Abstract C125: Multiple myeloma incidence, mortality and survival differences at the intersection of sex, age, and race/ethnicity in the United States and Puerto Rico: 2015-2019

Abstract Background: Multiple myeloma (MM) is an incurable malignancy of plasma cells. Overall 5-year survival rate has increased in recent years due to new treatments. However, this improvement has not been equal across sociodemographic groups. Older adults, males, and non-Hispanic Blacks (NHB) are at higher risk of developing and dying from MM. Therefore, this study investigated the intersectionality among age, sex, and race/ethnicity to better understand the patterning of MM incidence, mortality, and survival. These groups are usually considered separately, which may mask the inequities experienced among them. Methods: The sources of information for this study were the Puerto Rico (PR) Central Cancer Registry database and the US Surveillance, Epidemiology, and End Results (SEER) Program database. We analyzed incidence and mortality trends of MM from 2001 to 2019 using joinpoint regression models to calculate Annual Percent Change (APC). Age-standardized rate ratios (SRR) for MM incidence and mortality were used to compare PR with US racial/ethnic groups from 2015 to 2019. The SRRs were stratified by two age groups (<65, ≥65) and sex. Furthermore, 5-year survival analyses of MM were performed. Results: Regardless of age and race/ethnicity, males have higher incidence and mortality rates of MM than females. In terms of trends, PR had a higher increase in MM incidence rates than other racial/ethnic groups, regardless of sex and age (PR annual percent change [APC] = 4.3 among males <65, 3.1 among males ≥65, 6.3 among females <65, and 2.6 among females ≥65 years old). No significant change in mortality APCs (p>0.05) was observed in PR during the study period when stratified by age or sex. Across categories of age and sex, NHB had higher MM incidence and mortality rates than the other racial/ethnic groups. Nevertheless, when comparing males <65 years, PR has significantly higher incidence rates than non-Hispanic Whites (NHW) and US Hispanics (USH). However, PR has significantly lower mortality rates than NHW, NHB, and USH in the ≥65 age group. In terms of survival, PR showed the lowest observed 5-year survival rate among males <65 years (54.6%, 95% CI: 47.2-61.5) and males ≥65 years (33.8%, 95% CI: 28.5-39.1). Among females, USH showed the lowest observed 5-year survival for the age group <65 years (59.4%, 95% CI: 55.2-63.4) and NHW showed the lowest observed 5-year survival for the age group ≥65 years (37.0%, 95% CI: 35.4-38.6). In most categories, the highest observed 5-year survival rates were similar between two or more racial/ethnic groups. Conclusion: The incidence of MM increased in every racial/ethnic group over the study period, with PR having the highest APCs in all categories. Despite the introduction of new therapies, the mortality rates in PR have remained stable while the other racial/ethnic groups show significant decreases across categories of sex and age. These results highlight the need for more research in MM to better understand these disparities. Citation Format: Carlos R. Torres-Cintrón, Tonatiuh Suárez-Ramos, Maira A. Castañeda-Avila, Mara M. Epstein, Guillermo Tortolero-Luna, Karen J. Ortiz-Ortiz. Multiple myeloma incidence, mortality and survival differences at the intersection of sex, age, and race/ethnicity in the United States and Puerto Rico: 2015-2019 [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C125.