2096: Adenocarcinoma of the Esophagogastric (AEG) Junction: Elective Lymphatic Target Volume Definition Based on the Pattern of Metastatic Lymph Node Dissemination

Abstract

Purpose/Objective(s)The incidence of highly lethal AEG has increased dramatically in the last 4 decades. Neoadjuvant chemoradiation (CRT) is highly investigated, and the number of lymph nodes with metastasis after CRT predicts survival (Gu Y et al. 2006). However, there is no consensus on the delineation of the PTV regarding elective treatment of nodal areas. Furthermore, postoperative morbidity correlates especially with the volume of lung exposed to radiation. The aim of this study was to identify the positive lymph node (LN) groups that are associated with AEG to clarify the extent of elective treatment nodal areas required for such tumors.Materials/MethodsThe endoscopic and pathologic reports of patients who underwent resection for AEG between 1982 and 2004 were examined. LN groups were dissected from the main specimens and examined separately. Tumors were classified into 3 groups according to the International Gastric Cancer Association (IGCA): AEG I (distal esophagus, above the Z-line), AEG II (gastric cardia), and AEG type III (subcardial).ResultsNodal spread of 326 tumors with median nodal recovery of 37 nodes (15 - 102) was analyzed. T1 tumors (n=49, N0 in 83%) were excluded from further analysis. The remaining 277 tumors were classified T2 (180), T3 (78), and T4 (19) and these were N+ in 78%, 86%, and 90%, respectively. AEG subsites of T2–4 tumors were I (n=111), II (n=154) and III (n=12). The common abdominal sites were paracardiac and the lesser curvature LN.Within the mediastinum, the middle and lower paraesophageal LN were + in 47/111 (42%) AEG I vs. 29/154 (19%) AEG II. Paraesophageal LN of T3–4 tumors were + in 36/55 (65%) AEG I vs. 12/39 (31%) in AEG II. Cranial expansion to the distal esophagus was present in 162/166 (98%) of AEG II/III with a median of 20 mm (3 - 60 mm). Paraesophageal LN were + in 7/77 (9%) below the median vs. 25/84 (30%) with expansion ≥ 20 mm to the distal esophagus.In T2–4 tumors, nodal spread to the splenic hilum LN (AEG I: 5/111, 6% vs. AEG II: 15/154, 10%) and the splenic artery LN (AEG I: 4/111, 4% vs. AEG II: 18/154, 12%) was found. In T3–4 tumors spread to these LN was more frequent for AEG II but not for AEG I: splenic hilum (AEG II: 12/39, 31%) and the splenic artery (AEG II: 9/39, 23%).ConclusionsEndoscopic and endosonographic staging of AEG tumors according to the IGCA consensus should be routinely performed in all patients with AEG tumors prior to neoadjuvant CRT. The nodal stations to be irradiated electively in neoadjuvant CRT should include the middle and lower paraesophageal nodes for patients with (1) T2–4 AEG I, (2) with T2–4 AEG II with ≥ 2 cm involvement above the Z-line, and (3) with T3–4 AEG II irrespective of the extension above the Z-line. The splenic hilum and artery nodes can be spared in T2–4 AEG tumors. Purpose/Objective(s)The incidence of highly lethal AEG has increased dramatically in the last 4 decades. Neoadjuvant chemoradiation (CRT) is highly investigated, and the number of lymph nodes with metastasis after CRT predicts survival (Gu Y et al. 2006). However, there is no consensus on the delineation of the PTV regarding elective treatment of nodal areas. Furthermore, postoperative morbidity correlates especially with the volume of lung exposed to radiation. The aim of this study was to identify the positive lymph node (LN) groups that are associated with AEG to clarify the extent of elective treatment nodal areas required for such tumors. The incidence of highly lethal AEG has increased dramatically in the last 4 decades. Neoadjuvant chemoradiation (CRT) is highly investigated, and the number of lymph nodes with metastasis after CRT predicts survival (Gu Y et al. 2006). However, there is no consensus on the delineation of the PTV regarding elective treatment of nodal areas. Furthermore, postoperative morbidity correlates especially with the volume of lung exposed to radiation. The aim of this study was to identify the positive lymph node (LN) groups that are associated with AEG to clarify the extent of elective treatment nodal areas required for such tumors. Materials/MethodsThe