Diagnostic Immunocytostaining with Peroxisome Proliferator-Activated Receptor-Gamma in Urine Cytology Samples.

INTRODUCTION: Urine cytology is a common method for detection of urothelial carcinoma (UC), however, is not high sensitivity. Improvement of the accuracy of cytodiagnosis using immunocytostaining as an auxiliary method is needed. This study aimed to determine the cytodiagnostic usefulness of peroxisome proliferator-activated receptor-gamma (PPAR-γ) immunocytostaining in urine cytology for the detection of UCs, particularly low-grade urothelial carcinomas (LGUC). METHODS: PPAR-γ immunocytostaining was performed for 37 UC cases and 26 benign cases. Among the UC cases, 22 cases were of the papillary proliferation type, not including the mixed type comprising both papillary and flat growth. Fifteen LGUC cases of all papillary proliferation types were included. For comparison, the same samples were also immunocytostained for p53 and Ki-67. RESULTS: Of the UC cases, 25 of 37 were positive for PPAR-γ, while 24 of the 26 benign cases were PPAR-γ-negative. Regardless of histological grading, 13 of the 22 UC cases with papillary proliferation were PPAR-γ-positive. In particular, PPAR-γ immunocytostaining showed higher sensitivity for LGUC cases than that of the other biomarkers. Regarding LGUC specifically, 4 of 10 cases not identified by primary cytology were detected by PPAR-γ immunocytostaining. CONCLUSION: PPAR-γ immunocytostaining enhances the accuracy of urine cytodiagnosis. Furthermore, PPAR-γ is a more useful immunobiomarker in urine cytology than p53 and Ki-67, the commonly used immunobiomarkers for malignant cell detection.

Overexpression of the PPAR-γ protein in primary Ta/T1 non-muscle-invasive urothelial carcinoma.

Peroxisome proliferator-activated receptor-γ (PPAR-γ) is a well-known nuclear receptor that is activated in the nucleus to regulate several transcription factors. Its expression patterns have been examined in various types of cancer. The present study investigated the expression patterns of PPAR-γ in non-muscle-invasive urothelial carcinoma. The expression rates of PPAR-γ, p53 and Ki-67 were compared to determine whether PPAR-γ may be considered as an immunobiomarker for bladder cancer. The intensity and extent of PPAR-γ expression were evaluated in 79 cases of non-muscle-invasive urothelial carcinoma (30 cases of papillary carcinoma low-grade, 30 cases of high-grade and 19 cases of carcinoma in situ) and 30 non-malignant cases. The nuclear overexpression of PPAR-γ was frequently observed in non-muscle-invasive urothelial carcinoma (63/79 cases) but was rarely detected in non-malignant cases (2/30 cases). The histological proliferation types of non-muscle-invasive urothelial carcinoma revealed that PPAR-γ was more frequently overexpressed in papillary carcinoma (54/60 cases) than in carcinoma in situ (9/19 cases). Immunohistochemical staining demonstrated that PPAR-γ was more useful as an immunobiomarker than p53 or Ki-67 (diagnostic odds ratios; 55.13, 16.82 and 11.13, respectively). In summary, this study demonstrated that the expression patterns of PPAR-γ were associated with histological proliferation type and that PPAR-γ was expressed in the nuclei of papillary carcinoma cells. These findings suggested that immunohistochemical staining for PPAR-γ may be used to comprehensively detect non-muscle-invasive urothelial carcinoma.

Usefulness of liquid-based cytology in hormone receptor analysis of breast cancer specimens.

Immunohistochemical (IHC) analysis of the hormone receptor (HR) in breast cancer cytology is an important issue nowadays. Several studies have shown discrepancy in the HR status between the primary tumor and metastases. Cytology can be used for patients with metastatic disease. Although cytological assessment of HR is an excellent method, it has not been routinely used because of the difficulty in consistently preparing multiple good quality slides. Liquid-based cytology (LBC) preparation is considered as the key to resolving the aforementioned problem; however, few studies have reported the HR assessment in breast cancer using LBC. Therefore, the HR status of LBC slides from 82 breast cancers was compared with that of the corresponding surgical specimens. The HR assay in both the LBC slides and surgical specimens was conducted by IHC using an autostainer. For the IHC staining, the protocol recommended by the manufacturer for paraffin-embedded sections was used for both the cytology and histology specimens. The HR results of the cytology agreed with those of the histology in 80 of the 82 cases (accuracy rate, 98%) for estrogen receptor, and in 78 of the 82 cases (accuracy rate, 95%) for progesterone receptor. The overall accuracy of the HR status on the cytology and the histology was 99% in 81 of the 82 cases. In conclusion, in HR analysis of breast cancers, LBC followed by IHC using an autostainer was useful for the standard processing of cytological specimens and showed a good correlation with the results of analysis on the histology specimens.