The applicability of estimated glomerular filtration rate prediction equations in patients with renal cell carcinoma and analysis of related factors

Objective To evaluate the applicability of several estimated glomerular filtration rate (eGFR) prediction equations in patients with renal cell carcinoma, and analyze the related factors. Methods A total of 132 patients with renal cell carcinoma were collected in the Department of Urology of the First Affiliated Hospital of Bengbu Medical College from January 2017 to December 2018. Serum creatinine, age, sex, body mass index(BMI), complications and T stage were recorded before operation. Base on the standard result by dectecting exogenous radioactive marker technetium-99m diethylenetriamine penta-acetic acid (99mTc-DTPA), the following eight equations were evaluated with Bland-Altman analysis: modified MDRD-1, modified MDRD-2, CKD-EPI equation, combined SCr and cystatin C equation, Cockcroft-Gault (CG) equation, cystatin C-based equation 1, cystatin C-based equation 2 and simplified MDRD equation. And the influencing factors on these eight equations were analyzed by univariate analysis. Results Compared with the 95% consistency analysis of the eight formulas based on rGFR, the two formulas related to cystatin C underestimated the actual level of GFR, and the other six formulas overestimated the actual level of GFR in different ranges. The three formulas with smaller deviation were CKD-EPI(7.74), combined creatinine cystatin(7.87) and modified MDRD-1(7.98). The three formulas with the lowest percentage out of boundaries were improved MDRD-2(1.98%), improved MDRD-1(2.48%) and C-G formulas(2.97%). The formula with the greatest deviation was improved MDRD-2(22.22). The effects of sex, age, BMI, T stage and complications on the predictive formula were analyzed by univariate analysis. The results showed that there was no significant difference in the results of the eight methods in different sex, BMI and T stages of renal cancer patients(all P values>0.05). Except for cystatin C-1 and cystatin C-2, the results of the other six methods were different in different age groups. The eGFR value decreased with the increase of age, and the difference was statistically significant (all P values<0.05). Similar to the results, except for cystatin C-1 and cystatin C-2, the results of the other six calculation methods in the patients with complications were significantly lower than those in the patients without complications, and the difference was statistically significant (all P values<0.05). Conclusions CKD-EPI, creatinine cystatin and modified MDRD-1 are better for evaluating the applicability of renal cancer patients. The factors affecting the accuracy of eGFR are various. The age of patients and the presence of complications have a greater impact on the consistency of the prediction formula. Key words: Kidney function tests; Glomerular filtration rate; Prediction equation; Renal cell carcinoma; Applicability