Eunhae Cho1, In Ja Park2, Seung Mo Hong3, Jong Lyul Lee4, Chan Wook Kim4, Yong Sik Yoon4, Seok-Byung Lim4, Chang Sik Yu4, Jin Cheon Kim4. 1. Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. 2. Department of Colon and Rectal Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address: ipark@amc.seoul.kr. 3. Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. 4. Department of Colon and Rectal Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Abstract
INTRODUCTION: We evaluated the oncologic outcome of (y)pT0-2N+ rectal cancer and investigated the impact of metastatic lymph nodes (LNs) on oncologic outcome in the setting of preoperative chemoradiotherapy (PCRT). MATERIALS AND METHODS: The records of 1403 patients who underwent surgery for rectal cancer between January 2005 and December 2012 were analyzed. The patients were categorized according to the pathologic stage, including 728 patients with ypT0-2 and 675 with ypT3-4 disease. The oncologic outcomes in terms of the 5-year recurrence-free survival (RFS) and overall survival (OS) were analyzed. RESULTS: Metastatic LNs were observed in 11.5% (n = 84) of patients with ypT0-2 and 42.9% (n = 290) of patients with ypT3-4 disease. The RFS and OS were stratified according to ypT and ypN stage as ypT0-2N0, T0-2N+, T3-4N0, and T3-4N+. The ypT0-2N+ group had slightly lower RFS and OS than those in the ypT3-4N0 group. LN metastasis was significantly associated with RFS in both ypT0-2 and ypT3-4 disease, with a stronger association for ypT0-2 disease (hazard ratio, 3.473, 95% confidence interval, 2.058-5.261; P < .001 for ypT0-2 and hazard ratio, 2.038; 95% confidence interval, 1.601-2.684; P < .001 for ypT3-4, respectively). CONCLUSION: The oncologic outcomes of ypT0-2N+ disease were not favorable compared with those of ypT3-4N0 disease. These outcomes dispute the survival paradox traditionally believed for non-PCRT-treated patients with rectal cancer, and highlight the underestimated significance of post-PCRT nodal involvement. The prognostic importance of metastatic LNs should be considered when deciding the surgical strategy after PCRT. Further studies including larger numbers of patients with sufficient follow-up are needed to verify the oncologic impact of metastatic LNs within tumors contained within the bowel wall after PCRT.
INTRODUCTION: We evaluated the oncologic outcome of (y)pT0-2N+ rectal cancer and investigated the impact of metastatic lymph nodes (LNs) on oncologic outcome in the setting of preoperative chemoradiotherapy (PCRT). MATERIALS AND METHODS: The records of 1403 patients who underwent surgery for rectal cancer between January 2005 and December 2012 were analyzed. The patients were categorized according to the pathologic stage, including 728 patients with ypT0-2 and 675 with ypT3-4 disease. The oncologic outcomes in terms of the 5-year recurrence-free survival (RFS) and overall survival (OS) were analyzed. RESULTS: Metastatic LNs were observed in 11.5% (n = 84) of patients with ypT0-2 and 42.9% (n = 290) of patients with ypT3-4 disease. The RFS and OS were stratified according to ypT and ypN stage as ypT0-2N0, T0-2N+, T3-4N0, and T3-4N+. The ypT0-2N+ group had slightly lower RFS and OS than those in the ypT3-4N0 group. LN metastasis was significantly associated with RFS in both ypT0-2 and ypT3-4 disease, with a stronger association for ypT0-2 disease (hazard ratio, 3.473, 95% confidence interval, 2.058-5.261; P < .001 for ypT0-2 and hazard ratio, 2.038; 95% confidence interval, 1.601-2.684; P < .001 for ypT3-4, respectively). CONCLUSION: The oncologic outcomes of ypT0-2N+ disease were not favorable compared with those of ypT3-4N0 disease. These outcomes dispute the survival paradox traditionally believed for non-PCRT-treated patients with rectal cancer, and highlight the underestimated significance of post-PCRT nodal involvement. The prognostic importance of metastatic LNs should be considered when deciding the surgical strategy after PCRT. Further studies including larger numbers of patients with sufficient follow-up are needed to verify the oncologic impact of metastatic LNs within tumors contained within the bowel wall after PCRT.