Presurgical Sunitinib Reduces Tumor Size and May Facilitate Partial Nephrectomy in Patients with Renal Cell Carcinoma.

OBJECTIVE:To determine whether presurgical sunitinib reduces primary renal cell carcinoma (RCC) size and facilitates partial nephrectomy (PN).METHODS:Data from potential candidates for PN treated with sunitinib with primary RCC in situ were reviewed retrospectively. Primary outcome was reduction in tumor bidirectional area.RESULTS:Included were 72 potential candidates for PN who received sunitinib before definitive renal surgery on 78 kidneys. Median primary tumor size was 7.2 cm (interquartile range [IQR]: 5.3-8.7 cm) before and 5.3 cm (IQR: 4.1-7.5 cm) after sunitinib treatment (P<0.0001), resulting in 32% reduction in tumor bidirectional area (IQR: 14%-46%). Downsizing occurred in 65 tumors (83%), with 15 partial responses (19%). Tumor complexity per R.E.N.A.L. score was reduced in 59%, with median posttreatment score of 9 (IQR: 8-10). Predictors of lesser tumor downsizing included clinical evidence of lymph node metastases (P<0.0001), non-clear cell histology (P = 0.0017), and higher nuclear grade (P = 0.023). Surgery was performed for 68 tumors (87%) and was not delayed in any patient owing to sunitinib toxicity. Grade ≥ 3 surgical complications occurred in 5 patients (7%). PN was performed for 49 kidneys (63%) after sunitinib, including 76% of patients without and 41% with metastatic disease (P = 0.0026). PN was completed in 100%, 86%, 65%, and 60% of localized cT1a, cT1b, cT2, and cT3 tumors, respectively.CONCLUSION:Presurgical sunitinib leads to modest tumor reduction in most primary RCC, and many patients can be subsequently treated with PN with acceptable morbidity and preserved renal function. A randomized trial is required to definitively determine whether presurgical therapy enhances feasibility of PN.