Esophageal Cancer: Current Diagnosis and Management
Journal of Clinical Outcomes Management. 2014 August;21(8)
References
Diagnostic Studies
For patients with suspected esophageal cancer, a barium swallow is an inexpensive and readily available diagnostic study [39]. A barium swallow may show a mass lesion and/or a stricture. If the barium swallow is suggestive of cancer, the diagnosis is usually confirmed via an esophagogastroduodenoscopy (EGD) and biopsies, although in practice many patients with dysphagia and/or a history suspicious for esophageal cancer will proceed directly to EGD [40]. Findings suspicious for cancer are routinely biopsied [39].Traditionally, the more biopsies obtained (up to 7), the higher the diagnostic yield of cancer [41]. The addition of brush cytology to biopsies has also been found to increase the diagnostic accuracy, although this is not widely performed [41].
Once the diagnosis of cancer is confirmed, a computed tomography (CT) scan of the chest, abdomen, and pelvis with intravenous (IV) contrast is usually the next step in the patient’s evaluation, primarily to detect distant metastasis and to look for peritumoral adenopathy [39]. However, in terms of locoregional tumor staging, CT scans are less sensitive and specific than endoscopic ultrasonography (EUS) [42]. Patients who do not have evidence of metastasis on CT scan typically undergo EUS for definitive locoregional staging.
EUS combines high-frequency ultrasound and endoscopy, incorporating a small ultrasonic transducer into the end of the scope [43]. EUS is the most accurate method for tumor (T) and node (N) staging of esophageal cancer ( Figure 3 ) [44]. EUS has been shown to predict the tumor stage (depth of tumor invasion) in 80% to 90% of patients and the node stage (extent of lymph node involvement) in 70% to 80% of patients [39,45]. When compared to EUS alone, EUS with the addition of fine needle aspiration (FNA) of peritumoral nodes has been shown to increase the accuracy of the diagnosis of lymph node involvement [43]. The identification of lymph node metastases associated with esophageal carcinoma is critical as it influences overall staging and treatment significantly (ie, malignant adenopathy warrants neoadjuvant therapy in most patients).
EUS does have its limitations. Between 25% and 36% of patients with esophageal carcinoma present with high-grade malignant strictures that do not allow passage of the scope, although if the exam can show malignant adenopathy and/or tumor extension through the muscularis propria, further evaluation is often of little additional benefit [46]. Dilation of malignant esophageal strictures to facilitate EUS is uncommon as there is a high risk of perforation (up to 24%) [47]. High-frequency (12.5 MHz) EUS mini-probes have been used to interrogate tumors with a very narrow lumen; however, the mini-probes are limited by the penetration depth of the transducer, which can lead to an incomplete locoregional tumor assessment [48]. EUS is not usually used for restaging after neoadjuvant therapy [49].
Endoscopic mucosal resection (EMR) is another technique for staging and treatment of superficial neoplasms (see Treatment section for more details). EMR is critical for distinguishing between T1a lesions (often candidates for definitive endoscopic therapy given the low likelihood of nodal involvement) versus T1b lesions (invasive to submucosa and more likely to prompt surgical esophagectomy with lymph node sampling). The distinction between T1a and T1b disease cannot be established as reliably by EUS when compared with EMR. The American Society for Gastrointestinal Endoscopy 2013 guidelines recommend EMR for the treatment and staging of nodular Barrett’s esophagus and suspected intramucosal adenocarcinoma [50].
