Renal fossa recurrence after nephrectomy for renal cell carcinoma: prognostic features and oncological outcomes

Objectives To describe the clinicopathological features associated with increased risk of renal fossa recurrence (RFR) after radical nephrectomy (RN) and to describe the prognostic features associated with cancer-specific survival (CSS) among patients with RFR treated with primary locally directed therapy, systemically directed therapy or expectant management. Patients and Methods The records of 2 502 patients treated with RN for unilateral, sporadic, localized renal cell carcinoma (RCC) between 1970 and 2006 were reviewed. CSS after RFR was estimated using the Kaplan-Meier method. Associations with the development of RFR and CSS after RFR were evaluated using Cox proportional hazards regression models. Results A total of 33 (1.3%) patients developed isolated RFR (iRFR) and 30 (1.2%) patients developed RFR in the setting of synchronous metastases after RN (study cohort, N = 63). The median follow-up for the series was 9.0 years after RN and 6.0 years after RFR diagnosis. On multivariable analysis, advanced pathological stage (pT2: hazard ratio [HR] 4.36, P = 0.004; pT3/4: HR 4.39, P = 0.003) and coagulative necrosis (HR 2.71, P = 0.006) were independently associated with increased risk of iRFR. The median time to recurrence was 1.5 years after RN among the 33 patients with iRFR, and 1.4 years among all patients. Overall, the median CSS was 2.5 years after diagnosis of iRFR, 1.3 years after RFR in the setting of synchronous metastases, and 2.2 years overall. After primary locally directed therapy (surgery, ablation or radiation), systemic therapy or expectant management, the 3-year CSS rates among patients with iRFR were 63%, 50% and 13% (P = 0.001) and were 64%, 50% and 28% (P = 0.006) among all patients, respectively. On multivariable analysis, when compared with observation, locally directed therapies were associated with a significantly decreased risk of death from RCC (HR 0.26, P < 0.001). Conclusions Renal fossa recurrence is a rare event after RN for RCC and portends a poor prognosis, even in the absence of synchronous metastases. Development of iRFR is associated with advanced stage and aggressive tumour biology. Patients who underwent primary locally directed therapy had superior CSS compared with those treated with expectant management, supporting the use of aggressive local treatment in carefully selected patients with RFR. Future research is needed to determine the optimum role and sequencing of combined therapy in patients with this rare entity.