Renal cancer in families with hereditary renal cancer: prospective analysis of a tumor size threshold for renal parenchymal sparing surgery.

PURPOSE Patients with hereditary forms of renal cancer are at risk for new tumors and metastases. Renal parenchymal sparing surgery has been performed to preserve renal function and quality of life, and prevent metastases. We evaluated a 3 cm. threshold for performing renal parenchymal sparing surgery in patients with von Hippel-Lindau disease and hereditary papillary renal cancer. MATERIALS AND METHODS Patients with von Hippel-Lindau disease or hereditary papillary renal cancer and renal cancer were identified by screening affected kindred and by kindred history. Patients with small tumors were followed with serial imaging studies until the largest renal tumor was 3 cm., when renal parenchymal sparing surgery was performed. Renal tumors greater than 3 cm. were resected without delay. Parenchymal sparing techniques were used when possible in each group. RESULTS The 3 cm. surgical threshold was evaluated in 52 patients with von Hippel-Lindau disease (group 1) at a median followup of 60 months (range 6 to 205). None of these patients had metastatic disease and none has required renal transplantation or dialysis. In 44 patients with von Hippel-Lindau disease (group 2) renal tumors larger than 3 cm. developed. Median followup from the initial radiological diagnosis of renal cancer in this group was 66.5 months (range 0 to 321). Patients in group 1 underwent parenchymal sparing surgery instead of nephrectomy more frequently than those in group 2 (46 of 48 operations or 96% versus 45 of 72 or 63%, Fisher's exact test p <0.0001). In contrast to patients in group 1, metastatic renal cancer developed in 11 of the 44 in group 2 (25%) (Fisher's exact test p <0.0001). A total of 23 patients with hereditary papillary renal cancer were also identified. Median followup in these cases was 44 months (range 0 to 237). Ten patients had tumors less than 3 cm. No patient with tumors less than 3 cm. and 2 of the 13 (15%) with larger tumors had metastases. CONCLUSIONS Using a 3 cm. renal tumor diameter as an indication for renal surgery no patient with renal cancer and von Hippel-Lindau disease or hereditary papillary renal cancer had metastatic disease regardless of the number of tumors. Using a lesion size of 3 cm. as a threshold for performing renal parenchymal sparing surgery may help to prevent metastatic disease, unnecessary renal damage due to frequent surgery and renal dialysis or transplantation.