Investigative clinical study on prostate cancer part VI: Follicle-stimulating hormone and the pituitary-testicular-prostate axis at the time of initial diagnosis and subsequent cluster selection of the patient population

Are higher pre-diagnosis follicle stimulating hormone levels associated with long-term prostate cancer risk?

BACKGROUND

Follicle stimulating hormone (FSH) is a pituitary hormone that helps regulate testosterone homeostasis. Although it is generally accepted that FSH levels increase with LHRH-agonist therapy for prostate cancer (PC), the specific impact of FSH levels on risk of PC diagnosis is largely unknown. The objective of this study was to perform a population-level analysis to assess the association between FSH levels and PC diagnosis.

METHODS

All men (n = 386,018) who had a pre-PC diagnosis FSH level and complete data were identified within the Veterans Affairs Health System between 1999 and 2018. The association between FSH level and time from FSH test to PC diagnosis was tested using stratified Cox proportional hazards models. Multivariable models were adjusted for age, year, race, body mass index, and Charlson comorbidity index. Due to nonproportional hazards over time, time to PC was modeled separately: ≤4 years after an FSH test and >4 years following an FSH test.

RESULTS

Median age at first FSH level was 64 years (interquartile range [IQR]: 54-72), median year of FSH was 2010 (IQR: 2005-2014), and 70% of the cohort was white. Median follow-up was 76 months (IQR: 38-126) during which 17,519 men (4.5%) were diagnosed with PC. On multivariable analysis, in the first 4 years after FSH test, there was no association between FSH and time to PC diagnosis. Starting from 4 years after FSH test, on multivariable analysis, a higher FSH level was associated with lower risk of PC with continuous modeling, but found no association with log continuous and categorical modeling.

CONCLUSIONS

In this population-level study among male veterans receiving an FSH test for an unknown clinical indication, associations between FSH levels and PC risk were inconsistent and likely driven by selection bias and confounding variables. Future studies should consider different study designs.

Simultaneous Measurements of Follicle Stimulating Hormone and Total Testosterone and Associations in Clinically Localized Prostate Cancer

OBJECTIVES

To evaluate the potential relations of simultaneous measurements of basal levels of follicle stimulating hormone (FSH) and total testosterone (TT) in clinically localized prostate cancer (PCa).

MATERIALS AND METHODS

The study included 126 patients who had simultaneous measurements of prostate specific antigen (PSA), FSH, and TT before undergoing radical prostatectomy for clinically localized PCa. Correlations and independent associations between clinical and pathological factors were investigated by statistical methods.

RESULTS

The tumor volume (TV) was directly correlated to PSA and TT which was inversely related to FSH. Moreover, it was independently associated with both PSA and TT. In a multivariate linear regression model, FSH and TV were simultaneous independent factors associated with TT, and the association was inverse in the former and direct in the latter. In the patient population, the subset with FSH levels above the third quartile was related to lower median levels of TT that were associated with high grade cancer showing a lower TV. In localized PCa, basal levels of TT were associated with tumor parameters and inversely related to FSH levels, and the subset FSH levels above the third quartile were related to lower TT levels that were associated with high grade cancers showing a lower tumor load.

CONCLUSION

Preoperative TT was associated with tumor parameters and inversely related to FSH levels. Patient with increased FSH levels was related to lower levels of TT, which was associated with high grade cancer.

[Change of the LHRH analogue in progressive castration-refractory prostate cancer]

INTRODUCTION

Medicinal or surgical castration remains the treatment of choice in metastatic, hormone-naive prostate cancer; however, 2-12% of patients never reach the target serum levels for medicinal castration. We analyzed the therapeutic efficacy of triptorelin pamoate (TP) as salvage treatment due to its higher potency than endogenous luteinizing hormone-releasing hormone (LHRH). The amino acid sequence of TP is identical to that of endogenous LHRH except for position 6 where L-glycine is replaced by D-tryptophane rendering the synthetic moiety less susceptible to cleavage by proteolytic enzymes.

PATIENTS AND METHODS

In this study 36 patients with prostate-specific antigen (PSA) progression following first line complete androgen blockade and antiandrogen (ADT) withdrawal were retrospectively analyzed. All patients demonstrated no or minimal metastatic disease. The PSA levels, PSA doubling time (PSADT), PSA velocity (PSAV) and testosterone serum concentrations were correlated with the therapeutic response. All patients received TP at a dose of 11.5 mg at 3-month intervals until documented progression.

RESULTS

The mean patient age was 69.2 years (range 52-79 years), the mean PSA level was 23.4 ng/ml (8.7-53.1 ng/ml) and the mean PSADT was 9.2 months (2.9-15.4 months). Mean testosterone serum concentration was 38.67 ng/dl (21-76 ng/dl), the mean time between start of ADT and progression was 42.4 months (13-76 months) and the median time was 46.8 months (16-82 months). A PSA decrease of ≥50% was reached in 9 out of 36 (25%) patients, 3 out of 36 (13.9%) patients each demonstrated stable PSA levels and a prolongation of PSADT from 6.2 to 9.8 months. Mean progression-free survival (PFS) was 21.4 weeks (7-53 weeks). PSA-responders exhibited a PFS of 53.2 weeks (26-64 weeks) as compared to 28 weeks (17-35 weeks) in nonresponders. PSA responders demonstrated significantly higher testosterone serum concentrations of 48.3 ng/dl (29-76 ng/dl) as compared to nonresponders with 32.6 ng/dl (21-62 ng/dl, p=0.02). Mean follow-up was 31.4 months (27-39 months), overall survival was 80.5% and cancer-specific survival was 88.9%.

CONCLUSION

Changing the LHRH analogue in castration-refractory prostate cancer (CRPC) with testosterone serum concentrations at or above the castration level results in a temporary PSA response. This treatment option might be included in the therapeutic algorithm of CRPC. Although the PFS is short it allows the continuation of a treatment option with minimal side effects in a mere palliative situation. The data underline the need for continuous monitoring of testosterone during treatment with LHRH analogues.