Development and Independent Validation of a Prognostic Gene Expression Signature Based on RB1, PTEN, and TP53 in Metastatic Hormone-sensitive Prostate Cancer Patients.

BACKGROUND: Androgen deprivation therapy (ADT) with docetaxel (D) and/or antiandrogen receptor therapies (ARTs) are the standard therapies in metastatic hormone-sensitive prostate cancer (mHSPC). Alterations in the tumor suppressor genes (TSGs) RB1, PTEN, and TP53 are associated with an aggressive evolution and treatment resistance in castration-resistant prostate cancer (CRPC). OBJECTIVE: To study the clinical implications of TSG mRNA expression in mHSPC patients. DESIGN, SETTING, AND PARTICIPANTS: This is a multicenter retrospective biomarker study in mHSPC patients. TSGlow status was defined when two or more out of the three TSGs presented low RNA expression by nCounter in formalin-fixed paraffin-embedded samples and TSGwt for the remaining cases. The microarray data from the CHAARTED trial were analyzed as an independent validation cohort. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Molecular data were correlated with CRPC-free survival (CRPC-FS) and overall survival (OS) by the Kaplan-Meier method and multivariate Cox analysis. RESULTS AND LIMITATIONS: A total of 226 patients were included, of whom 218 were eligible: 93 were treated with ADT and 125 with ADT + D; 75.7% presented de novo stage IV and 67.9% high-volume disease. TSGlow (19.2%) was independently correlated with shorter CRPC-FS (hazard ratio [HR] 1.8, p = 0.002) and OS (HR 2, p = 0.002). In the CHAARTED trial, TSGlow was independently correlated with lower CRPC-FS (HR 2.2, p = 0.02); no differences in clinical outcomes according to treatment were observed in TSGlow patients, while a significant benefit was observed for ADT + D in the TSGwt group for CRPC-FS (HR 0.4, p < 0.001) and OS (HR 0.4, p = 0.001). However, no interaction was observed between TSG signature and treatment in either series. Study limitations are the retrospective design, small sample size, and lack of inclusion of patients treated with ADT + ART. CONCLUSIONS: TSGlow expression correlates with adverse outcomes in patients with mHSPC. The investigation of new therapeutic strategies in these patients is warranted. PATIENT SUMMARY: The low RNA expression of tumor suppressor genes in the tumors is correlated with adverse outcomes in patients with metastatic hormone-sensitive prostate cancer.

Aspectos prácticos sobre la determinación de PD-L1 en el tratamiento de carcinoma urotelial. Consenso del grupo de uropatología de la SEAP / Practical aspects of PD-L1 assessment in the treatment of urothelial carcinoma: Consensus of the uropathology group of the SEAP

La reciente llegada de nuevos fármacos de inmunoterapia para el tratamiento del carcinoma urotelial hace necesario establecer criterios para armonizar la determinación de PD-L1 mediante inmunohistoquímica como factor pronóstico y para la selección de pacientes a tratar. En este escenario, un grupo de uropatólogos de la Sociedad Española de Anatomía Patológica, junto con un oncólogo médico como colaborador externo subespecializado en urooncología, ha elaborado este documento de recomendaciones basadas en la evidencia disponible. En la determinación de PD-L1 son especialmente relevantes la selección de la muestra analizada, su procesamiento, la plataforma de inmunohistoquímica y anticuerpo empleados, así como el algoritmo que se aplique para la lectura. Todos estos aspectos deben indicarse en el informe de resultados, que debería poder ser fácilmente interpretable en un contexto de rápida evolución de terapias inmunológicas.(AU)

The recent addition of novel immunotherapy drugs for the treatment of urothelial carcinoma makes it necessary the establishment of criteria to harmonize the immunohistochemical assessment of PD-L1, both as a prognostic factor and for the selection of patients to be treated. In this scenario, a group of uropathologists from the Spanish Society of Pathological Anatomy, together with a medical oncologist as an external collaborator subspecialized in uro-oncology, have prepared this document of recommendations based on the available evidence. During PD-L1 assessment it is especially relevant the selection of the sample, its processing, the immunohistochemical platform and antibody used, and the algorithm applied in the interpretation of results. All these aspects must be indicated in the results report, which should be easily interpretable in a context of rapid evolution of immunological therapies.(AU)

[Practical aspects of PD-L1 assessment in the treatment of urothelial carcinoma: Consensus of the uropathology group of the SEAP]. / Aspectos prácticos sobre la determinación de PD-L1 en el tratamiento de carcinoma urotelial. Consenso del grupo de uropatología de la SEAP.

