To determine whether the type of surgery (partial nephrectomy [PN] versus radical nephrectomy [RN]) has any effect on cancer outcome for renal cortical tumors 4 cm or larger. PN outcomes for large renal cortical tumors have been shown to be worse than outcomes for smaller tumors, but the upper limit of tumor diameter amenable to PN remains controversial.

We identified 33 patients from the Columbia University Comprehensive Urologic Oncology Database who underwent PN between 1988 and 2004 for renal cortical tumors 4 cm or larger. Each was matched with 2 patients undergoing RN on the basis of the tumor diameter. A survival analysis was conducted using the Kaplan-Meier method, and any differences between the two groups were compared using the log-rank test. The Cox regression model was used to determine which variables affected survival.

The estimated 5-year recurrence-free survival rate was 93.5% for the PN group and 83.3% for the RN group (P = 0.471). The estimated 5-year disease-specific survival rate was 96.2% for the PN group and 97.8% for the RN group (P = 0.893). Only tumor diameter had an impact on recurrence-free survival in the univariate (P = 0.005) and multivariate (P = 0.008) Cox regression models. Surgical technique had no impact on disease recurrence.

The results of our study have shown that cancer outcomes after PN do not differ from outcomes after RN for tumors of 4 cm or greater in diameter. The upper limit of 4 cm appears to have been determined arbitrarily. It is no longer advisable to restrict PN to patients with tumors smaller than 4 cm in diameter.