Prevalence and characteristics of gonadoblastoma in a retrospective multi-center study with follow-up investigations of 70 patients with Turner syndrome and a 45,X/46,XY karyotype.

Introduction: A gonadectomy is currently recommended in patients with Turner syndrome (TS) and a 45,X/46,XY karyotype, due to a potential risk of gonadoblastoma (GB). However, the quality of evidence behind this recommendation is low. Objective: This study aimed to evaluate the prevalence of GB, its characteristics, as well as its risk factors, according to the type of Y chromosomal material in the karyotype. Methods: Our study within French rare disease centers included patients with TS and a 45,X/46,XY karyotype, without ambiguity of external genitalia. Clinical characteristics of the patients, their age at gonadectomy, and gonadal histology were recorded. The regions of the Y chromosome, the presence of TSPY regions, and the percentage of 45,X/46,XY mosaicism were evaluated. Results: A total of 70 patients were recruited, with a median age of 29.5 years (21.0-36.0) at the end of follow-up. Fifty-eight patients had a gonadectomy, at a mean age of 15 ± 8 years. GB was present in nine cases. Two were malignant, which were discovered at the age of 14 and 32 years, without metastases. Neither the percentage of XY cells within the 45,X/46,XY mosaicism nor the number of TSPY copies was statistically different in patients with or without GB (P = 0.37). However, the entire Y chromosome was frequent in patients with GB (6/9). Conclusions: In our study, including a large number of patients with 45,X/46,XY TS, the prevalence of gonadoblastoma is 12.8%. An entire Y chromosome appears as the main risk factor of GB and should favor early gonadectomy. Significant statement: About 10% of patients with TS have a karyotype containing Y chromosomal material: 45,X/46,XY. Its presence is related to the risk of GB. Therefore, a prophylactic gonadectomy is currently recommended in such patients. However, the quality of evidence is low. Our objective was to evaluate the prevalence of GB according to the type of Y-chromosomal material. We found a prevalence of GB of 12.8% in a cohort of 70 TS patients. No sign of hyperandrogenism was observed. The entire Y chromosome was the most frequent type of Y-material in patients with GB. As the prognosis of these tumors was good, a delay of surgery might be discussed.

Renal cell carcinoma in children and adolescents: a retrospective study of a French-Italian series of 93 cases.

AIMS: Renal cell carcinomas (RCCs) represent 2-5% of kidney malignancies in children and adolescents. Appropriate diagnostic and classification are crucial for the correct management of the patients and in order to avoid inappropriate pre-operative chemotherapy, which is usually recommended if a Wilms' tumour is suspected. METHODS AND RESULTS: A French-Italian series of 93 renal cell carcinomas collected from 1990 to 2019 in patients aged less than 18 years was reclassified according to the 2016 World Health Organization (WHO) classification and the latest literature. TFE3 and TFEB fluorescence in-situ hybridisation (FISH) analyses and a panel of immunohistochemical stains were applied. The median age at diagnosis was 11 years (range = 9 months-17 years). MiT family (MiTF) translocation RCCs accounted for 52% of the tumours, followed by papillary (20%) and unclassified RCCs (13%). Other subtypes, such as SDHB-deficient and fumarate hydratase-deficient RCCs, represented 1-3% of the cases. We also described a case of ALK-rearranged RCC with a metanephric adenoma-like morphology. CONCLUSION: A precise histological diagnosis is mandatory, as targeted therapy could be applied for some RCC subtypes, i.e. MiTF-translocation and ALK-translocation RCC. Moreover, some RCC subtypes may be associated with a predisposition syndrome that will impact patients' and family's management and genetic counselling. A precise RCC subtype is also mandatory for the clinical management of the patients and inclusion in new prospective clinical trials.

[2021 update of the GEFPICS' recommendations for HER2 status assessment in invasive breast cancer in France]. / Mise à jour 2021 des recommandations du GEFPICS pour l'évaluation du statut HER2 dans les cancers infiltrants du sein en France.

The last international guidelines on HER2 determination in breast cancer have been updated in 2018 by the American Society of Clinical Oncology and College of American Pathologists, on the basis of a twenty-year practice and results of numerous clinical trials. Moreover, the emerging HER2-low concept for 1+ and 2+ non amplified breast cancers lead to refine French practices for HER2 status assessment. The GEFPICS group, composed of expert pathologists, herein presents the latest French recommendations for HER2 status evaluation in breast cancer, taking into account the ASCO/CAP guidelines and introducing the HER2-low concept. In the era of personalized medicine, HER2 status assessment remains one of the most important biomarkers in breast cancer and its quality guaranties the optimal patients' care. French pathologists' commitment in theranostic biomarker quality is more than ever required to provide the most efficient cares in oncology.

