Epidemiological and clinical features of multiple myeloma in Russia: results of a multicenter prospective study

Background. Epidemiological studies aggregating data on newly diagnosed multiple myeloma (MM) from real-world clinical practice allow to analyze various clinical and laboratory parameters characterizing general trends in MM diagnosis, treatment outcomes, and life expectancy. Aim. To determine overall survival rates in patients with newly diagnosed MM and to examine factors influencing survival in a population-based study. Materials and methods. A total of 3,184 patients with a newly diagnosed MM from 40 regions of Russia were enrolled in a multicenter prospective study from January 2, 2015, to October 4, 2018. Complete registration of newly diagnosed cases was conducted at each of the 44 participating centers. Information on clinical and laboratory parameters, antitumor therapy regimens administered to patients, including autologous transplantation, was analyzed. Results. The median age of MM patients in Russia was 63 years. It was shown that 39 % of the patients belonged to the older age group 66–90 years, and the percentage of patients under 55 years was 22 %. Only 9 % of patients underwent bone marrow cytogenetic testing. The proportion of patients with kidney damage was 26 %, while 5 % of patients were dialysis dependent. It was shown that 78 % of patients were diagnosed with stage 3 according to Durie–Salmon system, and in 52 % of cases, stage III according to International Staging System was diagnosed. Induction therapy included the use of bortezomib in 94 % of cases, the VCD regimen (bortezomib + dexamethasone + cyclophosphamide) was mainly used, lenalidomide was prescribed extremely rarely – in 1 % of cases. The proportion of patients under 65 years of age who received at least one autologous hematopoietic stem cell transplant was only 18 %. With autologous hematopoietic stem cell transplantation, the median overall survival was 107 months, and in the case of maintenance therapy with lenalidomide, it increased to 129 months. Five-year overall survival of the entire group of patients was 40 %. In a multivariate analysis, independent predictors of worse overall survival were Durie–Salmon stage III, substage B, profound anemia (hemoglobin ≤80 g/L), albumin ≤30 g/L, and hypercalcemia (≥3 mmol/L). Conclusion. This multicenter prospective study of the epidemiological and clinical parameters of newly diagnosed multiple myeloma is unique in Russia in terms of coverage and follow-up duration (over 10 years). Analysis of treatment data for newly diagnosed multiple myeloma identified key issues in diagnosis and treatment.