The recent addition of novel immunotherapy drugs for the treatment of urothelial carcinoma makes it necessary the establishment of criteria to harmonize the immunohistochemical assessment of PD-L1, both as a prognostic factor and for the selection of patients to be treated. In this scenario, a group of uropathologists from the Spanish Society of Pathological Anatomy, together with a medical oncologist as an external collaborator subspecialized in uro-oncology, have prepared this document of recommendations based on the available evidence. During PD-L1 assessment it is especially relevant the selection of the sample, its processing, the immunohistochemical platform and antibody used, and the algorithm applied in the interpretation of results. All these aspects must be indicated in the results report, which should be easily interpretable in a context of rapid evolution of immunological therapies.

P53 in Penile Squamous Cell Carcinoma: A Pattern-Based Immunohistochemical Framework with Molecular Correlation.

p53 immunohistochemistry (IHC) has been proposed as a surrogate for TP53 mutations in penile squamous cell carcinomas (PSCC). We aimed to evaluate the performance of a pattern-based evaluation of p53 IHC in PSCC. Human papilloma virus (HPV) DNA testing, p16 and p53 IHC, and whole exome sequencing were performed in a series of 40 PSCC. p53 IHC was evaluated following a pattern-based framework and conventional p53 IHC evaluation. Out of 40 PSCC, 12 (30.0%) were HPV-associated, and 28 (70.0%) were HPV-independent. The agreement between the p53 IHC pattern-based evaluation and TP53 mutational status was almost perfect (k = 0.85). The sensitivity and accuracy of the pattern-based framework for identifying TP53 mutations were 95.5% and 92.5%, respectively, which were higher than the values of conventional p53 IHC interpretation (54.5% and 70.0%, respectively), whereas the specificity was the same (88.9%). In conclusions, the pattern-based framework improves the accuracy of detecting TP53 mutations in PSCC compared to the classical p53 IHC evaluation.

Differential etiopathogenic features of vulvar squamous cell carcinomas in sub-Saharan Africa and Europe.

Two pathways have been described for vulvar squamous cell carcinomas (VSCC), one associated with human papillomavirus (HPV), and the other HPV-independent. We compared the etiopathogenic features of a series of VSCC from Mozambique, a sub-Saharan country with high prevalence of HPV and HIV, with those of Spain, a European country with low prevalence of HPV and HIV. All VSCC diagnosed at the two institutions from January 2018 to December 2020 were included (n = 35 and n = 41, respectively). HPV DNA detection and genotyping, and immunohistochemistry for p16 and p53 were performed. Tumors showing p16 positive staining and/or HPV DNA positivity were considered HPV-associated. 34/35 tumors (97%) from Mozambique and 8/41 (19%) from Spain were HPV-associated (P < .001). Mean age of the patients from Mozambique and Spain was 45 ± 12 and 72 ± 14, respectively (P < .001). No differences were found in terms of HPV genotypes or multiple HPV infection rates. 1/35 tumors (3%) from Mozambique and 29/41 (70%) from Spain showed abnormal p53 immunostaining (P < .001). In contrast with the predominance of HPV-independent VSCC affecting old women in Europe, most VSCC in sub-Saharan Africa are HPV-associated and arise in young women. This data may have important consequences for primary prevention of VSCC worldwide.

Penile Squamous Cell Carcinomas in Sub-Saharan Africa and Europe: Differential Etiopathogenesis.

Penile squamous cell carcinomas (PSCC) are classified by the World Health Organization into two categories based on their relationship with the human papillomavirus (HPV): HPV-associated and HPV-independent. We compared a cohort of PSCC from Mozambique, a sub-Saharan country in southeast Africa with a high prevalence of HPV and HIV infection, and Spain, a country in southwestern Europe with a low prevalence of HPV and HIV, to study the distribution of the etiopathogenic categories of these tumors in both sites. A total of 79 PSCC were included in the study (28 from Mozambique and 51 from Spain). All cases underwent HPV-DNA polymerase chain reaction (PCR) testing, genotyping, and immunohistochemistry for p16 and p53. Any PSCC showing either p16 overexpression or HPV-DNA in PCR analysis was considered HPV-associated. Overall, 40/79 (50.6%) tumors were classified as HPV-associated and 39 (49.4%) as HPV-independent. The two sites showed marked differences: 25/28 (89.3%) tumors from Mozambique and only 15/51 (29.4%) from Spain were HPV-associated (p < 0.001). HPV16 was the most frequent HPV type identified in 64.0% (16/25) of the HPV-associated tumors from Mozambique, and 60.0% (9/15) from Spain (p = 0.8). On average, patients from Mozambique were almost two decades younger than those from Spain (mean age 50.9 ± 14.9 and 69.2 ± 13.3, respectively [p < 0.001]). In conclusion, significant etiopathogenic differences between PSCC in Mozambique and Spain were observed, with a remarkably high prevalence of HPV-associated tumors in Mozambique and a relatively low prevalence in Spain. These data may have important consequences for primary prevention of PSCC worldwide.

