Tumor-to-Tumor Metastases Involving Clear Cell Renal Cell Carcinomas: A Diagnostic Challenge for Pathologists Needing Clinical Correlation.

Tumor-to-tumor metastasis is a rare event which it is specifically up to pathologists to bring to light correctly. The histological identification of such tumor-to-tumor cases is simple when the respective histologies are different but can be problematic if the case includes two carcinomas with similar cytoarchitecture viewed one inside the other under the microscope. We report four cases of this condition in which clear cell renal cell carcinoma is involved, either as a receptor or as a donor, and remark on the difficulties in recognizing some of them. Appropriate clinical-pathological correlation, including a review of the patient's antecedents and radiological exams, would be a great help in routinely identifying tumor-to-tumor metastases.

Cardiac Metastasis From Solid Cancers: A 35-Year Single-Center Autopsy Study.

CONTEXT.­: Cardiac metastases are more prevalent than primary cardiac tumors, and although rare, the incidence is anticipated to increase with the extended survival of oncology patients. OBJECTIVE.­: To estimate the current incidence of cardiac metastasis from solid tumors in adult autopsies. DESIGN.­: Adult autopsy cases from 1984 through 2019 from patients diagnosed with any type of solid cancer were retrieved. The medical charts and pathologic autopsy data were reviewed in detail. RESULTS.­: A total of 1294 adult autopsies performed on patients diagnosed with any type of cancer within the past 35 years were reviewed. We found 124 secondary cardiac tumors. Eighty-five were due to cardiac involvement by solid tumors. Of these, 61 were true cardiac metastases of solid cancers. We focused on these 61 cases. The age range was 32 to 85 years. Forty-four patients were men and 17 were women. The lung was the most common primary site, with 21 cases (34.43%). The most frequent histologic type was carcinoma, with 54 cases (88.52%). The predominant layer of the heart involved was the pericardium, with 35 cases (57.38%). Twenty-one cases (34.43%) had pericardial effusion, with 4 being hemorrhagic. All cases had multiple extracardiac metastases, with 56 cases (91.8%) having distant metastases in 4 or more different organs. CONCLUSIONS.­: Cardiac metastasis is a rare occurrence, with an incidence of 4.71% (61 of 1294 cases) in our series. Lung cancer accounted for most of the cardiac metastases seen, and carcinomas were the most frequent histologic type. The pericardium was the most frequent location. Cardiac metastases occurred most frequently in cases of massive metastatic dissemination.

Transvaginal Ultrasound Versus Magnetic Resonance Imaging for Assessing Myometrial Infiltration in Endometrioid Low Grade Endometrial Cancer: A Prospective Study.

OBJECTIVE: To compare the diagnostic accuracy of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) for assessing myometrial infiltration (MI) in patients with low grade endometrioid endometrial cancer. METHODS: Observational prospective study performed at a single tertiary care center from 2016 to 2020, comprising 156 consecutive patients diagnosed by endometrial sampling as having an endometrioid grade 1/grade 2 endometrial cancer. TVS and MRI were performed prior to surgical staging for assessing MI, which was estimated using subjective examiner's impression and Karlsson's method for both TVS and MRI. During surgery, intraoperative assessment of MI was also performed. Definitive pathological study considered as reference standard. Diagnostic accuracy for ultrasound, MRI, and intraoperative biopsy was estimated and compared. RESULTS: Sensitivity and specificity of TVS for detecting deep MI were 75 and 73.5% for subjective impression and 65 and 70% for Karlsson method, respectively (P = .54). Sensitivity and specificity of MRI for detecting deep MI were 80 and 87% for subjective impression and 70 and 71.3% for Karlsson method. MRI subjective impression showed a significant better specificity than MRI Karlsson method (P = .03). MRI showed better specificity than TVS when subjective impression was considered (P <.05), but not for Karlsson method. Sensitivity and specificity of intraoperative were 75 and 97%, respectively. Intraoperative biopsy showed better specificity than ultrasound and MRI either using examiner's impression or Karlsson method (P <.05). CONCLUSIONS: MRI revealed a significant higher specificity than TVS when assessing deep myometrial infiltration. However, the intraoperative biopsy offers a significant better diagnostic accuracy than preoperative imaging techniques.

