LOCAL RECURRENCE AFTER SIMPLE TUMOR ENUCLEATION FOR RENAL CELL CARCINOMA: RESULTS OF A PROSPECTIVE SINGLE CENTER STUDY

Introduction & Objectives: The tumour enucleation technique (TE) has found a growing number of supporters as nephron sparing surgery (NSS) due to the excellent results reported in retrospective series along with the prospective pathological confirmation of its oncological safety. The aim of the present study is to prospectively evaluate the risk of local recurrence in patients treated with blunt TE. The risk of local and systemic recurrence related to pseudocapsule (PS) status was also evaluated. Material & Methods: Between 2005 and 2007, data were gathered prospectively from 201 consecutive patients who had TE. TE was done by blunt dissection using the natural cleavage plane between the tumour and normal parenchyma. The degree and side of PS penetration, surgical margins (SM) and routinely available clinical and pathological variables were recorded. Patients had an abdominal CT at the last follow up visit. Results: Overall, 164 tumours were diagnosed as single sporadic RCC and thus included in the study. At the pathological examination, in 99 RCCs (60.3%) the PS was intact and free from invasion (PS-) while 44 RCC (26.9%) had PS penetrated on the parenchymal side (PSK) and 12.8% on the perirenal fat tissue side (PSF). In all cases the SM were negative. At a mean (SD, median, range) follow up of 33 months (11.4, 31, 19-67), no local recurrence were diagnosed. In particular, none of the PSK RCCs recurred locally thus confirming the pathological results. The 3- and 5-years cancer specific survival were 100% and 95%, respectively. The 3- and 5-year progression–free survival (PFS) for the entire series were 96% and 94.1%, respectively. Then we stratified PFS according to PS status and we showed PS status as a significant risk factor for systemic recurrence. The 4-year PFS for tumors PS-, PSK and PSF was 98.9%, 92.3% and 79.4%, respectively (p=0.002; PS- vs. PSF p=0.0009; PSK vs. PSF p=0.038; PS- vs. PSK p=NS). Conclusions: TE is an oncologically safe procedure. The presence of PSK is not associated with any greater risk of local recurrence. The presence of PSF is a significant prognostic factor of systemic disease recurrence.