Although still relatively uncommon in Western countries, esophageal cancer is fatal in the vast majority of cases. In the United States, an estimated 14,520 new cases will be diagnosed in the year 2005, and 13,570 deaths will result from the disease. This high percentage of deaths rivals that of pancreatic cancer and is more than four times that of rectal cancer. The esophagus extends from the cricopharyngeal sphincter to the gastroesophageal (GE) junction and is commonly divided into the cervical, upper to mid-thoracic, and thoracic portions. This can be important, as histology and optimal treatment approaches may vary considerably based on the site of the cancer. It may not be possible to determine the site of origin if the cancer involves the GE junction itself. Epidemiology Gender Esophageal cancer is seven times more common and slightly more lethal in men than in women. Age Adenocarcinoma of the esophagus (now more common in the United States than the squamous cell type) has a median age at diagnosis of 69 years. The incidence of squamous cell cancer of the esophagus increases with age as well and peaks in the seventh decade of life. Race The incidence of squamous cell esophageal cancer is three times higher in blacks than in whites, whereas adenocarcinomas are more common in white men. Geography Evidence for an association between environment and diet and esophageal cancer comes from the profound differences in incidence observed in different parts of the world. Esophageal cancer occurs at a rate 20-30 times higher in China than in the United States. An esophageal "cancer belt" extends from northeast China to the Middle East. Survival Although the overall outlook for patients diagnosed with esophageal cancer has improved in the past 30 years, most patients still present with advanced disease, and their survival remains poor. One-third to one-half of patients treated with either chemoradiation therapy or chemoradiation therapy plus surgery are alive at 2 years, without recurrence of esophageal cancer. Disease site The rate of cancer of the distal esophagus is about equal to that of the more proximal two-thirds. In general, squamous cell carcinoma is found in the body of the esophagus, whereas adenocarcinoma predominates in lesions closer to the GE junction. Etiology and risk factors Cigarettes and alcohol Squamous cell carcinomas of the esophagus have been associated with cigarette smoking and/or excessive alcohol intake. Furthermore, cigarette smoking and alcohol appear to act synergistically, producing high relative risks in heavy users of tobacco and alcohol. Esophageal adenocarcinoma is increased twofold in smokers. Diet High-fat, low-protein, and low-calorie diets have been shown to increase the risk of esophageal cancer. Exposure to nitrosamines has been proposed as a factor in the development of both squamous cell carcinoma and adenocarcinoma of the esophagus. Barrett's esophagus and other factors Gastroesophageal reflux disease (GERD) and Barrett's esophagus (adenomatous metaplasia of the distal esophagus) have been linked to adenocarcinoma of the esophagus. Tylosis, Plummer- Vinson syndrome, history of head and neck cancer, and achalasia have also been associated with a higher-than-normal risk of developing squamous cell cancer of the esophagus. Signs and symptoms Because symptoms do not alert the patient until the disease is advanced, few esophageal cancers are diagnosed at an early stage. Dysphagia The most common presenting complaint is dysphagia, which generally is not noted until the esophageal lumen is narrowed to one-half to onethird of normal, due to its elasticity. Weight loss is common and has a significant role in prognosis (> 10% of total body weight as poor prognosis). Cough that is induced by swallowing is suggestive of local extension into the trachea with resultant tracheoesophageal fistula. Odynophagia and pain Pain with swallowing (odynophagia) is an ominous sign. Patients who describe pain radiating to the back may well have extraesophageal spread. Supraclavicular or cervical nodal metastases may be appreciated on examination. Hoarseness may be a sign of recurrent laryngeal nerve involvement due to extraesophageal spread. Metastatic disease may present as malignant pleural effusion or ascites. Bone metastasis can be identified by pain involving the affected site or by associated hypercalcemia. The most common metastatic sites are retroperitoneal or celiac lymph nodes. The American College of Surgeons conducted a study utilizing its national cancer database to assess the presentation, stage distribution, and treatment of pa- tients diagnosed with esophageal cancer between 1994 and 1997 (n = 5,044). The most common presenting symptoms were dysphagia (74.0%), weight loss (57.3%), reflux (20.5%), odynophagia (16.6%), and dyspnea (12.1%). Fifty percent of patients had tumors located in the lower third of the esophagus. Squamous cell histology was found in 51.6%, and 42.0% of patients had adenocarcinomas. Barrett's esophagus was found in 39% of those patients with adenocarcinoma. Patients undergoing initial surgical resection had the following stage distribution: stage I (13.3%), II (34.7%), III (35.7%), and IV (12.3%). Diagnosis In Western countries, the diagnosis of esophageal cancer is