P0199ASSESMENT OF FILTRATION RATE IN ONCOLOGICAL PATIENTS

Abstract

Abstract Background and Aims Accuracy in the estimation of the glomerular filtration rate (GFR) in oncological patients is essential in order to adjust chemotherapy doses accordingly. Finding an appropriate formula for this subgroup of patients is a subject of ongoing debate. The present study introduces a cohort of the aforementioned patients followed in the Onconephrology outpatients clinic, in which different formulas were applied for the calculation of the GFR. Method A retrospective study with a cohort of 17 onconephrological patients was conducted. The following variables were evaluated: age, sex, height, weight, body mass index, body surface area and type of tumor. Renal function was estimated with the Cockcroft Gault, the Janowitz-Williams, the CKD-EPI, the adjusted by body surface-CKD-EPI, the MDRD, the adjusted by body surface-MDRD, the CKD-EPI Cystatin C, the adjusted by body surface-CKD-EPI Cystatin C formulas and 24-hour urine creatinine clearance. Every equation was compared with the Cr EDTA clearance which is considered the gold standard. The statistical analysis was carried out by means of the IBM SPSS Statistics software. Concordance between chromatography and the remaining formulas was assessed with the Wilcoxon (null hypothesis of no difference between medians) and Bland-Altman tests. Results 6 women and 11 men were included in the study, with a mean age of 64.24 years (SD 9.9), a mean BMI of 28.25kg/m2 (SD 7.98), and a mean Cr EDTA clearance was 37.07ml/min (SD 15.45). 15 patients suffered from solid malignancies, whereas the remaining 2 patients suffered from hematological tumors. The most common solid tumor was lung cancer (n=5), followed by rectal carcinoma (n=2). The null hypothesis was accepted for the adjusted for body surface-CKD-EPI Cystatin C equation (p-0,089) and 24-hour urine creatinine clearance (p 0.955), when compared to 51Cr EDTA clearance. The Bland-Altman test revealed the smallest differences between the 24-hour urine creatinine clearance and 51Cr EDTA clearance (-0.09867), with 95% concordance limits of -36.14 and 34.17, and a non-significant linear regression coefficient (p 0.915). Conclusion This study revealed that the 24-hour urine creatinine clearance is the closest formula to the gold standard for the assessment of the GFR in patients with malignancies. However, the small sample size hinders the generalization of these results. Larger sample size studies are mandatory to confirm these findings.