BERKELEY, CA (UroToday.com) - Sunitinib is the standard first-line treatment for advanced RCC; however, sunitinib-related adverse events such as influence on endocrine organ activity, hypothyroidism, impaired glucose tolerance, and increased levels of amylase and lipases have been reported. To date, the influence of sunitinib on prostate volume and urinary symptoms remains unclear. We therefore examined the prostate volumes and lower urinary tract symptoms in patients with advanced RCC to investigate the influence of long-term sunitinib therapy on them.
We evaluated the findings during clinical visits over 24 weeks and found reduction of prostate volume and residual urine volume at week 24. We suspect that improvement of urinary obstruction due to the reduced prostate volume results in a decreased volume of residual urine.
Sunitinib is a multitargeted tyrosine kinase inhibitor of VEGF receptors 1-3 and platelet-derived growth factor (PDGF) receptors α and β. Since VEGF and PDGF are the most potent mitogenic factors stimulating both endothelial and epithelial cells in the normal prostate gland, reduction in prostate volume might be caused by the inhibition of VEGF and PDGF receptors. Sunitinib might cause vascular insufficiency in the prostate and reduce the size of the enlarged prostate.
Benign prostate hyperplasia is a common urological condition found in aging men. In Japan, approximately 75% of male renal cancer patients have prostatic hyperplasia, and 50% receive treatment for prostatic hyperplasia. Actually, treatment of prostatic hyperplasia became unnecessary after sunitinib therapy in some of our patients. Careful attention to urinary function and drug dose adjustment are necessary in patients with comorbid benign prostatic hyperplasia or dysuria. Our findings should be of great interest to urologists and medical oncologists.
Takashi Hatano, MD, PhD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Department of Urology
JR Tokyo General Hospital
2-1-3 Yoyogi, Shibuya-ku, Tokyo 151-8528 Japan