RESUMEN
The CAG repeat in exon 1 of the androgen receptor (AR) genes has been postulated as both a susceptibility allele and phenotypic modifier in BRCA1-associated breast cancers. We have analysed this repeat in a set of 178 breast cancer cases who have been selected only for age of presentation at 65 years or less. No effect of repeat length on age of presentation was found and there was no association between repeat length and family history. In combination with the data from other workers, our findings suggest that the androgen receptor repeat does not act as a modifier gene or susceptibility locus outside the context of the hereditary breast/ovarian cancer syndrome.
Asunto(s)
Neoplasias de la Mama/genética , Receptores Androgénicos/genética , Repeticiones de Trinucleótidos/genética , Adulto , Edad de Inicio , Exones , Femenino , Humanos , Persona de Mediana EdadRESUMEN
AIMS: Telomerase is a ribonucleoprotein enzyme which appears to play an important role in carcinogenesis. Its reactivation is associated with the acquisition of immortalization and malignancy. The present study aims to examine the association between telomerase activity and prognosis in breast cancer. METHODS: Using a PCR-based assay, we retrospectively examined telomerase activity in 45 frozen human breast cancer specimens. Telomerase activity was compared with histopathological and clinical data. RESULTS: Telomerase activity was detected in 20 (44%) of 45 cases and was associated with advanced histopathological grade and tumour type (ductal vs. lobular). The association with these histological parameters was statistically significant (chi-squared test P<0.05). There was no significant difference in the overall survival rate (78 vs. 77%) or disease-free survival (73 vs. 69%) at 5 years (Kaplan-Meier method, log-rank test P>0.05). CONCLUSIONS: The present results indicate that telomerase activity in human breast cancer is not associated with nodal status or disease outcome.
Asunto(s)
Neoplasias de la Mama/enzimología , Telomerasa/metabolismo , Adulto , Anciano , Neoplasias de la Mama/mortalidad , Femenino , Secciones por Congelación , Humanos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Valor Predictivo de las Pruebas , Pronóstico , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
DNA repair defects might contribute both to cancer progression and to the extreme reactions to radiotherapy observed in approximately 5% of patients. Polymorphic microsatellites in three DNA repair genes, XRCC1, XRCC3 and XRCC5, were analyzed for possible linkage to cancer status or clinical radiosensitivity. XRCC1, 3 and 5 proteins are involved in single-strand DNA break rejoining, recombinational repair, and double-strand DNA break rejoining respectively. Mendelianly inherited microsatellite polymorphisms in these genes were analyzed in three groups: volunteers with no cancer history; radiosensitive cancer patients; cancer patients with acceptable reactions to radiotherapy. Rare heterozygous alterations in all three gene regions were found solely in the cancer subpopulation. Association testing between these rare polymorphisms and cancer status revealed a significant association for XRCC1 (P = 0.005), and XRCC3 (P = 0.004). There was also an association between these polymorphisms and clinical radiosensitivity for XRCC1 (P = 0.03), and XRCC3 (P = 0.005).