HPV-negative Penile Intraepithelial Neoplasia (PeIN) With Basaloid Features.

Most human papillomavirus (HPV)-independent penile squamous cell carcinomas (PSCCs) originate from an intraepithelial precursor called differentiated penile intraepithelial neoplasia, characterized by atypia limited to the basal layer with marked superficial maturation. Previous studies in vulvar cancer, which has a similar dual etiopathogenesis, have shown that about one fifth of HPV-independent precursors are morphologically indistinguishable from high-grade squamous intraepithelial lesions (HSILs), the precursor of HPV-asssociated carcinomas. However, such lesions have not been described in PSCC. From 2000 to 2021, 55 surgical specimens of PSCC were identified. In all cases, thorough morphologic evaluation, HPV DNA detection, and p16, p53, and Ki-67 immunohistochemical (IHC) staining was performed. HPV-independent status was assigned based on both negative results for p16 IHC and HPV DNA. Thirty-six of the 55 PSCC (65%) were HPV-independent. An intraepithelial precursor was identified in 26/36 cases (72%). Five of them (19%) had basaloid features, morphologically indistinguishable from HPV-associated HSIL. The median age of the 5 patients was 74 years (range: 67 to 83 y). All 5 cases were p16 and DNA HPV-negative. Immunohistochemically, 3 cases showed an abnormal p53 pattern, and 2 showed wild-type p53 staining. The associated invasive carcinoma was basaloid in 4 cases and the usual (keratinizing) type in 1. In conclusion, a small proportion of HPV-independent PSCC may arise on adjacent intraepithelial lesions morphologically identical to HPV-associated HSIL. This unusual histologic pattern has not been previously characterized in detail in PSCC. p16 IHC is a valuable tool to identify these lesions and differentiate them from HPV-associated HSIL.

Molecular Landscape of Vulvar Squamous Cell Carcinoma.

Vulvar squamous cell carcinoma (VSCC) is a rare malignancy with dual pathogenesis, Human papillomavirus (HPV)-associated and HPV-independent, with a poorly explored molecular landscape. We aimed to summarize the findings of the series analyzing molecular hallmarks of this neoplasm. In January 2021, we conducted a comprehensive literature search using Pubmed Medline and Scopus to identify publications focused on genomic profiling of VSCC. Observational studies, including both prospective and retrospective designs, evaluating molecular alterations in VSCC were deemed eligible. A total of 14 studies analyzing 749 VSCC were identified. The study series were heterogeneous in HPV testing and sequencing strategies, included small sets of tumors and cancer genes, and commonly lacked survival analysis. Only one extensive targeted next-generation sequencing-based study comprised a large cohort of 280 VSCC. The mutated genes, their number, and frequencies were highly variable between the series. Overall, TP53 and CDKN2A, followed by PIK3CA, HRAS, and PTEN, were the most frequently studied and mutated genes. Mutations involved in the PI3K/AKT/mTOR pathway, including TP53, HRAS, KRAS, and PIK3CA, have been consistently reported across the studies. However, the role of individual mutations or pathways in the development of VSCC remains unclear. In conclusion, heterogeneity and the small sample size of available molecular series contribute to a limited view of the molecular landscape of VSCC. Large-scale genome- or exome-wide studies with robust HPV testing are necessary to improve the molecular characterization of VSCC.

Pathogenesis of Penile Squamous Cell Carcinoma: Molecular Update and Systematic Review.

