Clinicopathological Features of Incidentally Detected Renal Cell Carcinoma in Japan.

Background : The objective of this study was to compare clinical outcomes between patients with symptomatic and incidental renal cell carcinoma (RCC) experienced in a single institution in Japan. Patients and methods : We reviewed the records of 178 consecutive patients who underwent radical or partial nephrectomy for RCC at our institution between April 1984 and March 2002. Several clinicopathological factors of these patients were analyzed according to the mode of presentation at initial diagnosis; that is, symptomatic or incidentally detected RCC. Results : Of the 178 patients, 102 (57.3%) were incidentally discovered. Significant differences between incidental and symptomatic tumors were observed in maximal tumor diameter, distant metastasis, tumorgrade, stage and microscopic venous invasion. Cause-specific survival in patients with incidental tumor was significantly higher than that in those with symptomatic tumor. Moreover, multivariate analysis demonstrated that maximal tumor size, metastasis, and the mode of presentation could be used as independent prognostic predictors in patients undergoing surgical resection of RCC. Conclusion : These findings suggest that incidentally detected tumors are of significantly lower stage and grade than symptomatic tumors, resulting in better survival patients with incidental tumor. Therefore, detection of RCC before symptom onset may contribute to an improved prognosis in RCC patients. [ABSTRACT FROM AUTHOR]