What is cancer?

Cancer starts in our cells. Cells are tiny building blocks that make up the organs and tissues of our body. Usually, these cells divide to make new cells in a controlled way. This is how our bodies grow, heal and repair. When a cell is no longer needed or can’t be repaired, it gets a signal to stop working and die. Cells receive signals from the body telling them when to divide and grow and when to stop growing.

Sometimes, this goes wrong and the cell becomes abnormal. The abnormal cell keeps dividing and making more and more abnormal cells. These cells form a lump, which is called a tumour.

Cells forming a tumour
Cells forming a tumour

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Not all lumps are cancerous. Doctors can tell if a lump is cancerous by removing a small sample of tissue or cells from it. This is called a biopsy. The doctors examine the sample under a microscope to look for cancer cells.

  • A lump that is not cancerous (benign) cannot spread to anywhere else in the body.
  • A lump that is cancer (malignant) can spread elsewhere in the body.

A lump that is cancer (malignant) can grow into nearby tissue. