Breast cancer and renal insufficiency.

Abstract

Abstract Abstract #6086 Background:
 The Belgian IRMA study (Renal Insufficiency and Anticancer Medications) reported the high prevalence of renal insufficiency (RI) in 1208 cancer patients, with a glomerular filtration rate (GFR) <90 ml/min for 64%. Furthermore, 78.1% were receiving potentially nephrotoxic drugs and 78.8% drugs necessitating dosage adjustment in case of renal dysfunction. We present here the results for the 510 BIRMA patients with breast cancer.
 Methods:
 Data were collected for patients presenting at one of the 7 BIRMA centers in March 2006: tumor, sex, age, weight, height, serum creatinine (SCR), bone metastasis (BM) and anticancer drugs (including dose modification). Glomerular Filtration Rate (GFR) was estimated by the aMDRD formula.
 Results:
 510 breast cancer patients were included: mean age 58.7 years, weight 68.1 kg, height 161.6 cm, 4 men, 46.9% of patients had BM. The prevalence of elevated SCR (>=1.2 mg/dL) was 7.3%, of GFR<90 ml/min/1.73m² 67.8%, and of GFR<60 (threshold for many anticancer drugs to consider dose modification) 15.9% (Table). 86.6% of treated patients (n=486) were receiving at least one drug needing dosage adjustment in case of renal dysfunction and 73.4% received at least one potentially nephrotoxic drug. Furthermore, the prevalence of GFR<90/60 was 74.9/24.3% for breast cancer patients with BM (Table). When comparing the prevalence of GFR<90 between patients with or without BM (for patients with available GFR), the frequency of RI was significantly higher for BM patients (78.9 vs 69.9%, p=0.03).
 Conclusions:
 The results of the BIRMA study showed that RI is highly frequent in breast cancer patients in Belgium and that nearly 94% of the patients receive potentially nephrotoxic drugs and/or drugs for which dosage must be adjusted in RI. Furthermore, patients with BM had a higher rate of RI than patients without. These frequencies are higher compared to data from the NHANES study in the US general population, especially for breast cancer patients with a stage 3 RI for whom SCR was normal in 55.7% of the cases. This underlines that estimating renal function with formulae such as aMDRD is mandatory in every breast cancer patient, even when SCR is within the normal range.
 
 Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6086.