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Background/Objectives: Colorectal cancer (CRC) is the third leading cause of cancer death globally, with rising incidence. The immunohistochemistry (IHC) for mismatch repair (MMR) proteins is the first technique used in routine practice to evaluate an MMR status. Microsatellite instability (MSI) may be tested in case of doubt during IHC staining. This study introduces a novel high-resolution melt (HRM) protocol for MSI detection and compares it with traditional fragment length analysis (FLA) via capillary electrophoresis. Methods: A total of 100 formalin-fixed and paraffin-embedded CRC specimens were analyzed using two distinct protocols: one based on FLA (TrueMark MSI Assay kit) and another one based on HRM (AmoyDx® Microsatellite Instability Detection Kit). Results: Overall, 68 (68.0%) of the cases were MSS, and 32 (32.0%) were MSI-H. HRM analysis was first successfully carried out in all the cases. A perfect concordance in MSI evaluation between HRM and FLA was observed. HRM showed slightly shorter hands-on time and turnaround time. Conclusions: We provided evidence of the validity of this new HRM approach in determining the MSI status of colorectal carcinomas.

Background: The frontline management of non-oncogene addicted non-small cell lung cancer (NSCLC) involves immune-checkpoint inhibitors (ICI) alone or combined with chemotherapy (CT-ICI). The dynamic landscape of KRAS-positive NSCLC presents a spectrum of treatment options, including ICIs, targeted therapy and combination strategies currently under investigation. Methods: We conducted a prospective project to detect circulating tumor DNA (ctDNA) in patients with KRAS G12C, advanced NSCLC. We included patients undergoing upfront ICIs or subsequent line sotorasib. We planned three-time points: baseline (T0), after 3 months of treatment (T1) and at disease progression (T2). Results: 24 consecutive patients have been included. The most frequent baseline characteristics were: nonsquamous histology (95.8%), male gender (62.5%), ECOG PS 0–1 (79.2%), 3 metastatic sites (p ​= ​0.002) exhibited significantly elevated ctDNA. Median overall survival (OS) was 7.5 months, progression-free survival (PFS) was 4.0 months and the objective response rate (ORR) was 33.3%. Higher AF correlated with an increased risk of death (HR 1.04, p ​= ​0.03), though not progression. The mOS was 7.5 months (95% CI, 1.91-NR) in high-AF group and 11.3 months (95% CI, 6.6-NR) in low-AF group (p ​= ​0.38). Notably, a reduction in plasma DNA levels was significantly associated with objective response (p ​= ​0.01). Two patients received a T2 dosage showing increased ctDNA levels after a previous reduction associated with response. Conclusion: Early monitoring with ctDNA may offer potential benefits in the evolving scenario of KRAS G12C NSCLC treatment.

Thanks to the identification of crucial molecular pathways, the therapeutic landscape for advanced differentiated thyroid tumors (DTCs) has significantly improved during the last ten years. The therapeutic scenario has been greatly impacted by the discovery of mutually exclusive gene changes in the MAPK and PI3K/AKT pathways, such as RET or NTRK fusions and pathogenic mutations of the BRAF and RAS genes. Indeed, multi-kinase inhibitors and selective inhibitors have demonstrated outstanding efficacy for radioactive iodine-refractory (RAI-R) drug treatment, with overall response rates reaching up to 86%. Thus, for RAI-R DTCs, routine molecular testing for actionable gene alterations is now essential, for choosing the right therapy for the right patient.Additionally, tumor genotyping also allows to identify a subset of patients with worse prognosis disease, which may deserve a tailored clinical management. Thus, the right test should also include non-driver TERT, TP53, PIK3CA, and other mutations of aggressiveness, with the aim of a molecular-based risk stratification. Therefore, tumor genotyping should be considered in the diagnostic work-up of metastatic DTC patients or with highly aggressive histological features, in order to give the right drug for the right patient at the right time.

Abstract Canine liposarcoma is an uncommon tumor that shares morphological similarities with its human counterpart. In dogs, the genetic features of this tumor are unknown and, based on immunohistochemical studies, amplification of the gene MDM2 and the mutation of TP53 are suspected. In this study 51 cases of primary liposarcomas were immunohistochemically stained for MDM2 and p53 and subjected to fluorescent in situ hybridization and next-generation sequencing to detect MDM2 amplification and TP53 mutations, respectively. MDM2 and p53 were expressed in 21 and 6 cases, respectively. MDM2 amplification and TP53 mutations were identified in 10 and 15 cases, respectively. Statistical analysis revealed an association of the myxoid subtype and the mitotic count with p53 expression and TP53 mutation. No association was found between MDM2 amplification and MDM2 expression or tumor subtype. These results suggest that despite morphological similarities, canine liposarcoma differs from its human counterpart, for which MDM2 amplification is diagnostic for well differentiated and de-differentiated variants, and TP53 mutations are more common in pleomorphic liposarcoma rather than the myxoid one as occur in our cases. Furthermore, canine myxoid liposarcoma likely represents a distinct disease rather than a mere morphological variant.

