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

Background: 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. Patients and Methods: 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. Results: 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 CrC > 1.4 mg/dL and eGFR < 55mL/min. Conclusions: 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.