Functional preservation in patients with renal cortical tumors: the rationale for partial nephrectomy.

Renal cortical tumors (RCT) are a family of neoplasms with diverse histology and metastatic potentials. Conventional clear cell tumors account for 54% of all RCT and 90% of those that metastasize. Liberal use of abdominal imaging detects 70% of RCT incidentally and at a small size (< 4 cm in diameter). Emerging evidence strongly favors partial nephrectomy (PN) as the primary treatment when technically possible for tumors 7 cm or smaller. This approach provides local tumor control equivalent to radical nephrectomy (RN) and prevents or delays chronic kidney disease (CKD) onset. CKD is present in 26% of apparently well patients with such small renal tumors and is an independent risk factor for cardiovascular disease, hospitalization, and death. The likelihood of freedom from an estimated glomerular filtration rate lower than 45 mL/min/1.73m2, a level of significant CKD, is 95% after PN, but only 64% after RN. RN should be reserved for patients with massive renal tumors in whom PN is not an option. Increased training in PN and its wider application is essential.