If gastroscopy was done a few months ago and no abnormality was found, and the recent examination confirms esophageal cancer, then most of them should not be in advanced stage yet, but the specific early, middle and late stages should still be determined according to the symptoms, signs and auxiliary examination results. Using gastroscopy to diagnose esophageal cancer, the chance of confirming the diagnosis is still relatively high, which can reach 95%, because gastroscopy has to pass through the mouth, throat, esophagus, and then to the stomach, but there is still a small portion of them which may result in missed diagnosis. It usually takes three to six months for a tumor to develop into a symptomatic mass. Early diagnosis of esophageal cancer can be confirmed by doing fiberoptic gastroscopy, X-ray barium meal imaging, esophageal mucosal exfoliative cells, etc. Symptoms of esophageal cancer in early stage are often not obvious, and the most common ones are choking sensation, pain at the back of sternum and under the raphe, feeling of food retention and foreign body sensation, dryness and tightness in throat, and there are usually no clear signs during physical examination in early stage. In advanced stage of esophageal cancer, the main symptoms are progressive difficulty in swallowing, food reflux, hoarseness and shortness of breath, etc. Moreover, patients can be seen to be emaciated, anemic, malnourished and malignant. When the cancer metastasizes, enlarged and hard lymph nodes or enlarged and nodular liver can be touched. Therefore, if esophageal cancer was not detected by gastroscopy 7 months ago and found only in recent examination, further examination is needed to clarify the staging. If there is no distant metastasis, the symptoms are not serious, and only the lesion is confined to the esophagus, then it should be in early stage.