Significance of Lateral Pelvic Lymph Node Dissection in Resectable Stage IV Low Rectal Cancer: Experience from a...

To investigate the significance of lateral pelvic lymph node dissection (LPLND) in resectable stage IV low rectal cancers, reviewing the treatment outcomes from a single cancer center dedicated to LPLND.

Consecutive 56 patients with stage IV low rectal cancers who underwent primary tumor resection (PTR) between 2007 and 2022 were identified. Sixteen patients with non-curative PTR were excluded, and 40 with curative PTR were analyzed.

The dominant metastatic organ was the liver in 30 (75.0%) patients, followed by the lung in 9 (22.5%). Seven (17.5%) patients had multiple organ metastasis. Five of 40 patients had cT1bN0 or cT2N0 disease, 8 did not receive LPLND for other reasons, and accordingly, 27 (67.5%) finally received LPLND. A total of 15 patients (37.5% of all 40 cases and 55.5% of 27 LPLND cases) had LPLN metastasis. Six (15.0%) patients had bilateral metastasis, and 6 (15.0%) had LD3 metastasis. Eight (20.0%) patients developed local recurrence (LR), and the 5Y-LR rate was 22.3%. Twelve (30.0%) patients underwent preceding chemotherapy before PTR, 26 (65.0%) received chemotherapy after PTR, and 23 (57.5%) achieved complete resection. Twelve (52.2%) of 23 patients developed distant recurrence after complete resection. 5Y-overall survival for all patients was 42.4%.

A high rate of LPLN metastasis implies the significance of management for LPLN metastasis; meanwhile, an unsatisfactory complete resection rate and overall survival implies that LPLN metastasis in this cohort should be dealt with as a systemic disease.