Giorgia Acquaviva

Possible association between hepatitis C virus and malignancies different from hepatocellular carcinoma: A systematic review

AIM To summarize the current knowledge about the potential relationship between hepatitis C virus (HCV) infection and the risk of several extra-liver cancers. METHODS We performed a systematic review of the literature, according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) Statement. We extracted the pertinent articles, published in MEDLINE and the Cochrane Library, using the following search terms: neoplasm/cancer/malignancy/tumor/carcinoma/adeno-carcinoma and non-Hodgkin lymphomas, kidney/renal-, cholangio-, pancreatic-, thyroid-, breast-,oral-, skin-, prostate-, lung-, colon-, stomach-, haematologic. Case series, case-series with control-group, case-control, cohort-studies as well as meta-analyses, written in English were collected. Some of the main characteristics of retrieved trials, which were designed to investigate the prevalence of HCV infection in each type of the above-mentioned human malignancies were summarised. A main table was defined and included a short description in the text for each of these tumours, whether at least five studies about a specific neoplasm, meeting inclusion criteria, were available in literature. According to these criteria, we created the following sections and the corresponding tables and we indicated the number of included or excluded articles, as well as of meta-analyses and reviews: (1) HCV and haematopoietic malignancies; (2) HCV and cholangiocarcinoma; (3) HCV and pancreatic cancer; (4) HCV and breast cancer; (5) HCV and kidney cancer; (6) HCV and skin or oral cancer; and (7) HCV and thyroid cancer. RESULTS According to available data, a clear correlation between regions of HCV prevalence and risk of extra-liver cancers has emerged only for a very small group of types and histological subtypes of malignancies. In particular, HCV infection has been associated with: (1) a higher incidence of some B-cell Non-Hodgkin-Lymphoma types, in countries, where an elevated prevalence of this pathogen is detectable, accounting to a percentage of about 10%; (2) an increased risk of intra-hepatic cholangiocarcinoma; and (3) a correlation between HCV prevalence and pancreatic cancer (PAC) incidence. CONCLUSION To date no definitive conclusions may be obtained from the analysis of relationship between HCV and extra-hepatic cancers. Further studies, recruiting an adequate number of patients are required to confirm or deny this association.

BRAF V600E and risk stratification of thyroid microcarcinoma: a multicenter pathological and clinical study.

Studies from single institutions have analyzed BRAF in papillary microcarcinomas, sometimes with contradictory results. Most of them have provided limited integration of histological and clinical data. To obtain a comprehensive picture of BRAF V600E-mutated microcarcinomas and to evaluate the role of BRAF testing in risk stratification we performed a retrospective multicenter analysis integrating microscopical, pathological, and clinical information. Three hundred and sixty-five samples from 300 patients treated at six medical institutions covering different geographical regions of Italy were analyzed with central review of all cases. BRAF V600E statistical analysis was conducted on 298 microcarcinomas from 264 patients after exclusion of those that did not meet the required criteria. BRAF V600E was identified in 145/298 tumors (49%) including the following subtypes: 35/37 (95%, P<0.0001) tall cell and 72/114 (64%, P<0.0001) classic; conversely 94/129 follicular variant papillary microcarcinomas (73%, P<0.0001) were BRAF wild type. BRAF V600E-mutated microcarcinomas were characterized by markedly infiltrative contours (P<0.0001) with elongated strings of neoplastic cells departing from the tumor, and by intraglandular tumor spread (P<0.0001), typically within 5 mm of the tumor border. Multivariate analysis correlated BRAF V600E with specific microscopic features (nuclear grooves, optically clear nuclei, tall cells within the tumor, and tumor fibrosis), aggressive growth pattern (infiltrative tumor border, extension into extrathyroidal tissues, and intraglandular tumor spread), higher American Thyroid Association recurrence risk group, and non-incidental tumor discovery. The following showed the strongest link to BRAF V600E: tall cell subtype, many neoplastic cells with nuclear grooves or with optically clear nuclei, infiltrative growth, intraglandular tumor spread, and a tumor discovery that was non-incidental. BRAF V600E-mutated microcarcinomas represent a distinct biological subtype. The mutation is associated with conventional clinico-pathological features considered to be adverse prognostic factors for papillary microcarcinoma, for which it could be regarded as a surrogate marker. BRAF analysis may be useful to identify tumors (BRAF wild type) that have negligible clinical risk.

