Effect of 12-months testosterone replacement therapy on bone mineral density and markers of bone turnover in testicular cancer survivors – results from a randomized double-blind trial

Abstract

Background

Testicular cancer survivors (TCS) are at risk of Leydig cell insufficiency, which is a condition characterized by elevated luteinising hormone (LH) in combination with low levels of testosterone. It has been suggested that this condition is associated with impaired metabolic profile and low bone mineral density (BMD). The primary aim of the randomized double-blind trial NCT02991209 was to evaluate metabolic profile after 12-months testosterone replacement therapy (TRT) in TCS with mild Leydig cell insufficiency. Here we present the secondary outcomes of changes in BMD and markers of bone turnover.

Methodology

In total, 69 TCS with mild Leydig cell insufficiency were randomized 1:1 to 12 months TRT (n = 35) (Tostran, gel, 2%, applied transdermally, with a maximum daily dose of 40 mg) or placebo (n = 34). BMD and markers of bone turnover were evaluated at baseline, after 6- and 12-months TRT, and 3-months post-treatment. Linear mixed effects models were used to analyse changes in BMD, N-terminal propeptide of type 1 procollagen (P1NP) and C-terminal telopeptide of type I collagen (CTX).

Results

After 12 months treatment, TRT was not associated with a statistically significant difference in BMD compared to placebo; total body BMD: 0.01 g/cm2 (95% confidence interval (CI): −0.01 − 0.02), BMD of the lumbar spine: 0.01 g/cm2, (95% CI: −0.01–0.03), BMD of the left femoral neck: 0.00, (95% CI: −0.01–0.02). TRT was associated with a small but statistically significant increase in P1NP: 11.65 µg/L (95% CI: 3.96, 19.35), while there was no difference in CTX.

Conclusion

12 months of TRT did not change BMD, while there was as small and clinically irrelevant increase in P1NP compared to placebo in TCS with mild Leydig cell insufficiency. The findings need validation in a larger cohort.

Keywords:

• Testicular cancer
• bone mineral density
• markers of bone turnover
• testosterone
• hypogonadism
• osteoporosis
• late effects

Acknowledgments

The Danish Cancer Society, The Danish Cancer Research Foundation and Rigshospitalet have supported the study. Kiowa Kirin International covered expenses for Tostran and placebo.

Disclosure statement

The authors report there are no competing interests to declare.

Data availability statement

According to Danish law individual patient data that underlie the results reported in this paper cannot be shared. Anonymized access to data might be possible, please contact the corresponding author regarding this. Study protocol can be shared upon request.