Expanding the clinicopathological spectrum of succinate dehydrogenase-deficient renal cell carcinoma with a focus on variant morphologies: a study of 62 new tumors in 59 patients.

Most succinate dehydrogenase (SDH)-deficient renal cell carcinomas (RCCs) demonstrate stereotypical morphology characterized by bland eosinophilic cells with frequent intracytoplasmic inclusions. However, variant morphologic features have been increasingly recognized. We therefore sought to investigate the incidence and characteristics of SDH-deficient RCC with variant morphologies. We studied a multi-institutional cohort of 62 new SDH-deficient RCCs from 59 patients. The median age at presentation was 39 years (range 19-80), with a slight male predominance (M:F = 1.6:1). A relevant family history was reported in 9 patients (15%). Multifocal or bilateral tumors were identified radiologically in 5 patients (8%). Typical morphology was present at least focally in 59 tumors (95%). Variant morphologies were seen in 13 (21%) and included high-grade nuclear features and various combinations of papillary, solid, and tubular architecture. Necrosis was present in 13 tumors, 7 of which showed variant morphology. All 62 tumors demonstrated loss of SDHB expression by immunohistochemistry. None showed loss of SDHA expression. Germline SDH mutations were reported in all 18 patients for whom the results of testing were known. Among patients for whom follow-up data was available, metastatic disease was reported in 9 cases, 8 of whom had necrosis and/or variant morphology in their primary tumor. Three patients died of disease. In conclusion, variant morphologies and high-grade nuclear features occur in a subset of SDH-deficient RCCs and are associated with more aggressive behavior. We therefore recommend grading all SDH-deficient RCCs and emphasize the need for a low threshold for performing SDHB immunohistochemistry in any difficult to classify renal tumor, particularly if occurring at a younger age.

One-Step Nucleic Acid Amplification (OSNA) of Sentinel Lymph Node in Early-Stage Endometrial Cancer: Spanish Multicenter Study (ENDO-OSNA).

The objective of this study was to evaluate the efficacy of one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node (SLN) metastasis compared to standard pathological ultrastaging in patients with early-stage endometrial cancer (EC). A total of 526 SLNs from 191 patients with EC were included in the study, and 379 SLNs (147 patients) were evaluated by both methods, OSNA and standard pathological ultrastaging. The central 1 mm portion of each lymph node was subjected to semi-serial sectioning at 200 µm intervals and examined by hematoxylin-eosin and immunohistochemistry with CK19; the remaining tissue was analyzed by OSNA for CK19 mRNA. The OSNA assay detected metastases in 19.7% of patients (14.9% micrometastasis and 4.8% macrometastasis), whereas pathological ultrastaging detected metastasis in 8.8% of patients (3.4% micrometastasis and 5.4% macrometastasis). Using the established cut-off value for detecting SLN metastasis by OSNA in EC (250 copies/µL), the sensitivity of the OSNA assay was 92%, specificity was 82%, diagnostic accuracy was 83%, and the negative predictive value was 99%. Discordant results between both methods were recorded in 20 patients (13.6%). OSNA resulted in an upstaging in 12 patients (8.2%). OSNA could aid in the identification of patients requiring adjuvant treatment at the time of diagnosis.

Understanding the Molecular Mechanism of miR-877-3p Could Provide Potential Biomarkers and Therapeutic Targets in Squamous Cell Carcinoma of the Cervix.

No therapeutic targets and molecular biomarkers are available in cervical cancer (CC) management. In other cancer types, micro-RNA-877-3p (miR-877-3p) has been associated with events relevant for CC development. Thus, we aimed to determine miR-877-3p role in CC. miR-877-3p levels were examined by quantitative-PCR in 117 cervical lesions and tumors. Effects on CC cell proliferation, migration, and invasion were evaluated upon anti-miR-877-3p transfection. miR-877-3p dependent molecular mechanism was comprehensively explored by proteomics, dual-luciferase reporter assay, western blot, and immunohistochemistry. Cervical tumors expressed higher miR-877-3p levels than benign lesions. miR-877-3p promoted CC cell migration and invasion, at least partly by modulating cytoskeletal protein folding through the chaperonin-containing T-complex protein 1 complex. Notably, miR-877-3p silencing synergized with paclitaxel. Interestingly, miR-877-3p downregulated the levels of an in silico-predicted target, ZNF177, whose expression and subcellular location significantly distinguished high-grade squamous intraepithelial lesions (HSILs) and squamous cell carcinomas of the cervix (SCCCs). Cytoplasmic ZNF177 was significantly associated with worse progression-free survival in SCCC. Our results suggest that: (i) miR-877-3p is a potential therapeutic target whose inhibition improves paclitaxel effects; (ii) the expression and location of its target ZNF177 could be diagnostic biomarkers between HSIL and SCCC; and (iii) cytoplasmic ZNF177 is a poor-prognosis biomarker in SCCC.