We read with great interest the paper by Cosme and co-workers about the differences between incidentally (ITC) and non-incidentally (NITC) diagnosed papillary thyroid carcinoma (PTC) (1). We congratulate the authors for the excellent work-up of the study cohort that comprised 122 ITCs and 103 NITCs. Intriguingly, the study revealed no significant difference between ITC and NITC groups regarding the pTNM staging, American Thyroid Association (ATA) recurrence risk, proportion of aggressive PTC subtypes, frequency of radioactive iodine (RAI) prescription, and RAI activity. Moreover, the diagnostic modality (incidental vs symptomatic) had no impact on disease persistence at the 5-year follow-up both on univariate and on multivariate analyses. Although ITCs were smaller and of lower pT status than NITCs (which was expected given the definition of the groups), a considerable proportion of ITCs (36%) were yet larger than 2 cm in size.

Abstract Introduction Biomarker testing is mandatory for the clinical management of patients with advanced non-small cell lung cancer (NSCLC). Myriads of technical platforms are now available for biomarker analysis with differences in terms of multiplexing capability, analytical sensitivity, and turnaround time (TAT). We evaluated the technical performance of the diagnostic workflows of 24 representative Italian institutions performing molecular tests on a series of artificial reference specimens built to mimic routine diagnostic samples. Methods Sample sets of eight slides from cell blocks of artificial reference specimens harboring exon 19 EGFR (epidermal growth factor receptor) p.E746_AT50del, exon 2 KRAS (Kirsten rat sarcoma viral oncogene homologue) p.G12C, ROS1 (c-ros oncogene 1)-unknown gene fusion, and MET (MET proto-oncogene, receptor tyrosine kinase) Δ exon 14 skipping were distributed to each participating institution. Two independent cell block specimens were validated by the University of Naples Federico II before shipment. Methodological and molecular data from reference specimens were annotated. Results Overall, a median DNA concentration of 3.3 ng/µL (range 0.1–10.0 ng/µL) and 13.4 ng/µL (range 2.0–45.8 ng/µL) were obtained with automated and manual technical procedures, respectively. RNA concentrations of 5.7 ng/µL (range 0.2–11.9 ng/µL) and 9.3 ng/µL (range 0.5–18.0 ng/µL) were also detected. KRAS exon 2 p.G12C, EGFR exon 19 p.E736_A750del hotspot mutations, and ROS1 aberrant transcripts were identified in all tested cases, whereas 15 out of 16 (93.7%) centers detected MET exon 14 skipping mutation. Conclusions Optimized technical workflows are crucial in the decision-making strategy of patients with NSCLC. Artificial reference specimens enable optimization of diagnostic workflows for predictive molecular analysis in routine clinical practice.

Recently, human epidermal growth factor receptor 2 (HER2) has emerged as a therapeutic target of interest for non-small-cell lung cancer in humans. The role of HER2 in canine pulmonary adenocarcinomas is poorly documented. To address this gap, this study employed three methodologies: immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and next-generation sequencing (NGS) to investigate the protein expression, gene amplification, and mutation of HER2 in 19 canine primary pulmonary adenocarcinomas. By IHC, 3 out of 19 cases were overexpressed 3+, 6 were 2+, and 10 were negative. With FISH, 2 cases were amplified (12.5%), 3 were inadequate for the analyses, and the others were non-amplified. With NGS, seven cases were inadequate. All other cases were wild-type, except for one IHC 3+ case, which was amplified with FISH and with a specific mutation already described in human pulmonary adenocarcinoma, V659E. This mutation is probably sensitive to tyrosine kinase inhibitory drugs. These results are similar to those in human medicine and to the few data in the literature on canine lung carcinomas; the presence of 12.5% of amplified cases in dogs lays the foundation for future targeted drugs against HER2 alterations.

Cutaneous melanoma is one of the most lethal tumors among skin cancers, characterized by complex genetic and molecular alterations that result in uncontrolled cell proliferation and metastatic spread. Next-generation sequencing (NGS) enables the simultaneous examination of numerous genes, making this molecular technique essential for melanoma diagnosis, prognostic stratification, and therapy planning. Herein, we present the experience with our laboratory-designed NGS panel for the routine assessment of advanced-stage melanoma. A total of 260 specimens of advanced-stage melanomas were evaluated utilizing a laboratory-developed multi-gene NGS panel, which allowed the investigation of 229 amplicons in 25 oncogene/oncosuppressor genes. The NGS panel proved to be a reliable tool, failing to produce results in only 1.2% of the samples tested. BRAF and TERT were the two more commonly altered genes in 44.0% and 59.9% of samples, respectively. In 59.3% of the mutated cases, at least two concomitant variants were detected. In eight cases, both primary lesion and metastatic disease were analyzed by NGS. In all specimens (8/8, 100%), a perfect concordance in variants harbored by the primary and recurrence lesions was observed. Finally, this study described the validity of a laboratory-developed multi-gene NGS panel built specifically for advanced-stage melanomas in ordinary clinical practice.