Contribution of microRNA analysis to characterisation of pancreatic lesions: a review

Pancreatic tumours are usually very aggressive cancer with a poor prognosis. A limitation of pancreatic imaging techniques is that lesions are often of ambiguous relevance. The inability to achieve a definitive diagnosis based on cytological evaluation of specimens, due to sampling error, paucicellular samples or coexisting inflammation, might lead to delay in clinical management. Given the morbidity associated with pancreatectomy, a proper selection of patients for surgery is fundamental. Many studies have been conducted in order to identify specific markers that could support the early diagnosis of pancreatic lesions, but, to date, none of them allow to diagnose pancreatic cancer with high sensitivity and specificity. MicroRNAs (miRNA) are small non-coding RNAs (19–25 nucleotides) that regulate gene expression interacting with mRNA targets. It is now established that each tissue shows a characteristic miRNA expression pattern that could be modified in association with a number of different diseases including neoplasia. Due to their key role in the regulation of gene expression, in the last years several studies have investigated miRNA tissue-specific expression, quantification and functional analysis to understand their peculiar involvement in cellular processes. The aim of this review is to focus on miRNA expression in pancreatic cancer and their putative role in early characterisation of pancreatic lesions.

RET mutation and increased angiogenesis in medullary thyroid carcinomas

Advanced medullary thyroid cancers (MTCs) are now being treated with drugs that inhibit receptor tyrosine kinases, many of which involved in angiogenesis. Response rates vary widely, and toxic effects are common, so treatment should be reserved for MTCs likely to be responsive to these drugs. RET mutations are common in MTCs, but it is unclear how they influence the microvascularization of these tumors. We examined 45 MTCs with germ-line or somatic RET mutations (RETmut group) and 34 with wild-type RET (RETwt). Taqman Low-Density Arrays were used to assess proangiogenic gene expression. Immunohistochemistry was used to assess intratumoral, peritumoral and nontumoral expression levels of VEGFR1, R2, R3, PDGFRa, PDGFB and NOTCH3. We also assessed microvessel density (MVD) and lymphatic vessel density (LVD) based on CD31-positive and podoplanin-positive vessel counts, respectively, and vascular pericyte density based on staining for a-smooth muscle actin (a-SMA), a pericyte marker. Compared with RETwt tumors, RETmut tumors exhibited upregulated expression of proangiogenic genes (mRNA and protein), especially VEGFR1, PDGFB and NOTCH3. MVDs and LVDs were similar in the two groups. However, microvessels in RETmut tumors were more likely to be a-SMA positive, indicating enhanced coverage by pericytes, which play key roles in vessel sprouting, maturation and stabilization. These data suggest that angiogenesis in RETmut MTCs may be more intense and complete than that found in RETwt tumors, a feature that might increase their susceptibility to antiangiogenic therapy. Given their increased vascular pericyte density, RETmut MTCs might also benefit from combined or preliminary treatment with PDGF inhibitors.

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET–PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular‐patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non‐invasive follicular thyroid neoplasm with papillary‐like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen‐activated protein kinase and phosphoinositide 3‐kinase–PTEN–AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance.

Non-canonical IDH1 and IDH2 mutations: a clonal and relevant event in an Italian cohort of gliomas classified according to the 2016 World Health Organization (WHO) criteria

According to the 2016 World Health Organization (WHO) classification of tumors of the central nervous system, assessment of exon 4 mutations in isocitrate dehydrogenase 1 or 2 genes (IDH1 or IDH2) is an essential step in the characterization of gliomas. The p.R132H mutation is the most frequent alteration in IDH genes, however other non-canonical IDH mutations can be identified. The aim of this study is to investigate in depth the prevalence of non-R132H IDH (“non-canonical”) mutations in brain tumors classified according to the 2016 WHO scheme and their clonal distribution in neoplastic cells. A total of 288 consecutive cases of brain gliomas (grade II–IV) were analyzed for exon 4 IDH1 and IDH2 mutations. IDH1 and IDH2 analysis was performed using next generation sequencing. Non-canonical IDH mutations were identified in 13/52 (25.0%) grade II gliomas (astrocytomas: 8/31, 25.8%; oligodendrogliomas: 5/21, 23.8%) and in 5/40 (12.5%) grade III gliomas (astrocytomas: 3/25, 12.0%; oligodendrogliomas: 2/15, 13.3%). They were not identified in 196 grade IV gliomas (192 glioblastomas, 4 gliosarcomas). In the large majority (>80%) of tumors IDH mutations, both IDH1-R132H and the non-canonical ones, were present in the large majority (>80%) of neoplastic cells. Our data highlight the importance of investigating not only the IDH1-R132H mutation but also the non-canonical ones. These mutations are clonally distributed, with proportions of mutated neoplastic cells overlapping with those of p.R132H, a finding consistent with their driver role in gliomagenesis.

