Gynaecomastia following cytotoxic therapy for testicular cancer

Sixteen patients in complete remission after chemotherapy or radiotherapy for testicular cancer developed gynaecomastia which appeared 2 to 9 months after the end of therapy and had a mean duration of 4.8 months. These patients had statistically significant higher levels of oestradiol, FSH and oestradiol/testosterone ratio than a control group without gynaecomastia that had received similar treatment. Both groups tended to have testosterone levels in the lower normal range and all patients had normal levels of beta-HCG, prolactin and progesterone. The gynaecomastia in our patients was probably the result of an absolute increase in oestradiol or an increase relative to testosterone. Cytotoxic therapy affects both spermatogenesis and Leydig cell function, with a resultant rise in gonadotrophins which may in turn increase testicular oestrogen secretion. In testicular cancer patients, gynaecomastia may be a sign of tumour activity but it may also be caused by hormonal changes resulting from cytotoxic therapy. It is our experience that the latter treatment-related type is harmless, transient and unrelated to the patient's prognosis.