[en] In patients treated for malignant testicular tumours without clinical and/or radiological signs of tumour, the following serum hormone levels were found. In 15% of the patients there was a slight to moderate rise in luteinising hormone (LH) levels (up to 6μg/1) due to increased pituitary gonadotrophin production; this was particularly evident soon after radiotherapy/chemotherapy. In 50% of the patients there was a slight to marked increase to follicle stimulating hormone (FSH) levels (up to 11μg/1), especially after radiotherapy/chemotherapy. Serum testosterone levels were in the low range (up to 20 nmol/1) in the majority of the hemicastrated patients regardless of previous treatment. A slight to moderate rise in serum oestradiol-17β and serum prolactin levels was noted. During combination chemotherapy with vincristine, Adriamycin D, cyclophosphamide, actinomycin D and medroxyprogesterone acetate the serum testosterone levels were extremely low (below 6 nmol/1) with LH and FSH levels within the normal range. The decrease in testosterone levels was reversible after completion of the combination chemotherapy. (author)