EWSR1-PATZ1 fusion sarcoma - A new case report and review of the literature / Sarcome avec transcrit de fusion EWSR1-PATZ1 - Une nouvelle observation avec revue de la littérature.

Sarcoma with EWSR1-PATZ1 gene fusion is an exceedingly rare and newly described Ewing-like sarcoma harboring EWSR1 rearrangements involving fusion partners other than ETS family genes. The clinical, histopathologic and immunophenotypic features of cases reported in literature are fairly diverse and not specific. We report a new case report posing real challenges for histological and molecular diagnosis.

Age Dependency of the Prognostic Impact of Tumor Genomics in Localized Resectable MYCN-Nonamplified Neuroblastomas. Report From the SIOPEN Biology Group on the LNESG Trials and a COG Validation Group.

PURPOSE: For localized, resectable neuroblastoma without MYCN amplification, surgery only is recommended even if incomplete. However, it is not known whether the genomic background of these tumors may influence outcome. PATIENTS AND METHODS: Diagnostic samples were obtained from 317 tumors, International Neuroblastoma Staging System stages 1/2A/2B, from 3 cohorts: Localized Neuroblastoma European Study Group I/II and Children's Oncology Group. Genomic data were analyzed using multi- and pangenomic techniques and fluorescence in-situ hybridization in 2 age groups (cutoff age, 18 months) and were quality controlled by the International Society of Pediatric Oncology European Neuroblastoma (SIOPEN) Biology Group. RESULTS: Patients with stage 1 tumors had an excellent outcome (5-year event-free survival [EFS] ± standard deviation [SD], 95% ± 2%; 5-year overall survival [OS], 99% ± 1%). In contrast, patients with stage 2 tumors had a reduced EFS in both age groups (5-year EFS ± SD, 84% ± 3% in patients < 18 months of age and 75% ± 7% in patients ≥ 18 months of age). However, OS was significantly decreased only in the latter group (5-year OS ± SD in < 18months and ≥ 18months, 96% ± 2% and 81% ± 7%, respectively; P = .001). In < 18months, relapses occurred independent of segmental chromosome aberrations (SCAs); only 1p loss decreased EFS (5-year EFS ± SD in patients 1p loss and no 1p loss, 62% ± 13% and 87% ± 3%, respectively; P = .019) but not OS (5-year OS ± SD, 92% ± 8% and 97% ± 2%, respectively). In patients ≥ 18 months, only SCAs led to relapse and death, with 11q loss as the strongest marker (11q loss and no 11q loss: 5-year EFS ± SD, 48% ± 16% and 85% ± 7%, P = .033; 5-year OS ± SD, 46% ± 22% and 92% ± 6%, P = .038). CONCLUSION: Genomic aberrations of resectable non-MYCN-amplified stage 2 neuroblastomas have a distinct age-dependent prognostic impact. Chromosome 1p loss is a risk factor for relapse but not for diminished OS in patients < 18 months, SCAs (especially 11q loss) are risk factors for reduced EFS and OS in those > 18months. In older patients with SCA, a randomized trial of postoperative chemotherapy compared with observation alone may be indicated.

DNA FISH Diagnostic Assay on Cytological Samples of Thyroid Follicular Neoplasms.

Although fine-needle aspiration cytology (FNAC) is helpful in determining whether thyroid nodules are benign or malignant, this distinction remains a cytological challenge in follicular neoplasms. Identification of genomic alterations in cytological specimens with direct and routine techniques would therefore have great clinical value. A series of 153 cases consisting of 72 and 81 histopathologically confirmed classic follicular adenomas (cFAs) and classic follicular thyroid carcinomas (cFTCs), respectively, was studied by means of different molecular techniques in three different cohorts of patients (pts). In the first cohort (training set) of 66 pts, three specific alterations characterized by array comparative genomic hybridization (aCGH) were exclusively found in half of cFTCs. These structural abnormalities corresponded to losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X. The second independent cohort (validation set) of 60 pts confirmed these data on touch preparations of frozen follicular neoplasms by triple DNA fluorescent in situ hybridization using selected commercially available probes. The third cohort, consisting of 27 archived cytological samples from an equal number of pts that had been obtained for preoperative FNAC and morphologically classified as and histologically verified to be follicular neoplasms, confirmed our previous findings and showed the feasibility of the DNA FISH (DNA fluorescent in situ hybridization) assay. All together, these data suggest that our triple DNA FISH diagnostic assay may detect 50% of cFTCs with a specificity higher than 98% and be useful as a low-cost adjunct to cytomorphology to help further classify follicular neoplasms on already routinely stained cytological specimens.

