Microvessel density, expression of proto-oncogenes, resistance-related proteins and incidence of metastases in primary ovarian carcinomas

Tumor interstitial fluid pressure-a link between tumor hypoxia, microvascular density, and lymph node metastasis

High microvascular density (MVD) in the primary tumor has been shown to be associated with increased incidence of lymph node metastases and poor clinical outcome. Other investigations have revealed that a large fraction of hypoxic tissue in the primary tumor is associated with metastatic disease and impaired survival. These data are apparently incompatible because tumor hypoxia is primarily a consequence of poor oxygen supply caused by an inadequate vasculature with increased intervessel distances. Here, we provide an explanation of these observations. Human melanoma xenografts were used as preclinical cancer models. Tumors that metastasized to lymph nodes showed higher interstitial fluid pressure (IFP) than those that did not metastasize, and compared with tumors with low IFP, tumors with high IFP showed large hypoxic fractions centrally, high MVD in the periphery, high peritumoral density of lymphatics, and elevated expression of vascular endothelial growth factor A (VEGF-A) and VEGF-C. Significant correlations were found between peripheral MVD and central hypoxia, and lymph node metastasis was associated with high values of both parameters. These findings suggest that the outcome of cancer may be associated with both high MVD and extensive hypoxia in the primary tumor. We propose that proangiogenic factors are upregulated in the tumor center and that the outward interstitial fluid flow caused by the elevated IFP transports these factors to the tumor surface where they evoke hemangiogenesis and lymphangiogenesis, and consequently, that the IFP serves as a link between tumor hypoxia, peripheral tumor hemangiogenesis, peritumoral lymphangiogenesis, and lymph node metastasis.

Protein expression profile of primary human squamous cell lung carcinomas indicative of the incidence of metastases

The purpose of this investigation was to evaluate firstly whether different protein expression patterns exist in primary squamous cell lung carcinomas of patients with and without lymph node involvement and secondly, whether or not different patterns exist in tumours with positive lymph nodes. For this reason, formalin-fixed, paraffin-embedded specimens from 130 patients with squamous cell lung carcinomas were analyzed by immunohistochemistry. In a first step, proteins were selected which showed a relationship to lymph node involvement. The expression of JUN, ERBB2, MYC, cyclin D, PCNA, bFGF, VEGF and Hsp70 proteins revealed a positive correlation to lymph node involvement. In contrast, caspase-3, Fas ligand, Fas/CD95, and PAI showed an inverse correlation to lymph node involvement. In a second step, these parameters were further analyzed by hierarchical cluster analyses. The resulting clusters were correlated to patients with or without lymph node involvement. The data show that different protein expression patterns exist between primary squamous cell lung carcinomas with and without lymph node involvement and within carcinomas with lymph node involvement. The data suggest that various metastasis profiles exist.