Several causes may lead to CRC, either extrinsic (sporadic forms) or genetic (hereditary forms), such as Lynch syndrome (LS). Most sporadic deficient mismatch repair (dMMR) CRC cases are characterized by the methylation of the MLH1 promoter gene and/or BRAF gene mutations. Usually, the first test performed is the mismatch repair deficiency analysis. If a tumor shows a dMMR, BRAF mutations and then the MLH1 promoter methylation status have to be assessed, according to the ACG/ASCO screening algorithm. In this study, 100 consecutive formalin-fixed and paraffin-embedded samples of dMMR CRC were analyzed for both BRAF mutations and MLH1 promoter methylation. A total of 47 (47%) samples were BRAF p.V600E mutated, while MLH1 promoter methylation was found in 77 cases (77.0%). The pipeline “BRAF-followed-by-MLH1-analysis” led to a total of 153 tests, while the sequence “MLH1-followed-by-BRAF-analysis” resulted in a total of 123 tests. This study highlights the importance of performing MLH1 analysis in LS screening of BRAF-WT specimens before addressing patients to genetic counseling. We show that MLH1 analysis performs better as a first-line test in the screening of patients with LS risk than first-line BRAF analysis. Our data indicate that analyzing MLH1 methylation as a first-line test is more cost-effective.

Abstract Papillary thyroid carcinoma tall cell variant (PTC‐TCV), a form of PTC regarded as an aggressive subtype, shares several morphologic features with oncocytic tumors. Pathogenic homoplasmic/highly heteroplasmic somatic mitochondrial DNA (mtDNA) mutations, usually affecting oxidative phosphorylation (OXPHOS) complex I subunits, are hallmarks of oncocytic cells. To clarify the relationship between PTC‐TCV and oncocytic thyroid tumors, 17 PTC‐TCV and 16 PTC non‐TCV controls (cPTC) were subjected to: (1) transmission electron microscopy (TEM) to assess mitochondria accumulation, (2) next‐generation sequencing to analyze mtDNA and nuclear genes frequently mutated in thyroid carcinoma, and (3) immunohistochemistry (IHC) for prohibitin and complex I subunit NDUFS4 to evaluate OXPHOS integrity. TEM showed replacement of cytoplasm by mitochondria in PTC‐TCV but not in cPTC cells. All 17 PTC‐TCV had at least one mtDNA mutation, totaling 21 mutations; 3/16 cPTC (19%) had mtDNA mutations (p

IntroductionThe European Society of Gynecologic Oncology/European Society of Radiation Therapy and Oncology/European Society of Pathology (ESGO/ESTRO/ESP) committee recently proposed a new risk stratification system for endometrial carcinoma (EC) patients that incorporates clinicopathologic and molecular features. The aim of the study is to compare the new ESGO/ESTRO/ESP risk classification system with the previous 2016 recommendations, evaluating the impact of molecular classification and defining a new algorithm for selecting cases for molecular analysis to assign the appropriate risk class.MethodsThe cohort included 211 consecutive EC patients. Immunohistochemistry and next-generation sequencing were used to assign molecular subgroups of EC: POLE mutant (POLE), mismatch repair deficient (MMRd), p53 mutant (p53abn), and no specific molecular profile (NSMP).ResultsImmuno-molecular analysis was successful in all cases, identifying the four molecular subgroups: 7.6% POLE, 32.2% MMRd, 20.9% p53abn, and 39.3% NSMP. The recent 2020 guidelines showed a 32.7% risk group change compared with the previous 2016 classification system: the reassignment is due to POLE mutations, abnormal p53 expression, and a better definition of lymphovascular space invasion. The 2020 system assigns more patients to lower-risk groups (42.2%) than the 2016 recommendation (25.6%). Considering the 2020 risk classification system that includes the difference between “unknown molecular classification” and “known,” the integration of molecular subgroups allowed 6.6% of patients to be recategorized into a different risk class. In addition, the use of the proposed algorithm based on histopathologic parameters would have resulted in a 62.6% reduction in molecular analysis, compared to applying molecular classification to all patients.ConclusionApplication of the new 2020 risk classification integrating clinicopathologic and molecular parameters provided more accurate identification of low-and high-risk patients, potentially allowing a more specific selection of patients for post-operative adjuvant therapy. The proposed histopathologic algorithm significantly decreases the number of tests needed and could be a promising tool for cost reduction without compromising prognostic stratification.

