloma in NZ Pacific peoples is especially high at 8.4 per 100,000. The incidence of myeloma in NZ Maori at 6.4 per 100,000 is intermediate between that of the NZ non Maori, non Pacific population and that of Pacific peoples.