Deep sequencing of KIT, MET, PIK3CA, and PTEN hotspots in papillary thyroid carcinomas with distant metastases

Well-differentiated papillary thyroid carcinoma (PTC) accounts for w90% of all thyroid cancers. While the majority of these tumors tend to behave as indolent lesions, a fraction of PTCs is highly aggressive and results in disseminated systemic spread to distant sites (Pellegriti et al. 2013). Numerous studies attempted to define the prognostic markers able to discriminate at diagnosis PTCs with more aggressive behavior from those with an indolent course (Handkiewicz-Junak et al. 2010). Nonetheless, the usefulness of genetic analysis in PTC patient management is still controversial, probably due to the fact that our knowledge about the genetic asset of aggressive PTCs is still very limited. The low occurrence of distant metastases and death among the overall PTC cases, and hence the difficulty in collecting large cohorts of PTCs that developed distant metastases (DM-PTCs), has been an important limitation for studies that attempted to correlate genetic alterations with prognosis and outcome of PTC patients. An additional level of complexity on this issue comes from the genetic heterogeneity of tumors. Mutations that are drivers of aggressiveness are likely to occur as late secondary events during tumor progression and to be confined to small sub-populations of cells, which may compromise the possibility of detecting them using the standard sequencing technique. Based on this consideration, we investigated a large cohort of 39 DM-PTCs and 20 control PTCs (without distant metastases), by performing a deep sequencing analysis of eight mutational hotspots in KIT, MET, PI3KCA, and PTEN genes. These hotspots were chosen as they were associated with aggressive features of various epithelial cancers, but they have been scarcely investigated or rarely found mutated in the general population of non-aggressive welldifferentiated PTCs (Garcia-Rostan et al. 2005, Wasenius et al. 2005, Hou et al. 2007, Broecker-Preuss et al. 2008, Santarpia et al. 2008, Xing 2010).

The Role of Next-Generation Sequencing in the Cytologic Diagnosis of Pancreatic Lesions

CONTEXT - Integration of the analysis of genetic markers with endoscopic ultrasound-guided fine-needle aspiration and cytologic evaluation has increased the accuracy of the preoperative diagnosis of pancreatic lesions. The application of high-throughput gene panel analysis using next-generation sequencing platforms is now offering a great opportunity for further improvements. OBJECTIVE - To review the application of next-generation sequencing to the preoperative diagnosis of pancreatic lesions. DATA SOURCES - For data acquisition, a PubMed search using the terms next-generation sequencing, pancreas, pancreatic lesions, pancreatic tumors, and EUS-FNA was performed covering the years 2000-2017. CONCLUSIONS - KRAS remains the gene most widely studied for preoperative single-gene tests. Next-generation sequencing reliably allows analysis of multiple gene markers starting from limited amounts of DNA. The study of multigene panels has become a very attractive option for the management and preoperative risk stratification of patients with pancreatic cancer.

The percentage of Epidermal Growth Factor Receptor (EGFR)-mutated neoplastic cells correlates to response to tyrosine kinase inhibitors in lung adenocarcinoma

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.

Role of microRNAs in the main molecular pathways of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignant neoplasia. HCC is characterized by a poor prognosis. The need to find new molecular markers for its diagnosis and prognosis has led to a progressive increase in the number of scientific studies on this topic. MicroRNAs (miRNAs) are small non-coding RNA that play a role in almost all main cellular pathways. miRNAs are involved in the regulation of expression of the major tumor-related genes in carcinogenesis, acting as oncogenes or tumor suppressor genes. The aim of this review was to identify papers published in 2017 investigating the role of miRNAs in HCC tumorigenesis. miRNAs were classified according to their role in the main molecular pathways involved in HCC tumorigenesis: (1) mTOR; (2) Wnt; (3) JAK/STAT; (4) apoptosis; and (5) MAPK. The role of miRNAs in prognosis/response prediction was taken into consideration. Bearing in mind that the analysis of miRNAs in serum and other body fluids would be crucial for clinical management, the role of circulating miRNAs in HCC patients was also investigated. The most represented miRNA-regulated pathway in HCC is mTOR, but apoptosis, Wnt, JAK/STAT or MAPK pathways are also influenced by miRNA expression levels. These miRNAs could thus be used in clinical practice as diagnostic, prognostic or therapeutic targets for HCC treatment.