[The significance of tumor diameter in renal cell carcinoma]

The data of 740 patients who were operated on for renal cell carcinoma between 1975 and 1986 have been evaluated. We studied the relation between tumour size and other factors influencing the prognosis, such as tumour stage, infiltration of renal veins and incidence of metastases at the time of nephrectomy, and between tumour grading and postoperative survival. Sixty-six patients with small tumours were divided in groups according to tumour size: less than 20 mm, less than 25 mm, less than 30 mm, less than 40 mm. All 740 patients were separated into groups according to tumour size: less than 4 cm, 4-6 cm, 6-8 cm, 8-10 cm and greater than 10 cm. Stage pT1 carcinomas (less than 25 mm) occurred in 1.4% of patients and tumours exceeding 10 cm in size in 30%. The prognosis with regard to survival becomes worse the greater the diameter of the tumour: the incidence of renal vein involvement, metastases and higher grades of malignancy increases. Postoperative survival decreases in relation to the increase in tumour size. Carcinomas less than 30 mm in diameter were found to have distant metastases in only 1 case, while invasion of renal veins occurred in 2 cases. In tumours up to 3 cm in diameter, a kidney-preserving tumour resection seems possible without limiting the radicalness of the surgery.