One of the earliest hormone therapies (ADT) given to men to treat prostate cancer was estrogen. Estrogen, commonly known as the female hormone, was used as an ADT treatment in the early 1950s.

Initially, the estrogen was administered orally and the most common estrogen drug used was diethylstilbestrol (DES). DES (estrogen) both reduces testosterone levels in men and it also directly kills prostate cancer cells thus providing a one, two punch. Although it was effective, its use fell out of favor when it became known that the estrogen also caused severe and dangerous cardiovascular side effects. The actual side effects included high blood pressure, blood clot formation, fluid retention and pulmonary embolisms. These side effects probably killed as many men as the drug helped.

Many now believe that current technology now allows for the successful management of these cardio-vascular problems. Diuretics, antihypertensive drugs and Coumadin, when properly used, can ameliorate many of the common problems caused by the oral estrogen drugs.

Many physicians believe that the side effects of oral estrogen may also be prevented by administering estrogen transdermally, through the skin, with patches or in a gel form.

The administration of estrogen through the skin (patches or gel) has been well studied in women where it is clear that there are many advantages. The biggest advantage is that the estrogen is directly absorbed into the blood stream, bypassing the liver, thus reducing the production of clotting factors and the resulting blood clot risks.

A study published in the Journal of Urology (Ockrim, et al) concluded that transdermal estradiol is both safe and effective for men with prostate cancer. They found that the estradiol both inhibited the production of testosterone and directly killed prostate cancer cells while avoiding the full scope of dangerous side effects common with oral administration.

Transdermal estradiol can also be used to suppress hot flashes caused by other forms of ADT and is also less expensive than other forms of hormone therapy in use today.

Estrogen, particularly transdermal estradiol, should be considered as a good second line hormone therapy when needed.

Joel T Nowak, M.A., M.S.W.