Cystatin C as a parameter of glomerular filtration rate in patients with ovarian cancer.

Aims: To evaluate the potential role of serum cystatin C as a marker of renal function in patients with ovarian cancer.

Methods: Treatment of consecutive ovarian cancer patients who were eligible for chemotherapy with paclitaxel (135 mg/m²/24 h) and cisplatin (75 mg/m²) every 3 weeks in 6 cycles. Glomerular filtration rate (GFR) markers, i.e. serum levels of creatinine and cystatin C, estimated by the Cockcroft-Gault and Modification of Diet in Renal Disease formulas, were recorded before each cycle and 3 weeks after the 6th course.

Results: The median age of 34 patients was 54 years. In the initial stage of treatment, we did not observe any correlation between cystatin C and other GFR markers. We noted a significant association between cystatin C and tumor extent on spiral CT scans (diameter: >1 cm) performed at baseline (p = 0.004), and after the 1st (p = 0.03) and 2nd cycle (p = 0.026). We observed a correlation between cystatin C and CA-125 level before chemotherapy (R = 0.4; p = 0.02) and after the 1st cycle (R = 0.43; p = 0.04).

Conclusion: The results of our study suggest that cystatin C is not a reliable marker of the GFR in ovarian cancer patients, probably due to its nature as a cysteine protease inhibitor.