FLOW-CYTOMETRIC AND QUANTITATIVE HISTOLOGIC PARAMETERS AS PROGNOSTIC INDICATORS FOR OCCULT RETROPERITONEAL, DISEASE IN CLINICAL-STAGE-I NONSEMINOMATOUS TESTICULAR GERM-CELL TUMORS

Our study was performed to clarify whether the combination of DNA flow -cytometric and quantitative histopathological parameters improves the prediction of occult metastatic disease in clinical stage-I non-semin omatous testicular germ cell tumors (NSGCT). We used archival paraffin primary-tumor tissue of 67 clinical stage-I NSGCT patients who had un dergone retroperitoneal lymph-node dissection (RPLND). According to th e RPLND specimens, 24 patients were at pathological stage I and 43 at pathological stage II. Archival blocks were redissected for histologic al re-evaluation. In addition, 50 mu m sections were prepared accordin g to the Hedley technique in order to obtain nuclear suspensions which were processed for flow cytometry (FC). In univariate analysis, the p ercentage of embryonal carcinoma, the percentage of immature teratoma and vascular invasion were the most accurate predictive histopathologi cal parameters. The percentage of aneuploid cells in S-phase was the b est predictive FC parameter. In multivariate analysis, the percentage of embryonal carcinoma and the S-phase fraction of aneuploid cells wer e the only independent markers for occult metastatic disease. Accordin g to this statistical approach, 91.0% of pathological stage-I and stag e-II cases were correctly classified. Sensitivity was 95.3% and specif icity was 83.3%. Using histopathological criteria alone, only 56.7% NS GCT patients were correctly classified. (C) 1994 Wiley-Liss, Inc.