The aim of this study was to assess the effect of apical lymph node (APN) metastasis in predicting prognosis in curatively treated node-positive rectal cancer. We also investigated the relationship between APN metastasis and the total number of metastatic lymph nodes.Method
A retrospective study was performed of 510 curatively treated patients with node-positive rectal cancer. Clinicopathological variables, including APN status, were assessed in univariate and multivariate analyses. The prognostic significance of APN status in predicting patient outcomes and the relationship between APN status and American Joint Committee on Cancer (AJCC) N stage were analysed.Results
At a median follow up of 47 months, the 5-year local recurrence (LR) rate, the disease-free survival (DFS) rate and the overall survival (OS) rate were 18.3%, 55.5% and 58.8%, respectively. The 5-year OS rate was 69.6% for patients with no metastasis in APNs (APN(−)) and 40.8% for patients with metastasis in APNs (APN(+)). DFS and OS for patients with undetermined APN status were between those for APN(−) and APN(+). Subgroup analysis gave a 5-year OS rate of 48.7% in Stage N1 patients with APN(+) and 58.8% for Stage N2 patients with APN(−) (P = 0.0004).Conclusion
APN metastasis is an important prognostic factor in node-positive rectal cancer, which provides additional survival-related prognostic classification irrespective of N stage. As the APN is usually outside the radiation field, in the era of multidisciplinary treatment its assessment should be incorporated into prognostic evaluation of rectal cancer.