Recurrence Patterns Of Thoracic Esophageal Cancer After Two-field Lymph Node Dissection

Objective:To investigate the local-regional recurrence in thoracic esophageal cancer of two-field lymph node dissection after radical surgery and provide evidence for postoperative radiotherapy.Methods:We reviewed local-regional recurrence for 134 cases with esophageal squamous cell cancer after radical surgery from 2004 to 2009. Patients were staged according to the AJCC/UICC cancer staging criteria for esophageal cancer (7th edition, 2009). Among 134 cases of esophageal squamous cell carcinoma: 17 located at the upper third esophagus, 99 in the middle and 18 in the lower esophagus.As for the depth of tumor invasion, 14 cases had a T1 tumor, 23 cases with T2, 84 cases with T3,and 13 cases with T4. 78 cases demonstrated no lymph node metastasis (N0), whereas 41 cases with N1, 14 cases with N2 and 1 cases with N3. According to the system of the 1996 AJCC-UICC Regional Lymph Node Classification for Lung Cancer Staging , mediastinal lymph node was divided into sixteen regions. According to simulation guided by Computerized Tomography, supraclavicular lymph node was divided into four regions including para-recurrent nerve (regionⅠ), para-internal jugular vein (regionⅡ), supraclavicular region (regionⅢ), as well as the other regions except for the mentioned above (regionⅣ). Recurrence types of Thoracic Esophageal Cancer after two-field lymph node dissection conclude lymph node metastasis, anastomotic recurrence and tumor bed recurrence. Recurrence rate of every type and lymph node metastasis rate in every region were analyzed.Results:In 134 cases,lymph node metastasis rate was identified in 94.0% (126/134), 9.7% (13/134) recurrence with anastomosis,and 3.7% (5/134) recurrence with tumor bed respectively. The difference among the groups was statistically significant(P=0.000). As to 126 cases with lymph node metastasis, mediastinal metastasis80.2%(101/126) were significantly higher than those of supraclavicular metastasis43.7% ( 55/126) and Abdominal lymph node metastasis13.5%(17/126) showing the difference with statistical significance (P=0.000).Furthermore, the results showed that the relative metastasis rate in upper mediastinum 73.8%(93/126), middle mediastinum 39.7%(50/126) and the lower mediastinum 1.6%(2/126) had obvious significant difference, while the difference among the groups were statistically significant (P=0.000). Nevertheless, it showed no association with the lymph node metastasis of the upper third esophagus, middle esophagus and the lower chest esophagus in supraclavicular region,mediastinum and abdomen(P=0.404 , P=0.718 ,P=0.169). In upper mediastinum,the lymph node metastasis rate of region 1R was 43.7%( 55/126) and significantly higher than the other regions。Moreover, the results also shown that lymph node metastasis rate was notably increased in regionⅠandⅡof the right supraclavicular region compared with those of the left supraclavicular region, showing statistical significance (P=0.013,P=0.003).In addition, multivariate analysis found that lymph node metastasis in region 1 was high risk factor for lymph node metastasis of region I(P=0.000,P=0.002),lymph node metastasis in regionⅢand region 2 were high risk factors for lymph node metastasis of regionⅡ(P=0.000 and P=0.005,P=0.004 and P=0.047). The total of lymph node metastasis rate were 43.7% (55/126) in left para-recurrent laryngeal nerve(IL,1L,2L,4L and 5 region) and 46.8%(59/126) in the right(IR and 1R region).Conclusions:The main characteristics of local-regional recurrence may be lymph node metastasis for esophageal squarnous cell cancer after radical surgery.On the contrary, tumor bed recurrence was rare. The dangerous regions concluded supraclavicular nodes , recurrent laryngeal nerve nodes,azygos nodes as well as subcarinal nodes,and it is advisable to contain the outer margin of internal jugular vein in supraclavicular area for radiotherapy target volume.