Do you prefer monitoring creatinine over cystatin C levels in patients with lymphoma and chronic kidney disease given the potential for cystatin C levels to be increased with certain malignancies?  

My default is to monitor creatinine, not cystatin C, in all patients with malignancies except: if patients have had weight loss and down-trending creatinine, patients are at eGFR cutoffs for chemotherapy drug dosing, leading to concern for potential over/under-dosing, there is concern for pseudo-...