Belching is listed as an uncommon symptom of esophageal cancer. my understanding is a gastric belch flows through the les, through the esophagus, through the ues, and out the mouth. why would a tumor contribute to an increased belching frequency?

Esophageal cancer often gives the sensation of something stuck in the chest creating the urge to belch. Forcing yourself to belch makes one swallow air and, thus may continue the urge to belch. I'm not sure this answers your question, though.

An esophageal tumor can physically irritate the diaphragm and can cause it to contract, which results in a hiccup