Prominent Information of jN3 Positive in Stage III Colorectal Cancer Removed by D3 Dissection: Retrospective Analysis of 6866 Patients From a Multi-institutional Database in Japan

BACKGROUND: The presence of main or lateral lymph node metastasis in colorectal cancer is classified as jN3 by the Japanese Society for Cancer of the Colon and Rectum. Whether information on jN3 status adds value to the TNM classification remains unclear. OBJECTIVE: We aimed to assess the prognostic relevance of colorectal cancer nodal staging through the Japanese jN3 categorization compared with that through TNM. DESIGN: This was a retrospective study. SETTING: The study used the multi-institutional database of the Japanese Society for Cancer of the Colon and Rectum. PATIENTS: Clinical and pathological data of 6866 patients with histologically proven stage III colorectal cancer who underwent curative surgery (R0) with D3 dissection between 1995 and 2006 were derived from the database. MAIN OUTCOME MEASURES: We investigated the prognostic significance of jN3 status in each TNM N class N1/N2a/N2b) and stage (IIIA/IIIB/IIIC) based on cancer-specific survival. RESULTS: Comparison of cancer-specific survival rates revealed significant differences between jN3+ and jN3-colorectal cancer patient groups according to the TNM N status (5-year cancer-specific survival; N1, 70.4% (jN3+) vs 85.5% (jN3-), p<0.001; N2a, 59.2% vs 77.0%, p<0.001; N2b, 39.2% vs 68.7%, p<0.001) and the TNM stage (stage IIIA, 72.5% vs 94.9%, p<0.001; stage IIIB, 67.9% vs 84.0%, p<0.001; stage IIIC, 42.4% vs 70.6%, p<0.001). LIMITATIONS: This study was limited by its retrospective nature. CONCLUSIONS: Assessment and inclusion of jN3 status are of clinical importance for patients with stage III colorectal cancer with D3 dissection, because it contributes to improved understanding of recurrence risk and subsequent decision-making for follow-up procedures and adjuvant therapy. See Video Abstract at http://links.lww.com/DCR/A506.