Defining a hilar "danger zone" to guide surgical decision-making in T1 renal cell carcinoma
Zihao Li1, Li Wang1, Chunzhi Qi1
1The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Background:
Laparoscopic partial nephrectomy (LPN) is a preferred surgical approach for early-stage renal cell carcinoma. However, there is ongoing debate regarding the optimal surgical technique for highly complex renal hilar tumors. Moreover, long-term follow-up data assessing the applicability and outcomes of LPN for renal hilar tumors remain limited.
Methods:
A retrospective analysis was conducted on patients with pT1-stage clear cell renal cell carcinoma (ccRCC). We proposed an imaging-based "danger zone" defining the critical boundary of hilar vascular structures. Based on spatial location and surgical approach, patients were stratified into 4 groups: non-hilar partial nephrectomy (NHPN), hilar partial nephrectomy outside (HPNOUT) or inside (HPN-IN) the danger zone, and hilar radical nephrectomy (HRN). We compared perioperative parameters, postoperative renal function (eGFR), and recurrence-free survival (RFS) across these cohorts.
Results:
A total of 323 patients were included (NHPN, n = 204; HPNOUT, n = 46; HPN-IN, n = 21; HRN, n = 52). Over a median follow-up of 3,276 days, 24 overall oncologic events were recorded. The HPNOUT group demonstrated perioperative outcomes, postoperative eGFR, and RFS (HR = 1.16, 95% CI: 0.28-4.85, P = 0.836) comparable to the NHPN cohort. Conversely, the HPN-IN group exhibited significantly higher estimated blood loss (adjusted difference: +136.3 ml, 95% CI: 99.2-173.4, P < 0.001) compared to the HPNOUT group. However, when evaluating tumors exclusively within the danger zone, a distinct clinical trade-off emerged. Compared to HRN, the HPN-IN group experienced greater perioperative morbidity but achieved significantly superior long-term renal function preservation (across 3-month, 1-year, and 5-year follow-ups; all P < 0.05). Importantly, long-term oncological control remained comparable between these 2 approaches (RFS HR = 2.06, 95% CI: 0.60-7.09, P = 0.250).
Conclusions:
The proposed "danger zone" concept offers an exploratory anatomical tool to assist in the preoperative risk assessment of T1 hilar tumors. Initial data suggest that LPN remains a viable option for lesions located outside the danger zone. When tumors invade the danger zone, LRN provides a safer perioperative course at the expense of functional preservation, whereas oncological efficacy seems equivalent between modalities. These preliminary observations necessitate rigorous prospective validation prior to clinical application.
