RESUMO
BACKGROUND: Intratumoral human epidermal growth factor receptor 2 (HER2) heterogeneity of gastric cancer can be an obstacle to accurate HER2 assessment. Serum HER2, concentrations of the HER2 extracellular domain shed into the bloodstream, has a potential to compensate HER2 immunohistochemistry (IHC) but has not been scrutinized in gastric cancer. This study sought to explore the clinical utility of serum HER2 in gastric cancer. METHODS: We performed a prospective multicenter trial (SHERLOCK trial) involving patients with all-stage gastric or gastro-esophageal junction cancer. Serum HER2 was measured using direct chemiluminescence while tissue HER2 status was determined using IHC and fluorescent in situ hybridization. For stage IV cases, concordance between local and central laboratories in tissue HER2 assessment was also evaluated. RESULTS: Of 224 patients enrolled, both tissue HER2 status and serum HER2 levels were successfully determined in 212 patients and 21% (45/212) were tissue HER2-positive. Serum HER2 levels, ranged from 4.5 to 148.0 ng/ml (median 10.3), correlated with tissue HER2 status (p = 0.003). At a cut-off level of 28.0 ng/ml determined by receiver operating characteristics analysis, sensitivity, specificity, positive and negative predictive values of serum HER2 were 22.6%, 100%, 100% and 82.3%, respectively. All nine cases with elevated serum HER2 were tissue HER2-positive stage IV cases. Among 61 stage IV cases, the agreement rate for IHC scoring between the local and the central laboratories was 82% and tissue HER2 judgment was conflicting in five (8.2%) cases. Of these five cases, four were confirmed as false-negative and two of these four patients demonstrated elevated serum HER2. CONCLUSIONS: Serum HER2 levels correlated with tissue HER2 status in gastric cancer. Although the low sensitivity is a drawback, serum HER2 might be a useful adjunct tool to detect tissue HER2 false-negative gastric cancer.
Assuntos
Biomarcadores/análise , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Amplificação de Genes , Humanos , Técnicas Imunoenzimáticas , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Curva ROC , Receptor ErbB-2/genética , Neoplasias Gástricas/genéticaRESUMO
BACKGROUND: A subset of familial isolated primary hyperparathyroidism (FIHP) is a variant of hyperparathyroidism-jaw tumour syndrome (HPT-JT). AIM/PATIENTS AND METHODS: We investigated the involvement of the HRPT2, MEN1 and CASR genes in 11 provisional FIHP families and two HPT-JT families. RESULTS: Germline mutations of HRPT2 were found in two of the 11 FIHP families and one of the two HPT-JT families. One FIHP family with parathyroid carcinoma and atypical adenomas and another FIHP family with cystic parathyroid adenoma had novel frameshift mutations of 518-521del and 62-66del, respectively. In a patient with HPT-JT, a de novo germline mutation of 39delC was detected. Novel somatic HRPT2 mutations of 70-73del and 95-102del were found in two of five parathyroid tumours in a family with a 518-521del mutation. Biallelic inactivation of HRPT2 by a combination of germline and somatic mutation was confirmed in the parathyroid tumours. The finding that two families diagnosed with FIHP carried HRPT2 mutations suggests that they have occult HPT-JT. In the remaining 10 families, one family had a missense MEN1 mutation. No mutations of CASR were detected. CONCLUSION: Our results confirm the need to test for HRPT2 in FIHP families, especially those with parathyroid carcinomas, atypical adenomas or adenomas with cystic change.
Assuntos
Genes Supressores de Tumor , Hiperparatireoidismo Primário/genética , Neoplasias Maxilomandibulares/genética , Mutação , Proteínas Supressoras de Tumor/genética , Adenoma/genética , Adulto , Idoso , Análise Mutacional de DNA , Feminino , Mutação da Fase de Leitura , Deleção de Genes , Genótipo , Mutação em Linhagem Germinativa , Humanos , Perda de Heterozigosidade , Masculino , Metilação , Repetições de Microssatélites , Pessoa de Meia-Idade , Neoplasia Endócrina Múltipla Tipo 1/genética , Neoplasias das Paratireoides/genética , Linhagem , Regiões Promotoras Genéticas , Receptores de Detecção de Cálcio/genética , Análise de Sequência de DNARESUMO
Human minisatellite B6.7 shows extensive allele length and structural variability in north Europeans. We analysed this locus in the Japanese population. Allele size distributions showed that Japanese retain extensive allele length variability but have significantly smaller alleles compared with north Europeans. In contrast, there is very little variation in flanking DNA, with only one single-nucleotide polymorphism (SNP) near the minisatellite. Ninety-two Japanese alleles were further characterised by minisatellite variant repeat mapping by polymerase chain reaction (MVR-PCR). These alleles showed a wide variety of internal MVR structures, despite their relative shortness, with most alleles observed only once in the sample. The true heterozygosity is estimated at 99.95%, with well in excess of 2000 different alleles existing in the Japanese population. Dot matrix analysis showed that groups of related alleles sharing structural motifs could be identified within Japanese and in north Europeans, and that these groups are population specific with no examples of significant similarity between any Japanese and north European alleles. Minisatellite B6.7 therefore shows huge allele variability and fast repeat turnover in Japanese as well as north European populations, and provides novel lineage markers for exploring very recent events in human population history.