Penile squamous cell carcinoma (PSCC) is a rare but aggressive neoplasm with dual pathogenesis (human papillomavirus (HPV)-associated and HPV-independent). The development of targeted treatment is hindered by poor knowledge of the molecular landscape of PSCC. We performed a thorough review of genetic alterations of PSCC focused on somatic mutations and/or copy number alterations. A total of seven articles have been identified which, overall, include 268 PSCC. However, the series are heterogeneous regarding methodologies employed for DNA sequencing and HPV detection together with HPV prevalence, and include, in general, a limited number of cases, which results in markedly different findings. Reported top-ranked mutations involve TP53, CDKN2A, FAT1, NOTCH-1 and PIK3CA. Numerical alterations involve gains in MYC and EGFR, as well as amplifications in HPV integration loci. A few genes including TP53, CDKN2A, PIK3CA and CCND1 harbor both somatic mutations and copy number alterations. Notch, RTK-RAS and Hippo pathways are frequently deregulated. Nevertheless, the relevance of the identified alterations, their role in signaling pathways or their association with HPV status remain elusive. Combined targeting of different pathways might represent a valid therapeutic approach in PSCC. This work calls for large-scale sequencing studies with robust HPV testing to improve the genomic understanding of PSCC.

Complete Loss of EPCAM Immunoexpression Identifies EPCAM Deletion Carriers in MSH2-Negative Colorectal Neoplasia.

The use of epithelial cell adhesion molecule (EPCAM) immunohistochemistry (IHC) is not included in the colorectal cancer (CRC) screening algorithm to detect Lynch syndrome (LS) patients. The aim of the present study was to demonstrate that EPCAM IHC is a useful tool to guide the LS germ-line analysis when a loss of MSH2 expression was present. We retrospectively studied MSH2 and EPCAM IHC in a large series of 190 lesions composed of malignant neoplasms (102), precursor lesions of gastrointestinal (71) and extra-gastrointestinal origin (9), and benign neoplasms (8) from different organs of 71 patients suspicious of being LS due to MSH2 alterations. LS was confirmed in 68 patients, 53 with MSH2 mutations and 15 with EPCAM 3'-end deletions. Tissue microarrays were constructed with human normal tissues and their malignant counterparts to assist in the evaluation of EPCAM staining. Among 154 MSH2-negative lesions, 17 were EPCAM-negative, including 10 CRC and 7 colorectal polyps, and 5 of them showed only isolated negative glands. All lesions showing a lack of EPCAM expression belonged to patients with EPCAM 3'-end deletions. EPCAM IHC is a useful screening tool, with 100% specificity to identify LS patients due to EPCAM 3'-end deletions in MSH2-negative CRC and MSH2-negative colorectal polyps.

Correlation of mRNA-PCA3 urine levels with the new grading system in prostate cancer / Correlación de mRNA-PCA3 en orina con el nuevo sistema de gradación de cáncer de próstata

Purpose: To evaluate the PCA3 (Prostate Cancer 3 gene) as a tool to improve prostate cancer (PCa) screening and its capability to predict PCa aggressiveness. Patients and methods: A retrospective study with data from consecutive patients with suspected PCa seen in the urology department between November 2009 and April 2016 and who were candidates for prostate biopsy. A total of 1038 urine samples were tested in our laboratory with a kit that generated a PCA3 score (s-PCA3). A prostate biopsy was recommended only in those patients with s-PCA3≥35. Associations between variables were analyzed using the R software. Results: In patients with a positive s-PCA3 (44.5%), a subsequent biopsy was recommended. Of a total of 151 biopsies studied, 56.3% yielded a diagnosis of PCa. The probability of a positive biopsy increased as the s-PCA3 increased (p=0.041). The percentage of affected cylinders increased as the s-PCA3 increased (p=0.015). A statistically significant relationship was observed between s-PCA3 and both the Gleason score and the Grade Group (p=0.001 and 0.008, respectively). The best log-linear models and a logistic model confirmed the relationships shown previously with Fisher's exact tests. Conclusions: S-PCA3 may serve as an additional marker to reduce the indication for biopsies and avoid overdiagnosis and overtreatment of patients with suspected PCa. The prognostic significance of s-PCA3 was confirmed, as it was associated with tumor volume and Gleason score. Importantly, to our knowledge this is the first time that an association has been demonstrated between s-PCA3 and the new Grade Group

