Esophageal Cancer: An Updated Review

Michael DiSiena, MD; Alexander Perelman, DO; John Birk, MD; Houman Rezaizadeh, MD


South Med J. 2021;114(3):161-168. 

In This Article


AC and SCC are staged based on TNM (primary tumor, regional lymph node, and distant metastasis) classification. T1 lesions are divided into T1a (invades lamina propria and muscularis mucosae) and T1b (invades submucosa). T1a malignancies are subdivided into M1 (intraepithelial), M2 (lamina propria), and M3 (muscularis mucosa) invasion, and T1b lesions are subdivided into Sm1 (superficial submucosa invasion), Sm2 (invasion to center of submucosa), and Sm3 (deep submucosal invasion). T2 lesions invade the muscularis propria. T3 malignancies invade the adventitia. T4 lesions metastasize to adjacent structures (common sites are the pleura, pericardium, diaphragm, peritoneum, azygos vein, aorta, vertebral body, and airway). N classification is based on the number of lymph nodes that have been metastasized to; with N1 noting metastasis in 1 to 2 regional lymph nodes, N2 in 3 to 6 regional lymph nodes, and N3 having ≥7 (SCC commonly invade regional lymph nodes of the esophagus, celiac, and aorta, whereas AC tends to metastasize to celiac and perihepatic nodes). Finally, M1 notes distant metastasis (common sites include the liver, lung, bone, and adrenals).[66]

A useful modality for staging EC is endoscopic ultrasound (EUS) because it can accurately assess the tumor depth and lymph node involvement of local and regional disease. The sensitivity and specificity of T staging has been reported for T1 as 81.6% (95% CI 77.8–84.9) and 99.4% (95% CI 99.0–99.7), respectively, and for T4, EUS sensitivity is noted to be 92.4% (95% CI 89.2–95.0) with a specificity of 97.4% (95% CI 96.6–98.0) in a meta-analysis of 2558 cases.[67] In another study assessing the effects of malignant stricture dilatation on the accuracy of EUS staging (without fine-needle aspiration [FNA]), it was noted that if no stricture is present, T-stage accuracy is 81% and N-stage accuracy is 86%; but with a stricture present, this accuracy diminishes to approximately 30% and 75%, respectively.[68] Dilatation did not affect these numbers. When combined with FNA, EUS N staging becomes highly accurate. One study assessing 457 patients with 554 lesions noted that EUS N-stage accuracy reached 92% with FNA.[69] If the malignancy is at or above the carina, then patients also should undergo a bronchoscopy to assess invasion into the tracheobronchial tree.

Patients diagnosed as having EC generally also undergo a CT scan for staging. If there is advanced disease on CT but no evidence of stage III or IV cancer, then an EUS is in order. Patients also should have a positron emission tomography scan to better assess stage and resectability. After neoadjuvant therapy, EUS has diminished accuracy, and therefore the positron emission tomography scan is the test of choice for restaging.[70]