ABSTRACT
Recent developments in molecular genetic testing methods (e.g. next-generation sequencing [NGS]-panels) largely accelerated the process of finding the most appropriate targeted therapeutic intervention for cancer patients based on molecularly targetable genetic alterations. In Hungary, a centralized approval system following the recommendation of the National Molecular Tumor Board was launched for the coordination of all aspects of comprehensive genetic profiling (CGP) including patient selection and therapy reimbursement. AIM: The study aims to evaluate the clinical benefit of CGP in our Comprehensive Cancer Center Methods and patients: CGP was introduced into our routine clinical practice in 2021. An NGS-based large (> 500 genes) gene panel was used for cases where molecular genetic testing was approved by the National Molecular Tumor Board. From 2021 until August 2023 163 cases were tested. The majority of them were ECOG 0-1 patients with advanced-stage diseases, histologically rare cancer, or cancers with unknown primary tumours. RESULTS: Seventy-four cases (74 of 163, 45%) had clinically relevant genetic alterations. In 34 patients, the identified variants represented an indication for an approved therapy (approved by the Hungarian authorities, on-label indication), while in 40 cases the recommended therapy did not have an approved indication in Hungary for certain tumour types, but off-label indication could be recommended. Based on our CGP results, 24 patients (24/163; 14.7%) received targeted therapy. Treatment duration was between 1 and 60 months. In total 14 (14/163; 8.5% of the tested cases) patients had a positive clinical response (objective response or stable disease) and were treated for more than 16 weeks. INTERPRETATION: NGS-based CGP was successfully introduced in our institution and a significant number of patients benefited from comprehensive genetic tests. Our preliminary results can serve as the starting point of Drug Rediscovery Protocol (DRUP) studies.
Subject(s)
Genetic Testing , High-Throughput Nucleotide Sequencing , Neoplasms , Precision Medicine , Humans , Hungary , Precision Medicine/methods , Neoplasms/genetics , Neoplasms/drug therapy , Neoplasms/therapy , Male , Female , High-Throughput Nucleotide Sequencing/methods , Middle Aged , Aged , Adult , Genetic Testing/methods , Aged, 80 and over , Young Adult , Adolescent , Molecular Targeted Therapy/methods , Biomarkers, Tumor/geneticsABSTRACT
Genome-wide association studies (GWAS) using population-based designs have identified many genetic loci, at which common variants can influence the risk of developing the sporadic colon cancers. These are single nucleotide polymorphisms (SNPs) located on different chromosomes, close to genes involved in cancer developing process, and the SNPs modify their functions, and as a consequence the cancer risk is increased. Our aim was to provide frequency distributions data of variable (risk) allele of six independent SNPs in patients with colorectal cancers and in control Hungarian population, predicting the increased risk effect of sequence variant of SNPs. We also investigated the frequency distribution of tumor localization between right or left half of large bowel as well as the RAS mutation status. 47 non-tumorous patients and 47 patients with colorectal cancer were given oral mucosa cells or blood samples for SNP analysis. After DNA isolation, an LC480 (Roche) type PCR instrument, asymmetric LATE PCR method and melting point analysis were used for detection of sequence variations, by the assistance of two SNP specific primers, unlabeled specific probe and intercalating fluorescent dye. Genomic frequency distribution of variable alleles of SNPs predisposed to tumor development have been investigated in colorectal cancer carrier patients and the results have been compared with the same allele frequency distribution data obtained from the non-tumorous control patients and from CEU population stored in SNPnexus data base. The homozygous risk alleles of SNPs showed a 1.5-2.3-time increase in colorectal cancer carrier patients then in control and CEU patients, but the heterozygous risk allele distribution was identical in tumorous and control population. The frequency distribution of homozygous risk alleles of six SNPs was also investigated in the same time and some patients. Among 47 patients with colorectal cancer, in 3 patients carrying 3 SNPs with homozygous risk alleles, in additional 5 tumor samples two and 24 samples contain only one SNP's homozygous risk alleles, and in 15 patients, SNPs with homozygous risk alleles do not occur. In 47 control patients, only 3 samples contain two SNPs with homozygous risk alleles and 17 samples contain only one SNP with homozygous risk alleles. Significant differences of the tumorous and the control population can be seen detected. NRAS mutation was not found. Our results showed a real increased risk effect of several newly recognized low-penetrance colorectal cancer susceptibility genetic variants by influence of the regulation of neighboring genes, however, the degree of cancer risk is individual, and influenced by others environmental factors, such as dietary factors. Orv Hetil. 2018; 159(40): 1614-1623.
