Utility of cytokeratin 7, S100A1 and caveolin-1 as immunohistochemical biomarkers to differentiate chromophobe renal cell carcinoma from renal oncocytoma

Contemporary Clinical Definitions, Differential Diagnosis, and Novel Predictive Tools for Renal Cell Carcinoma

Despite significant progress regarding clinical detection/imaging evaluation modalities and genetic/molecular characterization of pathogenesis, advanced renal cell carcinoma (RCC) remains an incurable disease and overall RCC mortality has been steadily rising for decades. Concomitantly, clinical definitions have been greatly nuanced and refined. RCCs are currently viewed as a heterogeneous series of cancers, with the same anatomical origin, but fundamentally different metabolisms and clinical behaviors. Thus, RCC pathological diagnosis/subtyping guidelines have become increasingly intricate and cumbersome, routinely requiring ancillary studies, mainly immunohistochemistry. Meanwhile, RCC-associated-antigen targeted systemic therapy has been greatly diversified and emerging, novel clinical applications for RCC immunotherapy have already reported significant survival benefits, at least in the adjuvant setting. Even so, systemically disseminated RCCs still associate very poor clinical outcomes, with currently available therapeutic modalities only being able to prolong survival. In lack of a definitive cure for advanced RCCs, integration of the amounting scientific knowledge regarding RCC pathogenesis into RCC clinical management has been paramount for improving patient outcomes. The current review aims to offer an integrative perspective regarding contemporary RCC clinical definitions, proper RCC clinical work-up at initial diagnosis (semiology and multimodal imaging), RCC pathological evaluation, differential diagnosis/subtyping protocols, and novel clinical tools for RCC screening, risk stratification and therapeutic response prediction.

A triple-classification for differentiating renal oncocytoma from renal cell carcinoma subtypes and CK7 expression evaluation: a radiomics analysis

Background

To investigate the value of computed tomography (CT)-based radiomics model analysis in differentiating renal oncocytoma (RO) from renal cell carcinoma subtypes (chromophobe renal cell carcinoma, clear cell carcinoma) and predicting the expression of Cytokeratin 7 (CK7).

Methods

In this retrospective study, radiomics was applied for patients with RO, chRCC and ccRCC who underwent surgery between January 2013 and December 2019 comprised the training cohort, and the testing cohort was collected between January and October 2020. The corticomedullary (CMP) and nephrographic phases (NP) were manually segmented, and radiomics texture parameters were extracted. Support vector machine was generated from CMP and NP after feature selection. Shapley additive explanations were applied to interpret the radiomics features. A radiomics signature was built using the selected features from the two phases, and the radiomics nomogram was constructed by incorporating the radiomics features and clinical factors. Receiver operating characteristic curve was calculated to evaluate the above models in the two sets. Furthermore, Rad-score was used for correlation analysis with CK7.

Results

A total of 123 patients with RO, chRCC and ccRCC were analyzed in the training cohort and 57 patients in the testing cohort. Subsequently, 396 radiomics features were selected from each phase. The radiomics features combining two phases yielded the highest area under the curve values of 0.941 and 0.935 in the training and testing sets, respectively. The Pearson’s correlation coefficient was statistically significant between Rad-score and CK7.

Conclusion

We proposed a non-invasive and individualized CT-based radiomics nomogram to differentiation among RO, chRCC and ccRCC preoperatively and predict the immunohistochemical protein expression for accurate clinical diagnosis and treatment decision.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-01099-0.

Identification and Validation of an Apoptosis-Related Gene Prognostic Signature for Oral Squamous Cell Carcinoma

To identify an apoptosis-related gene (ARG) prediction model for oral squamous cell carcinoma (OSCC), we analyzed and validated the data from TCGA and GEO, respectively. Kaplan–Meier survival analysis and ROC curves showed a good prognostic ability of the model both in the internal training set and in the external testing set. Furthermore, we built a nomogram using these ARGs to forecast the survival probability of OSCC patients. Moreover, we evaluated the rate of immune cells infiltrating in the tumor samples and found obvious, different patterns between the high and low risk groups. GO and KEGG analyses demonstrated multiple molecular biological processes and signaling pathways connecting with this prognostic model in OSCC. The expression of these risk genes in clinical specimens was higher in the non-survival patients than in the well-survival patients by immunohistochemical staining analysis. In conclusion, we established a signature made up of six risk apoptosis-related genes to predict the survival rate of OSCC. These genes could also be targets for the treatment of OSCC.

