Significant variation of immunohistochemical marker expression in paired primary and metastatic clear cell renal cell carcinomas

Diagnosis of lung adenocarcinoma with clear cell features in pleural effusion: Cytomorphologic features, immunocytochemical studies, and differential diagnosis

Clear cell adenocarcinoma (CCA) of the lungs is no longer referred to as a subtype in recent classifications of lung adenocarcinoma. Like signet ring features, clear cell features are regarded as cytological features rather than histological subtypes. Additionally, in serous fluids, adenocarcinoma metastasis with clear cell features is a diagnostic challenging entity due to other tumors that come to mindfirst during the differential diagnosis. Here we report a case, diagnosed as CCA of lung metastasis in pleural fluid and evaluated its differential diagnosis.

Impact of Preanalytical Factors on the Measurement of Tumor Tissue Biomarkers Using Immunohistochemistry

Analysis of formalin-fixed paraffin-embedded (FFPE) tissue by immunohistochemistry (IHC) is commonplace in clinical and research laboratories. However, reports suggest that IHC results can be compromised by biospecimen preanalytical factors. The National Cancer Institute's Biospecimen Preanalytical Variables Program conducted a systematic study to examine the potential effects of delay to fixation (DTF) and time in fixative (TIF) on IHC using 24 cancer biomarkers. Differences in IHC staining, relative to controls with a DTF of 1 hr, were observed in FFPE kidney tumor specimens after a DTF of ≥2 hr. Reductions in H-score and/or staining intensity were observed for c-MET, p53, PAX2, PAX8, pAKT, and survivin, whereas increases were observed for RCC1, EGFR, and CD10. Prolonged TIF of 72 hr resulted in significantly reduced H-scores of CD44 and c-Met in kidney tumor specimens, compared with controls with 12-hr TIF. An elevated probability of altered staining intensity due to DTF was observed for nine antigens, whereas for prolonged TIF an elevated probability was observed for one antigen. Results reported here and elsewhere across tumor types and antigens support limiting DTF to ≤1 hr when possible and fixing tissues in formalin for 12-24 hr to avoid confounding effects of these preanalytical factors on IHC.

Targeted genomic landscape of metastases compared to primary tumours in clear cell metastatic renal cell carcinoma

Background

The genomic landscape of primary clear cell renal cell carcinoma (ccRCC) has been well described. However, little is known about cohort genomic alterations (GA) landscape in ccRCC metastases, or how it compares to primary tumours in aggregate. The genomic landscape of metastases may have biological, clinical, and therapeutic implications.

Methods

We collected targeted next-generation sequencing mutation calls from two independent cohorts and described the metastases GA landscape and descriptively compared it to the GA landscape in primary tumours.

Results

The cohort 1 (n = 578) consisted of 349 primary tumours and 229 metastases. Overall, the most common mutations in the metastases were VHL (66.8%), PBRM1 (41.87%), and SETD2 (24.7%). TP53 was more frequently mutated in metastases compared to primary tumours (14.85% versus 8.9%; p = 0.031). No other gene had significant difference in the cohort frequency of mutations between the metastases and primary tumours. Mutation burden was not significantly different between the metastases and primary tumours or between metastatic sites. The second cohort (n = 257) consisted of 177 primary tumours and 80 metastases. No differences in frequency of mutations or mutational burden were observed between primaries and metastases.

Conclusions

These data support the theory that ccRCC primary tumours and metastases encompass a uniform distribution of common genomic alterations tested by next-generation sequencing targeted panels. This study does not address variability between matched primary tumours and metastases or the change in genomic alterations over time and after sequential systemic therapies.

Elucidating mechanisms of sunitinib resistance in renal cancer: an integrated pathological-molecular analysis

Upon sunitinib treatment of metastatic renal cell carcinoma patients eventually acquire resistance. Our aim was to investigate microRNAs behind sunitinib resistance.

We developed an in vivo xenograft and an in vitro model and compared morphological, immunhistochemical, transcriptomical and miRNome data changes during sunitinib response and resistance by performing next-generation mRNA and miRNA sequencing. Complex bioinformatics (pathway, BioFunction and network) analysis were performed. Results were validated by in vitro functional assays.

