Early hormonal data from a multicentre phase II trial using transdermal oestrogen patches as first-line hormonal therapy in patients with locally advanced or metastatic prostate cancer

Abstract

Objective: To assess the hormonal effects of Fem7 (Merck, KGaA, Darmstadt, Germany) 100 microg transdermal oestrogen patches on men undergoing first-line androgen-deprivation therapy for prostate cancer.

Patients and methods: PATCH is a multicentre, randomized, phase II trial for men with locally advanced or metastatic prostate cancer, comparing luteinizing hormone-releasing hormone agonist therapy with oestrogen patches. To assess the dosing schedule for the patches, as this was the first time that this brand of patch had been used in men, and to reassure patients and participating clinicians, the Independent Data Monitoring Committee agreed to early release of hormonal data from this study.

Results: Oestradiol, testosterone and prostate-specific antigen (PSA) levels are presented for the first group of 14 patients who received the patches (with 1 withdrawal) and for whom there were > or =12 weeks of follow-up by March 2007. After 12 weeks, testosterone levels (nmol/L) in eight of the 13 patients were <1.7, two were 1.7-2 and three were >2. The median (range) serum oestradiol levels was 442 (52.1-1542) pmol/L and all patients had a PSA response, with eight having a PSA level of <4 ng/mL.

Conclusion: These results confirm that oestrogen patches produce castrate levels of testosterone and concomitant PSA responses. They also highlighted the potential differences between different brands of oestrogen patches, and the need to monitor hormonal response, toxicity and efficacy until more experience with oestrogen patches for this clinical indication is obtained. The number of patches recommended in the PATCH study has now been increased.

FIG. 1

Oestradiol concentration profiles over 3 days (82 h) for patches delivering 100 μg/day oestradiol. The continuous line denotes Fem7 [11], and the dashed line Estradot [13].