Objetivo: Evaluar el estudio de PCA3 (gen Prostate Cancer 3) en orina como test complementario para mejorar el cribado de cáncer de próstata (CaP), así como su capacidad de predecir la agresividad tumoral antes de la biopsia. Pacientes y métodos: En este estudio retrospectivo se incluyeron pacientes consecutivos con sospecha de CaP y candidatos a biopsia, que se presentaron en la consulta del urólogo entre noviembre de 2009 y abril de 2016. Se testaron en nuestro laboratorio un total de 1.038 muestras de orina con un kit que generó un PCA3 score (s-PCA3). Se recomendó la biopsia en aquellos pacientes con s-PCA3≥35. Las asociaciones entre variables se analizaron con el software R. Resultados: En los pacientes con s-PCA3 positivo (44,5%) se recomendó la realización de una biopsia. Se estudiaron un total de 151 biopsias de las que un 56,3% fueron diagnosticadas de CaP. La probabilidad de obtener una biopsia positiva aumentó a medida que lo hacia el s-PCA3 (p=0,041). El porcentaje de cilindros afectados aumentó a medida que lo hacía el s-PCA3 (p=0,015). El s-PCA3 presentó una relación estadísticamente significativa con el grado de Gleason (p=0,001) y el grado grupo (p=0,008). El mejor modelo Log-lineal, así como el modelo logístico confirmaron las relaciones observadas previamente con las pruebas exactas de Fisher. Conclusiones: El s-PCA3 es una herramienta complementaria que permite reducir la indicación de biopsias y evitar el sobrediagnóstico y sobretratamiento de pacientes con sospecha de CaP. La significación pronóstica del s-PCA3 fue confirmada al demostrarse su asociación con el volumen tumoral y el grado de Gleason. Según la información de la que disponemos, este es el primer estudio en el que se demuestra la asociación entre el s-PCA3 y el nuevo sistema de gradación del CaP

Correlation of mRNA-PCA3 urine levels with the new grading system in prostate cancer.

PURPOSE: To evaluate the PCA3 (Prostate Cancer 3 gene) as a tool to improve prostate cancer (PCa) screening and its capability to predict PCa aggressiveness. PATIENTS AND METHODS: A retrospective study with data from consecutive patients with suspected PCa seen in the urology department between November 2009 and April 2016 and who were candidates for prostate biopsy. A total of 1038 urine samples were tested in our laboratory with a kit that generated a PCA3 score (s-PCA3). A prostate biopsy was recommended only in those patients with s-PCA3≥35. Associations between variables were analyzed using the R software. RESULTS: In patients with a positive s-PCA3 (44.5%), a subsequent biopsy was recommended. Of a total of 151 biopsies studied, 56.3% yielded a diagnosis of PCa. The probability of a positive biopsy increased as the s-PCA3 increased (p=0.041). The percentage of affected cylinders increased as the s-PCA3 increased (p=0.015). A statistically significant relationship was observed between s-PCA3 and both the Gleason score and the Grade Group (p=0.001 and 0.008, respectively). The best log-linear models and a logistic model confirmed the relationships shown previously with Fisher's exact tests. CONCLUSIONS: S-PCA3 may serve as an additional marker to reduce the indication for biopsies and avoid overdiagnosis and overtreatment of patients with suspected PCa. The prognostic significance of s-PCA3 was confirmed, as it was associated with tumor volume and Gleason score. Importantly, to our knowledge this is the first time that an association has been demonstrated between s-PCA3 and the new Grade Group.

Carcinoma seroso peritoneal y adenocarcinoma mucinoso apendicular sincrónicos. Estudio inmunohistoquímico y molecular / Synchronous serous peritoneal carcinoma and mucinous appendicular adenocarcinoma. Immunohistochemical and molecular study

Paciente mujer de 60 años, en seguimiento por historia familiar de cáncer de mama y ovario, en la que se detectaron implantes tumorales peritoneales y depósitos de mucina en serosa apendicular. Los implantes peritoneales fueron diagnosticados de carcinoma seroso tipo ovárico/peritoneal con inmunofenotipo característico, siendo la mucina acelular. Se realizaron estudios de mutación de KRAS y BRAF mediante PCR que demostró la presencia de mutación GD12 únicamente en el componente mucinoso, lo que permitió mostrar la existencia de una doble neoplasia. La cirugía posterior confirmó la existencia sincrónica de un adenocarcinoma mucinoso apendicular y un carcinoma seroso peritoneal. Creemos que este caso permite ilustrar que la incorporación de los estudios moleculares en la actividad asistencial del patólogo puede aportarnos información adicional con valor diagnóstico (AU)

