After a gastroscopy, you can visually determine the shape of the stomach and see if there are any polyps or ulcers, and generally a gastroscopy biopsy is not a suspicion of cancer, but rather a way to confirm the condition.
After examination, if polyps and ulcers are present, it is not possible to determine directly what the disease is, and it is not possible to determine if there is a malignant tumor, but it is necessary to look at the tissue section, microscopically, to determine if there are cytopathic lesions. The results of the biopsy are usually superficial gastritis or mild gastric ulcer disease.
If the polyps and ulcers in the stomach are more severe, specific testing is needed to determine if there is malignant cell division by biopsy, and thus whether it is cancer or a benign tumor.