Abstract Background Congenital brain tumors are extremely rare in the neonatal population, and often associated with a poor prognosis. The diagnostic suspicion is often aroused at antenatal scans or postnatally, if clinical signs and symptoms of increased intracranial pressure become evident. We present a case of definitely congenital glioblastoma multiforme incidentally diagnosed in a preterm infant, aiming to raise clinical awareness on this condition and to highlight the challenges of the related diagnostic work-up. Case presentation This female infant was born at 31 weeks’ gestation after an uneventful pregnancy. No abnormalities were detected at antenatal ultrasound scans and genetic tests. Head circumference at birth was on the 25th centile. A routine brain ultrasound scan performed on day 1 revealed a large, inhomogeneous lesion in the right cerebral hemisphere, with contralateral midline shift, which was confirmed by brain magnetic resonance imaging (MRI). Eye fundus and routine blood exams, including platelets count, coagulation screening and C-reactive protein, were normal. Given the high risk of complications, surgical biopsy of the lesion was temporarily hold and a daily sonographic follow-up was undertaken. Although head circumference growth was steady on the 25th centile, progressive changes of the lesion were detected by cranial ultrasound. The repeat MRI scans showed a significant enlargement of the mass, with contralateral midline shift and signs of intralesional and intraventricular bleeding. In view of this worsening, surgical resection was performed. The histological examination of the lesion biopsy documented a GFAP+ highly cellular neoplasm, with no mutation on SMARCB1 gene. At the molecular analysis, mutations on IDH and H3F3A genes were absent, whereas MGMT promoter was unmethylated. The diagnosis was grade IV glioblastoma IDH wild-type. Conclusions Congenital glioblastoma multiforme is an extremely rare but highly aggressive neoplasm. Since intralesional biopsy is not often feasible in affected neonates, knowledge of the associated clinical and neuroradiological features is particularly important, as they can also add useful information on the neoplasm behavior. Specimens from open surgical resection allow to perform a definite histological analysis and an extended molecular characterization, with relevant prognostic implications.

We are recently faced with a progressive evolution of the therapeutic paradigm for radioiodine refractory differentiated thyroid cancer (RAI-R DTC), since the advent of tissue agnostic inhibitors. Thus, tumor genotype assessment is always more relevant and is playing a crucial role into clinical practice. We report the case of an elderly patient with advanced papillary thyroid carcinoma (PTC) harboring RET-CCDC6 fusion with four co-occurring mutations involving PI3KCA, TP53, and hTERT mutations, treated with pralsetinib under a compassionate use program. Despite the high histological grade and the coexistence of aggressive RET co-mutations, an impressive metabolic and structural tumor response has been obtained, together with a patient’s prolonged clinical benefit. A timely comprehensive molecular testing of those cases wild-type for the common thyroid carcinoma BRAF V600E-like and RAS-like driver mutations may uncover actionable gene rearrangements that can be targeted by highly selective inhibitors with great potential benefit for the patients.

BackgroundSDH-deficient gastrointestinal stromal tumors (GIST) account for 20–40% of all KIT/PDGFRA-negative GIST and are due to mutations in one of the four SDH-complex subunits, with SDHA mutations as the most frequent. Here we sought to evaluate the presence and prevalence of SDHA variants in the germline lineage in a population of SDHA-deficient GIST.MethodsGermline SDHA status was assessed by Sanger sequencing on a series of 14 patients with gastric SDHA-deficient GIST.ResultsAll patients carried a germline SDHA pathogenic variant, ranging from truncating, missense, or splicing variants. The second hit was the loss of the wild-type allele or an additional somatic mutation. One-third of the patients were over 50 years old. GIST was the only disease presentation in all cases except one, with no personal or familial cancer history. Seven metastatic cases received a multimodal treatment integrating surgery, loco-regional and medical therapy. The mean follow-up time was of 10 years, confirming the indolent clinical course of the disease.ConclusionSDHA germline variants are highly frequent in SDHA-deficient GIST, and the disease may occur also in older adulthood. Genetic testing and surveillance of SDHA-mutation carriers and relatives should be performed.

IntroductionThe Cancer Genome Atlas (TCGA) project identified four distinct prognostic groups in endometrial cancer (EC), among which two are correlated with an intermediate prognosis: the MisMatch Repair-deficient (MMRd) and the No Specific Molecular Profile (NSMP) groups. The two groups represent a heterogeneous subset of patients frequently harboring CTNNB1 alterations with distinctive clinicopathologic features. The study aimed to evaluate the miRNA expression in ECs to identify potential biomarkers of prognosis.MethodsWe analyzed miRNA expression in 72 ECs classified as MMRd or NSMP including 15 ECs with CTNNB1 mutations. In the discovery step, miRNA expression was evaluated in 30 cases through TaqMan miRNA arrays. Subsequently, four miRNAs were validated in the total cohort of ECs. The data were further tested in the TCGA cohort, and correlations with overall survival (OS) and progression-free interval (PFI) were evaluated.ResultsmiR-499a-3p and miR-499a-5p resulted to be overexpressed in CTNNB1 mutant EC patients at intermediate risk. Similarly, in the TCGA cohort, miR-499a-3p and miR-499a-5p were differentially expressed between CTNNB1 mutant and wild-type patients (p < 0.0001). NSMP patients with low miR-499a-5p expression showed longer OS (p = 0.03, log-rank test). By combining miR-499a-3p or -5p expression levels with the CTNNB1 status, ECs with CTNNB1 mutation and lower miR-499a-5p expression showed better OS compared with the other subgroups (p = 0.03, log-rank test), among the NSMP patients. Moreover, in a multivariate analysis, combination of wild type CTNNB1 status and high miR-499a-5p expression was indipendently associated with high risk of death [HR (95%CI): 3.53 (1.1-10.5), p = 0.02].ConclusionOur results suggest that the combination of CTNNB1 status and miR-499a-5p allows a better stratification of NSMP patients and could promote a personalization of the treatment in intermediate-risk patients.

