Shrinkage of Prostate Volume in Sunitinib-treated Patients with Renal Cell Carcinoma

Sunitinib is widely used to treat patients with advanced renal cell carcinoma; however, its influences on the prostate volume and lower urinary tract symptoms remain unclear. To investigate the influence of sunitinib on clinical findings of urinary tract, we recruited a total of 20 male patients with advanced renal cell carcinoma who are treated with sunitinib. We evaluated clinical findings during clinical visits over 24 weeks: International Prostate Symptom Score, urine flow rate, residual urine volume, serum prostate-specific antigen level and prostate volume. Residual urine and prostate volumes were significantly decreased at Week 24. The residual urine volume was especially decreased in patients with a high residual volume at baseline. No differences were observed in the International Prostate Symptom Score total score, International Prostate Symptom Score quality of life score, maximal urinary flow rate or prostate-specific antigen level. We observed a reduction in prostate volume and an improvement in urinary symptoms through relief from urinary tract obstruction during sunitinib treatment. Careful attention to urinary functions and drug dose adjustment seems to be necessary in patients with comorbid benign prostatic hyperplasia or dysuria.