A 60 year old female with a family history of ovarian and breast cancer underwent a follow-up laparoscopic exploration which revealed peritoneal implants and mucinous deposits on the appendicular surface. The peritoneal implants were diagnosed as serous carcinoma with a characteristic immunophenotype, while the mucinous material was acellular. KRAS and BRAF mutation studies with PCR showed a GD12 mutation in the mucinous component only, suggesting the presence of a synchronous carcinoma. Subsequent cytorreductive surgery confirmed the presence of an infiltrating appendicular mucinous adenocarcinoma, synchronous with the peritoneal infiltrating serous carcinoma. We believe that this case, where the different immunohistochemical and molecular profiles allowed a correct diagnosis of two independent neoplasms, emphasizes the value of molecular studies in routine diagnostic procedure (AU)

EGFR mutations in lung cancer / Mutaciones de EGFR en cancer de pulmón

The study of epidermal growth factor receptor mutations has become essential for the treatment of lung cancer. The aim of this study was to find a correlation between morphological changes and EGFR mutational status using both immunohistochemistry and molecular techniques. We also analyzed the cross-reaction of the L858R mutation-specific monoclonal antibody in cases with HER2 amplification described previously in breast and gastric cancer. A series of 100 primary lung adenocarcinomas were examined. Exon 19 E746_A750del and exon 21 L858R mutations were studied using immunohistochemistry with two specific monoclonal antibodies. Gene mutational status was determined using real-time PCR or Sanger sequencing followed by real-time PCR when negative. EGFR mutations were detected in 22 cases (22%) by molecular techniques, being significantly more frequent in women, low grade carcinoma and lepidic subtype, (p-value <0.05 in all cases). In addition, in our series presence of tumoral necrosis correlated with absence of mutations. The anti-E746_A750del antibody achieved a 100% positive predictive value and a negative predictive value of 97.7% which could restrict the use of molecular techniques to the 7% of cases with an equivocal result. The antibody for L858R mutation showed inconsistent results compared to molecular techniques, giving false positive result in two adenocarcinomas with HER2 amplification. However, its negative predictive value was very high (98.9%). The use of real-time PCR identifies mutations not detected by the other two techniques. These new antibodies could be useful as a screening tool prior to EGFR molecular techniques (AU)

El estudio de las mutaciones de EGFR ha resultado ser esencial en el tratamiento del cáncer de pulmón. La finalidad de este trabajo ha sido estudiar la correlación entre los cambios morfológicos y el estado mutacional de EGFR utilizando técnicas de inmunohistoquímica y moleculares. Asimismo se analizó la reacción cruzada del anticuerpo anti-L858R en casos con amplificación de HER2 descrita previamente en cáncer de mama y gástrico. La serie consta de 100 adenocarcinomas pulmonares primarios. Las mutaciones E746_A750del exón-19 y L858R exón-21 se estudiaron por inmunohistoquímica con dos anticuerpos monoclonales específicos. El estado mutacional del gen se determinó mediante PCR en tiempo-real o secuenciación por Sanger seguida de PCR en tiempo-real cuando resultó negativa. Se detectaron mutaciones de EGFR en 22 casos (22%) por técnicas moleculares, siendo significativamente más frecuente en mujeres, carcinoma de bajo grado y subtipo lepídico, (p-valor<0,05 en todos los casos). Además, en nuestra serie la presencia de necrosis tumoral se correlaciona con ausencia de mutaciones. El anticuerpo anti-E746_A750del presentó un valor-predictivo-positivo del 100% y un valor-predictivo-negativo del 97,7%, lo que podría restringir el uso de técnicas moleculares al 7% de casos no-concluyentes. El anticuerpo anti-L858R mostró resultados inconsistentes en comparación con las técnicas moleculares, dando resultado falso-positivo en dos adenocarcinomas con amplificación de HER2. Sin embargo, su valor-predictivo-negativo es muy alto (98,9%). El uso de PCR en tiempo-real rescata mutaciones no detectadas por las otras dos técnicas. Estos nuevos anticuerpos podrían ser útiles como herramienta de cribado previo al estudio de EGFR mediante técnicas moleculares (AU)

Mimickers of prostate cancer in needle biopsies.

The diagnosis of prostate cancer is made based on the architecture of the glandular proliferation and nuclear atypia, but some normal structures (seminal vesicle, Cowper's glands, prostatic central zone) or nonneoplastic proliferative lesions can mimic carcinoma. Of the 3 patterns of prostate cancer--solid, cribriform, and microglandular, the microglandular pattern is the one that imitates carcinoma most frequently on needle biopsy. The demonstration of basal cells can be the best method to identify these prostate cancer mimickers.

