Oncological control associated with surgical resection of isolated retroperitoneal lymph node recurrence of renal cell carcinoma

Objective To evaluate the outcome of patients after surgical resection of isolated retroperitoneal lymph node (RPLN) recurrence of renal cell carcinoma (RCC) using a multicentre international cohort. Patients and Methods In all, 50 patients were identified who underwent resection of isolated RPLN recurrence of RCC at four institutions after nephrectomy for pT_anyN_anyM0 disease. Progression-free (PFS) and cancer-specific survival (CSS) were estimated using the Kaplan-Meier method. Cox proportional hazards regression models were used to assess the association of clinicopathological characteristics with disease progression. Results The median (interquartile range, IQR) age at resection was 57.0 (50.0-62.5) years. The median (IQR) time to RPLN recurrence after nephrectomy was 12.6 (6.9-39.5) months, with no significant difference in median time to RPLN recurrence between patients with N+ disease at nephrectomy (10.7 [6.5-24.6] months) and those with Nx/pN0 disease at nephrectomy (13.7 [8.7-44.2] months) (P = 0.66). The median (IQR) size of the RPLN recurrence before resection was 2.6 (1.9-5) cm. The most common site for RPLN recurrence was within the interaortocaval region (34%). The median (IQR) follow-up after RPLN resection for patients alive at last follow-up was 28.0 (13.7-51.2) months. During follow-up, 26 patients developed RCC recurrence, at a median (IQR) of 9.9 (4.0-18.5) months after RPLN resection. Of those who developed a secondary recurrence, disease was again isolated to the retroperitoneum in seven patients. In all, 11 patients subsequently died, including 10 who died from disease. The median PFS after RPLN resection was 19.5 months, with a 3- and 5-year PFS of 40.5% and 35.4%, respectively. We also found that RPLN recurrence at ≤12 months after nephrectomy was associated with a significantly inferior median PFS (12.3 months) compared with RPLN recurrence at >12 months after nephrectomy (47.6 months; P = 0.003). Moreover, on multivariate analysis, a shorter time to recurrence remained associated with a significantly increased risk for subsequent disease progression (hazard ratio 3.51; P = 0.005). Conclusion Surgical resection of isolated RPLN recurrence from RCC may result in durable cancer control in appropriately selected patients. Recurrence at ≤12 months after nephrectomy was associated with a significantly increased risk of progression after resection, underscoring the importance of this variable for risk stratification. Thus, we recommend that, in the setting of isolated RPLN recurrence of RCC (in patients without precluding comorbidities), careful consideration with the patients and medical oncology colleagues be undertaken about the relative and individualised benefits of surgical resection, systemic therapy, and surveillance.