Nephron sparing surgery for renal cell carcinoma 4 cm. or less in diameter: Indicated or under treated?

Purpose: Although radical nephrectomy is the standard treatment for localized unilateral renal cell carcinoma with a normal contralateral kidney, there is ongoing interest in the use of nephron sparing surgery or partial nephrectomy in such cases. The extent of radical surgery in such cases has also been reconsidered in view of the uncertainty regarding the malignant or benign nature. Materials and Methods: Of 14,793 autopsies in Jena from 1985 until 1995 there were 260 renal cell carcinomas. Of the 260 renal cell carcinomas the diameter was 40 mm. or less in 104. These 104 tumors were divided into group 1-20 mm. or less (33 cases), group 2-21 to 30 mm. (28) and group 3-31 to 40 mm. (43). Results: Grade 1 renal cell carcinomas decreased in frequency with increasing tumor diameter, while an opposite result was noted for grade 3. Lymph node and distant metastases were well correlated with tumor size. With an increase in tumor size the frequency of venous involvement increased as well. Significantly more multifocal malignant renal cell carcinomas were seen in tumors between 21 and 40 mm. compared to those 20 mm. or less in diameter. Conclusions: The metastatic potential and biology of these small nodules are not yet known. To lower the risk of local recurrence the results of our study suggest that nephron sparing surgery might be advisable in patients with renal cell carcinoma 20 mm. or less in diameter.