Māori and Pacific Peoples With Multiple Myeloma in New Zealand are Younger and Have Inferior Survival Compared to Other Ethnicities: A Study From the Australian and New Zealand Myeloma and Related Diseases Registry (MRDR)

Abstract

Background: Māori and Pacific peoples (MPP) in New Zealand (NZ) have poorer health outcomes than other ethnicities. However, this has not been clinically investigated in multiple myeloma (MM). Using data from the Australian and NZ Myeloma and Related Diseases Registry for all participating centers in NZ, we compared MPP demographics, clinical characteristics, diagnostics, treatment, and outcomes to non-MPP.

Patients and methods: MPP were defined as having ≥1 grandparent of this heritage. We tested ethnicity as a predictor of overall survival (OS) with multivariable Cox regression.

Results: Of 568 NZ patients with MM (September 2012 to April 2021) and ethnicity data, 138 were MPP. They were diagnosed younger than non-MPP (median age 63 [IQR: 57-72] vs. 70y [62-77], P < .001). Obesity (53 vs. 27%, P < .001), diabetes (24 vs. 8%, P < .001), renal insufficiency (28 vs. 17%, P = .005), pulmonary disease (10 vs. 5%, P = .02) and FISH abnormalities (54 vs. 42%, P = .04) were more common in MPP, and a lower proportion received first-line drug therapy (88 vs. 94%, P = .03) and autologous stem cell transplant (ASCT) (age <70y: 56 vs. 70%, P = .03). OS for MPP was shorter than non-MPP even after adjusting for age, comorbidities, disease stage, performance status, FISH abnormalities and treatment (HR 1.58 [1.04-2.39], P = .03).

Conclusion: MPP with MM in NZ were younger, a greater proportion had comorbidities and FISH abnormalities at diagnosis, fewer received first-line treatment and/or ASCT, and they had poorer OS than non-MPP. Investigation of modifiable factors to improve outcomes and discern why MM occurs at a younger age in MPP is needed.

Keywords: Comparative study; Ethnic groups; Haematological malignancy; Registries; Survival.