THE IMPACT OF A 4 CM. CUTOFF POINT FOR STRATIFICATION OF T1N0M0 RENAL CELL CARCINOMA AFTER RADICAL NEPHRECTOMY

Purpose: The 1997 TNM classification defines T1 tumors as those smaller than 7 cm. Recently, a cutoff point of 4 cm. has been proposed to create a subclass of T1 tumors. We evaluated the validity of this cutoff point by assessing the pathological findings and prognoses of patients with T1N0M0 renal cell carcinoma following radical nephrectomy.Materials and Methods: We reviewed the hospital charts of 333 patients with T1N0M0 tumors, followed as long as 282 months (median 63) after radical nephrectomy. The validity of tumor size cutoff point for predicting survival outcome was tested in relation to other prognostic factors, including patient age, tumor position, nuclear grade, tumor histopathology and degree of microscopic venous invasion.Results: During followup 32 patients (9.6%) had tumor recurrence and 21 (6.3%) died of renal cell carcinoma. A 5 cm. cutoff point maximized the differences in cancer specific survival rates and a 4 cm. cutoff point maximized the differences in disease-free survival rates. ...