Alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in testicular germ cell tumours. A comparison of histologic and serologic occurrence of tumour markers.

Abstract

170 patients with testicular germ cell tumours (88 seminomas and 82 non-seminomas) were examined with immunologic techniques for the presence of the tumour markers alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in tumour tissue and preoperative serum samples. Patients with pure seminomas had AFP negative tumour tissue and normal levels of serum AFP, whereas 13% had HCG demonstrated in the tumour tissue, mainly in syncytiotrophoblast-like cells (STLC), and 9% had raised serum HCG. 55% of patients with HCG positive seminomas had raised serum HCG. HCG positive seminomas did not occur in higher frequency in metastatic disease than in localized. 65% of patients with non-seminomas had AFP positive tumour tissue and 66% had raised serum AFP. 85% of the former group had raised serum AFP and 83% of the latter had AFP demonstrated in the tumour tissue. 69% of the patients with raised serum AFP had a positively stained yolk sac tumour (YST) component, while 15% had positively stained tumour components other than YST, inclusive teratoma components. Although 71% of patients with metastatic disease had raised serum AFP, AFP positive tumours with or without raised serum AFP did not occur with higher frequency in metastatic than in localized disease at the time of diagnosis. 46% of patients with non-seminomas had HCG positive tumours and 29% had raised serum HCG. 61% of the former group had raised serum HCG and 96% of the latter had HCG demonstrated in the tumour tissue. HCG positive tumours with or without raised serum HCG did not occur more frequently in metastatic than in localized disease at the time of diagnosis. 28% of patients with non-seminomas had raised serum AFP as well as HCG, whereas 23% had neither AFP nor HCG in tumour tissue and serum. A search for new tumour markers in this rather large marker negative group of patients is recommended.