Effect of improved diagnosis of renal cell carcinoma on the course of the disease

The impact of the improved diagnosis of renal cell carcinoma (RCC) on the course of the disease was evaluated in 188 patients who were diagnosed and treated at a single medical center. Sixty‐seven patients (group A) who had undergone nephrectomy between 1979 and 1983 for RCC initially diagnosed by intravenous pyelography (IVP) were compared with 121 patients (group B) who had undergone nephrectomy between 1983 and 1989, diagnosed by ultrasound and/or computed tomography (CT) scan. Incidental asymptomatic tumors were found in 18 of 67 (26.9%) group A patients and in 57 of 121 (47.1%) group B patients (P < 0.001). The incidence of small tumors of