Interest in the use of DES to treat prostate cancer in men continues today. However, use of bioidentical parenteral estrogens like polyestradiol phosphate has been advocated in favor of oral synthetic estrogens like DES due to their much lower risk of cardiovascular toxicity. In addition to prostate cancer, some interest in the use of DES to treat breast cancer in women continues today as well. However, similarly to the case of prostate cancer, arguments have been made for the use bioidentical estrogens like estradiol instead of DES for breast cancer.