Improved survival in myeloma patients- a nationwide registry study of 4647 patients ≥75 years treated in Denmark and Sweden

The prevalence of multiple myeloma (MM) is increasing in the Nordic countries and the rest of the Western World. Patients aged ≥75 years at diagnosis constitute an increasing proportion of all MM patients, but are underrepresented in randomized clinical trials. There is an urgent need for studies of the characteristics, treatment and outcome in this cohort. We present data from two nationwide population-based registries of all MM patients diagnosed in Denmark January 1st 2005 until February 18th 2020, and in Sweden from January 1st 2008 until December 31st 2019, including treatment data for patients diagnosed until 2018 (Denmark) and 2019 (Sweden). In total 4647 patients were 75 years or older at diagnosis, compared to 7378 younger patients. Patients ≥75 years, comprising approximately 40% of all MM patients, are a distinct cohort with more advanced disease at diagnosis, reflected by higher ISS (International Staging System), and a higher proportion with renal failure and anemia. We find a more gradual introduction of modern medications in the older cohort than the younger, despite simultaneous changes in guidelines. Compared to the randomized controlled trials that guide the treatment of non-transplant eligible patients, we find a higher proportion of patients ≥75 years and presenting with ISS III in real world data. Nevertheless, response rates and survival are increasing, reflecting that modern treatment regimens are effective and well tolerated, also in elderly MM patients in real-world populations.