Our morphological, immunhistochemical, transcriptomical and miRNome data all pointed out that during sunitinib resistance tumor cells changed to migratory phenotype. We identified the downregulated miR-1 and miR-663a targeting FRAS1 (Fraser Extracellular Matrix Complex Subunit 1) and MDGA1 (MAM Domain Containing Glycosylphosphatidylinositol Anchor 1) in resistant tumors. We proved firstly miR-1-FRAS1 and miR-663a-MDGA1 interactions. We found that MDGA1 knockdown decreased renal cancer cell migration and proliferation similarly to restoration of levels of miR-1 and miR-663.

Our results support the central role of cell migration as an adaptive mechanism to secure tumor survival behind sunitinib resistance. MDGA1, FRAS1 or the targeting miRNAs can be potential adjuvant therapeutic targets, through inhibition of cancer cell migration, thus eliminating the development of resistance and metastasis.

Immunohistochemistry, carcinomas of unknown primary, and incidence rates

Pathologists use immunohistochemistry is their day-to-day practices to assist in distinguishing site of origin of metastatic carcinomas. Here, the work-up is discussed neuroendocrine carcinomas, squamous cell carcinomas and adenocarcinomas with particular attention to tumor incident rates and predictive values of the best-performing immunohistochemical markers.

Histological heterogeneity in primary and metastatic classic combined hepatocellular-cholangiocarcinoma: a case series

Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare and aggressive primary liver cancer with both hepatocellular and cholangiocellular differentiation. Due to its bi-phenotypic component, cHCC-CC is a heterogeneous tumour and histopathological analysis of metastatic deposits is poorly characterized. In this retrospective study, we describe four patients in whom the histology from resected specimens of both primary and recurrent and/or metastatic tumour was available for comparison and immunohistochemical characterization. Our study shows that recurrent or metastatic deposits replicate the heterogeneity of the primary cHCC-CC, that even originally small foci of divergent differentiation can become predominant later on and that hepatocellular and cholangiocellular components can show different tropism in distant organs. In our experience, the behaviour of recurrent/metastatic cHCC-CC is unpredictable and histological examination is necessary to guide treatment options at present.

The proteomic landscape of renal tumors

INTRODUCTION

Renal cell carcinoma (RCC) is the most fatal of the common urologic cancers, with approximately 35% of patients dying within 5 years following diagnosis. Therefore, there is a need for non-invasive markers that are capable of detecting and determining the severity of small renal masses at an early stage in order to tailor treatment and follow-up. Proteomic studies have proved to be very useful in the study of tumors. Areas covered: In this review, we will detail the current knowledge obtained by the different proteomic approaches, focusing on MS-based strategies, used to investigate RCC biology in order to identify diagnostic, prognostic and predictive biomarkers on tissue, cultured cells and biological fluids. Expert commentary: Currently, no reliable biomarkers or targets for RCC have been translated into the clinical setting. Moreover, despite the efforts of proteomics and other -omics disciplines, only a small number of them have been observed as shared targets between the different analytical platforms and biological specimens. The difficulty to define a specific molecular pattern for RCC and its subtypes highlights a peculiar profile and a heterogeneity that must be taken into account in future studies.

Sulfonamide derivative targeting carbonic anhydrase IX as a nuclear imaging probe for colorectal cancer detection in vivo

Hypoxic microenvironment is a common situation in solid tumors. Carbonic anhydrase IX (CA9) is one of the reliable cellular biomarkers of hypoxia. The role of CA9 in colorectal cancer (CRC) remains to be clarified. CA9 inhibitor such as sulfonamides is known to block CA9 activation and reduce tumor growth consequently. Here, we aimed to investigate the CA9 expression in serum and tumor from different stages of CRC patients and utilize sulfonamide derivative with indium-111 labeling as a probe for CRC nuclear imaging detection in vivo. The serum CA9 was correlated with the tumor CA9 levels in different stages of CRC patients. Hypoxia increased cell viability and CA9 expression in colorectal cancer HCT-15 cells. Sulfonamide derivative 5-(2-aminoethyl)thiophene-2-sulfonamide (ATS) could bind with CA9 in vitro under hypoxia. Moreover, tumor tissues in HCT-15-induced xenograft mice possessed higher hypoxic fluorescence signal as compared with other organs. We also found that the radioisotope signal of indium-111 labeled ATS, which was utilized for CRC detection in HCT-15-induced xenograft mice, was markedly enhanced in tumors as compared with non-ATS control. Taken together, these findings suggest that CA9 is a potential hypoxic CRC biomarker and measurement of serum CA9 can be as a potential tool for diagnosing CA9 expressions in CRC clinical practice. The radioisotope-labeled sulfonamide derivative (ATS) may be useful to apply in CRC patients for nuclear medicine imaging.

