Adenocarcinoma of the esophagus (ORPHA:99976)
Esophageal adenocarcinoma (EAC) is a sub-type of esophageal carcinoma (EC; see this term) affecting the glandular cells of the lower esophagus at the junction with the stomach.
Epidemiology
It has an estimated annual incidence of 1/35,000.
Clinical description
The age of onset is between 50-60 years and it is more frequently seen in males. EAC is usually asymptomatic until an advanced disease stage with common presenting symptoms being dysphagia and unintentional weight loss. There is often a history of chronic gastroesophageal reflux disease (GERD). When symptoms are present it often has advanced locally and may have spread through the lining of the esophagus and involve lymph nodes or more distant sites.
Etiology
The exact etiology is unknown. There is a strong association with GERD and obesity. There is no specific, known genetic link. The principal pathologic precursor is Barrett's esophagus (BE; see this term) which is characterized by metaplasia in the lining of the esophagus for variable distances above the stomach, and is identified through endoscopy and pathology. A high percentage of cases of EAC arise in a background of BE.
Diagnostic methods
Endoscopy and a biopsy establish the diagnosis. For staging, a computed tomography (CT) scan of the neck, chest and abdomen, or CT combined with a positron emission tomography (CT-PET) scan will identify the primary tumor in most cases as well as any spread to the lymph nodes and organs such as the liver, lungs and bone. Endoscopic ultrasound (EUS) is also increasingly used for staging, and is of particular value for early cancers. Laparoscopy is used in selected cases for further staging.
Differential diagnosis
Differential diagnoses include idiopathic achalasia, gastric cancer (see these terms) and a benign esophageal stricture.
Management and treatment
Treatment may be with curative intent when the disease is confined to the esophagus and even when local nodes of the primary tumor are involved, and when the patient is fit enough for treatment. The mainstay of treatment of EAC is surgical resection, usually via a transthoracic resection, and occasionally a neck incision. In selected cases a transhiatal esophagectomy (without opening the chest) is performed. In patients diagnosed with early cancers, in particular patients undergoing surveillance for BE, the use of endoscopic surgery, often in combination with radiofrequency ablation (RFA), may supplant the need for open surgery. There is also an increasing use of chemotherapy or of the combination of chemotherapy and radiation therapy before and after surgery. A number of clinical trials support this practice, particularly where the tumor is locally advanced, and this is increasingly the standard of care in Europe and North America. The chemotherapeutic drugs most often used in combination are epirubicin, cisplatin and 5-fluorouracil (known as ECF). Capecitabine and oxaliplatin are less toxic agents that can be used in those with cardiac and renal problems. In patients who are unsuitable for approaches involving surgery, high-dose radiotherapy and chemotherapy is an increasingly used alternative. For palliative approaches, self-expanding metal stents (SEMS) can relieve dysphagia, and chemotherapy, radiation therapy and laser-based approaches are also considered.
Prognosis
As diagnosis often occurs at an advanced disease stage, the prognosis is poor with the overall estimated 5-year survival rate of 10-20%. However, the cure rate is now approximately 40% for patients treated with curative intent, in part because of increased early diagnoses, and in part because of improved treatments.

                            Last update: 
                            January 2013


                            - Expert reviewer(s): 
                            Dr Claire DONOHOE  - Dr John REYNOLDS