LUNG METASTASIS OF TESTICULAR TUMOR AND NUMERICAL SIMULATION

54 patients of primary testicular tumor were treated at the University Hospital during a decade, 1968 to 1977. Forty-seven cases of them were diagnosed as malignant nature through histopathologic examinations. Crude survival rate, observed survival rate and expected survival rate were calculated on each consecutive year to make relative survival rates. As the results, poor survival rate was obtained in the non-seminomatous tumor group bearing stage B3 or more advanced stage. Especially, the survival of the case with pulmonary metastasis was short. Ten cases out of 47, were found to have lung metastasis at the initial treatment and their clinical courses were studied. Metastatic lesions were checked on chest X-ray films to determine the growth rate measured by tumor diameter as 1/2×(long axis + short axis) mm on the film. Time series analysis of the tumor growth was carried out by curve fitting work using minicomputer. None of these case showed' low correlation coefficients on exponential (a exp. Bt) model on regression procedure. On the other hand, after beginning of effective chemotherapy, every responsive lesion will reduce its size according to parabolic (at2+bt+c) function model. There is no way to explain alteration of fitting model before and after chemotherapy yet. However, these results suggest that second choice chemotherapy should be started at the lowest bottom of parabolic curve (a>0) in time series simulation. More attempts should take account in advanced case, for instance, multivariate analysis to determine the most optimal dose of chemotherapy or autologous bone marrow re-infusion after anti-neoplastic therapy to prevent severe suppression of hematopoietic marrows