Etiology and PathogenesisTop
The pathogeneses of squamous cell carcinoma and adenocarcinoma are different; the only common risk factors are smoking (greater effect on the risk of squamous cell carcinoma) and previous mediastinal radiotherapy.
Squamous cell carcinoma: Risk factors for developing the disease include alcohol consumption and low socioeconomic status. Precancerous conditions: the risk of esophageal squamous cell carcinoma increases several folds in patients with corrosive esophageal burns, Howel-Evans syndrome (palmoplantar hyperkeratosis and esophageal cancer), Plummer-Vinson syndrome (iron deficiency anemia accompanied by dysphagia due to postcricoid spasm); achalasia increases the risk ~30-fold.
Adenocarcinoma: The main risk factor is gastroesophageal reflux disease; the precancerous condition is Barrett esophagus (risk of cancer is 0.1%-0.4% per year).
Clinical Features and Natural HistoryTop
Esophageal cancer occurs mostly in men (~80%), almost exclusively after the age of 40 years; >90% of esophageal malignancies are squamous cell carcinoma or adenocarcinoma. Fifty percent of cases of squamous cell carcinoma are located in mid-esophagus and its incidence is decreasing, whereas 75% of adenocarcinomas are located in the lower esophagus and its incidence is growing. Symptoms appear late, when there is a significant stricture or rigidity of the esophagus, causing difficulties swallowing solid, and then also liquid, food. The most common symptoms are dysphagia, weight loss, and odynophagia, less frequently dyspnea, cough, hoarseness, and retrosternal pain. Malnutrition and cachexia develop over time. In advanced disease findings include lymph node enlargement, especially in the left supraclavicular area (Virchow node), hepatomegaly, and features of pleural involvement. In 25% of patients with esophageal squamous cell carcinoma, focal dysplasia (carcinoma in situ) or invasive laryngeal cancer and/or bronchial cancer may coexist.
1. Endoscopy is the primary diagnostic method that may be used to detect a flat mucosal lesion, ulcerations, tumors protruding into the esophagus, rigidity of the esophageal wall caused by malignant infiltrates, or esophageal stricture, as well as to obtain samples for histologic examination. Approximately 60% of cases of squamous cell carcinoma are polypoid, 25% are ulcerative, and 15% are flat (intramural). Early adenocarcinomas may look like a small nodule, erosion, or an area of a more fragile mucosa, while more advanced tumors are usually ulcerated. Due to the tendency for multifocal occurrence of squamous cell carcinoma of the head and neck area, bronchoscopy and laryngoscopy should also be considered.
2. Endoscopic ultrasonography (EUS) allows for the assessment of the depth of malignant invasion into the esophageal wall and adjacent structures as well as involvement of regional lymph nodes, and may be used to guide a targeted fine-needle aspiration biopsy of the enlarged lymph node.
3. Multiphase computed tomography (CT) of the chest, supraclavicular areas, and abdominal cavity, and positron emission tomography (PET)–CT are used to assess disease advancement.
4. Contrast-enhanced esophageal radiography is very rarely used (mainly in strictures preventing endoscope passage). In the case of dysphagia, use a water-soluble contrast medium due to the risk of aspiration.
Diagnosis is based on histologic evaluation of lesion specimens. To determine the treatment method, it is necessary to assess the stage of the disease using EUS (to assess the depth of invasion into the esophageal wall), bronchoscopy (to determine the presence of tracheal or bronchial infiltrates), and CT or PET-CT (to assess local tumor invasion and metastases according to the tumor, node, metastasis [TNM] classification).
Other causes of dysphagia.
Radical treatment is possible in patients without distant metastases. Surgical treatment is used (from endoscopic methods in early cancer to total or near-total esophagectomy, often with neoadjuvant chemoradiation [before surgery]), or chemoradiation alone (in patients not eligible for surgery). In patients with tumors located in the cervical portion of the esophagus, the method of choice is chemoradiation alone (efficacy similar to that of surgery, with larynx sparing).
If radical treatment is not possible, palliative chemotherapy and/or radiotherapy, molecularly targeted treatment, and immunotherapy are sometimes used, as well as other procedures to enable nutrition. Endoscopic stenting of the site of stricture with self-expanding stents is preferred; electrocoagulation and argon coagulation are also used. If necessary, percutaneous gastrostomy may be established for enteral feeding of the patient.
Tracheoesophageal fistulas manifesting as cough with production of copious purulent secretions (or food) and fever; pneumonia develops due to the retention of gastric content in the respiratory tract.
Treatment involves stenting of the esophagus and trachea/bronchi.
In most cases the disease is diagnosed at advanced stages; therefore survival is usually limited to several months, and the average overall 5-year survival rates are 5% to 10%.