Hana Vošmiková

High-risk human papillomavirus infection and p16INK4a protein expression in laryngeal lesions.

A total of 88 samples of laryngeal lesions (23 vocal cord nodules (VCNs), 23 papillomas (PAs), 18 dysplasias (DYs), and 24 carcinomas (CAs)) were analyzed for p16INK4a protein (p16) expression by immunohistochemistry and for high-risk human papillomavirus (HR-HPV) infection using chromogene in situ hybridization (CISH) and polymerase chain reaction (PCR). The series comprised 62 males and 26 females, aged 1-87 years (median 55 years). p16 expression was detected in 2 of 23 (9%) VCNs, 18 of 23 (78%) PAs, 9 of 18 (50%) DYs, and 14 of 24 (58%) CAs. Using CISH, HR-HPV DNA was detected in 3 of 23 (13%) VCNs, in 19 of 23 (83%) PAs, in 12 of 18 (67%) DYs, and in 14 of 24 (58%) CAs. HR-HPV DNA was found in six of nine (67%) PAs by PCR. A statistically significant difference in p16 expression and HR-HPV DNA presence detected by CISH was observed between VCNs and PAs (p<0.000001). The sensitivity and specificity of p16 expression for HR-HPV DNA presence detected by CISH was 0.612 and 0.773, respectively. Our study confirms a potential role of HR-HPV infection not only in the pathogenesis of malignant, but also in benign laryngeal lesions.

SMARCB1/INI1-deficient sinonasal carcinoma shows methylation of RASSF1 gene: A clinicopathological, immunohistochemical and molecular genetic study of a recently described entity.

The aim of the study was detailed clinicopathological investigation of SMARCB1/INI1-deficient sinonasal carcinomas, including molecular genetic analysis of mutational status and DNA methylation of selected protooncogenes and tumor suppressor genes by means of next generation sequencing (NGS) and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). A total of 4/56 (7%) cases of SMARCB1/INI1-deficient carcinomas were detected among 56 sinonasal carcinomas diagnosed over a 19year period using immunohistochemical screening. The series comprised 3 males and 1 female, aged 27-76 years (median 64 years). All tumors arose in the nasal cavity. Three neoplasms were diagnosed in advanced stage pT4. During the follow-up period (range 14-111 months (median 72 months)), three tumors recurred locally, but none of the patients developed regional or distant metastases. Ultimately, two patients died due to the tumor. Microscopically, all tumors consisted of infiltrating nests of polygonal basaloid cells with a variable component of rhabdoid cells with eosinophilic cytoplasm. Immunohistochemically, there was almost diffuse expression of cytokeratins (CK), p16, p40 and p63 in all cases, while expression of CK5/6, CK7 and vimentin was only focal or absent. The detection of NUT gave negative results. In three cases, the absence of SMARCB1/INI1 expression was due to deletion of SMARCB1/INI1 gene. Methylation of SMARCB1/INI1 gene was not found. One tumor harbored HPV18 E6/E7 mRNA. All 12 genes (BRAF, BRCA1, BRCA2, KIT, EGFR, KRAS, NRAS, PDGFRA, PIK3CA, PTEN, RET, and ROS1) tested for mutations using NGS were wild-type. Regarding DNA methylation, all four SMARCB1/INI1-deficient tumors showed methylation of RASSF1 gene by means of MS-MLPA. There was a statistically significant difference in RASSF1 gene methylation between SMARCB1/INI1-deficient and SMARCB1/INI1-positive tumors (p=0.0095). All other examined genes (ATM, BRCA1, BRCA2, CADM1, CASP8, CD44, CDKN1B, CDKN2A, CDKN2B, CHFR, DAPK1, ESR1, FHIT, GSTP1, HIC1, KLLN, MLH1a, MLH1b, RARB, and VLH) were unmethylated. In summary, we described four cases of SMARCB1/INI1-deficient sinonasal carcinoma with detailed clinicopathological data indicating that these tumors can be regarded as a distinct entity with aggressive behaviour. For the first time, we performed analysis of DNA methylation in SMARCB1/INI1-deficient sinonasal carcinomas, reporting on significantly higher methylation of RASSF1 gene in this neoplasm.

