Incidence and predictors of ipsilateral local recurrence following partial nephrectomy

Purpose: Ipsilateral local recurrence (LR) after partial nephrectomy (PN) for renal cell carcinoma (RCC) may result from a metachronous tumor or PN bed recurrence. To date, literature has predominantly reported ipsilateral LRs collectively, although the pathophysiology and prognostic implications of these event may be distinct. We sought to assess variables associated with LR and evaluated associations of LR with metastasis and death from RCC. Materials and methods: We identified adults undergoing PN for unilateral, sporadic, localized RCC from 2000 to 2019 using a prospectively maintained, single institution registry. LR was defined as new, enhancing tumor within/near the PN bed on MRI/CT. Cox proportional hazards models were used to create a preoperative risk score for LR and to examine the association of LR with metastasis and CSS following PN among patients with clear cell RCC. Results: In a cohort of 2,164 PNs, 106 true LRs were identified, for a 10-year incidence of 6.2%. A preoperative risk score for LR based on age, symptoms, solitary kidney, complex tumor necessitating open partial nephrectomy, and cT stage was created (c-index = 0.73). Postoperatively, positive margins, pT stage, and clear cell subtype were associated with LR. Notably, 21% (23/106) of patients with LR presented with synchronous metastases. Following LR, 5-year metastasis-free and cancer-specific survival were 64% and 71%, respectively. LR remained associated with metastasis (HR 6.25; P < 0.001) and death from RCC (HR 1.93; P = 0.03) on multivariable analysis. Conclusions: We developed a preoperative risk score to identify patients at risk for LR following PN. LR was an independent risk factor for metastasis and death from RCC. Further study is warranted to determine whether treatment of LR improves oncologic outcomes.