Despite the efforts made in the management of PDAC, the 5-year relative survival rate of pancreatic ductal adenocarcinoma (PDAC) still remains very low (10%). To date, precision oncology is far from being ready to be applied in cases of PDAC, although studies exploring the molecular and genetic alterations have been conducted, and the genomic landscape of PDAC has been characterized. This study aimed to apply a next-generation sequencing (NGS) laboratory-developed multigene panel to PDAC samples to find molecular alterations that could be associated with histopathological features and clinical outcomes. A total of 68 PDACs were characterized by using a laboratory-developed multigene NGS panel. KRAS and TP53 mutations were the more frequent alterations in 75.0% and 44.6% of cases, respectively. In the majority (58.7%) of specimens, more than one mutation was detected, mainly in KRAS and TP53 genes. KRAS mutation was significantly associated with a shorter time in tumor recurrence compared with KRAS wild-type tumors. Intriguingly, KRAS wild-type cases had a better short-term prognosis despite the lymph node status. In conclusion, our work highlights that the combination of KRAS mutation with the age of the patient and the lymph node status may help in predicting the outcome in PDAC patients.

Since the Cancer Genome Atlas (TCGA) project identified four distinct groups based on molecular alterations, mutation analyses have been integrated into the characterization of endometrial carcinomas (ECs). ARID1A seems to be the subunit more involved in the loss of function of the SWI/SNF complex in ECs. The aim of this study is to define the relevance of ARID1A alterations in a cohort of EC, studying the possible associations between DNA mutation (genomic level), RNA expression (transcriptomic level), and protein expression (proteomic level). A total of 50 endometrial carcinomas were characterized for ARID1A mutations (using targeted DNA next-generation sequencing—NGS), ARID1A gene expression (using RNAseq and qRT-PCR), and ARID1A protein expression (using immunohistochemistry—IHC). Moreover, we have investigated if ARID1A mutations may alter the protein structure, using the Protein Data Bank sequence. We found a good correlation between ARID1A mutations and protein immunostaining, even if we did not find statistically significant differences in the ARID1A expression levels. In conclusion, our data demonstrated that the molecular characterization of ARID1A should be associated with IHC analysis, mainly in those cases harboring “novel” ARID1A mutations or in those alterations with “uncertain” pathogenic significance.

Anaplastic thyroid cancer (ATC) is a rare but highly aggressive form of thyroid cancer. By contrast, differentiated papillary thyroid cancer (PTC) only rarely behave aggressively and develop distant metastasis. Whether distantly metastatic PTC (DM-PTC) and ATC share a common genetic background is still to be defined. We used next-generation sequencing (NGS) to explore the genetic background of a cohort of ATC and DM-PTC and a group of well-differentiated PTCs that did not developed distant metastasis as control (ctrl-PTC). A panel of 128 amplicons within 21 thyroid cancer-related genes was analyzed in a set of 151 thyroid cancer samples including 66 ATCs and DM-PTCs. We showed that the ATC/DM-PTC group had an overall mutational load higher than ctrl-PTCs and that ATCs and DM-PTCs are characterized by a different genetic background, with the exception of mutations in the TERT promoter that were overrepresented in both ATCs (61.1%) and DM-PTCs (48.2%) vs non-aggressive ctrl-PTCs (7.6%). In ATCs, TERT promoter mutations were frequently associated with TP53 mutations, while in the DM-PTCs no significant co-occurrence was observed. No significant association of MED12 mutations with aggressiveness of thyroid cancer was observed in our analysis. Finally, correlation analysis showed that increasing number of mutations negatively impact on patient overall survival also within the ATC and DM-PTC group. In conclusions, overall our analysis further highlights the relevance of TERT promoter mutations in driving aggressiveness and provides new pieces of information in the definition of aggressiveness evolution of thyroid cancer lesions.

The authors wish to make the following corrections to this paper [...]

Ovarian carcinomas represent a heterogeneous group of neoplasms consisting of separate entities with distinct risk factors, precursor lesions, pathogenesis, patterns of spread, molecular profiles, clinical course, response to chemotherapy, and outcomes. The histologic subtype and the related molecular features are essential for individualized clinical decision-making. The fifth edition of the World Health Organization classification of tumors of the female genital tract divides ovarian carcinomas into at least five main and distinct types of ovarian carcinomas: high-grade serous carcinoma, low-grade serous carcinoma, endometrioid carcinoma, clear cell carcinoma, and mucinous carcinoma. Molecular pathology has improved the knowledge of genomic landscape of ovarian carcinomas identifying peculiar alterations for every histologic subtype. It is well-known that high-grade and low-grade serous carcinomas are separate entities with entirely different morphologic and molecular characteristics. TP53 and BRCA mutations are typical of high-grade serous carcinoma, whereas BRAF and KRAS mutations frequently occur in low-grade serous carcinoma. Endometrioid and clear cell carcinomas are frequently associated with endometriosis. Endometrioid tumors are characterized by β-catenin alterations, microsatellite instability, and PTEN and POLE mutations, while ARID1A mutations occur in both endometrioid and clear cell carcinomas. Mucinous carcinomas are uncommon tumors associated with copy-number loss of CDKN2A and KRAS alterations and metastasis from other sites should always be considered in the differential diagnosis.