Deregulation of selected microRNAs in sinonasal carcinoma: Value of miR-21 as prognostic biomarker in sinonasal squamous cell carcinoma

Tumors occurring in the sinonasal area are characterized by unfavorable outcome due to difficult diagnosis, treatment, and prognosis of the disease corresponding with the anatomic complexity of the area.

Hypersensitivity to chemoradiation in FANCA carrier with cervical carcinoma-A case report and review of the literature.

OBJECTIVE Compared to Fanconi anemia (FA) patients with homozygous defective two-alleles inheritance, there is a scarce or no evidence on one defective allele FANCA carriers, with respect to their cancer incidence, clinical and in vitro radiosensitivity and chemosensitivity. On that account, we report a case of a 30-year old FANCA mutation carrier woman with uterine cervix adenocarcinoma who was treated with chemoradiotherapy, in which unexpected acute toxicity and fatal late morbidity occured. METHODS We also report the results of an in vitro test for radiosensitivity, immunohistochemical examination with FANCA staining and human papillomavirus genotypization, and a review of the literature for FA carrier patients with respect to cancer incidence, clinical and in vitro response to chemo/radiotherapy, options of early heterozygosity detection, and methods of in vitro prediction of hypersensitivity to oncologic treatment. CONCLUSION Although there are no standard guidelines for management of FA carriers with malignancies and reports about chemo- or radiosensitivity in this population are scarce; patients with FA-A heterozygosity may have a high rate of complications from chemo/radiotherapy. Up to now, an optimum method for the prediction of radiosensitivity and the best parameter has not been found. Clinical radioresponsiveness is unpredictable in FA carriers and there is a pressing need of new rapid and predictive in vitro assays of radiation responses. Until then, the treatment of FA carriers with malignancies should be individualized, with respect to potential hypersensitivity to ionizing radiation or cross-linking agents.

MicroRNA expression in SMARCB1/INI1-deficient sinonasal carcinoma: a clinicopathological and molecular genetic study

Carcinomas of the sinonasal tract comprise of a heterogenous group of rare malignant tumors, of which the etiopathogenesis is largely unknown. In about 20–30% of sinonasal squamous cell carcinomas, high-risk human papillomavirus (HPV) has been identified, making the sinonasal area the second hot spot for HPV-associated carcinomas of the head and neck, after the oropharynx [1–3]. Genome abnormalities associated with sinonasal carcinoma have not (yet) been fully elucidated. The nuclear protein in testis (NUT) carcinoma is an exception, as this very aggressive malignancy is defined by rearrangement of the NUT gene on chromosome 15q14 [4]. A distinct subset of sinonasal carcinoma, characterized by loss of expression of the SMARCB1/INI1 (SWI/SNF-related matrix-associated actindependent regulator of chromatin subfamily B member 1/ integrase interactor 1) protein, has been identified recently [5, 6]. Although about 60 cases of SMARCB1/INI1deficient sinonasal carcinomas have been reported to date [5–10], their molecular features have not been described in detail. In a previous study [11], we analyzed SMARCB1/INI1deficient sinonasal carcinomas for DNA methylation of 24 selected tumor suppressor genes and found in all cases methylation of the RASSF1 gene promoter, which is involved in microtubule stability, apoptosis, and cell cycle regulation [12]. The aim of the present study was to investigate by polymerase chain reaction (PCR) expression of selected microRNAs (miRNAs) in SMARCB1/INI1-deficient sinonasal carcinomas.

