Retrospectively evaluation of relevance between toxicity of melphalan and renal failure in the patients treated with autologous hematopoetic stem cell transplantation

Autologous hematopoietic stem cell transplantation (Auto-HSCT) is the primary treatment modality for the patients who are diagnosed with multiple myeloma (MM) below 65 years old and relapsed/refractory lymphoma. Renal failure, which is the significant comorbidities of diagnosis with especially MM patients, affects the treatment modality significantly. The purpose of this study, which consists of 138 patients with 107 MM and 31 lymphomas, is to retrospectively determine the efficacy and side effect profile of melphalan chemotherapy used as a preparative regimen in patients who have renal failure and treatment plan for Auto-HSCT. One hundred thirty-eight patients, who are above 18 years old and treated with Auto-HSCT in January 2010-January 2019 at Bursa Uludag University Department of Internal Medicine Stem Cell Transplantation Unit, were included in the study. The patients' electronic files are examined retrospectively by using the epicrisis of the stem cell transplantation unit and the data processing system of our center. Primary diagnosis of patients, treatment before transplantation, renal functions, the regimen of stem cell collection, the regimen of transplantation, complications during transplantation, engraftment duration, the existence of relapse, and overall survival were investigated. Patients were divided into two groups, according to GFR (GFR<60, GFR≥ 60). Male patients were higher in both groups. Median age is defined as 58 years old for GFR below 60 and 55 for normal GFR. 107 MM and 31 lymphomas were diagnosed in 138 patients, and there were no significant differences between two GFR groups in terms of primary diagnosis. Lenalidomide usage was defined as significantly higher for MM diagnosis patients in the lower GFR group (p:0,041). While there were no significant differences in two groups in terms of stem cell collection regime, it is determined that the 140mg/m2 dosage of melphalan was much more preferred for the lower GFR groups as transplantation regime (p<0,001). When the side effects of melphalan chemotherapy in patients with MM were evaluated, the prevalence of mucositis and grade is higher in the patients who have lower GFR (p: 0,016). While there were no differences between into two groups in terms of median neutrophile and platelet >20.000/mm3 engraftment duration, it was determined that platelet >50.000/mm3 engraftment duration is longer into the group lower GFR. After the comparison of the melphalan dosage during transplantation preparation, it was not defined significant differences in two groups about side effects, disease-free survival, and overall survival. Also, it was not identified significant differences in patients with MM according to GFR in terms of disease-free survival and overall survival in the survival analysis. In conclusion, melphalan chemotherapy is an effective treatment regimen that can be used safely as a preparative regimen for Auto-HSCT in patients with renal insufficiency. It is not determined a significant difference between 140mg/m2 and 200mg/m2 dosage of melphalan in terms of side effects and survival rate. Keywords: Autologous hematopoietic stem cell transplantation, melphalan, renal failure, multiple myeloma.