Background: Non-canonical mutations of the isocitrate dehydrogenase (IDH) genes have been described in about 20–25% and 5–12% of patients with WHO grade II and III gliomas, respectively. To date, the prognostic value of these rare mutations is still a topic of debate. Methods: We selected patients with WHO grade II and III gliomas and IDH1 mutations with available tissue samples for next-generation sequencing. The clinical outcomes and baseline behaviors of patients with canonical IDH1 R132H and non-canonical IDH1 mutations were compared. Results: We evaluated 433 patients harboring IDH1 mutations. Three hundred and ninety patients (90.1%) had a canonical IDH1 R132H mutation while 43 patients (9.9%) had a non-canonical IDH1 mutation. Compared to those with the IDH1 canonical mutation, patients with non-canonical mutations were younger (p < 0.001) and less frequently presented the 1p19q codeletion (p = 0.017). Multivariate analysis confirmed that the extension of surgery (p = 0.003), the presence of the 1p19q codeletion (p = 0.001), and the presence of a non-canonical mutation (p = 0.041) were variables correlated with improved overall survival. Conclusion: the presence of non-canonical IDH1 mutations could be associated with improved survival among patients with IDH1 mutated grade II–III glioma.

Background. Stimulated thyroglobulin levels measured at the time of remnant ablation (A-hTg) and BRAFV600E mutation had shown prognostic value in predicting persistent disease in differentiated thyroid cancer (DTC). The aim of this study was to evaluate the prognostic role of A-hTg combined with the BRAFV600E status in association with the revised American Thyroid Association (ATA) risk stratification. Material and Methods. 620 patients treated for a DTC were included in this study with a median follow-up duration of 6.1 years. All patients underwent total thyroidectomy followed by radioiodine ablation. Patients with positive anti-thyroglobulin antibodies were excluded. The predictive value of A-hTg was calculated by receiver operating characteristic curve (ROC curve) analysis. The Cox proportional hazard regression model, including the BRAF status, A-hTg, and ATA classification system, was assessed to evaluate the existing persistent disease risk. Results. Taken together, the BRAF status and A-hTg levels improve the ATA risk classification in all categories. In particular, in the low-risk ATA classification, only the combination of BRAFV600E+A-hTg>8.9ng/ml was associated with persistent disease (P=0.001, HR 60.2, CI 95% 5.28-687). In the intermediate-risk ATA classification, BRAFWT+A-hTg>8.9ng/ml was associated with persistent disease (P=0.029, HR 2.71, CI 95% 1.106-6.670) and BRAFV600E+A-hTg>8.9ng/ml was also associated with persistent disease (P8.9 ng/ml were associated with persistent disease (P=0.042, HR 5.963, CI 95% 1.069-33.255 and P=0.002, HR 11.564, CI 95% 2.543-52.576, respectively). Conclusions. The BRAF status and stimulated thyroglobulin levels at ablation time improve the ATA risk stratification of differentiated thyroid cancer; therefore, even A-hTg could be included in risk classification factors.

Next generation sequencing (NGS) allows parallel sequencing of multiple genes at a very high depth of coverage. The need to analyze a variety of targets for diagnostic/prognostic/predictive purposes requires multi-gene characterization. Multi-gene panels are becoming standard approaches for the molecular analysis of solid lesions. We report a custom-designed 128 multi-gene panel engineered to cover the relevant targets in 22 oncogene/oncosuppressor genes for the analysis of the solid tumors most frequently subjected to routine genotyping. A total of 1695 solid tumors were analyzed for panel validation. The analytical sensitivity is 5%. Analytical validation: (i) Accuracy: sequencing results obtained using the multi-gene panel are concordant using two different NGS platforms and single-gene approach sequencing (100% of 83 cases); (ii) Precision: consistent results are obtained in the samples analyzed twice with the same platform (100% of 20 cases). Clinical validation: the frequency of mutations identified in different tumor types is consistent with the published literature. This custom-designed multi-gene panel allows to analyze with high sensitivity and throughput 22 oncogenes/oncosuppressor genes involved in diagnostic/prognostic/predictive characterization of central nervous system tumors, non-small-cell lung carcinomas, colorectal carcinomas, thyroid nodules, pancreatic lesions, melanoma, oral squamous carcinomas and gastrointestinal stromal tumors.