Cross-reactivity of EGFR L858R mutation-specific antibody in HER2 positive gastric adenocarcinomas / Reacción cruzada del anticuerpo específico para la mutación EGFR L858R en los adenocarcinomas gástricos HER2 positivos

Recently, the study of the EGFR mutations in lung cancer has become mandatory due to their usefulness in target therapy. Lately, the use of specific antibodies to study the most prevalent of these mutations has been introduced. The newly published discovery of the existence of a cross-reaction between the HER2 protein and the EGFR L858R-specific antibody in breast cancer led us to corroborate this cross-reactivity in other tumors; specifically, we have chosen gastric carcinomas where HER2 is routinely evaluated as a molecular therapy driver. Our series consists of 15 primary gastric carcinomas, 7 HER2 cases positive for overexpression/amplification and 8 negative cases for both techniques. EGFR L858R mutation was studied with immunohistochemistry and complemented with real time PCR when positive. Immunohistochemistry assay with EGFR L858R was positive in 5 of the HER2 positive carcinomas (71%), none of which was confirmed by PCR, and negative in all HER2 negative carcinomas. Conclusions: The EGFR L858R antibody gives false positive results in most gastric carcinomas with HER2 overexpression/amplification, confirming the results described previously in breast cancer. It is also important to bear in mind that HER2 has also been described in other carcinomas, including lung cancer (AU)

En los últimos años, el estudio de las mutaciones de EGFR en cáncer de pulmón se ha convertido en esencial por su utilidad como diana terapéutica. Recientemente se ha introducido el uso de anticuerpos para la detección de las mutaciones más prevalentes. El descubrimiento de la existencia de una reacción cruzada entre la proteína HER2 y el anticuerpo específico EGFFR L858R, recientemente publicado en cáncer de mama, nos condujo a explorar la existencia de dicha reacción cruzada en otros tumores. Seleccionamos en primer lugar el cáncer gástrico, en el que se evalúa HER2 de forma rutinaria para la identificación de candidatos a tratamiento con terapia dirigida. La serie incluyó 15 carcinomas gástricos primarios, 7 casos positivos para sobreexpresión/amplificación de HER2 y 8 casos negativos para ambas técnicas. La presencia de la mutación EGFR L858R se estudió por inmunohistoquímica, y en caso de resultado positivo se complementó con el estudio molecular por PCR a tiempo real para su confirmación. El estudio inmunohistoquímico de EGFR L858R resultó positivo en 5 de los carcinomas HER2 positivos (71%), sin que ninguno se confirmara por PCR, y fue negativo para todos los carcinomas HER2 negativos. Conclusiones: El anticuerpo EGFR L858R presenta resultado falso positivo en la mayoría de carcinomas con sobreexpresión/amplificación de HER2, confirmando los resultados descritos previamente en cáncer de mama. Es importante tener presente que la presencia de HER2 ha sido descrita en otros carcinomas, incluido el cáncer de pulmón (AU)

Cross-reactivity of EGFR mutation-specific immunohistochemistry assay in HER2-positive tumors.

The coexpression of HER2 and EGFR L858R in a solitary nodule removed from the lung, whose mutation was not confirmed by molecular techniques, made us think about the possible existence of a cross-reaction between HER2 and the EGFR L858R-specific antibody. Our study was designed to further analyze the existence of this cross-reaction and stress the need to exclude a metastatic breast cancer when dealing with EGFR L858R-positive cases. The series consists of 42 primary breast carcinomas, 22 HER2 positive for overexpression and amplification, and 20 negative for both. EGFR mutations were studied by immunohistochemistry and confirmed using real-time PCR when positive. Immunohistochemistry assay with EGFR L858R was positive in 19 (86%) of the HER2-positive breast carcinomas and negative in all HER2-negative carcinomas. The EGFR L858R antibody gives false-positive results in most of the breast carcinomas with HER2 overexpression/amplification. As a consequence, it is essential to confirm any EGFR L858R-positive cases by molecular methods or at least discard the presence of HER2 overexpression/amplification before rendering a diagnosis. It is also important to consider that HER2 has been described in other carcinomas such as urothelial, gastric or ovarian, as well as lung, although infrequently.

ERG expression and prostatic adenocarcinoma.