Subject(s)
Colorectal Neoplasms/genetics , Gene Frequency , Polymorphism, Single Nucleotide , Alleles , Case-Control Studies , Female , Genetic Predisposition to Disease , Genetic Variation , Genome-Wide Association Study , Genotype , Humans , Hungary , MaleABSTRACT
AIMS: Low-grade serous neoplasms of the testis are rare neoplasms that show striking morphological similarities with the better-understood ovarian neoplasms. This study is to see if there are similar molecular abnormalities in these two tumours. The cell of origin, relationship with serous ovarian tumour and the pathogenesis of these neoplasms are not fully established. METHODS AND RESULTS: As low-grade serous ovarian neoplasms are known to harbour mutations in the MAPK pathway, we investigated the involvement of BRAF and KRAS mutations in low-grade testicular serous tumour by performing mutational analysis of seven cases. Mutational analysis was performed by melting curve analysis followed by bidirectional sequencing. Our findings showed BRAF and/or KRAS mutations in three of the seven cases, which is similar to the proportions reported in low-grade ovarian serous neoplasms. Of these three cases, one showed co-mutation of BRAF and KRAS. CONCLUSION: The findings of this study are in support of a role of aberrant signalling of the MAPK pathway in the pathogenesis of low-grade serous testicular neoplasms, and provide a genetic link between low-grade testicular and ovarian serous tumours.
Subject(s)
Cystadenocarcinoma, Serous/genetics , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Testicular Neoplasms/genetics , Adult , Aged , DNA Mutational Analysis , Humans , Male , Middle AgedABSTRACT
NTRK-rearranged uterine sarcoma is a recently described entity that represents a subset of uterine sarcomas with distinct clinicopathological features. From a molecular point of view, this tumour is defined by NTRK gene rearrangement, resulting in overexpression or constitutive activation of Trk receptors. The presence of NTRK fusion is indicative of treatment response with a selective small-molecule inhibitor of the Trk kinases. Here, we report a case of an NTRK-rearranged sarcoma of the uterine cervix in a 43-year-old patient, measuring 80 mm in its largest dimension, with a novel NUMA1-NTRK1 fusion, not previously reported in NTRK-rearranged uterine sarcomas or other NTRK-rearranged tumours. The fusion, involving NUMA1 exon 14 (NM_006185.4) and NTRK1 exon 11 (NM_002529.4), was identified by next-generation sequencing (NGS) studies (FusionPlex Pan Solid Tumor v2 panel). Although the presence of NTRK fusion has been reported in a variety of neoplasms, a fusion involving NUMA1 (nuclear mitotic apparatus protein 1) and a tyrosine kinase partner has previously been reported in human neoplasms only in a handful of cases. The resulting fusion protein comprises the oligomerization domain of NUMA1, which is predicted to cause constant activation of the tyrosine kinase domain of NTRK1. The recognition and accurate diagnosis of these tumours are important due to the availability of potential targeted therapeutic options.
