Abstract/Text: Follow-up data were obtained for 96 cases of thymoma. The one-year survival rate was 84.3%, the three-year 77.1%, the five-year 74.1%, and the ten-year 57.1%. The five-year survival rate of total resection group was 88.9%; that of non-radically treated group was 44.4%. Clinical stages were defined: Stage I--macroscopically encapsulated and microscopically no capsular invasion; Stage II--1. macroscopic invasion into surrounding fatty tissue of mediastinal pleura, or 2. microscopic invasion into capsule; Stage III--macroscopic invasion into neighboring organ; Stage IVa--pleural or pericardial dissemination; Stage IVb--lymphogenous or hematogenous metastasis. Five-year survival rates of each clinical stage were 92.6% in Stage I, 85.7% in Stage II, 69.6% in Stage III, and 50% in Stage IV. Recurrence after total resection was found in six of 69 cases. Seven of 13 patients treated by subtotal resection survived more than five years with postoperative radiotherapy.

Abstract/Text: BACKGROUND: Primary germ cell tumors of the mediastinum are unusual neoplasms with histopathologic features that are similar to those of germ cell tumors in the gonads. However, their clinical features, behavior, and spectrum of pathologic features in the mediastinum have not yet been fully defined.
METHODS: The clinical and pathologic features of 322 cases of primary mediastinal germ cell tumors were reviewed, with special emphasis on teratomatous lesions. The tumors were divided into groups according to their histologic features and correlated with their order of frequency, patient gender and age distribution, and morphologic features. A clinical staging scheme based on the extent and location of the lesions was devised.
RESULTS: The overwhelming majority of patients were men (320); only 2 were women (both had teratomatous lesions with additional malignant components). The patients' ages ranged from 1 to 79 years (mean, 40 years). Histologically, all types of germ cell tumors were represented, including 138 teratomas (87 mature teratomas, 6 immature teratomas, and 45 teratomas with additional malignant components); 120 seminomas; 52 nonseminomatous, nonteratomatous germ cell tumors (38 yolk sac tumors, 6 embryonal carcinomas, and 8 choriocarcinomas); and 12 combined germ cell tumors without teratomatous components. The teratomatous lesions with additional malignant components were further separated into subtypes based on the histologic types of their malignant components, i.e., epithelial, mesenchymal, etc. Clinical staging was possible in 242 cases, with 191 cases (79%) in Stage I, 4 cases (1.6%) in Stage II, and 47 cases (19.4%) in Stage III. In each group, the clinical staging correlated well with the clinical outcome for the majority of patients.
CONCLUSIONS: The results of this study showed that mediastinal germ cell tumors have demographic and histopathologic distributions similar to those of tumors occurring in the male gonads, with teratomatous and seminomatous lesions being the most common. Among the nonseminomatous germ cell tumors in this study, the yolk sac tumors appeared to occur the most frequently (the ratio of yolk sac tumor occurrence to embryonal carcinoma occurrence was 6.1:1). In addition, the subclassification of teratomas with additional malignant components based on the histologic types of malignancies may lead to more therapy choices for patients. At the same time, the use of a clinical staging scheme may be of value in predicting clinical outcome and planning therapy.

Abstract/Text: PURPOSE: Cisplatin-containing chemotherapy has dramatically improved the outlook for patients with metastatic germ cell tumors (GCT), and overall cure rates now exceed 80%. To make appropriate risk-based decisions about therapy and to facilitate collaborative trials, a simple prognostic factor-based staging classification is required.
MATERIALS: Collaborative groups from 10 countries provided clinical data on patients with metastatic GCT treated with cisplatin-containing chemotherapy. Multivariate analyses of prognostic factors for progression and survival were performed and models were validated on an independent data set.
RESULTS: Data were available on 5,202 patients with nonseminomatous GCT (NSGCT) and 660 patients with seminoma. Median follow-up time was 5 years. For NSGCT the following independent adverse factors were identified: mediastinal primary site; degree of elevation of alpha-fetoprotein (AFP), human chorionic gonadotropin (HCG), and lactic dehydrogenase (LDH); and presence of nonpulmonary visceral metastases (NPVM), such as liver, bone, and brain. For seminoma, the predominant adverse feature was the presence of NPVM. Integration of these factors produced the following groupings: good prognosis, comprising 60% of GCT with a 91% (89% to 93%) 5-year survival rate; intermediate prognosis, comprising 26% of GCT with a 79% (75% to 83%) 5-year survival rate; and poor prognosis, comprising 14% of GCT (all with NSGCT) with a 48% (42% to 54%) 5-year survival rate.
CONCLUSION: An easily applicable, clinically based, prognostic classification for GCT has been agreed on between all the major clinical trial groups who are presently active worldwide. This should be used in clinical practice and in the design and reporting of clinical trials to aid international collaboration and understanding.