Cancer of the Esophagus and Esophagogastric Junction: An Eighth Edition Staging Primer

Abstract

This primer for eighth edition staging of esophageal and esophagogastric epithelial cancers presents separate classifications for the clinical (cTNM), pathologic (pTNM), and postneoadjuvant pathologic (ypTNM) stage groups, which are no longer shared. For pTNM, pT1 has been subcategorized as pT1a and pT1b for the subgrouping pStage I adenocarcinoma and squamous cell carcinoma. A new, simplified esophagus-specific regional lymph node map has been introduced. Undifferentiated histologic grade (G4) has been eliminated; additional analysis is required to expose histopathologic cell type. Location has been removed as a category for pT2N0M0 squamous cell cancer. The definition of the esophagogastric junction has been revised. ypTNM stage groups are identical for both histopathologic cell types, unlike those for cTNM and pTNM.

Keywords: AJCC/UICC eighth edition staging; Esophageal cancer; Esophagogastric cancer; Staging.

Figure 1

Eighth edition TNM categories. T is categorized as Tis: high-grade dysplasia (HGD). T1 is cancer that invades the lamina propria, muscularis mucosae, or submucosa and is subcategorized into T1a (cancer that invades the lamina propria or muscularis mucosae) and T1b (cancer that invades the submucosa); T2 is cancer that invades the muscularis propria; T3 is cancer that invades the adventitia; T4 is cancer that invades the local structures and is subcategorized as T4a (cancer that invades adjacent structures such as the pleura, pericardium, azygos vein, diaphragm, or peritoneum) and T4b (cancer that invades the major adjacent structures, such as the aorta, vertebral body, or trachea). N is categorized as N0 (no regional lymph node metastasis), N1 (regional lymph node metastases involving one to two nodes), N2 (regional lymph node metastases involving three to six nodes), and N3 (regional lymph node metastases involving seven or more nodes). M is categorized as M0 (no distant metastasis) and M1 (distant metastasis).

Figure 2

Lymph node maps for esophageal cancer. Regional lymph node stations for staging esophageal cancer from the left (A), right (B), and anterior (C). 1R, right lower cervical paratracheal nodes, between the supraclavicular paratracheal space and apex of the lung; 1L, left lower cervical paratracheal nodes, between the supraclavicular paratracheal space and apex of the lung; 2R, right upper paratracheal nodes, between the intersection of the caudal margin of the brachiocephalic artery with the trachea and apex of the lung; 2L, left upper paratracheal nodes, between the top of the aortic arch and apex of the lung; 4R, right lower paratracheal nodes, between the intersection of the caudal margin of the brachiocephalic artery with the trachea and cephalic border of the azygos vein; 4L, left lower paratracheal nodes, between the top of the aortic arch and the carina; 7, subcarinal nodes, caudal to the carina of the trachea; 8U, upper thoracic paraesophageal lymph nodes, from the apex of the lung to the tracheal bifurcation; 8M, middle thoracic paraesophageal lymph nodes, from the tracheal bifurcation to the caudal margin of the inferior pulmonary vein; 8Lo, lower thoracic paraesophageal lymph nodes, from the caudal margin of the inferior pulmonary vein to the esophagogastric junction; 9R, pulmonary ligament nodes, within the right inferior pulmonary ligament; 9L, pulmonary ligament nodes, within the left inferior pulmonary ligament; 15, diaphragmatic nodes, lying on the dome of the diaphragm and adjacent to or behind its crura; 16, paracardial nodes, immediately adjacent to the gastroesophageal junction; 17, left gastric nodes, along the course of the left gastric artery; 18, common hepatic nodes, immediately on the proximal common hepatic artery; 19, splenic nodes, immediately on the proximal splenic artery; 20, celiac nodes, at the base of the celiac artery. Cervical periesophageal level VI and level VII lymph nodes are named as per the head and neck map.

Figure 3

Location of esophageal cancer primary site, including typical endoscopic measurements of each region measured from the incisors. Exact measurements depend on body size and height. Location of cancer primary site is defined by cancer epicenter. Cancers involving the esophagogastric junction (EGJ) that have their epicenter within the proximal 2 cm of the cardia (Siewert types I/II) are to be staged as esophageal cancers. Cancers whose epicenter is more than 2 cm distal from the EGJ, even if the EGJ is involved, will be staged using the stomach cancer TNM and stage groups. LES, lower esophageal sphincter; UES, upper esophageal sphincter.

Figure 4

(A) Pathologic stage groups (pTNM): adenocarcinoma. (B) Pathologic stage groups (pTNM): squamous cell carcinoma.

Figure 5

Postneoadjuvant pathologic stage groups (ypTNM): adenocarcinoma and squamous cell carcinoma.

Figure 6

(A) Clinical stage groups (cTNM): adenocarcinoma. (B) Clinical stage groups (cTNM): squamous cell carcinoma.