endoscopic and pathologic reports of patients who underwent resection for AEG between 1982 and 2004 were examined. LN groups were dissected from the main specimens and examined separately. Tumors were classified into 3 groups according to the International Gastric Cancer Association (IGCA): AEG I (distal esophagus, above the Z-line), AEG II (gastric cardia), and AEG type III (subcardial). The endoscopic and pathologic reports of patients who underwent resection for AEG between 1982 and 2004 were examined. LN groups were dissected from the main specimens and examined separately. Tumors were classified into 3 groups according to the International Gastric Cancer Association (IGCA): AEG I (distal esophagus, above the Z-line), AEG II (gastric cardia), and AEG type III (subcardial). ResultsNodal spread of 326 tumors with median nodal recovery of 37 nodes (15 - 102) was analyzed. T1 tumors (n=49, N0 in 83%) were excluded from further analysis. The remaining 277 tumors were classified T2 (180), T3 (78), and T4 (19) and these were N+ in 78%, 86%, and 90%, respectively. AEG subsites of T2–4 tumors were I (n=111), II (n=154) and III (n=12). The common abdominal sites were paracardiac and the lesser curvature LN.Within the mediastinum, the middle and lower paraesophageal LN were + in 47/111 (42%) AEG I vs. 29/154 (19%) AEG II. Paraesophageal LN of T3–4 tumors were + in 36/55 (65%) AEG I vs. 12/39 (31%) in AEG II. Cranial expansion to the distal esophagus was present in 162/166 (98%) of AEG II/III with a median of 20 mm (3 - 60 mm). Paraesophageal LN were + in 7/77 (9%) below the median vs. 25/84 (30%) with expansion ≥ 20 mm to the distal esophagus.In T2–4 tumors, nodal spread to the splenic hilum LN (AEG I: 5/111, 6% vs. AEG II: 15/154, 10%) and the splenic artery LN (AEG I: 4/111, 4% vs. AEG II: 18/154, 12%) was found. In T3–4 tumors spread to these LN was more frequent for AEG II but not for AEG I: splenic hilum (AEG II: 12/39, 31%) and the splenic artery (AEG II: 9/39, 23%). Nodal spread of 326 tumors with median nodal recovery of 37 nodes (15 - 102) was analyzed. T1 tumors (n=49, N0 in 83%) were excluded from further analysis. The remaining 277 tumors were classified T2 (180), T3 (78), and T4 (19) and these were N+ in 78%, 86%, and 90%, respectively. AEG subsites of T2–4 tumors were I (n=111), II (n=154) and III (n=12). The common abdominal sites were paracardiac and the lesser curvature LN. Within the mediastinum, the middle and lower paraesophageal LN were + in 47/111 (42%) AEG I vs. 29/154 (19%) AEG II. Paraesophageal LN of T3–4 tumors were + in 36/55 (65%) AEG I vs. 12/39 (31%) in AEG II. Cranial expansion to the distal esophagus was present in 162/166 (98%) of AEG II/III with a median of 20 mm (3 - 60 mm). Paraesophageal LN were + in 7/77 (9%) below the median vs. 25/84 (30%) with expansion ≥ 20 mm to the distal esophagus. In T2–4 tumors, nodal spread to the splenic hilum LN (AEG I: 5/111, 6% vs. AEG II: 15/154, 10%) and the splenic artery LN (AEG I: 4/111, 4% vs. AEG II: 18/154, 12%) was found. In T3–4 tumors spread to these LN was more frequent for AEG II but not for AEG I: splenic hilum (AEG II: 12/39, 31%) and the splenic artery (AEG II: 9/39, 23%). ConclusionsEndoscopic and endosonographic staging of AEG tumors according to the IGCA consensus should be routinely performed in all patients with AEG tumors prior to neoadjuvant CRT. The nodal stations to be irradiated electively in neoadjuvant CRT should include the middle and lower paraesophageal nodes for patients with (1) T2–4 AEG I, (2) with T2–4 AEG II with ≥ 2 cm involvement above the Z-line, and (3) with T3–4 AEG II irrespective of the extension above the Z-line. The splenic hilum and artery nodes can be spared in T2–4 AEG tumors. Endoscopic and endosonographic staging of AEG tumors according to the IGCA consensus should be routinely performed in all patients with AEG tumors prior to neoadjuvant CRT. The nodal stations to be irradiated electively in neoadjuvant CRT should include the middle and lower paraesophageal nodes for patients with (1) T2–4 AEG I, (2) with T2–4 AEG II with ≥ 2 cm involvement above the Z-line, and (3) with T3–4 AEG II irrespective of the extension above the Z-line. The splenic hilum and artery nodes can be spared in T2–4 AEG tumors.