Racial and Ethnic Differences in Incidence and Disease Specific Survival of Multiple Myeloma- New Mexico Tumor Registry Based Study

Background:

Multiple Myeloma is a plasma cell neoplasm which is characterized by an increase in monoclonal proteins or light chains and end-organ damage. Multiple Myeloma accounts for 1.8% of all new cancer cases in the United States, with an estimated 32,110 new cases annually. In population-based studies, African Americans have a higher incidence of Myeloma and inferior outcomes when compared to Caucasians. Disparities in the incidence of Myeloma for other races in the United States also exist but are not well studied.(1). Analyses of Surveillance, Epidemiology, and End Results program (SEER) data showed that Hispanics had poor or delayed access to novel agents and transplant, and poor overall survival.(2). Data for Native Americans was not reported due to small or insignificant numbers. New Mexico is a majority minority state, with approximately 1 million Hispanics residing in the state, constituting 49.1% of the total population and the largest statewide percentage of Hispanic residents nationally. (3) New Mexico also has a sizable population of 219,237 Native Americans, who make-up nearly 10.5% of the state's entire population. (3) Hence, the significant minority population in New Mexico allows the comparison of incidence between racial and ethnic subgroups as well as disease specific survival of Myeloma in New Mexico residents using the New Mexico Tumor Registry.

Methods:

We utilized data from the New Mexico Tumor Registry to study patients with a documented diagnosis of Myeloma. Descriptive statistics including the incidence rates of myeloma and Kaplan-Meier product-limit methods to assess cause-specific survival for incident myeloma cases diagnosed among New Mexico residents during the time period 2008-2017. Other variables including transplantation rates were also studied but are not reported in this abstract.

Results:

Men had higher incidence of Myeloma compared to females (p<0.01) and Hispanic females had a higher incidence compared to Non-Hispanic white females (p<0.05). The incidence of Myeloma (for both sexes) was slightly increased in Hispanics (5.6 /per 100,000, CI- 5.1,6.2) and Native Americans (6.3/per 100,000, CI- 5.1,7.7) compared to Non- Hispanic Caucasians (5.1/per 100,000, CI- 4.7,5.5). (Fig. 1) However, these differences were not statistically significant. The incidence of multiple myeloma has been stable for all racial-ethnic group examined during 1981-2017. (Fig. 2) Modest differences in survival among Non-Hispanic whites, Hispanics, and American Indians were not statistically significant (log-rank test, p=0.3907). (Fig.3)

Conclusion:

Racial-ethnic differences in incidence and disease specific survival of Multiple Myeloma were evident but were not statistically significant in New Mexico, except incidence of Multiple Myeloma among Hispanic females compared to Non-Hispanic white females. Further study of disease-related factors (high risk disease, mutational profiles, stage at diagnosis) and patient-related factors (access to standard treatments, transplantation or clinical trials) may be needed to understand these differences and better care for the patients.

View largeDownload slide

View largeDownload slide

Close modal