RESUMEN
Loss of basement membrane integrity during neoplastic invasion may have some direct prognostic significance, which is worth investigating. We studied 151 cases of colorectal adenocarcinomas retrospectively. The aim of the study was to investigate the immunohistochemical expression as well as the distribution of laminin and collagen IV within the basement membranes of cancer cell formations. The results were related to histological grade of malignancy (I, II or III) and Dukes' staging of all tumours as well as to 3-year survival status in 52 patients. Using the immunostaining method of strept ABComplex/HRP and appropriate monoclonal or polyclonal antibodies, we assessed the continuity, the discontinuity of the distribution or the total loss of structural basement membrane components alongside the infiltrating borders of each tumour. The results were evaluated statistically. Either a considerable degree of discontinuity or a total loss of basement membrane components was more common in moderately and poorly differentiated adenocarcinomas (p = 0.002 and p = 0.005 for collagen IV and laminin, respectively) and they seemed to be adversely associated with survival status (p = 0.066 and p = 0.014 for collagen IV and laminin, respectively). Interestingly, no association with the stage of disease was noticed. The results of this study reinforce the value of laminin and collagen IV as possible prognostic factors independently to tumour stage. The total loss or considerable discontinuity of the basement membranes of cancerous cells can be considered as indicators of tumour aggressiveness.
Asunto(s)
Membrana Basal/metabolismo , Colágeno Tipo IV/metabolismo , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Laminina/metabolismo , Adenocarcinoma/clasificación , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Anciano , Membrana Basal/patología , Diferenciación Celular , Neoplasias Colorrectales/clasificación , Femenino , Humanos , Inmunohistoquímica , Masculino , Estadificación de Neoplasias , Pronóstico , Tasa de SupervivenciaRESUMEN
Activation of telomerase, present in the vast majority of all human cancers, is associated with elongation of chromosomal telomeres and consequent cell immortalization. Telomere length homeostasis is a dynamic process governed by the negative feedback mechanism of the telomeric repeat binding factor 1 (TRF1) which inhibits the action of telomerase in telomerase-positive cells. In an attempt to investigate markers of tumour growth as possible prognostic indicators in laryngeal cancer, we studied the expression of TRF1 and of the proliferation marker Ki67 on 96 invasive squamous carcinomas of the larynx. A standard three step immunoperoxidase staining method was applied on paraffin sections incubated with appropriate polyclonal antibodies. The percentages of Ki67- and TRF1-immunopositive cancerous cells were calculated by image analysis. Univariate and multivariate statistical analysis of the staining results were performed in order to detect any association of the examined immunomarkers with the tumours' classical clinicopathological variables including nuclear morphometric features as well as with patients' disease-free survival. Ki67 immunostaining was positively linked with advanced patients' age, nodal involvement as well as presence of early recurrence. No relation was found between proliferative fraction and TRF1 immunoexpression. TRF1 was expressed in 55.2% of all cases and was positively linked only to tumour size. Multivariate statistical analysis revealed the presence of lymph nodal metastasis and Ki67 immunopositivity index > or = 20% as significant predictors of relapse. Increased Ki67 immunostaining appears to be a promising marker of tumour aggressiveness in laryngeal cancer. After one point at the tumour's natural history, the maintenance of tumour growth does not seem to depend on cell proliferation but on TRF1 immunoexpression. Whether the latter can be used for the identification of immortalized cells in every-day practice is worth investigating.