RADICAL NEPHRECTOMY AND ELECTIVE NEPHRON-SPARING SURGERY LEAD TO EQUIVALENT ONCOLOGIC OUTCOMES IN ALL pT1 RENAL CARCINOMA: RESULTS OF THE SATURN STUDY

Aim of the study: To assess the oncological outcomes of elective nephron sparing surgery (NSS) as compared with radical nephrectomy (RN) in the treatment of all pT1 renal cancers. Material and methods: For the Surveillance And Treatment Update Renal Neoplasms (SATURN) project a computerized databank was generated collecting the data of 5463 patients surgically treated for renal cancer at 16 academic italian institutions between 1995 and 2007. Within this databank, the present study enrolled the 3220 patients (2107 males, 1113 females; mean age 61.3 anni +/- 12.2 anni) affected by pT1a/pT1b pN0/Nx M0 (TNM 2002) renal cell carcinoma submitted to RN or elective NSS (imperative cases were excluded) assessing their clinical (age, gender, symptoms at diagnosis, clinical tumor diameter), surgical, pathology (pathologic tumor diameter, tumor necrosis, sarcomatoid differentiation, TNM 2002 staging, Fuhrman' grading) and follow-up (total follow-up time, disease free survival time, state of the patient at latest examination) data. Results: Overall, 1832 patients had a pT1a renal cancer, 820 (44.8%) submitted to RN and 1012 (55.2%) to NSS, and 1388 had a pT1b renal cancer, 1178 (84.9%) submitted to RN and 210 (15.1%) to NSS. Statistical analysis showed that patients submitted to RN when compared with the ones treated by NSS, were older and affected by cancers more frequently symptomatic, larger in diameter, with a higher grading and with a longer follow-up time; moreover these patients had a higher rate of multifocality among pT1a cancers, a worse performance status and a higher rate of positive surgical margins among pT1b. Survival was significantly correlated to the age at diagnosis, grading and, only for pT1b cancers,multifocality, but not to the type of surgery (RN or NSS), also when the cases were grouped according to age, grading and multifocality. Conclusion: NSS and RN lead to an equivalent oncologic outcome in patients with intracapsular renal carcinoma up to 7 cm, thus confirming the recent idea to broaden the indication to NSS. The multicentric source of the data and the retrospective nature of the study, besides the significant differences in the characteristics of the cases that were selected for NSS and RN, represent relevant biases that must be considered when analyzing the results. Probably the amount of evidence collected so far is the base upon which to design a randomized prospective study.