Login to Access Video or Poster Abstract: MP55-04
Sources of Funding: None

Introduction

With adoption of partial nephrectomy (PN), the last few years have been marked by a growth in the use of PN for complex renal masses. This has led to an overall increase in the number of tumors found to have adverse pathological features. There are two types of pathological findings in the current T3a fat invasion renal cell carcinoma (RCC): renal sinus fat invasion (SFI) and perinephric fat invasion (PFI). From an anatomical perspective, after PN, RCC with SFI could be considered more likely to develop recurrence and may be associated with worse prognosis. _x000D_ The aim of our study was to evaluate the influence of SFI and PFI on progression-free survival and overall survival after PN for stage pT3a RCC.

Methods

We retrospectively reviewed our institutional review board-approved PN database. Data consisted of consecutive records of patients who underwent PN for cT1-3a renal cell carcinoma (RCC) between 2007 and 2016. Overall 1306 patients were included in this study. Of this cohort, 143 patients were staged pT3a with SFI (85 patients) or PFI (58 patients) on final pathology. Demographic, perioperative and pathological variables were reviewed. We compared the clinico-pathological characteristics, perioperative morbidity and oncological outcomes between SFI and PFI groups. Progression-free survival (PFS) and overall survival (OS) analyses were performed. Survival curves were compared using Log-rank test.

Results

There were no differences between the 2 groups in terms of age, gender, race, Body mass index, Charlson comorbidity index, cTstage and surgical approach. SFI group had a higher clear cell subtype (p<0.01), Higher R.E.N.A.L score (median 9 vs. 7, p<0.01), Higher hilar (h) location (p<0.01). Positive surgical margin rate was higher in SFI group (21.1% vs. 10.3%) but the difference was not statistically significant(p=0.09). _x000D_ SFI group had higher warm ischemia time (median 28 vs. 21, p<0.01), while estimated blood loss (p=0.6), transfusion rate (p=0.2), Clavien complications (p=0.6) were not different between the 2 groups. After a median 28 months, there were 19 recurrences (13.3%) and 7 deaths (4.9%). _x000D_ When comparing the survival curves between the 2 groups, there were no differences in PFS (Log rank, p=0.5) and OS (Log rank, p=0.8). Tumors size (HR:1.5, 95% CI [1.1-1.9], p <0.01, and tumor grade (HR:3.6, 95% CI [1.1-4.6], p=0.04) were independent predictors of recurrence.

Conclusions

In our cohort of patients with pT3a renal cell carcinoma following partial nephrectomy, sinus fat invasion compared to perinephric fat invasion was not associated with an increased risk of progression or death. The independent predictors of recurrence in this population were tumor size and tumor grade.

Funding

None