Predictive factors for the histologic nature of residual tumor mass after chemotherapy in patients with advanced testicular cancer.

Objectives: To further improve the accuracy of the prediction of histologic findings in the residual mass after chemotherapy in patients with metastatic germ cell tumors, various predictive factors were investigated.

Methods: A total of 23 patients with advanced testicular cancer underwent combination chemotherapy based on cisplatin following surgical removal of residual tumor mass in 20 patients and observation in 3.

Results: Complete fibrosis and/or necrosis was found in 6 (30%) operative specimens, teratoma in 3 (15%), and viable malignant tumor in 11 (55%). Three patients had no evidence of disease for a mean follow-up of 45 months. Five of the 6 patients and all of the 11 patients' results could be predicted by a combination of 4 factors, including absence of teratomatous element in the primary tumor, greater than 85% tumor reduction rate after chemotherapy, normal alpha-fetoprotein and beta-subunit of human chorionic gonadotropin levels after chemotherapy, and actual half-life of alpha-fetoprotein less than 7 days. Among these factors the tumor reduction rate and the actual half-life of alpha-fetoprotein were the most important predictions statistically on multivariate analysis. With the use of these criteria, the sensitivity rate, specificity rate, and overall predictive value of diagnosis for existence of viable malignant tumors were 83.3%, 100%, and 94.1%, respectively.

Conclusions: By determining these factors it seems possible to avoid surgical removal of the postchemotherapy residual mass in approximately 30% of patients with advanced metastatic testicular cancer.