Cystatin C as a predictor factor in patients with renal cell carcinoma treated by everolimus.
BACKGROUND
We evaluated the influence of serum cystatin C (CysC) with respect to other glomerular filtration rate (GFR) markers on the treatment effect of everolimus in a phase II study in patients with metastatic renal cell carcinoma (mRCC).


METHODS
Outcomes were from the study's primary analysis. GFR was calculated according to CKD-EPI-sCr equation, CKD-EPI-CysC equation and CKD-EPI-sCr-CysC equation, Modification of Diet in Renal Disease (MDRD) equation and Cockcroft-Gault (CG) equation, serum levels of creatinine (sCr) and CysC before the treatment.


RESULTS
We observed in 56 patients analysed patients high correlation (R Spearman from ±0.69 to ±1.00; P < 0.0001) between CysC level and GFR markers: sCr, CKD-EPI-sCr, CKD-EPI-CysC, CKD-EPI-sCr-CysC, MDRD, GFR (CG) before everolimus therapy. We observed that the adverse independent predictors for everolimus therapy were increased CysC level [HR: 2.85 (95 % CI 1.34-6.05), P = 0.0065], histologic grade G1/2 [HR: 3.38 (95 % CI 1.59-7.20), P = 0.0016] and increased LDH level [HR: 5.59 (95 % CI 2.52-12.40), P < 0.0001]. Worse OS was seen in multivariate analysis in patients with increased cystatin C level before treatment [HR: 2.60 (1.03-2.60), P = 0.0428], increased corrected calcium level [HR: 2.78 (95 % CI 1.03-7.54), P = 0.0441] and increased LDH level before treatment [HR: 2.34 (95 % CI 1.11-4.97), P = 0.0262].


CONCLUSIONS
Increased serum CysC level in contrast to other studied GFR markers had predictive significance in patients with mRCC.
Department of Oncology, Military Institute of Medicine, 128 Szaserow St., 04-141, Warsaw, Poland. lubo@esculap.pl.
Lubomir
L
Bodnar
Department of Oncology, Military Institute of Medicine, 128 Szaserow St., 04-141, Warsaw, Poland.
Rafał
R
Stec
Department of Laboratory Diagnostics, Military Institute of Medicine, Warsaw, Poland.
Małgorzata
M
Dzierżanowska
Department of Oncology, Military Institute of Medicine, 128 Szaserow St., 04-141, Warsaw, Poland.
Agnieszka
A
Synowiec
Department of Pathology, Military Institute of Medicine, Warsaw, Poland.
Szczepan
S
Cierniak
Department of Nephrology, Military Institute of Medicine, Warsaw, Poland.
Grzegorz
G
Kade
Department of Oncology, Military Institute of Medicine, 128 Szaserow St., 04-141, Warsaw, Poland.
Cezary
C
Szczylik
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002118:Calcium; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000473:pathology; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000378:metabolism*; D000068338:Everolimus / Q000627:therapeutic use*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D055316:Cystatin C; D000068338:Everolimus; D003404:Creatinine; D002118:Calcium
Cystatin C; Glomerular filtration rate; Predictor factor; Renal cell carcinoma