Mammary analogue secretory carcinoma: A case report.

BACKGROUND: Mammary analogue secretory carcinoma is a rare new entity of low-grade malignant tumor of salivary glands. It shared the same histologic features and the chromosomal translocation t(12;15)(p13;q25) as secretory carcinoma of the breast. AIM: To highlight the diagnosis approaches and the attitude of management in a case of MASC which is the first case reported in Tunisia. Reported case: A case of MASC of the lower left jugal mucosa was reviewed for its microscopic and immunohistochemical features. Fluorescence in situ hybridization (FISH) for the ETV6-NTRK3 translocation was performed. Surgery was the only treatment required in this case. No signs of local or regional recurrence during the one-year follow-up were noticed. COMMENTARIES: Secretory carcinoma was confused with other salivary gland tumors especially acinic cell carcinoma due to their morphological similarities, making diagnosis dilemma. Fluorescence in-situ hybridization (FISH) is the one definitive finding to confirm the diagnosis of MASC and to differentiate it from the other types of salivary gland tumor. At the present time, no specific therapy is available for patients with MASC.

Decision of adjuvant chemotherapy in intermediate risk luminal breast cancer patients: A prospective multicenter trial assessing the clinical and psychological impact of EndoPredict® (EpClin) use (UCBG 2-14).

PURPOSE: Genomic tests can identify ER-positive HER2-negative localized breast cancer patients who may not benefit from adjuvant chemotherapy. Such tests seem especially interesting in "intermediate" clinico-pathological risk categories. The psychological impact of the decision uncertainty in these women remains largely unexplored. We assessed the clinical and psychological impact of EndoPredict® (EpClin), a clinico-genomic test, in these patients. METHODS: This multicenter, single arm prospective study (NCT02773004) enrolled patients for which adjuvant chemotherapy was uncertain, based on predefined criteria. The primary endpoint was the proportion of change between initial adjuvant decision and final administration of chemotherapy. Secondary endpoints included post-test (Day 17) and 1-year patient reported outcomes. RESULTS: One third of 200 evaluable patients had a high EpClin score (≥3.32867; 10 years cumulative risk of distance failure ≥10%). The overall change rate of chemotherapy decision was 72/200 (35.8%, 95% CI 29.2-42.4). Chemotherapy was withdrawn in 57 cases (28.4% [22.2-34.8]) and added in 15 (7.5% [3.8-11.2]. 6 changes (8%) were based on patients' decisions. Anxiety and distress levels increased at Day 17 when adding chemotherapy after the test result (p < 10-7 and 0.00022 respectively), while stable in other situations. At 1-year, all patients had returned to the baseline anxiety and distress levels (mean anxiety 51.5, +/- SD = 2.5 [max. 80], mean distress 3±1 [max. 10]). CONCLUSIONS: EndoPredict ® (EpClin) is clinically useful in deciding whether or not to administer adjuvant chemotherapy in patients with intermediate risk. A single-step decision is preferable since adding chemotherapy at a later stage increases anxiety and distress.

[GEFPICS' guidelines for management of breast cancer tissue samples in the neoadjuvant setting]. / Recommandations du GEFPICS pour la prise en charge des prélèvements dans le cadre du traitement néoadjuvant du cancer du sein.

Neoadjuvant therapy is an increasing treatment option in the management of breast cancer. The tumor response to neoadjuvant therapy, especially the pathological complete response, is a validated endpoint frequently used in clinical trials. However, there is still a lack of standardization for the surgical specimen management in the neoadjuvant setting. This leads to heterogeneity in the specimen handling and might lead to significant bias for the prognostic assessment of patients or in clinical trials. The GEFPICS group, composed of expert breast cancer pathologists, herein presents guidelines for the management of breast and axillary specimen before treatment (management of biopsy, items of the pathological report) and after neoadjuvant therapy (specimen handling, histological assessment of response, items of the pathological report and response grading systems).

Various Genital and Reproductive Phenotypes in 46,XX/46,XY Chimeras.