Mismatch Repair Deficiency in Ovarian Carcinoma: Frequency, Causes, and Consequences.

Mismatch repair deficiency (MMRD) is involved in the initiation of both hereditary and sporadic tumors. MMRD has been extensively studied in colorectal cancer and endometrial cancer, but not so in other tumors, such as ovarian carcinoma. We have determined the expression of mismatch repair proteins in a large cohort of 502 early-stage epithelial ovarian carcinoma entailing all the 5 main subtypes: high-grade serous carcinoma, endometrioid ovarian carcinoma (EOC), clear cell carcinoma (CCC), mucinous carcinoma, and low-grade serous carcinoma. We studied the association of MMRD with clinicopathologic and immunohistochemical features, including tumor-infiltrating lymphocytes in EOC, the histologic type in which MMRD is most frequent. In addition, MLH1 promoter methylation status and massive parallel sequencing were used to evaluate the proportion of sporadic and Lynch syndrome-associated tumors, and the most frequently mutated genes in MMRD EOCs. MMRD occurred only in endometriosis-associated histologic types, and it was much more frequent in EOC (18%) than in CCC (2%). The most frequent immunohistochemical pattern was loss of MLH1/PMS2, and in this group, 80% of the cases were sporadic and secondary to MLH1 promoter hypermethylation. The presence of somatic mutations in mismatch repair genes was the other mechanism of MMRD in sporadic tumors. In this series, the minimum estimated frequency of Lynch syndrome was 35% and it was due to germline mutations in MLH1, MSH2, and MSH6. ARID1A, PTEN, KTM2B, and PIK3CA were the most common mutated genes in this series. Interestingly, possible actionable mutations in ERRB2 were found in 5 tumors, but no TP53 mutations were detected. MMRD was associated with younger age and increased tumor-infiltrating lymphocytes. Universal screening in EOC and mixed EOC/CCC is recommended for the high frequency of MMRD detected; however, for CCC, additional clinical and pathologic criteria should be evaluated to help select cases for analysis.

Absence of Nuclear p16 Is a Diagnostic and Independent Prognostic Biomarker in Squamous Cell Carcinoma of the Cervix.

The tumor-suppressor protein p16 is paradoxically overexpressed in cervical cancer (CC). Despite its potential as a biomarker, its clinical value and the reasons for its failure in tumor suppression remain unclear. Our purpose was to determine p16 clinical and biological significance in CC. p16 expression pattern was examined by immunohistochemistry in 78 CC cases (high-grade squamous intraepithelial lesions (HSILs) and squamous cell carcinomas of the cervix -SCCCs). CC cell proliferation and invasion were monitored by real-time cell analysis and Transwell® invasion assay, respectively. Cytoplasmic p16 interactors were identified from immunoprecipitated extracts by liquid chromatography-tandem mass spectrometry, and colocalization was confirmed by double-immunofluorescence. We observed that SCCCs showed significantly more cytoplasmic than nuclear p16 expression than HSILs. Importantly, nuclear p16 absence significantly predicted poor outcome in SCCC patients irrespective of other clinical parameters. Moreover, we demonstrated that cytoplasmic p16 interacted with CDK4 and other unreported proteins, such as BANF1, AKAP8 and AGTRAP, which could sequester p16 to avoid nuclear translocation, and then, impair its anti-tumor function. Our results suggest that the absence of nuclear p16 could be a diagnostic biomarker between HSIL and SCCC, and an independent prognostic biomarker in SCCC; and explain why p16 overexpression fails to stop CC growth.

Image-guided brachytherapy in cervical cancer: Experience in the Complejo Hospitalario de Navarra.

