The stratification of positive lymph nodes into pN1 and pN2 for upper urinary tract carcinoma is not prognostically...

The 3^rd-7^th edition of the American Joint Committee on Cancer had 3 categories for positive lymph nodes (pN1-3) in upper urinary tract carcinomas. The 8th edition removed pN3, defining pN1 as one lymph node with a tumor deposit ≤2 cm and pN2 as a node with a tumor deposit >2 cm or metastases in multiple nodes. The aim of this study was to assess if the current pN categories impact survival in renal pelvic and ureteral carcinomas. Nephroureterectomies performed at our institution for primary upper urinary tract carcinomas between 2010 and 2019 were reviewed. Lymphadenectomy was performed in 73.3% of cases (151/206, median = 9 nodes). Eighty-one (53.6%) patients were deceased at the last review (pN0, 53 [44.5%]; pN1-2, 28 [87.5%]). There was no difference in overall or recurrence-free survival between pN1 and pN2 with 5-year overall survival (95% confidence interval) of pN0, 60.7% (52.0-70.8%); pN1, 15.4% (4.3-35.2%); and pN2, 21.1% (8.8-40.3%). The metastatic deposit size threshold of 2 cm, the number of positive lymph nodes, as well as extranodal extension did not correlate with overall or recurrence-free survival. As such, pN1 and pN2 were grouped together with a 5-year overall survival of 18.8% (9.12-28.6%). The current stratification of upper urinary tract carcinomas into pN1 and pN2 does not provide prognostic information, and both yield a stage IV classification, regardless of pT or pM category. Therefore, we recommend further simplification of pN classification into one category for regional lymph node metastasis, irrespective of the lymph node deposit size or number of positive lymph nodes.