Esophageal Cancer: Current Diagnosis and Management
Journal of Clinical Outcomes Management. 2014 August;21(8)
References
Looking for distant metastasis, or M staging, is carried out with EUS, diagnostic laparoscopy/thoracoscopy, and CT and/or positron emission tomography (PET) scans. Despite the high accuracy of esophageal cancer staging with laparoscopy and thoracoscopy, these are invasive procedures and have generally been replaced by PET scan [39,51,52]. PET with 18F-fludeoxyglucose has been shown to significantly improve the detection rate of metastatic disease compared with the conventional staging methods (CT scan and EUS) [53]. In a prospective study, PET scans detected metastasis in 15% of patients who were thought to have localized cancer by conventional staging modalities [39,54].
Unlike several other cancers, tumor markers such as carbohydrate antigen (CA) 19-9, CA 125, and carcinoembryonic antigen (CEA) have low specificity and sensitivity in esophageal cancer and are not routinely obtained and/or followed [39,55].
Staging
In the 2010 edition of esophageal cancer staging from the American Joint Committee on Cancer (AJCC), the committee made changes to the staging of cancer based on a new database of esophagectomy patients from the Worldwide Esophageal Cancer Collaboration [56–58].Previous versions of the TNM staging system were based on orderly arrangement of increasing anatomic tumor, then node, then metastasis, which was not always consistent with cancer biology [56].The 2010 guidelines are based on risk-adjusted random forest statistical analysis of worldwide data (machine-learning method that focuses on predictability for future patients) [56,57].The current guidelines now take into account development of separate stage groups based on histopathologic cell type (ie, adeno-carcinoma versus SCC), histologic grade, and tumor location ( Table 1 and Table 2) [56].
Treatment
Early Stage
Historically, patients with early stage esophageal cancer (those without evidence of deep invasion into the esophageal wall and no evidence of peritumoral malignant adenopathy or metastases, typically T1N0M0) were referred for esophagectomy [59]. Recent treatment trends suggest proportionately more patients with T1 disease are being treated endoscopically (up to 29% of patients) and proportionately fewer with esophagectomy [60]. EMR has emerged as a viable alternative treatment to esophagectomy when the lesion is staged T1aN0 (tumor invading the lamina propria or muscularis mucosae but not the submucosa) [3]. EMR is performed via several techniques, but most commonly as follows. First, saline is injected under the lesion to create a submucosal cushion, separating the lesion from the underlying muscularis propria. The actual endoscopic resection of the lesion is usually accomplished via snare electrocautery and the resected lesion is sent for pathologic analysis. Endoscopic caps and band ligation devices are available to facilitate removal of the lesion in one or more pieces [61].
In a retrospective cohort study by Prasad et al of 178 patients from 1998 to 2007, the cumulative mortality in the EMR group was comparable to that of the surgery group (17% vs. 20%, respectively, P = 0.75) [62]. Recurrent cancer was detected in 12% of EMR patients; however, all patients were successfully re-treated without affecting overall survival.
In another study of 742 patients, long-term survival in those with early esophageal cancer managed with endoscopic therapy was comparable to that in patients treated with surgical resection [63]. The median cancer-free survival in the endoscopic group was not significantly different from that in the surgical group (56 and 59 months, respectively, P = 0.41) The study found that the relative hazard for 1esophageal cancer–specific mortality in the endoscopic group did not differ from that of the surgical group (relative hazard, 0.89; 95% CI, 0.51 to 1.56; P = 0.68).