What is the most common type of esophageal cancer in the United States?

Adenocarcinoma is the most common type of esophageal cancer in the United States, primarily due to the rising incidence of obesity and gastroesophageal reflux disease (GERD), which can lead to Barrett's esophagus, a precancerous condition. Adenocarcinoma typically arises in the lower esophagus, where the squamocolumnar junction is located, often in the setting of reflux-related changes.

In contrast, squamous cell carcinoma, while also a common form of esophageal cancer globally, has seen a decline in its incidence in the U.S., correlating with decreased rates of smoking and changes in dietary patterns. The other types listed, such as small cell carcinoma and transitional cell carcinoma, are much rarer when it comes to esophageal cancer and are not typically found in this anatomical region. Their rarity contributes to adenocarcinoma being the most prevalent type in the context of esophageal malignancies in the U.S.