PURPOSE: To evaluate dosimetric and clinical findings of MRI-guided HDR brachytherapy (HDR-B) for cervical carcinoma. MATERIAL AND METHODS: All patients had a CT, MRI and pelvic-paraaortic lymphadenectomy. Treatment: pelvic (+/-)para-aortic3D/IMRT radiotherapy (45 Gy), weekly cisplatin and HDR-B and pelvic node/parametrial boost 60 Gy until interstitial brachytherapy was done. Two implants: 2008-2011: 5 fractions of 6 Gy, 2011: 2016, 4 fractions of 7 Gy. MRI/TAC were done in each implant. The following were defined: GTV, CTH-HR, CTV-IR; OAR: rectum, bladder and sigmoid. RESULTS: From 2007 to 2016: 57 patients. Patients: T1b2-T2a: 4p, T2b 41p, T3a: 2p; T3B 8p T4a: 2p; N0: 32p, N1 21p, no lymphadenectomy: 4p. Median follow up: 74.6 m (16-122 m), recurrence: 5p local, 6p node, 9p metastasis and 37p without recurrence.Local control 5 years: 90.1%; Ib2-IIB: 94.8%, III-IVa: 72.2%. (p:0.01). RDFS 5y was 92.5%; IB2-IIB: 93%, III: 85% (p:0.024); for pN0: 100%; pN+ iliac-paraaortic: 71.4% (p: 0.007). MFS 5y was 84.1%. Overall survival (OS) at 5y: 66.6% and the cancer specific survival (CEOS) was 74%. Univariate analysis survival: stage Ib2-II 83% vs. III-IVa 41% (p = 0.001); histology: squamous 78%, adenocarcinoma 59.7% (p: ns); lymph node: N0 85% vs. PA+P- 72%, and PA+P+ 35% (p = 0.010). In relation with: HR-CTV dose > 85 Gy, CEOS: 82.5% vs. 77%, and volume CTV-HR < 30 cc: 81.8% and >30 cc: 67%; p: ns. Acute grade 2-3 toxicity: rectal 15.7%, intestinal 15.7% and vesical 15.5%. CONCLUSION: Use of interstitial HDR-BQ guided by RM increased CTV-HR dose and local control, like EMBRACE results. Nodal boost improves RDFS and perhaps OS.

Recomendaciones para la determinación de biomarcadores en cáncer de ovario epitelial. Consenso nacional de la Sociedad Española de Anatomía Patológica y de la Sociedad Española de Oncología Médica / Recommendations for biomarker testing in epithelial ovarian cancer. A national consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology

Debido a los avances en el conocimiento histológico y molecular del cáncer de ovario, ha sido posible conocer la existencia de 5 subtipos, lo que permite llevar a cabo un enfoque terapéutico más minucioso y un mejor diseño de ensayos clínicos. Cada uno de estos 5subtipos tiene características histológicas específicas y una expresión de biomarcadores propia, así como mutaciones en diferentes genes, algunas de las cuales tienen valor pronóstico y predictivo. CA125 y HE4 son biomarcadores característicos del cáncer de ovario que se utilizan en el diagnóstico y seguimiento de estas enfermedades; sin embargo, en la actualidad, las mutaciones somáticas y germinales en los genes BRCA1 y BRCA2 son los biomarcadores con valor pronóstico y predictivo más importantes en el cáncer de ovario epitelial. En este artículo un grupo de expertos de la Sociedad Española de Oncología Médica y de la Sociedad Española de Anatomía Patológica revisa las características histológicas y moleculares de 5subtipos de cáncer de ovario y describe los biomarcadores y mutaciones más importantes que pueden orientar en el cribado, el diagnóstico y el diseño de estrategias de tratamiento a medida (AU)

Advances in the understanding of the histological and molecular characteristics of ovarian cancer now allow 5subtypes to be identified, leading to a more refined therapeutic approach and improved clinical trials. Each of the subtypes has specific histological features and a particular biomarker expression, as well as mutations in different genes, some of which have prognostic and predictive value. CA125 and HE4 are examples of ovarian cancer biomarkers used in diagnosis and follow-up. Currently, somatic or germinal mutations on BRCA1 and BRCA2 genes are the most important biomarkers in epithelial ovarian cancer, having prognostic and predictive value. In this article, a group of experts from the Spanish Society of Medical Oncology and the Spanish Society of Pathology review the histological and molecular characteristics of the 5subtypes of ovarian cancer and describe the most useful biomarkers and mutations for diagnosis, screening and tailored treatment strategy (AU)

[Recommendations for biomarker testing in epithelial ovarian cancer. A national consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology]. / Recomendaciones para la determinación de biomarcadores en cáncer de ovario epitelial. Consenso nacional de la Sociedad Española de Anatomía Patológica y de la Sociedad Española de Oncología Médica.

