Carcinoma of the Esophagus

Achalasia

Achalasia is believed to be a premalignant condition associated with an increased risk of esophageal carcinoma; the prevalence of esophageal cancer in these patients ranges from 2% to 8%. ^, Malignant degeneration presumably results from chronic stasis esophagitis caused by retained food in a dilated, obstructed esophagus. Most such patients have had achalasia for 20 years or more before developing cancer. ^, Unfortunately, tumors occurring within a massively dilated esophagus may not cause dysphagia until they are far advanced. ^, Some investigators therefore believe that patients with long-standing achalasia should undergo endoscopic surveillance to detect developing cancers at the earliest possible stage. ^,

Lye Strictures

Patients with chronic lye strictures are at increased risk for esophageal carcinoma, possibly because of chronic inflammation and scarring from caustic esophagitis; the prevalence of esophageal cancer in these patients ranges from 2% to 16%. The average latent period between lye ingestion and cancer is 40 to 45 years, ^, so affected individuals may seek medical attention for suddenly worsening dysphagia many years after lye ingestion. Fortunately, carcinomas arising in lye strictures have a better prognosis than most esophageal cancers, with 5-year survival rates of 8% to 33%. This more favorable prognosis could be related to dense surrounding scar tissue that prevents early invasion of mediastinal structures. ^, Nevertheless, some investigators advocate periodic surveillance of patients with long-standing lye strictures for early detection of developing tumors.

Head and Neck Tumors

Patients with squamous cell carcinomas of the oral cavity, pharynx, and larynx have a considerably increased risk of developing separate squamous cell carcinomas of the esophagus. In various studies, 2% to 8% of patients with head and neck tumors who underwent endoscopic surveillance had synchronous esophageal cancers. ^, This association has been attributed to tobacco and alcohol consumption, which increases the risk of squamous cell carcinoma in both regions. Radiologic or endoscopic screening of the esophagus has therefore been advocated in the initial work-up of head and neck cancers in order to detect unrecognized esophageal cancers, which can dramatically alter patient management.

Celiac Disease

Celiac disease (nontropical sprue) is thought to be associated with an increased risk of esophageal carcinoma after malabsorption has been present for an average of 35 years. The pathogenesis of cancer has been attributed to carcinogens absorbed through an atrophic jejunal mucosa in advanced celiac disease. Whatever the explanation, some investigators advocate radiologic or endoscopic surveillance of the esophagus in patients with long-standing sprue.

Plummer-Vinson Syndrome

Plummer-Vinson syndrome (also known as Paterson-Kelly syndrome) is characterized by iron-deficiency anemia, glossitis, postcricoid webs, and dysphagia, predominantly in women of Scandinavian origin. The prevalence of hypopharyngeal or esophageal carcinoma in Plummer-Vinson syndrome ranges from 4% to 16%. Almost all such cancers are associated with postcricoid webs. Radiologic or endoscopic examinations may therefore be required to differentiate webs from superimposed hypopharyngeal or esophageal carcinomas in patients with this syndrome.

Radiation

Esophageal cancer is a rare complication of chronic radiation injury to the esophagus. Most reported cases have involved the cervical or upper thoracic esophagus after radiation doses of 20 to 50 Gy to the mediastinum or neck. ^, However, the average latent period between radiation therapy and the development of cancer is about 30 years, so these lesions could be coincidental cancers arising in previously irradiated areas.

Tylosis

Tylosis (Howel-Evans syndrome) is an extremely rare, hereditary, autosomal dominant dermatologic disorder in which the risk of developing esophageal cancer by age 65 is as high as 95%. ^, Most patients have advanced, unresectable tumors at the time of clinical presentation. Periodic surveillance of asymptomatic family members with tylosis has therefore been advocated to detect premalignant lesions before the development of overt carcinoma. Because of the high likelihood of developing esophageal cancer in these families, a prophylactic esophagectomy may be warranted.

Gross Features

Squamous cell carcinomas of the esophagus may be infiltrating, polypoid, ulcerative, or superficial spreading lesions. Infiltrating lesions (the most common type) cause irregular luminal narrowing; polypoid lesions are lobulated or fungating masses; primary ulcerative lesions are largely necrotic, ulcerated masses; and superficial spreading lesions extend longitudinally in the wall without invading beyond the mucosa or submucosa. Superficial spreading carcinomas therefore have a better prognosis than other more invasive forms of esophageal cancer.

Histologic Features

About 50% of esophageal cancers are squamous cell carcinomas and 50% are adenocarcinomas arising in Barrett’s mucosa. Regardless of type, esophageal cancers may be classified as early or advanced. The terms early esophageal cancer , superficial esophageal cancer , and small esophageal cancer have been used interchangeably, but these terms should not be considered synonymous because they have different histopathologic features that affect patient prognosis. According to the Japanese Society for Esophageal Diseases, early esophageal cancer is defined histologically as tumor confined to the mucosa or submucosa without lymph node involvement. Superficial esophageal cancer is also confined to the mucosa or submucosa, but these tumors may have lymph node metastases. Small esophageal cancer is another term used to describe tumors less than 3.5 cm in size, regardless of the depth of invasion or the presence or absence of lymph node metastases. ^, The 5-year survival rate for esophageal cancer decreases markedly when regional lymph nodes are involved by tumor. ^, Thus, some superficial or small esophageal cancers may be early lesions histologically, whereas others are already advanced lesions. ^,

Distribution

Squamous cell carcinomas of the esophagus tend to be located in the upper, mid, or, less commonly, distal esophagus. ^, Unlike adenocarcinomas arising in Barrett’s mucosa, squamous cell carcinomas of the distal esophagus almost never invade the stomach.

Direct Extension

Because the esophagus lacks a serosa, there is no anatomic barrier to prevent rapid spread of tumor into the mediastinum. As a result, esophageal cancer often invades contiguous structures in the neck or chest, such as the thyroid, larynx, trachea, bronchi, aorta, lung, pericardium, and diaphragm. ^, Tracheoesophageal or esophagobronchial fistulas develop in 5% to 10% of patients. ^, Rarely, aortoesophageal fistulas or even esophagopericardial fistulas may occur as a terminal complication of esophageal cancer due to tumor invading the aorta or pericardium. ^,

Lymphatic Spread

Lymph node metastases are found in 75% of patients with esophageal cancer. Because the esophagus contains a rich network of interconnecting lymphatic channels, “jump” metastases to lymph nodes in the neck or mediastinum often occur in the absence of segmental lymph node involvement. ^, Tumor in esophageal lymphatics spreads subdiaphragmatically to paracardiac, lesser curvature, and celiac nodes in the upper abdomen in 25% to 50% of patients. ^, Although cancers in the distal esophagus are more likely to metastasize to upper abdominal lymph nodes, cancers in the upper or midesophagus can also metastasize to these nodal groups.

Discrete lymphatic metastases or satellite nodules are found in the esophagus at autopsy in about 50% of patients with esophageal cancer. When two discrete lesions are detected in the esophagus, it may be impossible to differentiate lymphatic dissemination of a single cancer from synchronous primary esophageal cancers. ^,

Between 2% and 15% of patients dying of esophageal cancer have gastric metastases at autopsy. These lesions probably result from tumor emboli that seed the gastric fundus via submucosal esophageal lymphatics extending subdiaphragmatically into the stomach. ^, In such cases, the esophageal cancer may be located a considerable distance from the gastroesophageal junction.

Hematogenous Metastases

Hematogenous (blood-borne) metastases are often found in patients with advanced esophageal carcinoma. The most common sites of metastases are the lungs, liver, adrenals, kidneys, pancreas, peritoneum, and bones.