Subject(s)
Sarcoma , Uterine Cervical Neoplasms , Uterine Neoplasms , Female , Humans , Adult , Receptor, trkA/genetics , Uterine Cervical Neoplasms/genetics , Sarcoma/genetics , Sarcoma/pathology , Uterine Neoplasms/genetics , Uterine Neoplasms/pathology , Oncogene Proteins, Fusion/genetics , Gene Fusion , Cell Cycle Proteins/geneticsABSTRACT
The best predictive marker for the expected efficacy of PARP inhibitor therapy is mutations in BRCA1/2 or other homologous recombination repair genes. These tests are part of routine molecular pathology diagnostics. Among 281 patients with prostate adenocarcinoma, somatic pathogenic mutations in one of these genes were identified in 21.4% of patients. In 28.5% of the patients, the test was unsuccessful; the main limitation of successful testing was the age of the paraffin blocks and low DNA concentration. In the case of BRCA1/2 testing, the success rate was significantly reduced for samples older than 5 years, while in tests involving a broader set of homologous recombination repair genes, the success rate was significantly reduced for samples older than 2 years. Therefore, it is very important to test high-risk prostate cancers at the time of primary diagnosis, and probably also liquid biopsy testing of circulating tumor DNA will play an important role in safe diagnosis in the near future.
Subject(s)
Adenocarcinoma , Prostatic Neoplasms , Recombinational DNA Repair , Humans , Male , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Adenocarcinoma/drug therapy , Recombinational DNA Repair/genetics , Mutation , BRCA2 Protein/genetics , Mutation Rate , BRCA1 Protein/genetics , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Biomarkers, Tumor/genetics , Aged , Middle AgedABSTRACT
OBJECTIVE: Administration of targeted therapies provides a promising treatment strategy for urachal adenocarcinoma (UrC) or primary bladder adenocarcinoma (PBAC); however, the selection of appropriate drugs remains difficult. Here, we aimed to establish a routine compatible methodological pipeline for the identification of the most important therapeutic targets and potentially effective drugs for UrC and PBAC. METHODS: Next-generation sequencing, using a 161 cancer driver gene panel, was performed on 41 UrC and 13 PBAC samples. Clinically relevant alterations were filtered, and therapeutic interpretation was performed by in silico evaluation of drug-gene interactions. RESULTS: After data processing, 45/54 samples passed the quality control. Sequencing analysis revealed 191 pathogenic mutations in 68 genes. The most frequent gain-of-function mutations in UrC were found in KRAS (33%), and MYC (15%), while in PBAC KRAS (25%), MYC (25%), FLT3 (17%) and TERT (17%) were recurrently affected. The most frequently affected pathways were the cell cycle regulation, and the DNA damage control pathway. Actionable mutations with at least one available approved drug were identified in 31/33 (94%) UrC and 8/12 (67%) PBAC patients. CONCLUSIONS: In this study, we developed a data-processing pipeline for the detection and therapeutic interpretation of genetic alterations in two rare cancers. Our analyses revealed actionable mutations in a high rate of cases, suggesting that this approach is a potentially feasible strategy for both UrC and PBAC treatments.
