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BACKGROUND: Tumors arising from the renal tubular epithelium have variable characteristics and have been subject to a variety of histologic classifications. METHODS: The authors describe the distinct clinical, pathologic, phenotypic, and genotypic features of different types of renal tumors. RESULTS: The Mainz classification is now widely accepted because characteristic genetic alterations have been demonstrated in each tumor type. CONCLUSIONS: The increasing emphasis on utilizing genetic characteristics of specific tumors is reflected by the more widespread use of the Mainz classification for renal cell tumors.
RESUMEN
BACKGROUND: The ability to accurately predict tumor behavior and patient survival is a problem in managing patients with prostate cancer. Prognostic variables in predicting death from tumor include prostate-specific antigen (PSA) level, histological grade, and clinical stage. Observer subjectivity is inherent in determining grade and stage; thus, criteria that are more objective are needed to identify patients for appropriate treatment. METHODS: The authors correlated flow cytometric nuclear DNA ploidy with Gleason score, PSA level, and recurrence risk in patients who underwent radical retropubic prostatectomy and bilateral pelvic lymphadenectomy between 1987 and 1993 for histopathologic stage B prostate cancer (T2, N0, M0). RESULTS: Of the tumors analyzed, 64% were DNA diploid with a low proliferative fraction, 25% were DNA diploid with a high proliferative fraction, and 11% were DNA aneuploid. DNA aneuploidy was associated with high Gleason grade (7-10). All Gleason grade 10 tumors were DNA aneuploid. Both DNA aneuploidy and high proliferative fraction (S+G2M) were statistically correlated with high Gleason grade and adverse prognosis but not with PSA level or patient age. CONCLUSIONS: A direct relationship is shown between both DNA aneuploidy and a high proliferation index with aggressive biological behavior in stage B prostatic cancer. Objective tumor criteria are needed to choose treatment more selectively for individual patients.
RESUMEN
The apoptosis-inducer Fas and the apoptosis-suppresser Bcl-2 are members of the tumor necrosis factor receptor and Bcl-2 gene superfamilies, respectively. Bcl-2 is overexpressed in hormonally refractory prostate cancer. Fas is expressed in several prostatic carcinoma cell lines but its in vivo expression in normal prostate and in prostate cancer is poorly understood. Formalin-fixed tissue sections from 10 benign prostatic hyperplasias, 10 low-grade and 10 high-grade organ-confined prostate cancers, and 6 metastatic prostate cancers were evaluated for immunoreactivity with Fas and Bcl-2 monoclonal antibodies. In addition, Fas expression was quantitated by computerized cytometry. The results were compared by one-way analysis of variance followed by Bonferroni tests. In benign prostate samples, Bcl-2 and Fas were expressed on basal cells and secretory cells, respectively. Bcl-2 was not expressed in any organ-confined tumors and only in one of six metastatic tumors (17%). Fas was expressed in all organ-confined tumors and in two of six metastatic tumors (33%). Fas expression was significantly decreased (P < 0.001) in prostate cancer (0.20 pg/cell) compared with benign prostate (0.79 pg/cell). The decrease was inversely related to the malignant grade of the tumors (0.30 pg/cell in low-grade tumors, 0.19 pg/cell in high-grade tumors, and 0.003 pg/cell in metastatic tumors). Based on these preliminary data, decreased expression of Fas appears to be an early molecular event in prostate cancer. The decline begins in low-grade tumors. The lowest expression occurs in metastatic carcinomas, which are often Fas negative. Overexpression of Bcl-2 appears to be a later and unrelated molecular event. Both abnormalities may be implicated in tumor progression by prolonging tumor cell survival.