Can plain stomach x-ray with no contrast show stomach cancer?

No. : Most stomach cancers arise from the inner lining of the stomach. This can be best seen by upper endoscopy or an upper GI x-ray with contrast. In the latter study, the ingested dye will outline the lining of the stomach and may show a cancer. Of the two tests, endoscopy is much more sensitive and has the advantage of enabling tissue biopsy.

No: The only way to diagnose stomach cancer is by an endoscopy and biopsy. This is a procedure where a camera is placed down the mouth into the stomach. Imaging tests like a ct scan or xray with contrast can be highly suggestive of stomach cancer, but not definitive. A plain x-ray on its own is not useful since without contrast the body's tissues and tumor cannot be distinguished from one another.