Total number of lymph node metastases is a more significant risk factor for poor prognosis than positive lateral lymph node metastasis.

ABSTRACT

PURPOSE: Lateral lymph nodes (LLNs) along the iliac vessels are an important indicator of local recurrence; however, we are unaware of any study that investigates whether the number of LLN metastases influences the prognosis of patients with lower rectal cancer. METHOD: We analyzed retrospectively the records of 154 patients who underwent radical resection of T1-4 lower rectal adenocarcinoma at a single institution. RESULTS: Among the 88.3 % of patients who underwent LLN dissection, 13 (8.4 %) had LLN metastasis. The Cox proportional hazard model indicated that sex, histological grade, lymphatic or venous invasion, and LLN metastasis were not significantly associated with tumor recurrence, whereas tumor depth and more than three lymph node metastases were risk factors for recurrence (p = 0.002 and p = 0.02, respectively). Of the 13 patients with LLN metastasis, 6 whose mesenteric lymph nodes (MLNs) had been well dissected and examined did not have MLN metastasis. CONCLUSIONS: The presence of one or two LLN metastases in patients who have undergone LLN dissection with surgery for lower rectal cancer is not associated with poor prognosis. The number of LLN metastases is a more significant risk factor for poor prognosis.