Advances in the understanding of the histological and molecular characteristics of ovarian cancer now allow 5subtypes to be identified, leading to a more refined therapeutic approach and improved clinical trials. Each of the subtypes has specific histological features and a particular biomarker expression, as well as mutations in different genes, some of which have prognostic and predictive value. CA125 and HE4 are examples of ovarian cancer biomarkers used in diagnosis and follow-up. Currently, somatic or germinal mutations on BRCA1 and BRCA2 genes are the most important biomarkers in epithelial ovarian cancer, having prognostic and predictive value. In this article, a group of experts from the Spanish Society of Medical Oncology and the Spanish Society of Pathology review the histological and molecular characteristics of the 5subtypes of ovarian cancer and describe the most useful biomarkers and mutations for diagnosis, screening and tailored treatment strategy.

High levels of intratumor heterogeneity characterize the expression of epithelial-mesenchymal transition markers in high-grade clear cell renal cell carcinoma.

Immunohistochemistry is a basic routine in establishing the diagnosis of many tumors. However, immunomarkers are often irregularly distributed across different regions of the same tumor, alternating positive and negative areas without any apparent cause. Full identification of this type of intratumor heterogeneity is crucial for patients since the expression of many markers is linked to the prognosis and/or treatment of some tumors. We have quantified this variability testing 406 tumor samples from eight clear cell renal cell carcinomas using four epithelial-mesenchymal transition markers (vimentin, ZEB-1, ß-catenin, and E-cadherin) and two different sampling protocols. Routine sampling included an amount of 59 samples (average, 7.3 samples/case) and multisite tumor sampling did a total of 347 samples (average, 43.3 samples/case). High variability of immunostaining was detected with E-cadherin and ZEB-1 in all high-grade cases. Irregular patterns of expression were detected in all tumors including all histologically homogeneous low-grade tumors. Multisite tumor sampling protocol detected a significant decreased number of E-cadherin, ß-catenin and ZEB-1 positive samples in high-grade tumors. We conclude that high levels of intratumor heterogeneity characterize the immunohistochemical expression of epithelial-mesenchymal transition markers in high-grade clear cell renal cell carcinomas. Multisite tumor sampling protocol outperforms routine sampling in detecting immunohistochemical intratumor heterogeneity.

Tracking Cancer Evolution Reveals Constrained Routes to Metastases: TRACERx Renal.

Clear-cell renal cell carcinoma (ccRCC) exhibits a broad range of metastatic phenotypes that have not been systematically studied to date. Here, we analyzed 575 primary and 335 metastatic biopsies across 100 patients with metastatic ccRCC, including two cases sampledat post-mortem. Metastatic competence was afforded by chromosome complexity, and we identify 9p loss as a highly selected event driving metastasis and ccRCC-related mortality (p = 0.0014). Distinct patterns of metastatic dissemination were observed, including rapid progression to multiple tissue sites seeded by primary tumors of monoclonal structure. By contrast, we observed attenuated progression in cases characterized by high primary tumor heterogeneity, with metastatic competence acquired gradually and initial progression to solitary metastasis. Finally, we observed early divergence of primitive ancestral clones and protracted latency of up to two decades as a feature of pancreatic metastases.