Subject(s)
Adenocarcinoma , Urinary Bladder Neoplasms , Humans , Urinary Bladder/pathology , Proto-Oncogene Proteins p21(ras)/genetics , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Mutation , Urinary Bladder Neoplasms/pathology , High-Throughput Nucleotide SequencingABSTRACT
EGFR mutation in non-small cell lung cancer (NSCLC) offers a potential therapeutic target for tyrosine kinase inhibitor (TKI) therapy. The majority of these cases, however eventually develop therapy resistance, mainly by acquiring EGFR T790M mutation. Recently, third-generation TKIs have been introduced to overcome T790M mutation-related resistance. Cell free circulating tumor DNA (liquid biopsy) has emerged as a valuable alternative method for T790M mutation detection during patient follow up, when a tissue biopsy cannot be obtained for analysis. In this study, we summarized our experience with Super-ARMS EGFR Mutation Detection Kit (AmoyDx) on 401 samples of 242 NSCLC patients in a 3-year period in Hungary, comprising 364 plasma and 37 non-plasma samples. We also compared the performance of two commercially available detection kits, the cobas EGFR Mutation test v2 (Roche) and the Super-ARMS EGFR Mutation Detection Kit (AmoyDx). The same activating EGFR mutation was detected with the AmoyDx kit as in the primary tumor in 45.6% of the samples. T790M mutation was identified in 48.1% of the samples containing activating EGFR mutation. The detection rate of T790M mutation was not dependent on the DNA concentration of the plasma sample and there was no considerable improvement in mutation detection rate after a second, subsequent plasma sample. The concordance of EGFR activating mutation detection was 89% between the two methods, while this was 93% for T790M mutation detection. The AmoyDx kit, however showed an overall higher detection rate of T790M mutation compared to the cobas kit (p = 0.014). T790M mutation was detected at 29.8% of the patients if only plasma samples were available for analysis, while the detection rate was 70.2% in non-plasma samples. If the activating EGFR was detected in the plasma samples, the detection rate of T790M mutation was 42.4%. Although non-plasma samples provided a superior T790M mutation detection rate, we found that liquid biopsy can offer a valuable tool for T790M mutation detection, when a tissue biopsy is not available. Alternatively, a liquid biopsy can be used as a screening test, when re-biopsy should be considered in case of wild-type results.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Circulating Tumor DNA , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , ErbB Receptors/genetics , Circulating Tumor DNA/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Mutation/genetics , Protein Kinase Inhibitors/therapeutic use , Drug Resistance, Neoplasm/geneticsABSTRACT
BACKGROUND: Nucleic acid isolation from formalin-fixed, paraffin-embedded tissue (FFPET) samples is a daily routine in molecular pathology laboratories, but extraction from FFPET is not always easily achieved. Choosing the right extraction technique is key for further examinations. AIM: To compare the performance of four commercially available kits used for DNA extraction in routine practice. METHODS: DNA isolation was performed on 46 randomly selected formalin-fixed, paraffin-embedded (FFPE) colorectal adenocarcinoma (CRC) surgical specimens. Four commercially available extraction kits were used: two for manual DNA extraction (the PureLink Genomic DNA Mini Kit from Invitrogen and the High Pure FFPE DNA Isolation Kit from Roche) and two for automated DNA extraction (the iPrep Genomic DNA Kit from Invitrogen and the MagnaPure LC DNA Isolation Kit from Roche). The DNA concentration and quality (odds ratio) among the four systems were compared. The results were correlated with the clinicopathological aspects of CRC cases: age, gender, localization, macro- and microscopic features, lymph node metastases, and the lymph node ratio. RESULTS: The highest DNA concentration was obtained using the manual kits: 157.24 ± 62.99 ng/µL for the PureLink Genomic DNA Mini Kit and 86.64 ng/µL ± 43.84 for the High Pure FFPE DNA Isolation Kit (P < 0.0001). Lower concentrations were obtained with automated systems: 20.39 ± 21.19 ng/µL for the MagnaPure LC DNA Isolation Kit and 8.722 ± 6.408 ng/µL for the iPrep Genomic DNA Kit, with differences between the systems used (P < 0.0001). The comparison between age, gender, tumor localization, pT or pN stage and the lymph node ratio indicated no statistically significant difference in DNA concentration using any of the nucleic acid isolation kits. DNA concentration was influenced by the macroscopic features and grade of differentiation. A higher DNA concentration was obtained for well-differentiated polypoid colorectal adenocarcinomas (CRCs), compared with undifferentiated ulcero-infiltrative carcinomas, irrespective of the kit used. CONCLUSION: For research or diagnosis that needs high DNA concentrations, manual methods of DNA isolation should be used. A higher amount of DNA can be obtained from polypoid-type differentiated CRCs. Automated systems confer comfort and a lower amount of DNA that is, however, sufficient for classic polymerase chain reaction (PCR) and real-time quantitative PCR molecular examinations. All four commercially available kits can be successfully used in daily practice.
