Template-based lymph node dissection (LND) may provide more precise disease staging and enable better local disease control in patients with clinically node-negative upper tract urothelial carcinoma (UTUC) undergoing radical nephroureterectomy (RNU), according to investigators.
In a study, 96 of 105 patients with cTa-3N0M0 UTUC had complete regional LND with an anatomical template-based rule during laparoscopic RNU. (A median of 12 lymph nodes per patient were removed.) Lymph node metastases were observed in 7 patients upon routine pathology, and micrometastases were found in 5 additional patients based on pan-cytokeratin immunohistochemistry. No nodal metastases occurred in patients with less than pT1 UTUC.
Nonurothelial disease recurrence was observed in 20% of patients at a median of 10 months, including distant metastasis in 14.3%, locoregional recurrence in 4.8%, and both in 0.95%, Ryuji Matsumoto, MD, PhD, of Hokkaido University Graduate School of Medicine in Sapporo, Japan, and collaborators reported in Urologic Oncology. At 5 years, nonurothelial recurrence-free survival rates were 84.8% for node-negative patients, 53.3% for patients with micrometastases, and 19.1% for node-positive patients. Five-year cancer-specific survival rates followed the same pattern: 95.0% vs 53.3% vs 23.8%, respectively.
Template-based LND was routine at their 2 institutions, the authors stated.
“Because locoregional recurrence was the most frequent form of recurrence in the previous cohorts in which LND was skipped in a large proportion of patients, our observations strongly suggest that template-based LND could facilitate better local disease control by eliminating micrometastasis,” Dr Matsumoto’s team wrote.
Patients with micrometastases might have had insufficient LND in difficult areas, according to the investigators. For example, patients with lower ureteral tumors might have had insufficient LND around the internal iliac vessels. Such small nodal metastases might be overlooked by standard pathology, they added.
“The survival impact and ideal management of pNmicro+ disease should be evaluated in a larger cohort,” Dr Matsumoto’s team said.
Matsumotoo R, Abe T, Takada N, et al. Oncologic outcomes of laparoscopic radical nephroureterectomy in conjunction with template-based lymph node dissection: An extended follow-up study [published online June 10, 2020]. Urol Oncol. doi: 10.1016/j.urolonc.2020.05.013