Abstract
Multiple myeloma (MM) is a heterogeneous disease with the survival ranges from a few months to 10 years and more. The prevalence of MM varies according to ethnicity and geographical backgrounds. The real incidence of this disease in Russia is poorly understood. Available data are limited. Although the survival of MM patients has increased over the past 10-15 years, there is still a proportion of patients who die within a few months during induction therapy. The aim of this study was to examine the incidence of MM in Russia, describe characteristics of newly diagnosed MM patients, and assess patient survival, using the data from a population-based primary care database. Moreover we identified the clinical and laboratory features that are associated with early death within the first 12 months after initiation of antimyeloma therapy.
Methods. Patients with new diagnosed MM were identified in the Kirov regional population-based primary care database (dates of diagnosis ranged from 01 Jan 1994 to 31 Dec 2016). Demographic and clinical characteristics were described at time of diagnosis. Median overall survival (OS) was estimated using Kaplan-Meier methods using individual patient level data from diagnosis date to date of death or end of follow-up. Survival rates were stratified by 5-year periods by calendar year of diagnosis: 1994-1999, 2000-2005, 2006-2011 and 2012-Dec 2016.
Results. The five hundred and sixty seven patients with new diagnosed MM (male - 215, female - 352) were included in this study. Median age of the patients was 64 years (range, 29-90 years). The age-standardized incidence of MM was 1.8 cases per 100.000/year. During research period (23 years) we have the positive trend of the incidence and prevalence of MM and negative tendency of mortality every year. Our prognosis of the intensive incidence is 2.2-2.3 cases per 100.000 in 2017-2019 years. The 5-year OS rate was 18% (1994-1999); 24% (2000-2005) and 36% (2006-2011) respectively (Fig. 1). The median OS was 28; 26 and 38 months respectively. The median OS for patients who diagnosed in the period 2012-2016 was not achieved.
The incidence of early mortality was different in selected observation periods. In particular it was 45% between 1994 and 1999, 43% in 2000-2005, 36% in 2006-2011 and 11% between 2012 and 2016. These frequencies differed from each other (X-squared = 22.125, df = 3, p-value = 6.143e-05). The impact of age, hemoglobin and platelets levels, serum creatinine, LDH, albumin, B2-microglobulin, plasma cells in bone marrow, immature plasma cells in bone marrow, Durie-Salmon stage, IgA type and treatment by proteasome inhibitors (bortezomib) were estimated as predictors of a short survival rate. Based on the results of univariate analysis age, Durie-Salmon stage III, bortezomib treatment, hemoglobin level, B2-microglobulinum, serum creatinine and albumin were found to be significant (p<0.05). These factors were evaluated in multivariate analysis. In multivariate analysis the strongest predictors of death within <12 months were hemoglobin level (HR: 0.97, 95% CI: 0.94-0.99, p=0.04), B2-microglobulin (HR: 1.09, 95% CI: 1.03-1.15, p=0.002) and using bortezomib in treatment (HR: 0.17, 95% CI: 0.05-0.45, p=0.0007). According analysis the using bortezomib in treatment of MM patients reduce risk of early mortality in 5.9 times. The odds ratio for dying in the first year was 0.13 (CI: 0.07-0.25) for patients receiving a bortezomib compared to the rest.
Conclusion. The age-standardized incidence of MM in Kirov region (Russia) was 1.8 cases per 100.000/year. 5y-OS was 18% (1994-1999); 24% (2000-2005) and 36% (2006-2011). In newly diagnosed MM low hemoglobin level and high B2-microglobulin levels were associated with high risk of early mortality (<12 months after initiation of antimyeloma therapy). In 2006-2016 recent years a novel agents (bortezomib, lenalidomide) for treating MM have been introduced, which according to our database is associated good outcome and low risk of early mortality.
No relevant conflicts of interest to declare.
