CANCER OF OESOPHAGUS
The Gastrointestinal tract is the second most common noncutaneous site for cancer and the second major cause of the cancer related mortality in the United Stated.
Incidence
Cancer of the Oesophagus is a relatively un-common but extremely lethal malignancy. It occurs frequently within a geographic region extending from the southern shore of the Caspian Sea on the west to northern China on the east and encompassing parts of Iran, Central Asia, Afghanistan, Siberia, and Mongolia. The disease is more common in Blacks than whites and in males than females; it appears most often after age 50 and seems to be associated with a lower socioeconomic status.
Aetiology (Cause of Disease)
A variety of Causative factors have been implicated in the development of the disease. In the United States, esophageal cancer cases are either squamous cell carcinomas or adenocarcinomas. The aetiology of squamous cell esophageal cancer is related to excess alcohol consumption and/or cigarette smoking. The relative risk increases with the amount of tobacco smoked or alcohol consumed, with these factors acting synergistically. The consumption of whiskey is linked to a higher incidence than the consumption off wine or beer. Squamous cell esophageal carcinoma has also been associated with the ingestion of nitrites, smoked opiates, and fungal toxins in pickled vegetables, as well as mucosal damage caused by such physical insults as long term exposure to extremely hot tea, the ingestion of lye, radiation induced strictures, and chronic achalasia. The presence of an esophageal web in association with glossitis and iron deficiency and congenital hyperkeratosis and pitting of the palms and soles have rich been linked with squamous cell esophageal cancer, as have dietary deficiencies of molybdenum, zinc, and vitamin A.
The rate of adenocarcinoma has risen dramatically, particularly in white males. Adenocarcinoma arises in the distal esophagus in the presence of chronic gastric reflux and gastric maetaplasia of the epithelium, which is more common in obese persons. Adenocarcinomas arise within dysplastic columnar epithelium in the distal esophagus. These adenocarcinomas behave clinically gastric adenocarcinomas and now account for >50% of esophageal cancer.
Clinical Features
About 15% of esophageal cancers occur in the upper third of the esophagus, 35% in the middle third, and 50% in the lower third. Squamous cell carcinoma and adenocarcinomas of the esophagus cannot be distinguished radiographically or endoscopically.
Progressive dysphagia and weight loss of short duration are the initial symptoms in the vast majority of cases. Dysphagia initially occurs with solid foods and gradually progresses to include semisolids and liquids. By the time these symptoms develop, the disease is usually incurable, since difficulty in swallowing does not occur until >60% of the esophagus circumference is infiltrated with cancer. Dysphagia may associate with pain on swallowing, pain radiating to the chest and/or back, regurgitation or vomiting, aspiration pneumonia. The disease most commonly spread to adjacent and supra-clavicular lymph nodes, liver, lungs, pleura. Tracheo-esophageal fistula may develop when the disease advances, and may lead in to severe suffering. As with other squamous cell carcinomas, hypercalemia may occur in the absence of osseous metastasis, probably from parathormone related peptides secreted by tumour cells.
Diagnosis
Various modern techniques are used to find out the carcinomas, some important tests are:
Endoscopic and cytologic screening.
Routine contrast Radiographs.
Computed Tomography Scans.
Positron emission Tomography Scanning
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