Loss of caspase 7 expression is associated with poor prognosis in renal cell carcinoma clear cell subtype.

OBJECTIVE

To investigate the expression of CASP7 protein in renal cell carcinoma clear cell subtype (ccRCC) and its value to predict cancer-specific survival (CSS).

METHODS

A tissue microarray containing 120 samples of ccRCC, 45 non-ccRCC, and 66 nontumor paired samples from patients who underwent partial or radical nephrectomy was hybridized with anti-CASP7 antibody. Tissue sections were scored according to intensity and the percentage of stained cells. CASP7 immunostaining scores were used to estimate the association with clinicopathologic parameters and calculate Kaplan-Meier survival curves.

RESULTS

Reduced CASP7 expression was observed in ccRCC and non-ccRCC subtypes in comparison with nontumor renal tissues (P <.0001). CASP7 immunostaining was associated (P <.05) with clinicopathologic parameters (size, incidental tumor, clinical stage, renal vein invasion, and tumor necrosis) and correlated with CSS (P = .032) and global survival (P = .046) of patients with ccRCC. In addition, CASP7 expression was able to substratify patients with ccRCC with favorable prognosis according to low clinical stage, in which negative CASP7 staining was associated with patients with lower CSS (P = .045). Finally, CASP7 staining was able to provide significant stratification according to CSS (P = .018) among patients with ccRCC with disease relapse.

CONCLUSION

Our results implicate the loss of CASP7 expression in the aggressiveness of ccRCC and indicate its potential use as a clinical prognostic marker of the disease.