The epidemiological landscape of multiple myeloma: a global cancer registry estimate of disease burden, risk factors, and temporal trends.

BACKGROUND: Multiple myeloma accounted for 176 404 (14%) of 1 278 362 the incidence cases leukaemia, lymphoma, and multiple myeloma in 2020. Identifying its geographical distribution, risk factors, and epidemiological trends could help identify high-risk population groups. We aimed to examine the worldwide incidence, mortality, associated risk factors, and temporal trends of multiple myeloma by sex, age, and geographical region. METHODS: The incidence and mortality of multiple myeloma were extracted from Global Cancer Observatory (2020), Cancer Incidence in Five Continents, WHO mortality database, Nordic Cancer Registries, and Surveillance, Epidemiology, and End Results Program (1980-2019). The WHO Global Health Observatory data repository was searched for the age-standardised prevalence of lifestyle and metabolic risk factors (2010). Associations with risk factors were examined by multivariable regression. The temporal trends were evaluated by average annual percentage change (AAPC) using joinpoint regression. FINDINGS: The age-standardised rate (ASR) of multiple myeloma incidence was 1·78 (95% UI 1·69-1·87) per 100 000 people globally and mortality was 1·14 (95% UI 1·07-1·21) per 100 000 people globally in 2020. Increased incidence and mortality were associated with higher human development index, gross domestics product, prevalence of physical inactivity, overweight, obesity, and diabetes. Australia and New Zealand (ASR 4·86 [4·66-5·07]), northern America (4·74 [4·69-4·79]), and northern Europe (3·82 [3·71-3·93]) reported the highest incidence. The lowest incidences were observed in western Africa (0·81 [0·39-1·66]), Melanesia (0·87 [0·55-1·37]), and southeastern Asia (0·96 [0·73-1·27]). Overall, more countries had an increase in incidence, especially in men aged 50 years or older. The countries with the highest incidence increase in men older than 50 years were Germany (AAPC 6·71 [95% CI 0·75-13·02] p=0·027), Denmark (3·93 [2·44-5·45] p=0·00027), and South Korea (3·25 [0·69-5·88] p=0·019). For women aged 50 years or older, Faroe Islands (21·01 [2·15-43·34] p=0·032), Denmark (4·70 [1·68-7·82], p=0·0068), and Israel (2·57 [0·74-4·43] p=0·012) reported the greatest increases. Overall, there was a decreasing trend for multiple myeloma mortality. The highest mortality was observed in Polynesia (ASR 2·69 [0·74-9·81]), followed by Australia and New Zealand (1·84 [1·73-1·96]) and northern Europe (1·80 [1·73-1·88]). The lowest mortalities were reported in southeastern Asia (ASR 0·82 [0·62-1·09]), eastern Asia (0·76 [0·71-0·81]), and Melanesia (0·73 [0·61-0·87]). Men (1·41 [1·29-1·53]) were found to have mortality higher than women (0·93 [0·85-1·02]). INTERPRETATION: There was an increasing trend of multiple myeloma incidence globally, particularly in men, people aged 50 years or older, and those from high-income countries. The overall decreasing global trend of multiple myeloma mortality was more evident in women. Lifestyle habits, diagnosis capacity, and treatment availability should be improved to control the increasing trends of multiple myeloma in high-risk populations. Future studies should explore the reasons behind these epidemiological transitions. FUNDING: None.