ABSTRACT
A combination of ovarian tumors with the same histogenetic origin but different histologic subtype is relatively common, whereas a co-occurrence of tumors with different histogenetic origin is rare. We report a case of mixed ovarian tumor composed of Brenner tumor and adult-type granulosa cell tumor, a combination that to the best of our knowledge has not been reported in the literature until now.
Subject(s)
Brenner Tumor/pathology , Granulosa Cell Tumor/pathology , Neoplasms, Multiple Primary/pathology , Ovarian Neoplasms/pathology , Aged , Breast Neoplasms/pathology , Female , HumansABSTRACT
The implementation of targeted therapies revolutionized oncology. As the number of new oncogenic driver mutations, which provide molecular targets for prediction of effective and selective therapies, is increasing, the implementation of fast and reliable methods by molecular pathology labs is very important. Here we report our results with TruSeq Custom Amplicon assay performed on formalin-fixed and paraffin-embedded material. The oligo capture probes targeted the hotspot regions of 10 well-known oncogenes linked to clinical diagnosis and treatment of lung and colorectal adenocarcinomas, melanomas, and gastrointestinal stromal tumors. Fifteen previously genotyped formalin-fixed and paraffin-embedded DNA samples from different tumor types were selected for massively parallel sequencing. A bioinformatics pipeline was developed to identify high-quality variants and remove sequence artifacts. With the exception of 1 sample, which was of lower quality than the others, relevant mutations corresponding to tumor types could be reliable detected by the developed bioinformatical pipeline. This study indicates that the application of TruSeq Custom Amplicon assay is a promising tool in molecular pathology diagnostics, but it is important to standardize sample processing (including fixation, isolation procedure, sample selection based on quality assessment, and rigorous variant calling) to achieve the highest success rate and avoid false results.
Subject(s)
DNA, Neoplasm , Formaldehyde , High-Throughput Nucleotide Sequencing/methods , Neoplasms/genetics , Paraffin Embedding , Polymerase Chain Reaction/methods , Tissue Fixation , DNA, Neoplasm/chemistry , DNA, Neoplasm/genetics , DNA, Neoplasm/isolation & purification , Humans , Neoplasms/pathologyABSTRACT
We report our experience with a new real-time polymerase chain reaction (PCR) assay applicable for simultaneous quantification and characterization of MBR/JH translocation in follicular lymphomas. This technique, which combines amplification with the FRET probe with SYBR Green I melting curve analysis, allows efficient detection of tumor cells in bone marrow or peripheral blood and their comparison with the original neoplastic clone.
Subject(s)
Chromosomes, Human, Pair 14 , Chromosomes, Human, Pair 18 , Gene Rearrangement , Genes, bcl-2 , Lymphoma, Follicular/genetics , Translocation, Genetic , Bone Marrow Cells/pathology , Humans , Lymphoma, Follicular/pathology , Polymerase Chain Reaction/methodsABSTRACT
The aim of this study was to determine the frequency and significance of the tumor DNA content heterogeneity in 33 previously untreated human neuroblastomas. We used image cytometry to selectively analyze neuroblasts by excluding karyorrhectic or stromal cells from cytometric measurements. DNA content heterogeneity with more than one clonal subpopulation on DNA histogram was found in 8 of 33 cases. Of these 8 cases, 4 showed MYCN amplification. Double labeling fluorescent in situ hybridization with probes for the centromeric region of chromosome 2 and MYCN gene was used to confirm the DNA content heterogeneity. DNA content heterogeneity was associated with poorer prognosis in this study (P<0.05). There was a significant correlation between euploidy (di- and tetraploidy) and worse prognosis, but only when heterogeneous neuroblastomas with euploid cell population were assigned to euploid tumors (P=0.006). Our results may explain the conflicting data in the literature regarding ploidy and suggest that DNA content heterogeneity and the presence of a euploid population may predict worse prognosis in neuroblastoma patients.
