Cetuximab-induced nephrotic syndrome in a case of metastatic rectal cancer.

Proteinuria is common adverse effect that occurs after the use of bevacizumab, but it occurs rarely during administration of cetuximab. We report the first case of nephrotic syndrome induced by cetuximab after completing mFOLFOX6 with bevacizumab followed by sLV5FU2 with bevacizumab for metastatic rectal cancer. Prior to the administration of cetuximab, the patient had never presented proteinuria. After the completion of the loading (400 mg/m(2)) and two subsequent maintenance (250 mg/m(2)) infusions of cetuximab, edema of the lower extremities occurred concomitantly with facial acneiform rash. Based on the laboratory data, diagnosis of nephrotic syndrome was made and secondary diseases of nephrotic syndrome were excluded. Oral administration of prednisolone (0.6 mg/kg/day) was initiated, resulting in no response. The trigger of nephrotic syndrome other than cetuximab was not suggested and attention on occurrence of proteinuria must be devoted to this medicine.