PB2178 MULTIPLE MYELOMA IN PATIENTS UNDER 65 YEARS: AN ANALYSIS OF 56 CASES FROM SANATORIO DEL SALVADOR IN CORDOBA, ARGENTINA
Authors: D. Rodriguez, R. Ryser, J. Ryser, V. Gutierrez, M. J. Lopez, F. Ryser, M. V. Seifi, M. N. Luz, R. Navarro
Journal: HemaSphere (2019)

Background: The median age of developing multiple myeloma (MM) is approximately 70 years old (y.o), information regarding disease features in younger patients is not well known and it has been suggested that presents with less common features and more aggressive course, frequently delaying diagnosis and poor outcomes. Aims: To present an analysis of a cohort of patients &lt;65 y.o with symptomatic MM diagnosed and treated at Sanatorio Del Salvador, Cordoba, Argentina, over the past decade, and to estimate their survival and identify factors predicting for relapses. Methods We reviewed data of 56 pts between January 2008 and December 2018, included age, sex, Durie Salmon and ISS stage, type of immunoglobulin, treatment received and response reached; evidences of relapses had being documented assessed by IMWG 2018 criteria. The variables were assessed for correlation with prognosis. Statistical analyses were performed with the IBM SPSS Statistics 25.0, OS curves were estimated using the Kaplan‐Meier method and the influence of the variables was analyzed by Log Rank method; all tests were 2‐sided with significance set at p &lt; 0.05. Results: 56 pts (48% F 52% M), median age of 57 y.o (range 23‐65), median follow‐up was 49.42 months (mons); with known gammopathy in 11 pts (72% plasmacytoma, 18.2% MGUS and 9% both); two were brothers. Bone disease, anemia, hipercalcemia and creatinine levels &gt; 2 mg/dL were present 37,5%, 23%, 7.14% and 9%; six pts presented with extramedullary and one with osteosclerotic disease. M protein was detected in 85.7% (IgG/k in 39%). ISS stage II prevailed with 43%. Over two periods (2008–2014, 2015–2018),all received novel agents: the main induction was ThaDex (32%)in first and CyBorDex (52.5%)in second period; RD (28%)and regimens containing Carfilzomib (34.6%) were the most used salvage therapeutic options (media lines used 2.4);reaching VGPR in 39%; 90% of pts received maintenance[(Thalidomide 59.25% and Lenalidomide 85.7%)media of 18.3mons].Fifty‐seven percent received AHCT: 70% in first, 22% in second and 8% post three or more lines; single in 87.5% and second AHCT and allogeneic transplant in 9.5% and 3%. Relapses post AHCT were observed in 72%, with early relapses in 48%, and late relapses in 52%: 29% experienced biochemical while 66.6% had symptomatic relapse. Of the remaining, 10 continue in maintenance, a pt developed post‐transplant lymphoproliferative disorder and one was chemorefractory. Among pts whit symptomatic relapse, new bone lesions (32%) and anemia (31.25%) were the most seen. Overall survival was 87.5 mons, statistical analysis showed no significance for IG type [(IgG vs non IgG (p: 0.24)] and sex (p: 0.46), Durie‐Salmon or ISS (p: 021 and p: 0.24); although, median survival of for ISS I II and III was 75.5 ‐107.5 and 50.4 mons. Media time to relapse was 63.85 mons: we did not find statistical significance by using maintenance (p: 0.5)or ASCT (p:0.6); however, we did find significance by ISS groups [(I 60%, II 70%, and III 81.2%) p:0.02]. TRM was the most major cause of death (52%), followed by progression (19%). Summary/Conclusion: Our cohort had features comparable to the literature but longer survival; probably because of the impact of recent approvals for new therapeutic agents availables in our country, reflecting that the improvement in treatment practice with increasing usage of novel therapy impacts on the outcome of patients with multiple myeloma.