The Correlation of Tissue-Based Biomarkers in Primary and Metastatic Renal Cell Carcinoma Lesions: A Tissue Microarray Study

Abstract

Purpose The study was aimed to determine the correlations of tissue-based biomarker expressions between primary and metastatic specimens of renal cell carcinoma and with several well-known prognostic clinicopathological parameters. Materials and Methods The immunohistochemistry (IHC) was used to determine the expression levels of 9 tissue-based markers calculated in H-score expressed by percentage of expression multiplied by the intensity score (0, 1, 2, and 3 points). Using 17 patients' 38 specimens paired with primary renal lesion and its metastatic lesions collected between 2004 and 2015, Tissue microarray with IHC was performed with BAP1, PBRM1, pS6, PTEN, TGase2, PD-L1, CA9, PSMA, and Ki-67 on formalin-fixed paraffin-embedded sections. Pearson correlation and accuracy test were performed to analyze the correlation between primary and metastatic tissues. Results The 17 patients' mean age was 56.9 years old, mean tumor size was 7.9 cm, and the male to female ratio was 13:4 (76.5%:23.5%), respectively. Three patients had 2, 3, and 3 metastatic tissues, and the rest of 14 patients had only one metastatic tissue. The H-score (PSMA and Ki67) and intensity score (pS6 and PSMA) showed that some differential significant markers were identified which had statistical correlations of expression levels between primary and metastatic lesions among 9 markers. However, no real correlation of PSMA, Ki67, and pS6 markers were found their expressions of between primary and metastatic tissues because of their skewed expressions. Conclusions Tissue markers failed to correlate their expression levels in primary lesions with those of metastatic lesions. Key Words: Renal cell carcinoma; Metastasis; Tissue microarray; Biomarker; Immunohistochemistry.