Renal Insufficiency in Breast Cancer Patients: High Prevalence and Reduced Survival.
Authors: Launay-Vacher V. , Janus N. , Gligorov J. , Spano J. , Ray-Coquard I. , Oudard S. , Morere J. , Rey J. , Pourrat X. , Deray G. , Beuzeboc P. 
Published: December 2010

Abstract
BackgroundThe IRMA-1 study was the first to report on the high prevalence of renal insufficiency (RI) in 1898 breast cancer patients. The IRMA-2 study was started one year later, in another cohort of patients, and consisted of 2 phases: a cross-sectional study, similar to IRMA-1, and a 2-year retrospective follow-up of the patients to evaluate the impact of RI on survival. Data from the phase 1 of IRMA-2 were compared to the results of IRMA-1 in terms of RI prevalence and the potential association between RI and cancer survival was evaluated. We present here the results for IRMA-2 patients with breast cancer.Methods:The IRMA-1 and IRMA-2 studies included 4684 and 4945 patients, respectively, among which 1898 in IRMA-1 and 1816 in IRMA-2 had breast cancer (no dialysis). Sex, age, weight, serum creatinine (SCR), metastasis (bone and/or visceral), and anticancer drugs were collected. GFR was estimated with the aMDRD formula. RI was defined as aMDRD&lt;60 mL/min/1.73m². Patients were retrospectively followed during 2 years after the inclusion (IRMA-2). Anticancer drugs necessitating dosage adjustment and those potentially nephrotoxic were identified (both studies).Results:Median age 56.0 (vs. 55.0 in IRMA-1), mean weight 64.3 (vs. 64.2) and 19 men (vs. 20). The prevalence of an elevated SCR (SCR&gt;110µmol/l) was 2.0% (vs. 1.6% in IRMA-1), that of a GFR &lt; 90 ml/min/1.73m² was 50.0% (vs. 50.8%) and that of a GFR &lt; 60 ml/min/1.73m² was 7.7% (vs. 7.8%). No statistical different were found between the 2 populations.Among these 1816 patients, 1601 with available data (aMDRD and follow-up) were included in the survival analysis. RI at inclusion was strongly linked to mortality (Log Rank test, p&lt;0.0001). Mean survivals were 18.1 and 20.7 months for patients with GFR&lt;60 and &gt;=60, respectively, when analysing all patients.When the same analysis was performed for non-metastatic patients (n=918), by definition with a better prognosis, RI at inclusion was still associated with mortality (Log Rank test, p=0.01) with mean survivals of 21.2 and 22.9 months for patients with GFR&lt;60 and &gt;=60, respectively.At inclusion, 81.2% of treated patients (n=1572) were receiving at least one drug needing dosage adjustment and 75.9% received at least one nephrotoxic drug (vs. 90.4 and 76.7%, respectively).Conclusion:The results of IRMA-2 and IRMA-1 confirm the high prevalence of RI in breast cancer patients, on 2 cohorts of nearly 2000 breast cancer patients each. Furthermore, patients with aMDRD&lt;60 mL/min/1.73m² at inclusion had a lower survival rate at 2 years than patients without. Such results might be explained by the fact that most of these patients received drugs that needed dosage adjustement or were nephrotoxic. A misuse of anticancer drugs in RI patients could have lead to increased mortality. This underlines that assessing and monitoring renal function in cancer patients is crucial in order to ensure appropriate drug dosing in these patients.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2054.