Can chemoradiation allow for omission of lateral pelvic node dissection for locally advanced rectal cancer?

Objectives We evaluated the relationship between pretreatment clinical parameters and lateral pelvic node (LPN) recurrence in patients with rectal cancer treated with a combination of curative resection and chemoradiotherapy (CRT) and attempted to identify the patients who might benefit from LPN dissection. Methods This study involved 900 patients between June 2001 and June 2009. Pretreatment clinical parameters including radiological size of LPN were analyzed to identify risk factors associated with long‐term outcomes. Results Locoregional recurrence developed in 65 patients (7.2%); 42 (64.6%) had LPN recurrence, 20 (47.6%) of which had no distant metastasis. Multivariate analysis showed that LPN short‐axis diameter (<5, 5–<10, and ≥10 mm) was significantly associated with LPN recurrence‐free survival (5‐year survival rate (5YSR), 98.2, 91.7, and 40.1%, respectively, P < 0.05), locoregional recurrence‐free survival (5YSR, 95.5, 87.6, and 40.1%, respectively, P < 0.05), relapse‐free survival (5YSR, 76.8, 72.5, and 30.3, respectively, P < 0.05), and overall survival (5YSR, 86.3, 83.0, and 57.5%, respectively, P < 0.05). Conclusions Patients with an LPN short‐axis diameter ≥10 mm represent a potential subgroup at a high risk of LPN recurrence, even after CRT. Further study is needed to confirm whether LPN dissection is beneficial for these patients. J. Surg. Oncol. 2015 111:459–464 . © 2015 Wiley Periodicals, Inc.