수술 전 항암방사선 치료 후 절제를 시행 받은 직장암 환자에서 병리학적 림프절 반응 정도가 예후에 미치는 영향

Abstract

Background and Objectives: The response level of metastatic lymph nodes (LN) following preoperative chemoradiotherapy (PCRT) has not been considered in the current staging system in rectal cancer. The aim of this study was to evaluate the prognostic impact of the lymph node regression grade (LRG) in rectal cancer patients treated with PCRT followed by radical resection.

Materials and methods: From 2008 to 2011, 389 patients with rectal cancer treated with PCRT followed by radical resection were identified. The pathologic lymph node regression grade (pLRG) score was determined based on the proportion of tumor cells and fibrosis. Non-tumorous LN with normal architecture was scored as pLRG0; LN with 100% fibrosis as pLRG1, LN with <25% cancer cells as pLRG2, LN with 25-50% cancer cells as pLRG3, LN with >50% cancer cells as pLRG4, complete replacement with cancer cells as pLRG5. The sum of the pLRG of each evaluated LNs was used as the final LRG score, LRG-sum.

Results: The distribution of LRG-sum was significantly associated with tumor regression grade (TRG) of the primary tumor (p<0.001). Patients were categorized into 3 groups according to the cut-off points determined by using percentiles of LRG-sum distribution; LRG1 (0≤LRG-sum≤1), LRG2 (1 Conclusion: LRG was an important prognostic factor of oncologic outcomes in patients with rectal cancer treated with PCRT followed by radical resection.