Medulloblastoma is a highly aggressive brain tumor that typically affects children, while in adults it represents ~1% of all brain tumors. Little is known about microRNA expression profile of the rare adult medulloblastoma. The main aim of this study was to identify peculiar differences in microRNA expression between childhood and adult medulloblastoma. Medulloblastomas were profiled for microRNA expression using the Exiqon Human miRNome panel (I + II) analyzing 752 microRNAs in a training set of six adult and six childhood cases. Then, the most differentially expressed microRNAs were validated in a total of 21 adult and 19 childhood cases. Eight microRNAs (miR-196b-5p, miR-183-5p, miR-200b-3p, miR-196a-5p, miR-193a-3p, miR-29c-3p, miR-33b-5p, and miR-200a-3p) were differentially expressed in medulloblastoma of adults and children. Analysis of the validation set confirmed that miR-196b-5p and miR-200b-3p were significantly overexpressed in medulloblastoma of adults as compared with those of children. We followed an in silico approach to investigate direct targets and the pathways involved for the two microRNAs (miR-196b and miR-200b) differently expressed between adult and childhood medulloblastoma. Adult and childhood medulloblastoma have different miRNA expression profiles. In particular, the differential dysregulation of miR-196b-5p and miR-200b-3p characterizes the miRNA profile of adult medulloblastoma and suggests potential targets for novel diagnostic, prognostic, or therapeutic strategies.

Background/Aims: Iodide efflux from thyroid cells into the follicular lumen is essential for the synthesis of thyroid hormones, however, the pathways mediating this transport have only been partially identified. A calcium-activated pathway of iodide efflux has long been recognized, but its molecular identity unknown. Anoctamin 1 (ANO1) is a calcium-activated chloride channel (CaCC), and this study aims to investigate its contribution to iodide fluxes in thyroid cells. Methods: RT-PCR, immunohistochemistry, and live cell imaging with the fluorescent halide biosensor YFP-H148Q/I152L were used to study the expression, localization and function of ANO1 in thyroid cells. Results: ANO1 mRNA was detected in human thyroid tissue and FRTL-5 thyrocytes, and ANO1 protein was localized to the apical membrane of follicular cells. ATP induced a transient loss of iodide from FRTL-5 cells that was dependent on the mobilization of intracellular calcium, and was inhibited by CaCC/ANO1 inhibitors and siRNA against ANO1. Calcium-activated iodide efflux was also observed in CHO cells over-expressing the Sodium Iodide Symporter (NIS) and ANO1. Conclusion: ANO1 in thyrocytes functions as a calcium-activated channel mediating iodide efflux, and may contribute to the rapid delivery of iodide into the follicular lumen for the synthesis of thyroid hormones following activation by calcium-mobilizing stimuli.

Pancreatic adenocarcinoma (PAC) is a very aggressive cancer with a poor prognosis. To date, the causes and pathogenetic mechanisms involved in the development of this malignancy remain largely unknown. Therefore, additional studies are required to improve our knowledge of the events that occur during the process of pancreatic carcinogenesis. The purpose of this article is to describe the most recent evidence, concerning the possible risk factors and mechanisms that may contribute to determine the development of PAC, as well as models, such as the tensegrity model, that may explain this complex process. Available studies suggest that approximately 15-20% of human malignancies are somehow associated with chronic infection. Some epidemiological research has shown that some infectious agents represent risk factors for PAC. In particular, several reports showed that the infection caused by some micro-organisms, including helicobacter pylori and some bacterial species of oral microbiota, as well as by viral agents, such as human immunodeficiency virus (HIV), and hepatitis B (HBV) and C (HCV) viruses, is associated with an increased probability of developing PAC. For the first time, observational studies and meta-analyses have suggested that HBV and HCV, two hepatotropic viruses with oncogenic properties, may be also risk factors for PAC. However, the small number of available reports, nearly all performed in Asian populations, limits their validity to these ethnic groups. Therefore, additional studies focusing on populations of different geographical areas and enrolling larger series of patients are required to confirm this association. Furthermore, an accurate description and a better understanding of the events and of the pathogenetic mechanisms involved in the process of pancreatic carcinogenesis, as proposed by the tensegrity model, might be a useful approach to effectively deal with this pathology.

BACKGROUND:Epidermal Growth Factor Receptor (EGFR) molecular analysis is performed to assess the responsiveness to Tyrosine Kinase Inhibitors (TKIs) in patients with Non-Small Cell Lung Cancer (NSCLC). The existence of molecular intra-tumoral heterogeneity has been observed in lung cancers. The aim of the present study is to investigate if the percentage of mutated neoplastic cells within the tumor sample might influence the responsiveness to TKIs treatment. MATERIAL AND METHODS:A total of 931 cases of NSCLC were analyzed for EGFR mutational status (exon 18, 19, 20, 21) using Next Generation Sequencer. The percentage of mutated neoplastic cells was calculated after normalizing the percentage of mutated alleles obtained after next generation sequencer analysis with the percentage of neoplastic cells in each tumor. RESULTS:Next generation sequencing revealed an EGFR mutation in 167 samples (17.9%), mainly deletions in exon 19. In 18 patients treated with TKIs and with available follow-up, there was a significant correlation between the percentage of mutated neoplastic cells and the clinical response (P = 0.017). Patients with a percentage of mutated neoplastic cells greater than 56%, have a statistical trend (P = 0.081) for higher Overall Survival (26.3 months) when compared to those with a rate of mutated neoplastic cells lower than 56% (8.2 months). CONCLUSIONS:The percentage of EGFR-mutated neoplastic cells in the tumor is associated with response to TKIs. A "quantitative result" of EGFR mutational status might provide useful information in order to recognize those patients which might have the greatest benefit from TKIs.