Subject(s)
DNA, Neoplasm/analysis , Image Cytometry , Neuroblastoma/genetics , Aneuploidy , Cell Nucleus/chemistry , Child, Preschool , Female , Humans , In Situ Hybridization, Fluorescence , Infant , Male , N-Myc Proto-Oncogene Protein , Neoplasm Staging , Neuroblastoma/mortality , Neuroblastoma/pathology , Nuclear Proteins/genetics , Oncogene Proteins/genetics , Ploidies , Prognosis , Survival RateABSTRACT
INTRODUCTION: In the Western world the second most common type of non-Hodgkin's lymphomas is follicular lymphoma (FL) comprising 30-35% of all cases. According to the data of the National Cancer Registry and our institute, this ratio is lower in Hungary and is about 15-20%, but the occurrence shows an increasing tendency. AIMS: Our aim was to survey and revise FLs that had been diagnosed at the National Institute of Oncology between 1990-1995. We studied the diagnostic relevance of histology, immunohistochemistry and the detection of immunoglobulin heavy chain (IgH) and bcl-2 gene rearrangements. MATERIALS AND METHODS: We surveyed 53 cases that were previously diagnosed as follicular or centrocytic, centroblastic lymphoma. Following histological re-examination, immunohistochemistry (CD20, CD3, bcl-2, CD10, bcl-6, CD5, p53, cyclin D1 and Ki-67) was performed on each case. We also studied the IgH and bcl-2 (major breakpoint region=MBR) gene rearrangement on paraffin embedded samples with conventional PCR methods. The classification was made according to the new WHO classification. RESULTS: After the revision of the 53 cases we found 37 follicular, 11 diffuse large B-cell, 1 mantle cell and 1 marginal zone lymphomas, 1 nodular lymphocyte predominant Hodgkin's lymphoma and 2 follicular hyperplasias. The grade of the FLs correlated with the expression of different antigens. CD10, bcl-2 expression and the proliferation index with Ki-67 showed good correlation with the grade of FLs. We could detect bcl-2 gene rearrangement in 55% of the FLs. CONCLUSION: Considering the diagnostic relevance of the different methods we can conclude that histology alone is not sufficient to make a correct diagnosis. Ninety percent of our cases were solvable with the help of immunohistochemistry and in 10% of the cases the diagnosis was partly based on the molecular pathological results.
Subject(s)
Biomarkers, Tumor/analysis , Lymphoma, Follicular/diagnosis , Lymphoma, Large B-Cell, Diffuse/diagnosis , Antigens, CD/analysis , Cyclin D1/analysis , Diagnosis, Differential , Gene Rearrangement , Humans , Immunohistochemistry , Ki-67 Antigen/analysis , Lymphoma, Follicular/chemistry , Lymphoma, Follicular/genetics , Lymphoma, Follicular/pathology , Lymphoma, Large B-Cell, Diffuse/chemistry , Lymphoma, Large B-Cell, Diffuse/genetics , Lymphoma, Large B-Cell, Diffuse/pathology , Lymphoma, Mantle-Cell/diagnosis , Polymerase Chain Reaction , Proto-Oncogene Proteins c-bcl-2/analysis , Proto-Oncogene Proteins c-bcl-6/analysis , Retrospective Studies , Tumor Suppressor Protein p53/analysisABSTRACT
Choriocarcinoma is a rare, highly malignant trophoblastic tumor with gestational or, rarely, germ cell origin. Primary extragenital localization is extremely rare. This report describes a choriocarcinoma case clinically mimicking a primary renal cell carcinoma with multiplex pulmonary metastases. Differentiation from a sarcomatoid renal cell carcinoma with trophoblastic differentiation and identification of the exact origin, namely gestational or germ cell origin by molecular genetic methods is of great importance as it helps determine the prognosis and the most effective therapy of the disease. The Investigator Hexaplex ESS Kit was used for DNA polymorphism studies. This showed foreign alleles in the tumor DNA that confirmed the presence of paternal DNA and the gestational origin of the tumor.
