esophageal cancer
Meaning of esophageal cancer: Lacking the outer wrapping that surrounds other digestive organs, the esophagus lets a tumor reach neighboring structures early.
Definition of esophageal cancer
Esophageal cancer is cancer that develops in the lining of the esophagus, the muscular tube joining the throat to the stomach. It takes two main forms: squamous cell carcinoma, arising from the flat cells lining most of the tube, and adenocarcinoma, arising from glandular cells. The two differ in position, in risk factors and in where they are common.
What separates the two types?
| Squamous cell carcinoma | Adenocarcinoma | |
|---|---|---|
| Position | Upper and middle portions | Lower portion and the junction with the stomach |
| Cell of origin | The flat cells that normally line the tube | Glandular cells that have replaced them |
| Main risks | Tobacco and alcohol, especially together; very hot drinks; caustic injury | Long standing reflux, Barrett change, obesity, tobacco |
| Where common | The more frequent type worldwide | Predominant in North America and much of Western Europe |
The route to adenocarcinoma is the better understood of the two. Persistent esophageal reflux irritates the lower lining until it is replaced by cells resembling those of the intestine, a change called Barrett esophagus. That tissue tolerates acid better but carries a raised risk of turning cancerous, which is why it is monitored rather than ignored.
Why does it spread so early?
Most organs of the digestive tract are wrapped in a smooth outer membrane that acts as a barrier for a while. The esophagus has none. A tumor growing outward therefore meets the windpipe, the aorta, the lung and the nerves running alongside without crossing anything that slows it. The wall also carries an unusually rich network of lymphatic channels running lengthwise rather than only outward, so cells can travel some distance up or down the tube and reach lymph nodes well away from the visible tumor. Both features push the disease toward a higher stage at the point it is found.
How does it show itself?
The tube stretches, so a tumor can occupy a good deal of the channel before anything is noticed. The first symptom is usually difficulty swallowing, beginning with solid food such as bread or meat and progressing to softer food and eventually liquid. Weight loss follows, both from reduced intake and from the disease itself. Pain on swallowing, a hoarse voice from involvement of the nerve to the voice box, persistent cough and bleeding into the digestive tract occur as it advances.
Used in a sentence
Biopsy results confirmed adenocarcinoma in the area of esophageal cancer identified on endoscopy.
Good to know
Adenocarcinoma and squamous cell carcinoma of the esophagus carry different risk factors and tend to arise in different portions of the tube, a distinction confirmed by tissue biopsy rather than by location alone.