The use of endoscopic ultrasonography has allowed for improved detection and pathologic analysis of fine needle aspirate material for pancreatic lesion diagnosis. The molecular analysis of KRAS has further improved the clinical sensitivity of preoperative analysis. For this reason, the use of highly analytical sensitive and specific molecular tests in the analysis of material from fine needle aspirate specimens has become of great importance. In the present study, 60 specimens from endoscopic ultrasonography fine needle aspirate were analyzed for KRAS exon 2 and exon 3 mutations, using three different techniques: Sanger sequencing, allele specific locked nucleic acid PCR and Next Generation sequencing (454 GS-Junior, Roche). Moreover, KRAS was also tested in wild-type samples, starting from DNA obtained from cytological smears after pathological evaluation. Sanger sequencing showed a clinical sensitivity for the detection of the KRAS mutation of 42.1%, allele specific locked nucleic acid of 52.8% and Next Generation of 73.7%. In two wild-type cases the re-sequencing starting from selected material allowed to detect a KRAS mutation, increasing the clinical sensitivity of next generation sequencing to 78.95%. The present study demonstrated that the performance of molecular analysis could be improved by using highly analytical sensitive techniques. The Next Generation Sequencing allowed to increase the clinical sensitivity of the test without decreasing the specificity of the analysis. Moreover we observed that it could be useful to repeat the analysis starting from selectable material, such as cytological smears to avoid false negative results.

Selection of lung cancer patients for therapy with tyrosine kinase inhibitors directed at EGFR requires the identification of specific EGFR mutations. In most patients with advanced, inoperable lung carcinoma limited tumor samples often represent the only material available for both histologic typing and molecular analysis. We defined a next generation sequencing protocol targeted to EGFR exons 18-21 suitable for the routine diagnosis of such clinical samples. The protocol was validated in an unselected series of 80 small biopsies (n=14) and cytology (n=66) specimens representative of the material ordinarily submitted for diagnostic evaluation to three referral medical centers in Italy. Specimens were systematically evaluated for tumor cell number and proportion relative to non-neoplastic cells. They were analyzed in batches of 100-150 amplicons per run, reaching an analytical sensitivity of 1% and obtaining an adequate number of reads, to cover all exons on all samples analyzed. Next generation sequencing was compared with Sanger sequencing. The latter identified 15 EGFR mutations in 14/80 cases (17.5%) but did not detected mutations when the proportion of neoplastic cells was below 40%. Next generation sequencing identified 31 EGFR mutations in 24/80 cases (30.0%). Mutations were detected with a proportion of neoplastic cells as low as 5%. All mutations identified by the Sanger method were confirmed. In 6 cases next generation sequencing identified exon 19 deletions or the L858R mutation not seen after Sanger sequencing, allowing the patient to be treated with tyrosine kinase inhibitors. In one additional case the R831H mutation associated with treatment resistance was identified in an EGFR wild type tumor after Sanger sequencing. Next generation sequencing is robust, cost-effective and greatly improves the detection of EGFR mutations. Its use should be promoted for the clinical diagnosis of mutations in specimens with unfavorable tumor cell content.

The use of tyrosine kinase inhibitors (TKIs) requires the testing for hot spot mutations of the molecular effectors downstream the membrane-bound tyrosine kinases since their wild type status is expected for response to TKI therapy. We report a novel assay that we have called Allele Specific Locked Nucleic Acid quantitative PCR (ASLNAqPCR). The assay uses LNA-modified allele specific primers and LNA-modified beacon probes to increase sensitivity, specificity and to accurately quantify mutations. We designed primers specific for codon 12/13 KRAS mutations and BRAF V600E, and validated the assay with 300 routine samples from a variety of sources, including cytology specimens. All were analyzed by ASLNAqPCR and Sanger sequencing. Discordant cases were pyrosequenced. ASLNAqPCR correctly identified BRAF and KRAS mutations in all discordant cases and all had a mutated/wild type DNA ratio below the analytical sensitivity of the Sanger method. ASLNAqPCR was 100% specific with greater accuracy, positive and negative predictive values compared with Sanger sequencing. The analytical sensitivity of ASLNAqPCR is 0.1%, allowing quantification of mutated DNA in small neoplastic cell clones. ASLNAqPCR can be performed in any laboratory with real-time PCR equipment, is very cost-effective and can easily be adapted to detect hot spot mutations in other oncogenes.