Negative Impact of Borderline Creatinine Concentration and Glomerular Filtration Rate at Baseline on the Outcome of Patients With Multiple Myeloma Treated With Autologous Stem Cell Transplant

Renal impairment (RI) is one of the multiple myeloma (MM)-defining events for initiating therapy. After induction therapy, high-dose chemotherapy followed by autologous peripheral blood stem cell transplant (ASCT) remains the standard of care for transplant-eligible patients with MM. According to the International Myeloma Working Group (IMWG), the organ criterion for kidney damage is defined by a serum creatinine concentration (CrC)2 mg/dL or estimated glomerular filtration rate (eGFR) 40 mL/min. In this long-term study, we evaluated the impact of CrC and eGFR calculated by the Modification of Diet in Renal Disease equation on progression-free and overall survival using a lower threshold than the IMWG criteria.We studied the longitudinal outcomes as measured by progression-free survival and overall survival in 59 transplant-eligible patients with MM: 38 patients with normal renal function and 21 patients with RI defined as a CrC higher than upper limit of normal (≥ 1.1 mg/dL), eGFR 60 mL/min, treated with ASCT from 1998 to 2004.The risk of disease progression and death following ASCT increased by 16.5% (P = .005) and 19% (P .0009) per 1 mg/dL of CrC, respectively. The thresholds for the association of renal insufficiency and negative outcomes were CrC1.4 mg/dL and eGFR 55mL/min.We observed a negative correlation between minimal renal insufficiency and long-term outcomes. Management of patients with even marginally increased CrC and/or decreased eGFR not fulfilling IMWG RI criteria requires more concentrated effort to reverse even minimal renal insufficiency.