The effect of bisphosphonate use on treatment response and overall survival in multiple myeloma patients

Multiple Myeloma is a neoplastic plasma cell disease characterized by clonal proliferation of malignant plasma cells in the bone marrow, presence of monoclonal protein in serum or urine, and end-organ damage associated with this monoclonal protein. Bisphosphonates are pyrophosphate analogs with high affinity for calcium crystals. Due to the affinity of bisphosphonates for calcium, they bind rapidly to calcium-containing hydroxyapatite crystals, especially in the resorption zone. In this way, they prevent bone resorption. In this study, we aimed to investigate the effect of bisphosphonate use on treatment response and overall survival in patients with Multiple Myeloma. In this retrospective observational study, all patients aged 18 years or older who were diagnosed with multiple myeloma and followed in the Hematology clinic of Fırat University Hospital in the last 10 years were included. End organ involvement, laboratory parameters in diagnosis and follow-up, bisphosphonate use (duration and dose), treatments, response status and survival were investigated. Ninety-one patients were included in our study. Patients' age, gender, bisphosphonate intake, ISS staging, LDH level, CRAB findings, IG subtype were evaluated. There was a significant difference in mean survival times between ISS staging (p=0,004). There was a significant difference between the creatinine categories in terms of mean survival times (p=0,049). The survival time of those with normal LDH levels was found to be significantly higher than those with high LDH levels (p=0,007). There was no significant difference in survival between bisphosphonate intake status and IG subtypes (p>0,05). The progression-free survival time of patients with normal LDH level was found to be significantly higher than progression-free survival time of patients with high LDH level (p=0,01). There was no significant difference in progression-free survival between the ISS category, bisphosphonate intake status, creatinine category, and IG subtypes (p>0,05). In our study, the use of bisphosphonates in MM patients did not have an effect on OS and PFS of the patients. OS was found to decrease as ISS stage increased, but vi PFS was not affected. A negative effect of kidney failure on OS was detected, but no effect on PFS. It was observed that the increase in LDH level negatively affected survival. Keywords: Multiple myeloma, bisphosphonate, LDH, CRAB