ERG gene rearrangement has been identified as a highly specific alteration that is present in 40-50 % of prostate carcinomas. The standardization of an immunohistochemical assay with a novel anti-ERG antibody recently described would have significant diagnostic value. The aims of this study were to identify the incidence of this rearrangement in a Spanish population and to test the specificity of immunohistochemical ERG evaluation for prostate carcinomas. Three prostate tissue microarrays were constructed using radical prostatectomy specimens and related to grade, local invasion, and regional invasion. In addition to samples from malignant cases (160), specimens of prostatic hyperplasia (26) and high-grade prostatic intraepithelial neoplasia (10) were included. Tissue microarrays of 270 samples from most common malignant tumors (breast, colon, lung, and bladder) were also tested. All were analyzed by immunohistochemistry. Seventy-five out of 154 evaluable cases (49 %) of prostate carcinoma showed ERG expression; 52/75 showed strong staining. No ERG expression was observed in any of the high-grade prostatic intraepithelial neoplasia. ERG expression was independent of Gleason score (p = 0.160), extent of invasion (p = 0.517), and regional lymph node involvement (p = 0.816). No ERG expression was found in any other type of tumor, with the exception of one bladder cancer sample that showed focal and weak expression. The frequency of ERG detected in our study correlated with the results published for other Caucasian populations. Strong ERG protein expression was exclusively detected in prostate carcinomas, corroborating the specificity of ERG rearrangements for these tumors. Thus, detecting ERG using immunohistochemistry may be useful in routine practice in pathology departments.

Microsatellite instability of the colorectal carcinoma can be predicted in the conventional pathologic examination. A prospective multicentric study and the statistical analysis of 615 cases consolidate our previously proposed logistic regression model.

High microsatellite instability (MSI-H) allows the identification of a subset of colorectal carcinomas associated with good prognosis and a higher incidence of Lynch syndrome. The aim of this work was to assess the interobserver variability and optimize our MSI-H prediction model previously published based on phenotypic features.The validation series collected from five different hospitals included 265 primary colorectal carcinomas from the same number of patients. The eight clinicopathological parameters that integrate our original model were evaluated in the corresponding centers. Homogeneity assessment revealed significant differences between hospitals in the estimation of the growth pattern, presence of Crohn-like reaction, percentage of cribriform structures, and Ki-67 positivity. Despite this observation, our model was globally able to predict MSI-H with a negative predictive value of 97.0%. The optimization studies were carried out with 615 cases and resulted in a new prediction model RERtest8, which includes the presence of tumor infiltrating lymphocytes at the expense of the percentage of cribriform structures. This refined model achieves a negative predictive value of 97.9% that is maintained even when the immunohistochemical parameters are left out, RERtest6. The high negative predictive value achieved by our models allows the reduction of the cases to be tested for MSI to less than 10%. Furthermore, the easy evaluation of the parameters included in the model renders it a useful tool for the routine practice and can reinforce other published models and the current clinical protocols to detect the subset of colorectal cancer patients bearing hereditary nonpolyposis colorectal cancers risk and/or MSI-H phenotype.

The diagnostic yield of immediate postcryoablation biopsies of small renal masses.

AIM: To evaluate the diagnostic feasibility and reproducibility of immediate postcryoablation biopsies of small renal masses. MATERIALS AND METHODS: Between December 2006 and July 2007, 21 intraoperative pre- and postcryoablation (18-gauge core) biopsies of renal masses were obtained. Evaluation of the biopsies by the institutional uropathologist was followed by a blind assessment by two other uropathologists. Tumor subtype and Fuhrman grade were determined by the three pathologists, while biopsy timing (before or after cryoablation) was only assessed by the two blinded pathologists. The diagnostic yield of the pre- and postcryoablation biopsies and interobserver agreement were calculated. RESULTS: The mean size of the 21 cryoablated tumors was 2.8 cm. No significant bleeding occurred after any biopsy. Of the precryoablation biopsies 75-81% was correctly labeled as precryo, and 48% of the postcryoablation biopsies as postcryo. The diagnostic yield of the three pathologists for precryo biopsies ranged between 67% and 71%, and for postcryo biopsies between 48% and 71% (not statistically different). When combining both types of biopsies, the overall diagnostic yield was 81% for all pathologists. The interobserver agreement was "almost perfect" (kappa = 0.902) for precryo biopsies and "substantial" (kappa = 0.514) for postcryo biopsies. CONCLUSION: This study shows that it is feasible to obtain histopathological diagnoses from postcryoablation biopsies with a diagnostic yield and interobserver agreement similar to precryoablation biopsies.