# Local Recurrence After Nephron Surgery: What to Do? An Italian Multicentric Registry

## TL;DR

This study examines kidney cancer recurrence after surgery, finding that recurrence is more likely with cancer cells at the cut edge and aggressive cell types, and surgery offers the best cancer control.

## Contribution

The study identifies risk factors and optimal treatment strategies for local recurrence after kidney cancer surgery using a multicenter registry.

## Key findings

- Local recurrence typically occurs within 18 months and is more likely with cancer cells at the cut edge and aggressive cell types.
- Surgery for recurrence provides the best cancer control while preserving kidney function.
- Positive surgical margins and histological variants are independent risk factors for recurrence.

## Abstract

Patients who undergo surgery for kidney cancer could, in a small but important number of cases, see the cancer return near the original site. Because it is hard to predict who is at risk and which treatment works best, we studied real-world cases from several Italian centers. We analyzed 135 patients who experienced local recurrence after undergoing partial or complete kidney removal. Recurrence usually appeared within about 18 months. It was more likely when the first operation left cancer cells at the cut edge and when the cancer had more aggressive cell types. Treating the recurrence with surgery achieved the best cancer control, while kidney function was generally preserved across approaches. These findings can help refine follow-up schedules, identify higher-risk patients, and guide multidisciplinary care, informing future research and personalized treatment strategies.

Introduction and Objectives: Local recurrence (LR) in patients treated with surgery for renal cell carcinoma (RCC) remains a significant clinical challenge that requires thorough investigation. Our study aimed to identify the relative risk factors and explore the optimal clinical management of LR. Materials and Methods: We conducted a non-randomized, observational, retrospective multicentric registry involving multiple Italian urological centers. We included patients treated with surgery (either nephron-sparing or radical nephrectomy) who later developed LR, defined as recurrence in the ipsilateral kidney or renal fossa. Patients with hereditary syndromes or metastatic disease at the time of LR diagnosis were excluded. Results: We reported 135 cases of LR with the following characteristics: most primary lesions were monofocal (85.7%), with a median size of 42 mm (23–53), the median R.E.N.A.L. score was 7 (6–8), and the median Padua score was 7 (6–9). Patients were treated with robot-assisted techniques in 59% of cases, laparoscopic surgery in 32.4%, and open surgery in 8.6%. Nephron-sparing surgery was performed in 75.2% of cases. Ischemia occurred in 61% of the cases, with a median ischemia time of 21 min (15.5–24). Intraoperative complications occurred in 3.8% of cases, while postoperative complications were reported in 13.8%, all of which were grade ≤3 according to the Clavien–Dindo classification. The primary tumors were pT1a in 43.5% of cases, pT1b in 26.3%, pT2 in 14.7% and pT3 in 15.5%. Histologically, 84% of cases were clear cell, 11.3% papillary type 1 or 2, and 3.7% chromophobe. Sarcomatoid/rhabdoid variants were present in 10.5% of cases. The median rate of LR was 1.3% (range 0.2–3.6), while the median time to LR was 18 months (12–39). LR occurred in the ipsilateral kidney in 70.5% of cases and in the ipsilateral renal fossa in 29.5%. The median rate of PSM in LR cases at initial surgery was 2.4% (range 0–4.3), while the median rate of negative surgical margin (NSM) in LR cases at initial surgery was 0.1 (0–0.3). Following LR diagnosis, most patients (49.2%) underwent surgery, 29.1% received cryoablation or radiotherapy, 17.1% received systemic treatment alone, and 4.6% followed a watchful waiting/active surveillance approach. At a median follow-up of 62 months, the highest oncological control in terms of 5-year cancer-specific survival and overall survival rates was achieved in surgically treated patients. The PSM, the histological variant, and their combination were found to be independent variables correlated with the occurrence of LR, with relative risks of 3.62, 2.71, and 8.12, respectively. Conclusions: LR after nephron-sparing or radical nephrectomy represents a significant clinical dilemma. Known risk factors are not always sufficient to predict recurrence, emphasizing the necessity of consistent radiological follow-up per guideline recommendations. Early detection of recurrence and a multidisciplinary approach involving expert centers are crucial for optimizing patient outcomes.