A Critical Population Analysis of 57, 500 US Multiple Myeloma Patients: Impact of Race, Age, and Decade of Treatment on Overall Survival

Abstract

Abstract 2948 Background:Recent clinical observations and published reports have suggested that there has been a significant improvement in overall survival (OS) in patients with multiple myeloma (MM) during the last decade. Previous studies have also suggested that OS was superior in younger MM patients. A large population analysis studying the impact of different races on overall survival is lacking. For this reason, we aimed to study OS differences among patients of different races. We also hypothesized that OS had already improved from the 1970s to 2000s in all MM patients due to other factors, as well as the availability of novel agents. Methods: For the years from 1973 to 2008, data on 57, 574 MM patients were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program of the US National Cancer Institute. Statistical analysis evaluating patient population baseline characteristics (race, age) and year of diagnosis were performed by using univariate and multivariate Cox regression models for the OS endpoint. Results: The mean patient age at diagnosis was determined to be 68 (median = 69) years. Mean survival was determined to be 33 months (median = 21). Asian/Pacific Islander race was associated with an improved OS, HR 0.94 (CI 0.92–0.96, P <0.001). Multivariate hazard ratio analysis did not reveal any statistically significant differences in OS between patients in the white and black race (P =0.687). Younger age (age <65) was associated with improved OS when compared with patients aged 65–75 or patients aged >75 (both P <0.001). Recent treatment decades (1983–1992, 1993–2003, and 2004–2008) were associated with improved OS on multivariate analysis with HR 0.90 (CI 0.90–0.91, P <0.001), HR 0.79 (CI 0.78–0.79, P <0.001), and HR 0.71 (CI 0.69–0.74, P <0.001), respectively. Conclusions: As the largest population analysis to date, this study revealed a statistically significant improvement in OS for patients belonging to Asian/Pacific Islander race groups. In addition, MM patients from all subgroups who were treated in more recent decades, even before the availability of novel agents, exhibited superior OS. This may be due to advances in supportive care and/or earlier diagnosis, as well as an increased use of hematopoietic stem cell transplantation. With the availability of novel agents during the last decade, OS has significantly improved. Our study shows that older MM patients continued to have decreased levels OS even after the availability of novel agents. Future studies are needed to evaluate the effectiveness of novel agents in various age subpopulations.Table 1Multivariate hazard ratios, confidence intervals, and P values of patients with MM by racial groups, diagnosis year groups, and age groupsHazard RatioEstimate95% CIP value**Racial GroupsWhite*referenceBlack1.010.98–1.030.687Asian/Pacific Islander0.940.92–0.96< 0.001American Indian/Alaska Native1.100.99–1.230.081Diagnosis Year Groups1973-1982*reference1983-19920.900.90–0.91< 0.0011993-20030.790.78–0.79< 0.0012004-20080.710.69–0.74< 0.001Age Groups<65*reference65-751.501.46–1.53< 0.001>752.352.30–2.41< 0.001*Reference group against which other groups' survival experience are compared**P value for test if groups' survival experience is same as reference group Disclosures:No relevant conflicts of interest to declare.