Same difference: A pilot study of cyclin D1, bcl-2, AMACR, and ALDH-1 identifies significant differences in expression between primary colon adenocarcinoma and its metastases

Tumor heterogeneity implies the possibility of significantly different expression of key pathways between primary and metastatic clones. Colon adenocarcinoma is one of the few tumors where current practice includes resection of primary and isolated organ metastases simultaneously without neoadjuvant therapy. We performed a pilot study on 28 cases of colon adenocarcinoma resected simultaneously with metastases in patients with no history of neoadjuvant therapy. We assayed matched primary and metastatic tumors from each patient with common diagnostic antibodies to Bcl-2, Cyclin D1, AMACR, and ALDH-1 by immunohistochemistry with semi-quantitative interpretation on archived formalin fixed, paraffin embedded samples. We were powered for large, consistent differences between primary and metastatic expression, and found 21 of 28 had a significant difference in expression of at least one of the four proteins, accounting for multiplicity of testing. Cyclin D1 had significantly more cases with differential metastatic:primary expression than would be expected by chance alone (p-value 0.0043), favoring higher expression in the metastatic sample. Bcl-2 and ALDH-1 had trends in this direction (p-value 0.078 each). Proportionately more cases with significant differences were identified when a liver metastasis was tested. We conclude differences in expression between metastatic and primary colon adenocarcinoma within the same patient exist, and may have therapeutic and biomarker testing consequences.

Are primary renal cell carcinoma and metastases of renal cell carcinoma the same cancer?

Metastasis is a process consisting of cells spreading from the primary site of the cancer to distant parts of the body. Our understanding of this spread is limited and molecular mechanisms causing particular characteristics of metastasis are still unknown. There is some evidence that primary renal cell carcinoma (RCC) and metastases of RCC exhibit molecular differences that may effect on the biological characteristics of the tumor. Some authors have detected differences in clear cell and nonclear cell component between these 2 groups of tumors. Investigators have also determined that primary RCC and metastases of RCC diverge in their range of renal-specific markers and other protein expression, gene expression pattern, and microRNA expression. There are also certain proteins that are variously expressed in primary RCCs and their metastases and have effect on clinical outcome, e.g., endothelin receptor type B, phos-S6, and CD44. However, further studies are needed on large cohorts of patients to identify differences representing promising targets for prognostic purposes predicting disease-free survival and the metastatic burden of a patient as well as their suitability as potential therapeutic targets. To sum up, in this review we have attempted to summarize studies connected with differences between primary RCC and its metastases and their influence on the biological characteristics of renal cancer.

Metastatic carcinoma of unknown primary: diagnostic approach using immunohistochemistry

Carcinoma of unknown primary origin (CUP) is one of the 10 most prevalent malignancies. CUP patients in whom a site of origin can be ascribed have better outcomes than those in which the primary tumor remains unidentified. Among the tools available to pathologists in approaching these lesions, immunohistochemistry is a reliable, inexpensive, and widely available resource. New markers continue to emerge, which, in combination with other historically useful antibodies, allow rapid and accurate identification of primary site in an increasing number of cases. This review discusses the approach to the diagnosis of CUP using immunohistochemistry and outlines some of the most useful markers with a particular focus on the utility of lineage-restricted transcription factors, including CDX2, NKX3-1, PAX8, SATB2, TTF-1, and SF1.

The lung-restricted marker napsin A is highly expressed in clear cell carcinomas of the ovary

OBJECTIVES

We recently observed expression of the "lung" marker napsin A in ovarian clear cell carcinomas and therefore sought to determine the extent of napsin A expression in a subset of ovarian neoplasms.

METHODS

We identified an archival series of ovarian clear cell carcinomas (n = 36), serous borderline tumors (n = 21), high-grade serous carcinomas (n = 37), and endometrioid adenocarcinomas (n = 29). Using standard immunohistochemical techniques on whole sections of formalin-fixed, paraffin-embedded specimens, we employed a panel of antibodies: napsin A (IP64), estrogen receptor (SP1), WT-1 (6F-H2), PAX-8 (BC12), and TTF-1 (SPT24).