S100A1 is a Potential Biomarker for Papillary Thyroid Carcinoma Diagnosis and Prognosis

S100 calcium binding protein A1 (S100A1) is an important member of the S100 family and known to express in a variety of cancers. However, the biological functions of S100A1 in thyroid carcinoma have not been thoroughly studied. In this report, bioinformatics analyses and immunohistochemistry assays were applied to assess the expression profile of S100A1 as well as its relationship with the pathological features and prognosis of papillary thyroid carcinoma (PTC). Meanwhile, functions of S100A1 in PTC cells were analyzed with either in vitro or in vivo experiments. S100A1 was significantly up-regulated in PTC tissues compared with adjacent non-cancerous tissues. S100A1 protein expression was significantly associated with tumor size (p=0.0032) or lymph node metastasis (p=0.0331). More importantly, an elevated S100A1 expression was significantly correlated with a worse recurrence-free survival (RFS) (HR=2.26, p=0.042). Further, knockdown of S100A1 dramatically inhibited cell proliferation and migration as well as increased apoptosis of PTC cells. S100A1 knockdown inhibited tumor progression as seen in in vivo experiments. In terms of mechanism, down-regulation of S100A1 induced yes associated protein (YAP) phosphorylation in the cytoplasm and diminished Hippo/YAP pathway activation. Therefore, S100A1 may serve as a novel oncogene and a promising biomarker for PTC diagnosis and prognosis.

The Role of CK7, S100A1, and CD82 (KAI1) Expression in the Differential Diagnosis of Chromophobe Renal Cell Carcinoma and Renal Oncocytoma

Renal oncocytoma is a benign renal tumor originated from intercalated cells of collecting ducts like chromophobe renal cell carcinoma (RCC). The differential diagnosis of these 2 tumors is important because while they are histologically and cytologically similar, they show different biological behavior. For the differential diagnosis, several immunohistochemical markers have been investigated. But, differential diagnostic challenges remain and the identification of additional markers is needed. Cytokeratin 7 (CK7) is one of ductal-type keratins, which is expressed in tumors of breast, pancreas, lung, thyroid, ovary, endometrium, urinary bladder, and the kidney. S100A1 is the first defined member of the calcium-binding S100 protein family and it organizes several cellular functions including cell cycle progression and cell differentiation.CD82 is a tetraspanin membrane protein, which functions as a metastasis supressor. In this study, we immunohistochemically investigated the expressions of CK7, S100A1, and CD82 in 30 chromophobe RCC (23 classic and 7 eosinophilic variant) and 19 oncocytomas. When these markers were evaluated separately and together, their expressions in chromophobe RCC and renal oncocytoma show statistically significant difference (P<0.001). Similar statistically significant results were also seen between eosinophilic chromophobe RCC and oncocytoma (P<0.001). For both classic and eosinophilic-variant chromophobe RCCs, CK7+/S100A1-/CD82+ profile being the most common. In oncocytomas, the most frequently observed profile was CK7-/S100A1+/CD82-. Our results showed that the application of a panel consisting of CK7, S100A1, and CD82 may provide accurate categorization of the tumors in difficult cases.

Differentiation between renal oncocytomas and chromophobe renal cell carcinomas using dynamic contrast-enhanced computed tomography

PURPOSE

To evaluate the ability of inferior vena cava-lesion-attenuation-difference (ILAD) and lesion-cortex-attenuation-ratio (LCAR) to differentiate renal oncocytomas (RO) from chromophobe renal cell carcinomas (chRCC).

METHODS

Retrospective study with analysis of 84 cases of chRCC and 30 cases of RO confirmed by surgical pathology. ILAD was calculated by measuring the difference in Hounsfield units (HU) between the inferior vena cava and the lesion of interest on the same image slice on preoperative CT scan. Calculating LCAR using the CT attenuation ratio of lesion to renal cortex at the same image slice. Receiver operating characteristic (ROC) curves were plotted to analyze the diagnostic values of ILAD and LCAR for disease activity.

RESULTS

There were no statistically significant differences in demographic and lesion characteristics between patients with chRCC and RO (p > 0.05). ILAD has significant statistical differences in the identification of RO and chRCC in the arterial (p = 0.031), venous (p = 0.047), and delayed phase (p = 0.002). And LCAR showed a statistically significant difference between two lesions during the arterial (p = 0.043), venous (p = 0.026), and delayed phase (p = 0.008). When all significant variables were used in combination to build a predicting model (Mix), the AUC was 0.871 (95% CI 0.759-0.984) with 67.9% sensitivity and 100% specificity.

