Rapid Development of Spinal Epidural Lipomatosis after Treatment of Metastatic Castration-Resistant Prostate Cancer with Second-Generation Androgen Receptor Antagonists.

BACKGROUND

Previous studies have described the association of spinal epidural lipomatosis with several conditions including chronic steroid therapy, Cushing's syndrome, obesity, Paget disease, and hypothyroidism. We present a report of rapid development of spinal epidural lipomatosis after treatment with second-generation anti-androgen therapy, a new strategy for treatment of metastatic castration-resistant prostate cancer that has been increasingly employed in the past few years. A comprehensive discussion of the underlying molecular networks involving androgen receptor blockage and adipocyte differentiation, as well as the clinical implications of such a phenomenon, are provided.

CASE DESCRIPTION: We describe the clinical and radiological evolution of a 58-year-old male patient with metastatic prostate cancer, who developed new onset of rapidly progressing lumbosacral epidural lipomatosis with significant compression of the nerve roots of the cauda equina a few months after initiation of treatment with second-generation androgen receptor antagonists.

CONCLUSIONS

The underlying pathophysiology of adipose tissue growth following the administration of anti-androgen therapy is discussed, with emphasis on both the canonical Wnt/β-catenin pathway as well as in the Wnt-independent pathway involving direct activation of downstream transcription factors from the T-cell factor family by the androgen receptor. As second-generation androgen receptor antagonists have been increasingly used for treatment of castration-resistant stage metastatic prostate cancer, new onset of symptomatic epidural lipomatosis should be considered as a possible differential diagnosis, especially because the urinary symptoms of cauda equina compression may be improperly attributed to the primary prostate neoplasm.