RESULTS

Thirty-six of 36 clear cell carcinomas showed napsin A expression, typically in a uniform pattern. None of the serous borderline tumors or high-grade serous carcinomas manifested napsin A expression. Napsin A was expressed in three (10%) of 29 endometrioid adenocarcinomas, generally in a focal pattern.

CONCLUSIONS

Our study showed that napsin A is an extremely sensitive (100%) marker of ovarian clear cell carcinomas and exhibits very high specificity (100%) in distinguishing clear cell carcinomas from high-grade serous carcinomas and serous borderline tumors and 90% specificity in discriminating clear cell carcinomas from endometrioid carcinomas.

PAX-8 expression in renal tumours and distant sites: a useful marker of primary and metastatic renal cell carcinoma?

AIMS

Immunohistochemical stains have greatly improved the diagnostic accuracy of renal cell carcinoma (RCC) for primary and distant tumours. We evaluate a marker that has recently been incorporated in clinical practice, PAX-8, in primary and metastatic RCCs.

METHODS

Two distinct tissue microarrays were used, one consisting of over 334 renal tumours, 294 with adjacent normal kidney and the other with 40 matched nephrectomy and metastatic sites of RCC. PAX-8 expression was assessed by a method of quantitative immunofluorescence.

RESULTS

PAX-8 was positive in 96% (146/152) of normal renal tissue and 83% (227/272) of renal tumours. PAX-8 staining was positive in clear cell, papillary and chromophobe tumours in 80% (165/207), 95% (39/41) and 100% (6/6) of samples, respectively. Overall, intensity of PAX-8 expression was significantly higher in RCC metastatic sites than in the primary site (p=0.0047), however, in matched sites there was no statistically significant difference in the proportion of positive versus negative specimens (p=0.274).

CONCLUSIONS

As the role of molecular markers expands in the diagnostic algorithm, this study confirms that PAX-8 expression is a useful diagnostic marker for RCC. PAX-8 expression was found in the primary tumour and distant sites. Compared with normal tissue and other histological types, clear cell RCC has lower PAX-8 expression and is less frequently positive, therefore, the lack of expression does not exclude a tumour of renal origin.

The urinary proteome and peptidome of renal cell carcinoma patients: a comparison of different techniques

Renal cell carcinomas, originating from the renal cortex, account for about 80% of kidney primary malignancies. Small localized tumors rarely produce symptoms and diagnosis is often delayed until the disease is advanced. In contrast to other urological cancers, renal cell carcinomas are associated with a high degree of metastases and a low 5-year survival rate. The identification of diagnostic and prognostic markers, especially in the urine, remains an area of intense investigation. Different proteomic strategies have been applied so far to biomarker discovery in urine at the proteome or the peptidome level. Gel-based and gel-free strategies combined with mass spectrometry are the most-used strategies, have different success rates, and will be depicted here. We also prefigure a scenario in which the limitations of a single approach are overcome by applying new and complementary research strategies, relying on the excellent availability coupled to the intrinsic richness typical of urine samples.

Ocular Metastatic Renal Carcinoma Presenting With Proptosis

Metastatic renal carcinoma is the third most common source of ocular and second most common source of orbital metastases. This is the first published case of von Hippel-Lindau (vHL) disease that developed renal cell carcinoma metastatic to an eye with a retinal hemangioblastoma. A 73-year-old woman had a history of vHL disease that included prior retinal hemangioblastomas, 2 cerebellar hemangioblastomas, and bilateral renal cell carcinomas with sacral metastasis. After presenting with progressive, painful proptosis secondary to a large mass observable by ocular CT, an enucleation-orbitotomy was performed, and the surgical specimen was sent for histopathological analysis. The ophthalmic renal metastatic tumor, like the primary tumor, was a clear cell variant that involved both the eyeball and orbit in continuity. The intraocular component was larger than the extraocular portion, which was interpreted as an outward extension of an initial retinal metastasis that probably first settled within a hemangioblastoma. Clusters of ectatic ghost vessels with thickened walls produced by periodic acid Schiff-positive, redundant basement membrane material were partially infiltrated by tumor cells at their periphery, thereby lending some support for this hypothesis. Immunohistochemical positivity for the biomarkers cytokeratin 18, vimentin, carbonic anhydrase IX, PAX2, and PAX 8 confirmed the diagnosis. The patient has refused further treatment. Her anophthalmic socket has comfortably retained a porous polyethylene implant without clinical evidence of local recurrence during 5 months of follow up.