Objectives: We retrospectively analyzed our patients with advanced renal cell carcinoma who underwent presurgical targeted therapy with tyrosine kinase inhibitors to clarify the safety and clinical benefit. The histopathological effect of this treatment was also examined.
Methods: Between July 2005 and February 2010, nine patients with advanced renal cell carcinoma who were treated with tyrosine kinase inhibitors before surgery were the subjects of this study. Consolidative surgery was considered when these tumors showed clinical response or stable disease while on targeted therapy without evidence of disease progression at other sites.
Results: The agents used were sorafenib in seven patients and sunitinib in two. The median duration of presurgical therapy was 12.2 weeks, and seven patients had less than 4 months of treatment. Tumor reduction at 10-30% was obtained in all patients but one. Perioperative complications were observed in five of nine patients. Major complications occurred in two patients, including intraoperative excessive bleeding and delayed localized intraperitoneal abscess. Minor complications were found in three. The characteristics of the histopathological effect of tyrosine kinase inhibitors consisted of marked atrophy of the capillary sinus, confirming the pharmacological mechanisms of these agents. Other findings included nuclear pyknosis and degeneration of tumor cells.
Conclusions: Presurgical targeted therapy with tyrosine kinase inhibitors appears to be feasible in most patients with advanced renal cell carcinoma. However, the indications, the clinical benefit and the standard protocol still remain to be determined. Therapeutic effects in the histology were compatible to their pharmacological effects.