[New parameters for prediction of pathological stage in clinical stage I non-seminomatous testicular tumors].

Traditional histopathological risk factors have failed to predict pathological stage accurately in clinical stage I nonseminomatous testicular germ cell tumours. Histopathology, flow cytometry, cytophotometry, and immunohistochemical staining techniques were used in an effort to define high- and low-risk groups for occult metastasis in a consecutive series of 105 patients who underwent retroperitoneal lymph node dissection. After multiple logistic regression analysis, the proliferative S + G2M cell cycle fraction of the aneuploid tumour stemline was the most highly predictive parameter of pathological stage (P = 0.0004). Using a cut-off of 41%, pathological stage II patients were predicted with a sensitivity of 71%. There were 61 patients with S + G2M values below 41%, and 43 of them had pathological stage I disease (negative predictive value 87%). A low volume of embryonal carcinoma was predominant in low-risk patients, and MIB-1 immunohistochemical staining identified a subgroup of 23% of patients with pathological stage I disease and at extremely low risk of metastatic disease. Assessment of tumour cell proliferation does not allow accurate classification of high-risk patients at a level that is adequate for clinical application. Patients who are at low risk of metastasis, however, can be identified by flow cytometry, immunohistochemical proliferation markers and volume of embryonal carcinoma with 90% certainty. These parameters deserve further study, since identification of a subgroup of patients at extremely low risk of metastasis could potentially reduce the overall morbidity in the management of clinical stage I nonseminomatous testis cancer.