Evaluation of bortezomib-dexametasone (VD) and bortezomib-dexametasone-cyclophosphamide (VCD) treatment responses in the fist line therapy in new diagnosed multiple myeloma (MM) patients according to the international staging system (İSS) and revised international staging system (R-İSS)

Objective: Multiple myeloma (MM) is a malignant disease characterized by clonal plasma cell increase and constitutes 1% of all cancers and 10% of hematologic cancers. Although the survival time of patients is about 10 years with the use of new treatment agents, MM is still not a curable disease. The aim of this study was to retrospectively evaluate the treatment response and survival rates of newly diagnosed MM patients who received bortezomib-dexamethasone (VD) and bortezomib-cyclophosphamide-dexamethasone (VCD) as first-line therapy according to the International Staging System (ISS) and Revised International Staging System (R-ISS) at the Department of Hematology, Karadeniz Technical University Faculty of Medicine. Materials and Methods: A total of 264 patients who were followed up with the diagnosis of MM in the Hematology Department of Karadeniz Technical University Faculty of Medicine between 2008-2022 and who received on of the VD or VCD treatment regimens in first-line treatment were included in the study. Overall survival and treatment responses of patients were evaluated according to demographic characteristics, SLiM-CRAB criteria, prognostic factors (albumin, -2 microglobulin, lactate dehydrogenase (LDH), cytogenetic abnormalities (CA)), staging systems (ISS and R-ISS) and treatments. The efficacy of ISS and R-ISS staging systems in terms of prognosis were compared. Results: Of the 264 patients in our study, 151 (57%) were male and 113 (43%) were female with a male to female ratio of 1.34. The median age of the patients was 64 years. As fist-line therapy, 73 (28%) of the patient received VD and 191 (72%) received VCD. Autologous stem cell transplantation (ASCT) was performed in 64 (24%) patients. Regarding the effect of SLiM-CRAB criteria on OS, OS was found to be shorter in patients with bone marrow plasma cell ratio >60%, in the presence of bone lesions, hypercalcemia and hemoglobin <10 g/dl (p=0.004, p=0.002, p<0.001, p=0.001, respectively). According to the prognostic factors used in ISS and R-ISS, OS was shorter in patients with elevated LDH, presence of high-risk CA and β-2 microglobulin >5.5 mg/L (p=0.002, p<0.001, p<0.001, p<0.001, respectively). OS was longer in patients who received VCD and ASCT (p=0.035, p<0.001, respectively). According to the stages of ISS and R-ISS, OS was longer in both ISS and R-ISS stage I patients than in stage II and III patients (p<0.001). In both ISS and R-ISS staging systems, OS was longer in stage I in patients who were not performed ASCT (p=0.001, p<0.001, respectively), while OS was not different between stages in patients who were performed ASCT (p=0.96, p=0.63, respectively). R-ISS stage II patients had shorter OS in case of elevated LDH and high-risk CA (p=0.001, p=0.033, respectively). Recarding the overall response rates of patients who received VD, VCD and VCD+ASCT treatment, the highest overall response rate was observed in the patients who received VCD+ASCT, while the overall response rates between patients who received VD and VCD were not different (p=0.002, p=0.15, respectively). Conclusion: In our study, R-ISS was more effective than ISS in predicting prognosis in MM patients. OS durations were similar according to the two staging systems in patients who were performed ASCT. LDH and CA were more effective than albumin and 2- microglobulin in predicting prognosis. Significantly prolonged OS and better treatment responses were observed in patients who were performed ASCT after treatment with new agents.