Detection of EGFR Mutations in Circulating Tumor DNA (ctDNA) Retrieved from Plasma – Interlaboratory Quality Assessment in the Czech Republic

BACKGROUND Detection of EGFR mutations in tumor tissue represents a standard testing procedure in patients with non-small cell lung cancer. Molecular testing of circulating tumor DNA (ctDNA) in plasma enables detection of mutations in cases where tumor specimens are unavailable or when monitoring of therapeutic responses is necessary. In addition, according to the recent literature, ctDNA better reflects the heterogeneity of the neoplastic cell population than isolated tumor lesion or metastasis. We report a national interlaboratory evaluation aimed at assessing the analytical quality of ctDNA EGFR testing in plasma across seven reference laboratories in the Czech Republic. MATERIAL AND METHODS Aliquots of 13 plasma samples were sent to 7 laboratories and consisted of commercially available 2ml plasma specimens of genomic DNA with mutant allelic frequencies of 5, 0.5, 0.05, and 0% of the most common sensitizing mutations (deletion in exon 19, L858R) and the resistance mutation T790M. DNA extraction and EGFR testing were performed according to standard procedures. In 6/7 laboratories the cobas® EGFR Mutation Test v2 was used. One laboratory employed the Super-ARMS® EGFR Mutation Detection Kit. RESULTS In total, 91 genotypes were determined with an overall error rate of 24.2% (22/91). The overall error rates were 3.2% (2/63) for the 0.5% mutation frequency and 0% for the 5% mutation frequency (0/35), respectively. No false positive results were reported. The cobas® method achieved consistent results with the 0.05% mutation frequency for the exon 19 deletion. For L858R and T790M mutations, the threshold was above the 0.5% frequency. CONCLUSIONS The results show that EGFR testing for ctDNA in plasma has limited sensitivity, especially for detection of the T790M mutation. Particularly, in ctDNA testing of very low mutated DNA plasma fractions (below 0.01%), emphasis should be placed on the use of highly sensitive molecular methods. The outcomes of this quality assessment confirm the need for rebiopsy in patients with negative plasma results because of a higher false negative rate in comparison to tissue testing. Key words: circulating DNA - liquid biopsy - epidermal growth factor receptor - non-small cell lung cancer - quality control This work was supported by grants of AstraZeneca and the project of the Ministry of Health number 00064203 (Motol University Hospital). The authors declare they have no potential confl icts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 4. 6. 2018 Accepted: 1. 8. 2018.

Malignant Melanoma – from Classical Histology towards Molecular Genetic Testing

BACKGROUND Malignant melanoma is - in comparison with other skin tumors - a relatively rare malignant neoplasm with highly aggressive biologic behavior and variable prognosis. Recent data in pathology and molecular diagnostics indicate that malignant melanoma is in fact not a single entity but a group of different neoplasms with variable etiopathogenesis, biologic behavior and prognosis. New therapeutic options using targeted treatment blocking MAPK signaling pathway require testing of BRAF gene mutation status. This helps to select patients with highest probability of benefit from this treatment. AIM This article summarizes information on the correlation of morphological findings with genetic changes, discusses the representation of individual genetic types in various morphological subgroups and deals with the newly proposed genetic classification of melanoma and the current possibilities, pitfalls and challenges in BRAF testing of malignant melanoma. It also describes the current testing situation in the Czech Republic - the methods used, the representation of BRAF mutations in the tested population and the future of testing. It also shows the limitations of the BRAF and MEK targeted treatment concept resulting from the heterogeneity of the tumor population. Mechanisms of acquired resistance to MAPK pathway inhibitors, possibilities of their detection, and issues of combination of targeted therapy and immunotherapy are discussed.Key words: malignant melanoma - BRAF - mutation - molecular targeted therapy - tumor microenvironment - tumor heterogeneity This work was supported by projects PROGRES Q40/11, BBMRICZ LM2015089, SVV 260398 and GACR 17-10331S. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 28. 3. 2017Accepted: 16. 5. 2017.