Increased urinary androgen excretion is a hormonal abnormality detectable before the clinical onset of breast cancer.

Six patients who developed breast cancer between the ages of 27 and 55 years had been examined for their urinary excretion of testosterone and androstanediol 17 to 69 months before the clinical onset of their cancer. Each of them showed higher than normal excretion values of testosterone or androstanediol, or both. At the time of hormonal examination, the patients were considered at risk for breast cancer because their history had included one or more of the following factors: previous mammary disease, familiality, sterility or subfertility, menstrual cycle irregularities. On the basis of this evidence, it would seem that high androgenic activity is a risk factor for developing breast cancer in patients with the "adverse" history.