Tetragametic chimeras are due to the fusion of 2 different zygotes after fertilization. When occurring between embryos of different chromosomal sex, the phenotype ranges from fertile individuals to infertile patients and even to patients with variations in sex development. Here, we report 3 new cases of XX/XY chimeras, one in a young boy carrying an abnormal gonad which turned out to be an ovary and 2 in phenotypically normal infertile men, one of whom had been diagnosed previously as a XX-SRY negative male. These cases highlight the importance of combining several cytogenetic and molecular techniques on different tissues for a proper diagnosis and an appropriate prognosis.

Recurrence of Hereditary Hemorrhagic Telangiectasia After Liver Transplantation: Clinical Implications and Physiopathological Insights.

Liver transplantation (LT) has been proposed as a curative treatment in hereditary hemorrhagic telangiectasia (HHT) with severe hepatic involvement. We provide a long-term evaluation of graft status after LT for HHT, with a focus on the risk of recurrence. The present study included all patients prospectively followed up after LT for HHT in the Lyon Liver Transplant Unit from 1993 to 2010, with a survival of more than 1 year. Protocol clinical, radiological, and histological examinations were performed at regular intervals. Fourteen patients were included (13 women and one man). Median age at LT was 52.5 years (range: 33.1-66.7). In eight patients (seven female), disease recurrence was diagnosed by abnormal radiological features, suggestive of microcirculatory disturbances. Typical vascular lesions, including telangiectasia, were demonstrated by liver biopsy in five of these patients. The median interval between LT and diagnosis of recurrence was 127 months (range: 74-184). The risk of recurrence increased over time; estimated cumulative risk was 47.9% at 15 years. Liver tissue analysis found the coexistence of an angiogenic process combined with endothelial microchimerism, as shown by the presence of vascular lining cells of recipient origin. Conclusion: The present data show that disease recurrence occurs, usually after a long delay, in a significant number of patients treated by LT for liver complications of HHT. This strongly supports the necessity of a lifelong follow-up and suggests that therapeutic strategy needs discussion and evaluation, especially of the role of potential adjuvant treatments to LT, such as antiangiogenic medications, when recurrent disease appears.

Tumour and cellular distribution of activated forms of PR in breast cancers: a novel immunohistochemical analysis of a large clinical cohort.

BACKGROUND: The progesterone receptor (PR) is expressed by ∼70% of early breast tumours and is implicated in the progression of breast cancer. In cancerous tissues PR may be activated in the absence of a ligand, or when ligand concentrations are very low, resulting in aberrantly activated PR (APR). The presence of APR may indicate that patients with breast cancer are more likely to respond to antiprogestins. The aims of this study were to describe and classify the histological subnuclear morphology of active and inactive PR in archival breast cancer samples. METHODS: Archived tumour specimens from 801 women with invasive breast cancer were collected. Tissue samples (n=789) were analysed for PR isoforms A and B (PRA and PRB), Ki67 and estrogen receptors (ERα) status, using immunohistochemistry. Medical records were used to determine human epidermal growth factor 2 (HER2) status, tumour stage and grade. RESULTS: A total of 79% of tumours stained positive for either PRA or PRB, and of these 25% of PRA-positive and 23% of PRB-positive tumours had PR present in the activated form. APRA was associated with higher tumour grade (p=0.001). APRB was associated with a higher tumour grade (p=0.046) and a trend for a more advanced stage. Patients with PR-positive tumours treated with antiestrogens had better disease-free survival (DFS) than those with PR-negative tumours (p<0.0001). Cumulative progression rate and DFS were similar irrespective of APR status. Both APRA and APRB were independent of HER2, ERα and Ki67 expression. CONCLUSIONS: APR had a binary mode of expression in the breast cancer specimens tested, allowing separation into two tumour subsets. APR is an independent target at the cellular and tumour level and may therefore be a suitable predictive marker for antiprogestins, such as onapristone. Using the described technique, a companion diagnostic is under development to identify APR in solid tumours.

Concordance between HER-2 status determined by qPCR in Fine Needle Aspiration Cytology (FNAC) samples compared with IHC and FISH in Core Needle Biopsy (CNB) or surgical specimens in breast cancer patients.

