Abstract B020: Genetic markers, first-line treatment, and survival among Hispanic patients with multiple myeloma: A population-based study in Puerto Rico
Authors: Ramos Tonatiuh Suárez , Castañeda-Avila Maira A. , Torres-Cintrón Carlos R. , Gierbolini-Bermúdez Axel , Tortolero-Luna Guillermo , Ortiz-Ortiz Karen J. 
Published: December 2023

Abstract
Background: Research on the genetic markers, treatment, and survival of multiple myeloma (MM) among Hispanics is limited. Most population-based registries do not comprehensively collect cancer-related biological and genetic markers, which limits the use of these registries to address critical research questions. We used the Puerto Rico Central Cancer Registry (PRCCR) and the PRCCR-Health Insurance Linkage Database (PRCCR-HILD) to evaluate these factors among patients diagnosed with MM in Puerto Rico (PR). Methods: A retrospective cohort study was conducted among MM patients in PR between 2015 and 2019. We developed a robust sub-database that expands the quality and quantity of data regularly collected by the PRCCR and health insurance claims by integrating data from PRCCR’s cancer database, Electronic Medical Records, Pathology Reports database, and PRCCR-HILD. Descriptive statistics were used to present an epidemiological profile of the study group. Bivariate analyses were performed to evaluate associations between treatment patterns and patient characteristics. Multivariable Cox regression models were used to estimate the magnitude of the association between overall mortality among patients with MM and different characteristics. Results: The study cohort consisted of 716 patients; 49.6% were male, the median age at diagnosis was 69 years, and 76.7% had a comorbidity index score ³2. High-risk chromosomal abnormalities (HRCAs), which include at least one of t(4;14), t(14;16), Del(17p), and t(14;20), were found in 23.2% of patients. Around 88% of MM patients had documented evidence of treatment, and nearly half of all patients began treatment after 30 days (49.1%) of diagnosis. The most common treatment was bortezomib-based triplet (29.1%), followed by bortezomib-based doublet (25.9%). Based on the multivariable Cox models, the risk of dying was greater among patients who had chromosome 1 abnormalities (C1As) (HRAdjusted: 1.28, 95% CI: 0.99-1.66) or HRCAs (HRAdjusted: 1.39, 95% CI: 1.04-1.86) than patients without C1As or HRCAs, respectively. Furthermore, the risk of dying was lower among those receiving treatment after controlling by potential confounders (HRAdjusted: 0.44, 95% CI: 0.32-0.61). Among those receiving treatment, the bortezomib triplet showed better results than dexamethasone (HRAdjusted: 2.62, 95% CI: 1.63-4.20) and bortezomib-based doublet (HRAdjusted: 1.72, 95% CI: 1.14-2.60). Conclusion: This study provides the first description of the prevalence of genetic markers in patients with MM in PR, integrating epidemiological, clinical, and health claims data. Our analysis confirms that HRCAs and C1As remain as important predictor factors in determining the outcomes of MM patients. In addition, treatment patterns in PR Hispanic population suggest a longer median time to treatment initiation than other US studies, which warrants follow-up. These findings highlight the importance of establishing a broader understanding of the genetic and treatment-related factors associated with MM outcomes in different racial/ethnic groups.
Citation Format: Tonatiuh Suárez Ramos, Maira A. Castañeda-Avila, Carlos R. Torres-Cintrón, Axel Gierbolini-Bermúdez, Guillermo Tortolero-Luna, Karen J. Ortiz-Ortiz. Genetic markers, first-line treatment, and survival among Hispanic patients with multiple myeloma: A population-based study in Puerto Rico [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B020.