CD34 immunostaining enhances a distinct pattern of intratumor angiogenesis with prognostic implications in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma is an aggressive neoplasm related to VHL gene inactivation. The molecular events derived from this initial alteration lead to a permanent intracellular pseudo-hypoxic status that stimulates vascular proliferation. The resulting increased intratumor angiogenesis is the target of most modern therapies. Although intratumor angiogenesis has received full attention in the last years, few studies have focused on its potential importance from a strict morphological approach. Intratumor angiogenesis has been analyzed in a retrospective series of clear cell renal cell carcinomas (n = 208) with long-term follow-up (n = 177). Two different patterns of angiogenesis have been highlighted with CD34 at the front of tumor invasion, termed continuous and discontinuous, respectively. The continuous pattern of angiogenesis showed a complete microvascular network surrounding totally tumor nests. Conversely, the discontinuous pattern displayed an incomplete network around tumor nests. The continuous pattern was associated to shorter 5-year (p = 0.00064, hazard ratio = 2.8) and 15-year (p = 0.014, hazard ratio = 1.7) survivals. Cox regression multivariate analysis also showed that the continuous pattern (p = 0.016373) remains a significant variable when considered together with grade (p = 0.001755) and stage (p = 0.000952). These findings support the notion that a continuous CD34+ pattern of intratumor angiogenesis may be useful for pathologists in predicting tumor behavior in clear cell renal cell carcinomas.

Primary Langerhans Cell Histiocytosis of the Vulva: Case Report and Review of the Literature.

Langerhans cell histiocytosis (LCH) of the vulva is rare and even moreso in postmenopausal women. Twenty-six cases of primary vulvar LCH have been described in the current literature, and only 8 cases are in postmenopausal women. We report an additional case of primary vulvar LCH in a 59-yr-old woman with subsequent multiorgan involvement. In this article, we briefly describe the clinical presentation, histopathological findings, and immunohistochemistry results of vulvar LCH. We want to emphasize the importance of recognizing this entity in a woman with vulvar lesions both for the clinician and the pathologist.

Time resolved amplified FRET identifies protein kinase B activation state as a marker for poor prognosis in clear cell renal cell carcinoma.

PURPOSE: Clear cell Renal Cell Carcinomas (ccRCC), the largest group of renal tumours, are resistant to classical therapies. The determination of the functional state of actionable biomarkers for the assessment of these adenocarcinomas is essential. The dysregulation of the oncoprotein, PKB/Akt has been linked with poor prognoses in human cancers. MATERIAL & METHODS: We analysed the status of the PKB/Akt pathway in a representative tumour tissue microarray obtained from the primary tumours and their metastases in 60 ccRCC with long term follow up. We sought to define the evolution of this pathway from the primary tumour to the metastatic event and to know the impact of its functional state in tumour aggressiveness and patient survival. Two-site time resolved amplified FRET (A-FRET) was utilised for assessing the activation state of PKB/Akt and this was compared to conventional immunohistochemistry measurements. RESULTS: Activation state of PKB/Akt in primary tumours defined by A-FRET correlated with poorer overall survival (hazard ratio 0.228; p = 0.002). Whereas, increased protein expression of phosphoPKB/Akt, identified using classical immunohistochemistry, yielded no significant difference (hazard ratio 1.390; p = 0.548). CONCLUSIONS: Quantitative determination of PKB/Akt activation in ccRCC primary tumours alongside other diagnostics tools could prove key in taking oncologists closer to an efficient personalised therapy in ccRCC patients. GENERAL SIGNIFICANCE: The quantitative imaging technology based on Amplified-FRET can rapidly analyse protein activation states and molecular interactions. It could be used for prognosis and assess drug function during the early cycles of chemotherapy. It enables evaluation of clinical efficiency of personalised cancer treatment.

The Expression of Fibroblast Activation Protein in Clear Cell Renal Cell Carcinomas Is Associated with Synchronous Lymph Node Metastases.

Clear cell renal cell carcinoma (CCRCC) is a heterogeneous and complex disease that frequently develops distant metastases. Fibroblast activation protein (FAP) is a serine peptidase the expression of which in cancer-associated fibroblasts has been associated with higher risk of metastases and poor survival. The objective of this study was to evaluate the role of FAP in metastatic CCRCC (mCCRCC). A series of 59 mCCRCC retrospectively collected was included in the study. Metastases developed either synchronous (n = 14) or metachronous to renal disease (n = 45). Tumor specimens were obtained from both primary lesion (n = 59) and metastases (n = 54) and FAP expression was immunohistochemically analyzed. FAP expression in fibroblasts from primary tumors correlated with FAP expression in the corresponding metastatic lesions. Also, primary and metastatic FAP expression was correlated with large tumor diameter (>7cm), high grade (G3/4), high stage (pT3/4), tumor necrosis and sarcomatoid transformation. The expression of FAP in primary tumors and in their metastases was associated both with synchronous metastases and also with metastases to the lymph nodes. FAP expression in the primary tumor was correlated with worse 10-year overall survival. Immunohistochemical detection of FAP in the stromal tumor fibroblasts could be a biomarker of early lymph node metastatic status and therefore could account for the poor prognosis of FAP positive CCRCC.