Determining the status of HER2-neu amplification and overexpression in breast cancer is crucial for prognosis but mostly for treatment purposes. Standard techniques include the determination of IHC in combination with in situ hybridization techniques to confirm a HER2-neu amplification in case of IHC2+ using either a core-needle biopsy or a surgical specimen. qPCR has been also demonstrated to be able to determine HER2 status, mostly in core biopsies or in surgical specimens. Fine-needle aspiration is a reliable, quicker and less invasive technique that is widely used for diagnosis of invasive breast cancer. In this study, we assessed the performance of qPCR in invasive breast carcinomas to determine HER2-neu status by using fine-needle aspiration samples and comparing to standard IHC and FISH. From a total of 154 samples from patients who had nodular breast lesions and attended the 1-day-stop clinic at the Gustave Roussy from March 2013 to October 2014, qPCR was able to determine the HER2 status in a mean of 3.7 days (SD 3.1). The overall concordance with standard HER2-testing was very high: 97% (95% CI 0.94 to 0.99); sensitivity was 96% (0.87-1), specificity 98% (0.95-1) and positive and negative predictive values 88% (0.75-1) and 99% (0.98-1), respectively. In conclusion, our study demonstrates that qPCR performed using fine-needle aspiration samples from a primary tumour is a reliable and fast method to determine HER2/neu status in patients with early breast cancer.

Phenotypic and genetic heterogeneity of tumor tissue and circulating tumor cells in patients with metastatic castration-resistant prostate cancer: A report from the PETRUS prospective study.

Molecular characterization of cancer samples is hampered by tumor tissue availability in metastatic castration-resistant prostate cancer (mCRPC) patients. We reported the results of prospective PETRUS study of biomarker assessment in paired primary prostatic tumors, metastatic biopsies and circulating tumor cells (CTCs). Among 54 mCRPC patients enrolled, 38 (70%) had biopsies containing more than 50% tumour cells. 28 (52%) patients were analyzed for both tissue samples and CTCs. FISH for AR-amplification and TMPRSS2-ERG translocation were successful in 54% and 32% in metastatic biopsies and primary tumors, respectively. By comparing CellSearch and filtration (ISET)-enrichment combined to four color immunofluorescent staining, we showed that CellSearch and ISET isolated distinct subpopulations of CTCs: CTCs undergoing epithelial-to-mesenchymal transition, CTC clusters and large CTCs with cytomorphological characteristics but no detectable markers were isolated using ISET. Epithelial CTCs detected by the CellSearch were mostly lost during the ISET-filtration. AR-amplification was detected in CellSearch-captured CTCs, but not in ISET-enriched CTCs which harbor exclusively AR gain of copies. Eighty-eight percent concordance for ERG-rearrangement was observed between metastatic biopsies and CTCs even if additional ERG-alteration patterns were detected in ISET-enriched CTCs indicating a higher heterogeneity in CTCs.Molecular screening of metastatic biopsies is achievable in a multicenter context. Our data indicate that CTCs detected by the CellSearch and the ISET-filtration systems are not only phenotypically but also genetically different. Close attention must be paid to CTC characterization since neither approach tested here fully reflects the tremendous phenotypic and genetic heterogeneity present in CTCs from mCRPC patients.

Revised risk estimation and treatment stratification of low- and intermediate-risk neuroblastoma patients by integrating clinical and molecular prognostic markers.

PURPOSE: To optimize neuroblastoma treatment stratification, we aimed at developing a novel risk estimation system by integrating gene expression-based classification and established prognostic markers. EXPERIMENTAL DESIGN: Gene expression profiles were generated from 709 neuroblastoma specimens using customized 4 × 44 K microarrays. Classification models were built using 75 tumors with contrasting courses of disease. Validation was performed in an independent test set (n = 634) by Kaplan-Meier estimates and Cox regression analyses. RESULTS: The best-performing classifier predicted patient outcome with an accuracy of 0.95 (sensitivity, 0.93; specificity, 0.97) in the validation cohort. The highest potential clinical value of this predictor was observed for current low-risk patients [5-year event-free survival (EFS), 0.84 ± 0.02 vs. 0.29 ± 0.10; 5-year overall survival (OS), 0.99 ± 0.01 vs. 0.76 ± 0.11; both P < 0.001] and intermediate-risk patients (5-year EFS, 0.88 ± 0.06 vs. 0.41 ± 0.10; 5-year OS, 1.0 vs. 0.70 ± 0.09; both P < 0.001). In multivariate Cox regression models for low-risk/intermediate-risk patients, the classifier outperformed risk assessment of the current German trial NB2004 [EFS: hazard ratio (HR), 5.07; 95% confidence interval (CI), 3.20-8.02; OS: HR, 25.54; 95% CI, 8.40-77.66; both P < 0.001]. On the basis of these findings, we propose to integrate the classifier into a revised risk stratification system for low-risk/intermediate-risk patients. According to this system, we identified novel subgroups with poor outcome (5-year EFS, 0.19 ± 0.08; 5-year OS, 0.59 ± 0.1), for whom we propose intensified treatment, and with beneficial outcome (5-year EFS, 0.87 ± 0.05; 5-year OS, 1.0), who may benefit from treatment de-escalation. CONCLUSIONS: Combination of gene expression-based classification and established prognostic markers improves risk estimation of patients with low-risk/intermediate-risk neuroblastoma. We propose to implement our revised treatment stratification system in a prospective clinical trial.

