Reassessment of renal cell carcinoma lymph node staging: analysis of patterns of progression
Taekmin Kwon1, Cheryn Song, Jun Hyuk Hong
1Department of Urology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Objectives:
To evaluate the prognostic value of lymph node (LN) metastasis and the therapeutic role of LN dissection (LND) in patients with renal cell carcinoma.
Methods:
We reviewed the medical records of 1503 patients who had undergone nephrectomy from 1990 to 2007. The patients were stratified according to the number, location, and size of LN metastases. The disease-free survival, cancer-specific survival, and survival relative to the preoperative suspicion of LN metastasis were analyzed.
Results:
Of the 1503 patients, 726 (48.3%) had Stage pN0, 37 (2.5%) had Stage pN+, including 16 with pN1 and 21 with pN2, and 740 (49.2%) had Stage pNx. The average number of LNs removed was 5 (range 1-33), and the average size of the metastasized LNs was 2.4 cm (range 0.8-6). Of the patients without preoperative clinical evidence of LN metastasis, 203 underwent LND; all had Stage pN0. The LN stage was a significant predictor of distant metastasis-free survival (P = .002) and cancer-specific survival (P = .001) between the pNx/pN0 and pN+ groups but not between the pN1 and pN2 groups. Metastasized LN size (<3 vs ≥3 cm) also significantly predicted for distant metastasis-free survival (P = .003) and cancer-specific survival (P = .001). In LN-positive patients, LND improved local recurrence-free survival but not distant metastasis-free survival or cancer-specific survival.
Conclusions:
The current LN staging system, which is dependent on the number of metastatic LNs, did not significantly correlate with the prognosis in patients with renal cell carcinoma. In contrast, LN size (<3 vs ≥3 cm) better reflected the effect of this disease on survival. The therapeutic role of LND might be limited.