Multi-site tumor sampling (MSTS) improves the performance of histological detection of intratumor heterogeneity in clear cell renal cell carcinoma (CCRCC).

Current standard-of-care tumor sampling protocols for CCRCC (and other cancers) are not efficient at detecting intratumoural heterogeneity (ITH). We have demonstrated in silico that an alternative protocol, multi-site tumor sampling (MSTS) based upon the divide and conquer (DAC) algorithm, can significantly increase the efficiency of ITH detection without extra costs. Now we test this protocol on routine hematoxylin-eosin (HE) sections in a series of 38 CCRCC cases. MSTS was found to outperform traditional sampling when detecting either high grade (p=0.0136) or granular/eosinophilic cells (p=0.0114). We therefore propose that MSTS should be used in routine clinical practice.

Fibroblast activation protein predicts prognosis in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma is a complex disease with only partial response to therapy and scarce reliable clinical parameters indicative of progression and survival. Fibroblast activation protein expression has been correlated with prognosis in several malignancies but never in renal cancer. We aim to analyze the immunohistochemical expression of fibroblast activation protein in 208 clear cell renal cell carcinomas and to evaluate its impact on the prognosis and survival. A positive cytoplasmic immunostaining of this protein in the stromal fibroblasts associated to cancer cells is associated with large tumor diameter (≥4cm), high-grade (G3/4) tumors, and high-stage (≥pT3) tumors. Fibroblast activation protein-positive cases had significantly shorter survivals after 5 (P=.00015), 10 (P=.0000042), and 15 (P=.000043) years of follow-up, with a hazard ratio of 0.31. Multivariate analysis showed that fibroblast activation protein (P=.00117) was stronger than grade and stage in predicting clinical aggressiveness in clear cell renal cell carcinoma. This study confirms the usefulness of fibroblast activation protein detection in the stromal fibroblast associated to cancer in clear cell renal cell carcinoma and adds a new immunohistochemical marker to predict clinical behavior in these patients.

Snail heterogeneity in clear cell renal cell carcinoma.

BACKGROUND: Intratumor heterogeneity may be responsible of the unpredictable aggressive clinical behavior that some clear cell renal cell carcinomas display. This clinical uncertainty may be caused by insufficient sampling, leaving out of histological analysis foci of high grade tumor areas. Although molecular approaches are providing important information on renal intratumor heterogeneity, a focus on this topic from the practicing pathologist' perspective is still pending. METHODS: Four distant tumor areas of 40 organ-confined clear cell renal cell carcinomas were selected for histopathological and immunohistochemical evaluation. Tumor size, cell type (clear/granular), Fuhrman's grade, Staging, as well as immunostaining with Snail, ZEB1, Twist, Vimentin, E-cadherin, ß-catenin, PTEN, p-Akt, p110α, and SETD2, were analyzed for intratumor heterogeneity using a classification and regression tree algorithm. RESULTS: Cell type and Fuhrman's grade were heterogeneous in 12.5 and 60 % of the tumors, respectively. If cell type was homogeneous (clear cell) then the tumors were low-grade in 88.57 % of cases. Immunostaining heterogeneity was significant in the series and oscillated between 15 % for p110α and 80 % for Snail. When Snail immunostaining was homogeneous the tumor was histologically homogeneous in 100 % of cases. If Snail was heterogeneous, the tumor was heterogeneous in 75 % of the cases. Average tumor diameter was 4.3 cm. Tumors larger than 3.7 cm were heterogeneous for Vimentin immunostaining in 72.5 % of cases. Tumors displaying negative immunostaining for both ZEB1 and Twist were low grade in 100 % of the cases. CONCLUSIONS: Intratumor heterogeneity is a common event in clear cell renal cell carcinoma, which can be monitored by immunohistochemistry in routine practice. Snail seems to be particularly useful in the identification of intratumor heterogeneity. The suitability of current sampling protocols in renal cancer is discussed.