COMBINATION CHEMOTHERAPY AND RENAL ENZYME AND PROTEIN EXCRETION IN PATIENTS WITH BREAST-CANCER

This study investigated the effect of doxorubicin-based chemotherapy o n the kidney, as assessed by enzymuria, proteinuria and albuminuria in patients with breast cancer. Nine patients with breast cancer receive d primary (neo-adjuvant) chemotherapy - intravenous doxorubicin (50 mg /m(2)), vincristine (1.2 mg/m(2)), cyclophosphamide (1 g/m(2)) and ora l prednisolone (40 mg/day for 5 days) and venous blood and urine sampl es were taken before treatment and on days 1,10 and 20, after chemothe rapy (Pulse 1). This regime was then repeated (Pulse 2). Urine activit ies of gamma-glutamyltransferase (GGT), alanine aminopeptidase and N-a cetyl-beta-D-glucosaminidase (NAG), and proteinuria and albuminuria we re measured. After initiation of the first pulse of chemotherapy, sign ificantly increased NAG and GGT enzymuria were noted on days 1 and 20, while increased proteinuria was present only on day 1. Following the second pulse of chemotherapy increased proteinuria was observed on day s 1 and 10. Creatinine clearance rates remained unaltered throughout. A group of six healthy age- and sex-matched controls, with no known re nal disease, were also studied and enzymuria, proteinuria and creatini ne clearance rates were not significantly altered over the experimenta l period. This study indicates that chemotherapy produces a moderate r enal insult as manifested by increased NAG enzymuria and proteinuria w ithout affecting overall renal function. The results suggest that rena l function should be monitored in patients undergoing repeated cycles of chemotherapy, especially if there has been combinations with, or pr evious exposure to, chemotherapeutic agents with known nephrotoxic pot ential.