What are the early symptoms of esophageal cancer?

In its early stages, esophageal cancer commonly presents with symptoms including painful swallowing (odynophagia), a burning sensation behind the sternum, and a sensation of a foreign body during swallowing. These symptoms primarily result from localized pathological changes in esophageal tissue, which cause friction-induced pain during eating. As the local tumor enlarges, it typically forms a space-occupying lesion within the esophagus, leading to esophageal narrowing and consequently producing a sensation of obstruction during swallowing. Irritation caused by food entering the esophagus further contributes to the burning pain.