Chronic kidney disease stage 5 as the prognostic complement of International Staging System for multiple myeloma

Background: Reversal of renal impairment (RI) in patients with multiple myeloma (MM) has been evaluated using the estimated glomerular filtration rate (eGFRMDRD) formula developed by the Modification of Diet in Renal Disease study group. However, the prognostic impact of eGFRMDRD at diagnosis of MM is not well studied, particularly its use in conjunction with the International Staging System (ISS). Methods: Newly diagnosed patients with MM were enrolled between 1996 and 2007. Data on clinical features, laboratory tests, and overall survival were compared in terms of corresponding eGFRMDRD. Results: A total of 387 patients with MM (median age, 71 yr) were enrolled. At diagnosis, 56% had ISS stage III disease; the median values of serum creatinine (SCr) and eGFRMDRD were 1.4 mg/dL and 38.2 mL/min/1.73 m2, respectively. Thirty‐four percent of patients had SCr of ≥2.0 mg/dL, and 81.2% had chronic kidney disease stages 3–5 (CKD 3–5). Higher CKD stages were significantly more common in men, older patients (≥65 yr), and those with Durie–Salmon and ISS stage III, light‐chain diseases, anemia, thrombocytopenia, hypercalcemia, elevated serum β2 microglobulin, or lactate dehydrogenase. In the Cox regression model, CKD 4–5 or CKD 5 alone was independently associated with poor survival. A diagnosis of CKD 5 was shown to be useful in identifying the subgroup of ISS‐III patients at high risk – those with a median overall survival of 7.2 months. Conclusions: Our study demonstrates the prognostic impact of eGFRMDRD in patients with MM and CKD 5 as the ISS‐independent surrogate predictor of poorest prognosis.