CONCLUSION

ILAD and LCAR at the arterial phase, venous phase and delayed phase were shown to be useful CT attenuation parameter in discriminating RO from chRCC when histologic evaluation on biopsy is indeterminate.

Low-Grade Oncocytic Tumor of Kidney (CK7-Positive, CD117-Negative): Incidence in a single institutional experience with clinicopathological and molecular characteristics

Low-grade oncocytic tumor of the kidney (LOT) is characterized by cytoplasmic eosinophilia and a CK7-positive/CD117-negative immunophenotype. Morphologically, they exhibit overlapping features with oncocytoma and chromophobe renal cell carcinoma. Our aim was to obtain long-term clinical follow-up data, clinicopathological and molecular characteristics, and incidence of LOT. Tissue microarrays were constructed from 574 tumors historically diagnosed as oncocytoma and surgically treated at Mayo Clinic between 1970 and 2012, and immunostained for CK7 and CD117. An extended immunophenotype was obtained on whole slide sections, along with FISH for CCND1 rearrangement status and chromosomal microarray for copy number status. In addition, two cases were retrospectively identified in a set of tuberous sclerosis complex (TSC)-associated neoplasms and three more cases diagnosed on needle core biopsies were obtained during routine clinical practice. Twenty-four cases of LOT were identified among 574 consecutive tumors diagnosed as oncocytoma and treated with partial or radical nephrectomy, corresponding to an incidence of 4.18% of tumors historically diagnosed as oncocytomas, and 0.35% of 6944 nephrectomies performed between 1970 and 2012. Overall, 29 cases of LOT were identified in three clinical settings: sporadic, TSC-associated, and end-stage renal disease (ESRD). Multifocality was seen only in the setting of TSC and ESRD. No metastases attributable to LOT were identified (median follow-up 9.6 years). There were no recurrent arm level copy number changes detected by chromosomal microarray and all tested cases were negative for CCND1 rearrangement by FISH. LOT is an uncommon eosinophilic renal neoplasm with an indolent prognosis that constitutes ∼4% of tumors historically diagnosed as oncocytoma. The morphologic, immunophenotypic, and molecular features of this neoplasm suggest it is a distinct entity of renal neoplasia.

Cathepsin K (Clone EPR19992) Demonstrates Uniformly Positive Immunoreactivity in Renal Oncocytoma, Chromophobe Renal Cell Carcinoma, and Distal Tubules

Introduction. Cathepsin K is overexpressed in several tumors associated with microphthalmia transcription factor (MiTF) family or mechanistic target of rapamycin (mTOR) upregulation. Among renal neoplasms, MiTF translocation renal cell carcinoma (RCC), perivascular epithelioid cell neoplasms (PEComa), and eosinophilic solid and cystic RCC have demonstrated Cathepsin K immunoreactivity. In this study, we demonstrate a uniform Cathepsin K expression in oncocytoma, chromophobe RCC (CHRCC), and distal tubules. Design. We stained 13 oncocytomas, 13 CHRCC, 14 clear cell RCC (CCRCC), 9 papillary RCC (PRCC), 9 PEComas, and 5 MiTF RCC. Additionally, we assessed immunoreactivity for Cathepsin K in non-neoplastic renal parenchyma. Immunolabeling was performed on regularly charged slides from formalin-fixed paraffin-embedded tissue with monoclonal anti-rabbit antibodies to human Cathepsin K (clone EPR19992, Abcam). Results. All oncocytomas demonstrated diffuse strong cytoplasmic immunolabeling. CHRCC demonstrated uniform less intense immunolabeling in all cases with membranous accentuation. The assessment of the non-neoplastic renal parenchyma in all cases showed strong cytoplasmic immunoreaction in distal tubules and proximal tubules stained faintly. Mesangial cells were not immunoreactive. All MiTF RCC and PEComas were immunoreactive for Cathepsin K, whereas CCRCC and PRCC were negative in all cases. Conclusions. In this study, we expand the spectrum of renal neoplasms reactive with a particular clone of Cathepsin K (EPR19992). Distal tubules are strongly immunoreactive for Cathepsin K. Our conclusions need to be taken into consideration when differential diagnosis includes MiTF RCC or PEComa and this Cathepsin K clone is included in the immunohistochemical panel. This newer antibody clone was not tested in prior publications, potentially explaining the difference in conclusions.