Prognostic value of multifocality on progression and survival in localized renal cell carcinoma

Incidence of multifocality in Renal Cell Carcinoma (RCC) is estimated at between 5 and 25%. Multifocality has been largely studied because of the growing interest in conservative surgery which is a risk of local recurrence. The aim of this study is to evaluate the relationship between multifocality and other prognostic parameters and whether it is an independent prognostic factor.

From 1980 to 1990, 255 patients (median age: 60.9 years) were treated by radical nephrectomy for pT1 to pT3b N0M0 RCC. The median follow-up time was 183 months. Multifocality was defined as the existence of at least one other tumoral localization, macroscopically and microscopically diagnosed as renal cell carcinoma, in the same kidney. Studied parameters were: age, sex, side, size, stage, Fuhrman's grade, capsular invasion, renal vein involvement and microvascular invasion. Survival was assessed with Kaplan-Meier and Cox models.

37 cases of multifocal RCC were diagnosed (14.5%). There was only a significant correlation with stage (p=0.002) and with capsular invasion (p=0.002). No other factor was correlated with multifocality. It had no influence on the risk of metastatic progression, overall or specific survival.

There is a significant correlation between capsular invasion and multifocality that has to be considered before proposing conservative surgery for a localized RCC. Multifocality has no influence on survival or metastatic progression in case of radical nephrectomy.