[Time-course of plasma testosterone in patients with prostate cancer treated by endocrine therapy].

OBJECTIVE

To assess the time-course of plasma testosterone in patients with prostate cancer treated by endocrine therapy.

METHODS

A PubMed review of the literature on plasma testosterone and the various endocrine therapies for prostate cancer was performed.

RESULTS

The time-course of plasma testosterone varies according to the type of endocrine therapy. The effective castration level, classically considered to be 50 ng/dl, is currently tending to be replaced by 20 ng/dl. Following surgical castration, plasma testosterone reaches effective castration levels within several hours, while with LH-RH agonist therapy, plasma testosterone reaches its trough value after three to four weeks, and remains low for six months after stopping treatment. However, about 15% of patients treated with LH-RH agonists do not achieve effective castration levels. Plasma testosterone remains unchanged or even increases in response to anti-androgens. Plasma testosterone assay is of limited value in routine clinical practice in patients receiving endocrine therapy for prostate cancer, but should be performed in the case of elevation of PSA to ensure that the patient has achieved effective castration levels.

CONCLUSION

The correlation between plasma testosterone and progression of prostate cancer is unclear. Other studies are therefore necessary to define the value of plasma testosterone assay in patients treated for prostate cancer.