Purpose: We assessed the influence of clinical and pathological factors on multifocality of renal cell carcinoma.
Materials and methods: Between June 1995 and September 1999 radical nephrectomy was performed in 71 men and 32 women with a mean age of 56.5 years. The 103 removed kidneys with renal cell carcinoma were sectioned at 3 mm. intervals and inspected microscopically for satellite carcinomas. We evaluated pathological stage, grade, cell type, histological pattern, vascular involvement, tumor size and the incidence of multifocality. To determine cell type we used several classification systems.
Results: The primary tumor was 2 to 20 cm. (mean plus or minus standard deviation 7.10 +/- 3.48). Overall satellite carcinomas were present in 22 of the 103 cases (21.4%). When the predominant lesion was 5 cm. or smaller, the incidence of multifocality was 19%. The incidence of multifocality was statistically higher in patients with stage pT3 than in those with stage pT1 or pT2 disease (p = 0.022). Multiple logistic regression analysis demonstrated that only primary tumor pathological stage was a significant predictor of renal cell carcinoma multifocality in stages T3 versus T1 and T3 versus T2 cancer (odds ratio 3.45, 95% confidence interval 1.15 to 10.39 and 5.75, 1.31 to 25.29, respectively). Other parameters, such as tumor size, grade, vascular invasion, cell type and histological pattern, did not correlate with multifocality.
Conclusions: Our results imply that primary tumor stage is a significant factor for multifocal disease. Therefore, more precise preoperative staging of the primary lesion is required if nephron sparing surgery is indicated.