Significance of Lateral Pelvic Lymph Node Size in Predicting Metastasis and Prognosis in Rectal Cancer.

Aim: To evaluate the clinical significance of lateral pelvic lymph node (LLN) size in predicting pathological metastasis and prognosis in rectal cancer treated with preoperative chemoradiotherapy (CRT) followed by surgery. Patients and Methods: Fifty-two patients with rectal cancer who underwent curative surgery after preoperative CRT were included. Fifteen patients underwent total mesorectal excision (TME) alone, while 37 patients underwent TME with LLN dissection for clinical LLN metastasis. Results: Pathological metastasis was identified in seven (2.6%) out of 270 resected LLNs in six (16.2%) out of 37 patients. The cut-off value of the short-axis diameter was 7.0 mm before and 6.0 mm after CRT. The 5-year recurrence-free survival rate was significantly higher in patients with LLNs <7.0 mm than in those with LLNs >= 7.0 mm (85.7% versus 56.8%, p=0.038). Conclusion: Short-axis diameter of LLNs of 7.0 mm seems to be an optimal cut-off value before CRT for predicting pathological metastasis and prognosis.