[Pre-analytical stage for biomarker assessment in breast cancer: 2014 update of the GEFPICS' guidelines in France]. / Recommandations du GEFPICS concernant la phase pré-analytique pour l'évaluation de HER2 et des récepteurs hormonaux dans le cancer du sein : mise à jour 2014.

Biomarker assessment of breast cancer tumor samples is part of the routine workflow of pathology laboratories. International guidelines have recently been updated, with special regards to the pre-analytical steps that are critical for the quality of immunohistochemical and in situ hybridization procedures, whatever the biomarker analyzed. Fixation and specimen handling protocols must be standardized, validated and carefully tracked. Cooperation and training of the personnel involved in the specimen workflow (e.g. radiologists, surgeons, nurses, technicians and pathologists) are of paramount importance. The GEFPICS' update of the recommendations herein details and comments the different steps of the pre-analytical process. Application of these guidelines and participation to quality insurance programs are mandatory to ensure the correct evaluation of oncotheranostic biomarkers.

[2014 update of the GEFPICS' recommendations for HER2 status determination in breast cancers in France]. / Mise à jour 2014 des recommandations du GEFPICS pour l'évaluation du statut HER2 dans les cancers du sein en France.

International guidelines on HER2 determination in breast cancer have just been updated by the American Society of Clinical Oncology (ASCO) and College of American Pathologists (CAP), on the basis of more than ten-year practice, results of clinical trials and concordance studies. The GEFPICS group, composed of expert pathologists in breast cancer, herein presents these recommendations, adapted to the French routine practice. These guidelines highlight the possible diagnosis difficulties with regards to HER2 status determination, such as intra-tumor heterogeneity, special histological subtypes and biomarker re-evaluation during metastatic relapse. Pre-analytical issues and updated scoring criteria (especially for equivocal cases) are detailed, in order to decrease the occurrence of false negative cases. In the era of personalized medicine, pathologists are more than ever involved in the quality of oncotheranostic biomarker evaluation.

MET genetic abnormalities unreliable for patient selection for therapeutic intervention in oropharyngeal squamous cell carcinoma.

BACKGROUND: Identification of MET genetic alteration, mutation, or amplification in oropharyngeal squamous cell carcinoma (OPSCC) could lead to development of MET selective kinase inhibitors. The aim of this study was to assess the frequency and prognostic value of MET gene mutation, amplification, and protein expression in primary OPSCC. METHODS: A retrospective chart review was conducted of patients treated for single primary OPSCC between January 2007 and December 2009. Pre-treatment OPSCC tissue samples were analyzed for MET mutations, gene amplification, and overexpression using Sanger sequencing, FISH analysis, and immunohistochemistry respectively. Univariate and multivariate analyses were used to analyze correlations between molecular abnormalities and patient survival. RESULTS: 143 patients were included in this study. Six cases (4%) were identified that had a genetic variation, but previously described mutations such as p.Tyr1235Asp (Y1235D) or p.Tyr1230Cys (Y1230C) were not detected. There were 15 high polysomy cases, and only 3 cases met the criteria for true MET amplification, with ≥10% amplified cells per case. Immunohistochemistry evaluation showed 43% of cases were c-MET negative and in 57% c-MET was observed at the tumor cell level. Multivariate analysis showed no significant association between MET mutation, amplification, or expression and survival. CONCLUSIONS: Our study shows a low frequency of MET mutations and amplification in this cohort of OPSCC. There was no significant correlation between MET mutations, amplification, or expression and patient survival. These results suggest that patient selection based on these MET genetic abnormalities may not be a reliable strategy for therapeutic intervention in OPSCC.