Abstract
IntroductionAustralia has one of the highest incidence rates of multiple myeloma (MM) globally, and this burden is projected to increase significantly in the coming decades. Survival has improved over time, but it is not clear how this differs by socioeconomic group. Here, we used population-based data to evaluate survival differences by socioeconomic group and other prognostic factors of individuals with MM in Australia.MethodsThis retrospective study included individuals diagnosed with primary MM between 2008 and 2019, as recorded in the New South Wales Cancer Registry, with survival follow-up to 2020. The identified individuals with primary MM were classified into 3 socioeconomic groups (low, medium, high) based on their residential location at diagnosis. Competing-risk modelling was used to estimate sub-hazard ratios (SHR) for socioeconomic group adjusting for potential prognostic factors, including age at diagnosis, sex, year of diagnosis, remoteness areas, autologous stem cell transplantation (ASCT) use, and hospital type.ResultsOverall, 6,030 individuals were included in the study. The 5-year cumulative incidence of death due to MM was higher (p<0.0001) in low and medium socioeconomic groups (0.42 and 0.39), compared with the high socioeconomic group (0.34). Individuals in the high socioeconomic group were more likely to receive ASCT and to receive care at public principal referral/private hospitals. Compared to the high socioeconomic group, the excess risk of dying was higher (p<0.0001) in low (SHR=1.27, 95% CI: 1.14-1.42) and medium (SHR=1.20, 95% CI: 1.08-1.33) socioeconomic groups, but not statistically different (p=0.13) when other prognostic factors were considered.ConclusionSurvival disparity by socioeconomic groups among individuals with MM in Australia is largely accounted for by known prognostic factors, especially ASCT receipt and hospital type. Existing disparities suggest that a comprehensive evaluation of access to and availability of MM treatment, including identification of potential barriers to treatment receipt, is urgently needed.