Subject(s)
Choriocarcinoma/secondary , Germ Cells/pathology , Kidney Neoplasms/pathology , Lung Neoplasms/secondary , Pregnancy Complications, Neoplastic , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Choriocarcinoma/drug therapy , Choriocarcinoma/genetics , Chorionic Gonadotropin, beta Subunit, Human/blood , Chromosomes, Human, Y/genetics , Combined Modality Therapy , DNA, Neoplasm/analysis , Diagnosis, Differential , Female , Genotype , Humans , Kidney Neoplasms/drug therapy , Kidney Neoplasms/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Nephrectomy , Polymorphism, Genetic , Pregnancy , Remission Induction , Treatment OutcomeABSTRACT
Human papillomaviruses are known to cause cancers of the cervix and other anogenital tract sites. Epidemiologic and molecular pathology studies have also suggested that HPV infection may be associated with cancers of the head and neck. Modes of transmission of HPV infection in the head and neck region have not been fully resolved; however, perinatal transmission and an association between sexual behavior and risk for HPV-positive cancers have been presented. Among the HPV types infecting the mucosa, high-risk, intermediate-risk and low-risk genotypes are defined, depending on their presence in carcinoma or precursor lesions. The phylogenic groups of HPVs also showed a definite correlation with the morphology of head and neck tumors. The groups A6, A7, and A9 include viruses that are frequently demonstrated in basaloid and verrucosus squamous cell carcinomas known to associate with HPV infection. Integration of HPV DNA into the host cell genome occurs early in cancer development and is an important event in malignant transformation. There is a trend for patients with HPV-positive tumors to be nondrinkers or light drinkers, the majority of these patients are females, and the median age is lower than in the case of HPV-negative tumors, but this latter difference was not always statistically significant. In the Kaplan-Meier survival model, the HPV-positive verrucous and basaloid squamous cell carcinomas showed better survival rates than the HPV-negative typical squamous cell carcinomas. An increased radiocurability of HPV-positive head and neck squamous cell carcinoma (HNSCC) has also been demonstrated.
Subject(s)
Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/virology , Papillomaviridae/physiology , Papillomavirus Infections/pathology , Papillomavirus Infections/virology , Animals , Cell Transformation, Neoplastic , Genome, Viral , Head and Neck Neoplasms/metabolism , Humans , Papillomaviridae/genetics , Papillomaviridae/pathogenicity , Papillomavirus Infections/metabolism , Papillomavirus Infections/transmission , PhylogenyABSTRACT
We have used semiquantitative comparative and real-time quantitative polymerase chain reactions (PCR) to detect n-myc gene-amplification in 20 frozen neuroblastoma biopsies and IMR 32 cell line to predict biological behavior of the tumors. Two primer pairs were used for the semiquantitative method to co-amplify a 520-bp fragment of the beta-globin gene--used as a single copy reference standard--and a 258-bp fragment of the n-myc gene. After 30 cycles the PCR products were electrophoresed through an agarose gel and were compared to each other with use of a gel-densitometer. Real-time quantitative analyses were performed in a LightCycler instrument. A single primer pair was used to amplify a 120-bp fragment of the n-myc oncogene and a LC640-labeled fluorescent probe pair to detect the product. Calibration curve, set up from a serial dilution including samples with 1, 2, 10, 13, 25-fold n-myc oncogene amplification, was used for quantitative analysis. The semiquantitative method did not show distinct difference between tumor groups with no amplification and less than 10-fold amplification, whereas quantitative LightCycler analysis was able to detect even 2-fold amplification. Differentiated neuroblastomas seldom show n-myc amplification. In spite of this, we have found two partly differentiated tumor samples that contained n-myc amplification. In these cases in situ PCRs were performed to examine the tumor heterogeneity. We used biotinated ATP labeling and the same primer pair as for the LightCycler analysis. In both cases differentiated cells did not show n-myc gene amplification, whereas considerable amplification was detected in the neuroblasts.