Endocrinological studies in patients with metastatic malignant testicular germ cell tumours

In this study, various serum hormone levels were determined in patients with metastatic testicular germ cell tumours. Raised LH levels, due to a cross reaction with hCG in the radioimmunoassay, were observed in 20 out of 29 patients with active disease and were mainly caused by gonadotrophin production in the tumour tissue. Increased LH levels were frequently observed in the patients with non-seminomatous tumours, but were also found in 4 (out of 6) patients with metastatic seminoma. One should, however, preferably use a specific hCG radioimmunoassay in order to measure tumour hCG as a tumour marker with a high diagnostic accuracy. In patients with active disease despite ongoing combination chemotherapy which included LH suppressing medication, serum testosterone remained above 6 nmol/l in 11 out of 16 patients. These patients remained sexually potent, while testosterone values below 6 nmol/l usually were combined with sexual impotence in patients during combination chemotherapy. These data strongly suggest that the tumour hCG has a biological activity, stimulating the remaining testis to increased testosterone secretion in these patients. The serum E2-17 beta levels were slightly to moderately increased in half of the patients with metastatic disease. Markedly increased serum E2-17 beta levels (> 0.30 nmol/l) and very high prolactin values (> 32 micrograms/l) were observed only in patients with high LH levels (> 9.5 micrograms/l) and a large tumour burden. These observations indicate that E2-17 beta and prolactin determinations are of minor value for early detection of tumour manifestations. Serum FSH cannot serve as a tumour marker in patients with testicular germ cell tumours.