PS01.185: STATUS OF SUBCARINAL LYMPH NODE METASTASIS AND DISSECTION STRATEGY FOR THORACIC ESOPHAGEAL CARCINOMA

Abstract Background The subcarinal lymph node metastasis, although with the debate whether it is a characteristic of lung cancer or esophageal cancer, is prevalent in esophageal carcinoma, and with the incidence of 4.1%-17.5% according to some estimates. The aim of this study is to assess the pattern of subcarinal lymph node metastasis and the dissection strategy for thoracic esophageal carcinoma. Methods A large cohort, retrospective study was conducted on 596 patients with thoracic esophageal carcinoma treated from July 2008 to December 2010. The metastasis rate of subcarinal lymph node was investigated. Survival of patients treated by different dissection strategies was compared. The effectiveness index was used to assess the outcome of subcarinal lymph node dissection. Results Of 596 patients, 447 had documented subcarinal lymph node dissection (75.0%). According to whether the subcarinal lymph node was harvested or not, they were divided into two groups: dissection group (n = 447) and non-dissection group (n = 149). Their 5-year survival rates were 48.3 ± 1.7 months for dissection group vs. 38.1 ± 2.8 months for non-dissection group (P < 0.001). The overall subcarinal node metastasis rate in the dissection group was 12.5% (56/447). Based on the status of subcarinal nodes, there was a significant difference in survival, 52.3 ± 1.8 months with negative nodes (n = 391) compared to 19.9 ± 2.2 months for those with positive nodes (n = 56) (P < 0.001). Subgroup analysis was further conducted for the positive subcarinal nodes patients. The metastasis rates in patients with upper, middle and lower esophageal cancer were 5.4%, 15.1% and 10.1%, respectively (P < 0.05 for comparison between patients with upper and other segments). The effectiveness indices for these three groups of patients were as 0%, 4.8% and 27.2%, respectively. The metastasis rates for T0, T1, T2, T3 and T4 esophageal carcinoma were 0%, 0%, 3.5%, 10.7% and 19.0%, respectively (P < 0.05 for comparison between T0/T1/T2 and T3/T4 tumors. Conclusion Thoracic esophageal carcinoma has a high incidence of subcarinal lymph node metastasis, especially among those with middle and lower esophageal cancer, and for deeper invaded tumors. Therefore, for middle and lower esophageal tumors, subcarinal lymph node dissection is necessary, whereas for T1/2 upper esophageal tumors, subcarinal lymph node dissection can be spared from subcarinal lymph node dissection. Disclosure All authors have declared no conflicts of interest.