Background: Although testicular germ cell tumor is one of the most curable cancers, approximately 20% of advanced cases remain incurable. In this study we investigate factors that may predict a poor response to standard chemotherapeutic regimens and thus allow earlier initiation of more aggressive measures.
Methods: We analyzed the records of 19 patients with metastatic testicular germ cell tumors (8 seminomas and 11 nonseminomas). Sixteen patients underwent surgical exploration for residual tumors following chemotherapy, and the histological findings on the resulting specimens were correlated with reductions in tumor size observed on computed tomography and with changes in tumor marker levels.
Results: Complete necrosis was obtained in 10 of 12 lesions that shrank by at least 80%, while continued existence of teratoma or cancer was confirmed in 9 of 11 lesions with smaller size reductions. An initial human chorionic gonadotropin-beta subunit (HCG-beta) level more than 100 times the upper limit of normal appeared to predict poor histological response (teratoma/cancer) to chemotherapy. Slow fall (prolonged half-life) of tumor markers during chemotherapy also correlated with poor histological response.
Conclusion: Factors which predict poor histological response of tumors to chemotherapy include size reduction less than 80%, initial HCG-beta levels more than 100 times the upper limit of normal, and prolonged half-life of tumor markers (placental alkaline phosphatase, alpha-fetoprotein and HCG-beta).