Endoscopic appearance: Early cancers: superficial plaque, nodule, or ulceration Advanced lesions: strictures, ulcerated masses, circumferential masses, or large ulcerations
Preoperative staging is warranted in patients who are considered to be surgical candidates (“can help to take someone off the table”). If distant metastases are not demonstrated by CT or PET, upper EUS allows a more detailed evaluation of locoregional disease extent (T and N stage).
Modified from AJCC Cancer Staging Manual. 7 th ed. 2010.
Distant metastases including extraregional lymph node spread (including paraaortic or mesenteric) Malignant celiac nodes* Unresectable primary disease including invasion of the aorta, trachea, heart, great vessels, or presence of TE fistula Cervical esophageal tumors with infiltration into prevertebral fascia or posterior larynx, invasion of the membranous trachea to the level of the carina, or significant bilateral encasement of major neurovascular structures
In a meta-analysis of 2558 patients, pooled sensitivity and specificity of EUS to diagnose T4 were 92.4% and 97.4%. FNA increases sensitivity of EUS to diagnose N stage from 84.7% to 96.7%. (World J Gastroenterol 2008; 14(10): 1479-1490.)
Endosonographic criteria suggestive of malignant involvement of lymph nodes include: Width greater than 10 mm Round shape Smooth border Echo-poor pattern When all four suspicious features are present in a lymph node, there is an 80-100% chance of metastatic involvement. Only 25% of malignant nodes have all four features. Lymph node involvement supports the selection of induction chemoradiotherapy over surgery alone, particularly in T2 disease. EUS-FNA appears to improve accuracy of N staging as long as the primary tumor is not in the pathway of the aspiration needle.
Instrument cannot traverse a tumor- induced stenosis (affects 30% of patients), leading to understaging because the entire lesion and the celiac axis are not seen Lymph node assessment in the immediate vicinity of the tumor is restricted
Among expert endosonographers (>75 esophageal cancer examinations): Overstaging occurs in 8-14% of patients, more often with T2 lesions (peritumoral inflammation leading to overestimation of mural penetration?) Understaging in 3-15% of cases, more often with T3 tumors with microscopic infiltration of the adventitia beyond resolution capability of the echoendoscope Gatrointest Endosc 1996; 7: 162. Surg Endosc 1999; 13: 894. Endoscopy 1992; 24 Suppl 1: 324.
Accuracy of EUS for restaging after chemoradiation is poor Thought to be due to inability to differentiate between residual tumor and post-treatment inflammation and fibrosis Detection of locoregional recurrence EUS has sensitivity and specificity >92% and >96% for detecting locoregional relapse in patients with worrisome signs or symptoms that have a negative endoscopic and radiographic evaluation EUS surveillance of resected patients every 6 months for 2 years has been shown to have a strong positive predictive value (92%) for tumor recurrence, and two-thirds with EUS-shown relapse were asymptomatic at the time. BUT, has not been shown that early detection of tumor recurrence improves survival.