Postchemotherapy residual masses in germ cell tumor patients: content, clinical features, and prognosis. Medical Research Council Testicular Tumour Working Party

BACKGROUND: In a retrospective study that included a detailed histopathologic review, the clinicopathologic features of patients with germ cell tumors (GCT) and resectable residual masses after chemotherapy were assessed. METHODS: Histologic material from 153 patients was available for review. Recorded details included primary histologic diagnosis, location, size and number of metastases, marker levels before and after chemotherapy, and completeness of surgical excision. A median of seven histologic sections per resection were reviewed by two pathologists independently (and together when disagreement occurred). In each case, details were recorded regarding fibrosis, necrosis, hemorrhage, embryonal carcinoma (undifferentiated teratoma), yolk sac tumor, choriocarcinoma (trophoblastic tumor), differentiated teratoma (mature and immature), dysplasia in somatic tissues, and non- germ cell tumor (GCT) malignancies. The percentage of the sample that each of these components comprised was also estimated. RESULTS: The median postchemotherapy follow-up time was 7 years, and 38 of 153 patients (25%) experienced disease progression. In a multivariate analysis, incomplete resection of all residual masses (in 38 patients) and the presence of malignant elements (in 23 patients) were independent risk factors for progression. In the subset of patients in whom all masses were completely resected, the presence of embryonal carcinoma (undifferentiated teratoma) was the single most significant risk factor for progression. Seven percent of patients had this factor, which was associated with a 2-year progression free survival rate of 12.5%, compared with 88.0% where this component was absent. CONCLUSIONS: Progression free survival can be predicted well by the completeness of excision of residual masses and the presence of malignant germ cell elements. The latter confers a relatively poor prognosis even if all of these elements are completely resected.