Oral ethinylestradiol in castration‐resistant prostate cancer: A 10‐year experience

Abstract

Abbreviations & AcronymsObjectives: To describe our 10-year experience with the use of oral ethinylestradiol in the treatment of metastatic castration-resistant prostate cancer. Methods: From February 2000 to April 2010, 116 patients with a metastatic castrationresistant prostate cancer were prospectively submitted to oral ethinylestradiol monotherapy. Inclusion criteria were: diagnosis of castration-resistant prostate cancer after failure of at least two lines of androgen deprivation therapy and radiological evidence of metastases. Exclusion criteria were: symptomatic cases with a European Cooperative Oncology Group score >2 and severe or uncontrolled cardiovascular diseases. At inclusion in the study, all patients discontinued the previous androgen deprivation therapy and started oral ethinylestradiol at the daily dose of 1 mg. Aspirin (100 mg/daily) was concomitantly given. Results: The median ethinylestradiol therapy duration was 15.9 months (range 8-36 months), whereas the median follow up of patients was 28 months (range 13-36 months). During ethinylestradiol therapy, a confirmed prostate-specific antigen response was found in 79 patients (70.5%). The median time to prostate-specific antigen progression was 15.10 months (95% confidence interval 13.24-18.76 months). A toxicity requiring treatment cessation was observed in 26 patients (23.2%) at a median time of 16 months (mainly thromboembolism). Conclusions:Our 10-year experience shows that ethinylestradiol provides a prostatespecific antigen response in a high percentage of patients with metastatic castrationresistant prostate cancer. Cardiovascular toxicity can be managed through accurate patient selection, close follow up and a concomitant anticoagulation therapy.

Influence of prior oral ethinylestradiol use on the efficacy of enzalutamide for the treatment of castration‐resistant prostate cancer in men

“…11,12 In short, these studies reported PSA response rates of EE ranging 57.1-73.3%, and a median time to progression ranging 7-15.1 months. The PSA response rate (percent of patients achieving a decline in PSA >50% from baseline) and median time to progression during EE therapy were 51.1% and 12.2 months, respectively.…”

“…[9][10][11] Among estrogens, several authors investigated the effect of oral EE for CRPC treatment. [9][10][11] Among estrogens, several authors investigated the effect of oral EE for CRPC treatment.…”

“…On the contrary, older agents, such as estrogens or steroids, reportedly have certain anticancer effects in patients with CRPC and are available at considerable lower costs. [9][10][11] Among estrogens, several authors investigated the effect of oral EE for CRPC treatment. 11,12 They concluded that estrogen therapy is beneficial for CRPC, as it can induce PSA response (50% PSA decline) rates as high as 73.3% in selected patients with CRPC.…”

Therapies for castration‐resistant prostate cancer in a new era: The indication of vintage hormonal therapy, chemotherapy and the new medicines

“…In particular, the usefulness of ethinyl-estradiol has been assessed in retrospective studies, and favorable results have been obtained, showing PSA PFS of 10 months in CRPC patients in Japan, and PFS of 15.1 months in metastatic CRPC in Western countries. 4,13 Administration of low-dose estramustine phosphate for CRPC showed a favorable response before docetaxel treatment (7.1-month median PFS, and 42-month overall survival in 31 patients with CPRC). 5 Also for dexamethasone, which has been used extensively for CRPC in Japan because of the benefit in treatment of CRPC, 14 the usefulness has been reconfirmed by a prospective study in Western countries comparing dexamethasone and prednisone for treatment of CRPC, in which PFS periods were 9.7 and 5.1 months, respectively.…”

“…In addition, estrogen‐related drugs, such as estramustine phosphate and ethinyl‐estradiol, have also been used for post‐recurrence of alternative antiandrogen therapy. In particular, the usefulness of ethinyl‐estradiol has been assessed in retrospective studies, and favorable results have been obtained, showing PSA PFS of 10 months in CRPC patients in Japan, and PFS of 15.1 months in metastatic CRPC in Western countries . Administration of low‐dose estramustine phosphate for CRPC showed a favorable response before docetaxel treatment (7.1‐month median PFS, and 42‐month overall survival in 31 patients with CPRC) .…”