How Stomach Cancer Spreads

Stomach cancer tends to grow in a predictable way. It begins in the inner lining of the stomach, called the mucosa. When it grows, it penetrates into the stomach wall, through the stomach, and then outside of the stomach. If no one finds it before it has grown outside of the stomach, the cancer can spread to nearby organs such as the liver, large bowel, pancreas, or spleen. It may also spread to lymph nodes nearby.

In later stages, stomach cancer can spread to lymph nodes outside of the immediate area as well as to other parts of the abdomen. Sometimes, lymph nodes on the left neck or under the arm become enlarged. Stomach cancer can also spread to the peritoneum (the inner lining of the abdomen), lungs, adrenal glands, ovaries (in women), and near the rectum. In some cases it spreads to distant parts of the body.

When stomach cancer has spread to another part of the body, it’s not considered a new cancer. For instance, if stomach cancer spreads to the liver, it’s not considered liver cancer. It’s called metastatic stomach cancer.

There are also several kinds of cancer, such as kidney cancer, that can spread to your stomach. When this happens, the cancer is not called stomach cancer. This is because cancer is usually named for the site of the original tumor. For example, if kidney cancer spreads to your stomach, it will be treated as metastatic kidney cancer, not as stomach cancer.