generally made by endoscopic biopsy of the esophagus. In the Far East, cytologic evaluation is frequently utilized. Endoscopic ultrasonography (EUS) is extremely accurate (> 90%) in establishing the depth of tumor invasion (T stage) but less accurate (70%-80%) in determining nodal involvement (N stage) unless combined with fine-needle aspiration (FNA) of the involved nodes (93% accuracy) when nodes greater than 5 mm are biopsied. The addition of FNA increases the sensitivity from 63% to 93% and the specificity from 81% to 100%. EUS is not reliable in determining the extent of response to neoadjuvant treatment. Endoscopy and barium x-rays Endoscopy allows for direct visualization of abnormalities and directed biopsies. Barium x-rays are less invasive and provide a good assessment of the extent of esophageal disease. Bronchoscopy should be performed to detect tracheal invasion in all cases of esophageal cancer except adenocarcinoma of the distal third of the esophagus. CT scan Once a diagnosis has been established and careful physical examination and routine blood tests have been performed, a CT scan of the chest, abdomen, and pelvis should be obtained to help assess tumor extent, nodal involvement, and metastatic disease. PET A prospective trial designed to evaluate the utility of PET vs CT and EUS was performed by obtaining these studies in 48 consecutive patients prior to esophagectomy. PET achieved a 57% sensitivity, 97% specificity, and 86% accuracy compared with CT, which was 99% sensitive, 18% specific, and 78% accurate. In terms of nodal staging, PET was correct in 83% of cases, as compared with 60% of cases for CT and 58% for EUS (P = .006). This analysis suggests the improved accuracy of PET in the staging work-up of patients with esophageal cancer. Numerous studies report the accuracy of PET scanning in determining the presence of metastatic disease, with sensitivity approaching 90% and specificity over 90%. As PET becomes more widely available, its use will probably become an important part of the preoperative evaluation of these patients. In a prospective trial of 39 patients with esophageal cancer, PET detected additional sites of metastatic disease at the initial evaluation when compared with conventional imaging. After induction therapy, PET did not add to the estimation of locoregional resectability and did not detect new distant metastases. However, this study suggested that changes in [18fluorodeoxyglucose] FDG-PET following induction therapy may predict disease- free and overall survival after induction therapy and resection in patients with esophageal cancer. A large prospective national trial will evaluate the use of PET scan in the treatment of esophageal cancer. Bone scan A bone scan should be obtained if the patient has bone pain or an elevated alkaline phosphatase level. Thoracoscopy/laparoscopy Investigators have recently begun to examine the role of surgical staging prior to definitive therapy. These procedures are designed to allow pathologic review of regional lymph nodes and the accurate assessment of extraesophageal tumor spread by direct visualization. A recently completed multi-institution trial (Cancer and Leukemia Group B [CALGB] 9380) found these procedures to be feasible in over 70% of patients; they resulted in the upstaging of patients in 38% of cases reviewed. Further investigations need to be completed to determine the appropriate use of these tools in treatment algorithms for patients with esophageal cancer. Warning Staging studies should be undertaken only if management would change on the basis of specific findings. Screening and surveillance HIGH-RISK PATIENTS
Adenocarcinoma The role of screening patients with GERD and surveillance of patients with Barrett's esophagus by upper GI endoscopy remains under investigation. In 833 patients studied by endoscopy, there was a 13% incidence of intestinal metaplasia (Barrett's esophagus). Dysplasia or cancer was seen in 31% of patients with long-segment Barrett's esophagus, in 10% of short-segment Barrett's esophagus, and in 6% of GE-junction intestinal metaplasia. Squamous cell carcinoma Mass screening in the high-risk areas of China and Japan is considered appropriate. Pathology Adenocarcinoma The incidence of esophageal adenocarcinoma involving the GE junction has risen 4%-10% per year since 1976 in the United States and Europe. As a result, adenocarcinoma is now the predominant histologic subtype of esophageal cancer. The distal one-third of the esophagus is the site of origin of most adenocarcinomas. Squamous cell carcinomas occur most often in the proximal two-thirds of the esophagus. Squamous cell carcinoma is still the most prevalent histologic subtype worldwide. Other tumor types Other, less frequently seen histologic subtypes include mucoepidermoid carcinoma, small-cell carcinoma, sarcoma, adenoid cystic leiomyosarcoma, and primary lymphoma of the esophagus. Occasionally, metastatic disease from another site may present as a mass in the esophagus or a mass pressing on the esophagus. Metastatic spread The most common sites of metastatic disease are the regional lymph nodes, lungs, liver, bone, adrenal glands, and diaphragm. Adenocarcinoma can also metastasize to the brain.
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