Duration of androgen deprivation therapy and nadir of testosterone at 20 ng/dL predict testosterone recovery to supracastrate level in prostate cancer patients who received external beam radiotherapy

Pituitary-testis axis dysfunction following adjuvant androgen deprivation therapy

Men with high-risk, non-metastatic prostate cancer receive adjuvant androgen deprivation therapy (ADT) for at least 2 years according to Danish guidelines. It remains unclarified if patients regain the function of the pituitary-testis axis after cessation of ADT. Thus, we aimed to investigate the function of the pituitary-testis axis following adjuvant ADT. In this study, we included men who underwent external beam radiation therapy and ADT for high-risk prostate cancer. All patients underwent assessment of testosterone deficiency (TD) symptoms, full biochemical assessment of the pituitary-testis axis, and dynamic stimulatory tests of gonadotropin (gonadotropin-releasing hormone (GnRH) test) and testosterone production (human chorionic gonadotrophin (hCG) test). Patients were diagnosed with TD based on a combination of TD symptoms and testosterone below age-specific reference ranges. TD was characterized as primary, secondary, or mixed based on serum gonadotropins and stimulatory tests. We found that among the 51 patients included in the study, the median time on ADT was 3.2 years and median time since ADT cessation was 3.8 years. Twenty-eight patients were diagnosed with TD; 10 had primary TD (testicular dysfunction), 11 secondary TD (pituitary dysfunction), and 7 mixed TD (combined pituitary and testicular dysfunction). An inadequate testosterone response to hCG stimulation was shown in 42 patients, whereas only 11 patients had a subnormal gonadotropin response to GnRH. We conclude that persistent TD is a common long-term consequence of adjuvant ADT in prostate cancer survivors, equally distributed between pituitary and testicular dysfunction. The study emphasizes the necessity for systematic follow-up of full pituitary-testis axis function in patients receiving adjuvant ADT.

Higher serum testosterone levels predict poor prognosis in castration-resistant prostate cancer patients treated with docetaxel

BACKGROUND

The role of testosterone as a prognostic factor for castration-resistant prostate cancer treated with docetaxel in Japan was investigated.

METHODS

A total of 164 patients with castration-resistant prostate cancer who received docetaxel treatment at Chiba University Hospital and an affiliated hospital were retrospectively analyzed. Testosterone and other clinical factors at the start of docetaxel treatment were evaluated with respect to overall survival and progression-free survival.

RESULTS

Of the 164 patients, 69 had high-volume tumors. The median prostatic-specific antigen was 27.0 ng/mL. The median testosterone was 13.0 ng/dL. The rates of bone and visceral metastases were 80.1% and 8.8%, respectively. For progression-free survival, testosterone ≥13 ng/dL was an independent prognostic factor only on univariate analysis (hazard ratio, 1.81; P = .0108). For overall survival, testosterone ≥ 1.3 ng/dL (hazard ratio, 3.37; P < .0001), high volume (hazard ratio, 3.06; P = .0009), and prostate-specific antigen ≥ 27.0 ng/mL (hazard ratio, 2.75; P = .0013) were independent prognostic factors on multivariate analysis. When assessing related clinical factors, higher serum testosterone was associated with visceral metastasis, high volume, and prostate-specific antigen. Based on three prognostic factors (testosterone, high volume, prostate-specific antigen), a risk classification was developed. The high-risk group (3 risk factors) showed a significantly shorter overall survival compared to the moderate-risk (2 risk factors) and low-risk (0-1 risk factor) groups (P < .0001).

CONCLUSIONS

The present study identified higher serum testosterone (≥13 ng/dL) as a significant prognostic factor in castration-resistant prostate cancer patients treated with docetaxel therapy.