Matched Comparison Between Partial Nephrectomy and Radical Nephrectomy for T2 N0 M0 Tumors, a Study Based on the National Cancer Database.

OBJECTIVES: To compare overall survival (OS) and immediate postoperative outcomes between partial and radical nephrectomy (RN) for T2 N0 M0 tumors and identify significant factors for poor OS.

PATIENTS AND METHODS: Using the National Cancer Database, we identified patients with T2 N0 M0 renal cancer between 2004 and 2009 who were treated with partial or radical nephrectomy. The partial and RN groups were statistically matched by demographics and tumor characteristics. We used Cox multiple regression to identify significant factors for all-cause mortality and plotted survival curves for both groups. We compared immediate postoperative outcomes between groups by χ2 test and independent samples t-test.

RESULTS: After statistical matching, there were 527 patients in each group, with high similarities in age, gender, race, comorbid status, tumor size, histology, and grade. RN was associated with a higher risk of all-cause mortality (hazard ratio: 5.289; p < 0.001) than partial nephrectomy (PN), after adjusting for all available covariates. PN had significantly better OS than RN, with log-rank, Breslow, and Tarone-Ware tests consistently showing p-values of <0.001. Old age, high comorbidity index, and high Fuhrman grade were associated with increased risks of all-cause mortality, while papillary and chromophobe tumors had decreased risks. PN was associated with more positive surgical margins (PSM) than RN (4.4% vs 2.5%, p < 0.001).

CONCLUSION: T2 N0 M0 tumors treated with PN had better OS than those treated with RN, despite more PSM. Age, comorbidity index, histologic subtypes, and Fuhrman grade had significant impacts on OS.