Carcinoma of the Esophagus
Esophageal carcinoma accounts for over 95% of neoplasms of the esophagus and about 1% of cancers involving the gastrointestinal tract. It is highly lethal and causes about 2% of all cancer deaths in the United States (about 9000 per year). It is a disease of older people (over 50 years) and is more common in males and blacks. Cancer of the esophagus is much more common in the Far East (notably China) and in certain parts of Africa and Iran. In Iran, there is an unusual female preponderance of the disease. In the United States, the incidence of adenocarcinoma of the lower esophagus associated with Barrett's esophagus (metaplasia) is increasing rapidly.
In the United States, chronic alcoholism increases the risk of esophageal carcinoma 20- to 30-fold. Cigarette smoking increases the risk 10- to 20-fold. Smoking and alcoholism are less often factors in the epidemiology of esophageal cancer in China, Africa, and Iran. The cause of esophageal cancer in the high-incidence areas of the world is unknown. Hot rice and tea, nitrosamines and aflatoxins in food, contaminants in locally brewed beer, and smoked fish have all been suggested as causative factors—all without proof.
Many premalignant conditions are associated with an increased risk of esophageal carcinoma. These include lye strictures (squamous carcinoma), Plummer-Vinson syndrome (squamous carcinoma), Barrett's esophagus (adenocarcinoma), and achalasia of the cardia (low risk of squamous carcinoma).
In the United States, 50% of esophageal cancers arise in the middle third, 30% in the lower third, and 20% in the upper third of the organ. In Scandinavia, where Plummer-Vinson syndrome is common, upper esophageal cancer is more frequent.
The early lesion is a plaque-like thickening of the mucosa (Figure 37-10). From its mucosal origin, carcinoma may extend (1) into the lumen as a polypoid, fungating mass that may break down to form a malignant ulcer with raised everted edges (Figure 37-11); (2) transversely in the submucosa, to involve the whole circumference of the esophagus; or (3) into the wall of the esophagus. A marked desmoplastic (fibrotic) response causes fibrosis with esophageal narrowing (malignant stricture). The exact appearance of the carcinoma depends on which of these growth patterns predominates.
Carcinoma of the esophagus, showing ulceration and circumferential involvement of the mucosa.
Carcinoma of the esophagus, immediately superior to the gastroesophageal junction, showing a large ulcer with everted edges.
Microscopically, approximately 75% of esophageal carcinomas are squamous carcinomas. Adenocarcinoma (arising in Barrett's esophagus) accounts for the rest and is rapidly increasing in incidence in the United States. Most adenocarcinomas occur in the lower third of the esophagus.
Carcinoma of the esophagus, showing involvement of adjacent organs by local infiltration and methods of metastatic spread.
Local invasion through the esophageal wall to involve adjacent cervical and mediastinal structures occurs early. Invasion of the bronchial wall may rarely result in tracheoesophageal fistula, commonly complicated by necrotizing pneumonia. Invasion of the aorta may lead to massive hemorrhage. Recurrent laryngeal nerve involvement leads to vocal cord paralysis (hoarseness).
Lymphatic spread occurs early, and lymph node metastases are commonly present at the time of diagnosis. Bloodstream spread with metastases to liver and lung also occurs early.
Clinical Features & Diagnosis
Most patients present with dysphagia and severe weight loss, and most have large unresectable tumors at this stage. Less often, presentation is with anemia, hematemesis, or melena. The diagnosis is best established by endoscopic visualization of the tumor followed by biopsy.
Regular endoscopic surveillance of patients with Barrett's esophagus is effective in detecting high-grade dysplasia and early cancer.
Surgery is the primary treatment method. However, many patients with esophageal cancer have unresectable tumors at the time of presentation. The exception is in patients with early cancers detected during surveillance for known Barrett's esophagus. Radiotherapy may cause some regression of tumor but is not curative. Chemotherapy is not very effective, although new regimens are starting to provide a glimmer of hope.
The overall prognosis is very poor, with 70% of patients dead within 1 year after diagnosis and fewer than 10% surviving after 5 years. Patients with early cancers restricted to the esophagus that are detected during surveillance for Barrett's esophagus have an excellent prognosis, with over 80% 5-year survival. Often the aim of treatment is palliation to relieve pain and to permit swallowing.
Other Neoplasms of the Esophagus
Neoplasms other than carcinomas are rare in the esophagus. Leiomyoma is the most common benign neoplasm, but it rarely causes symptoms. Leiomyosarcoma, malignant lymphoma, malignant melanoma, and carcinoid tumors have been reported.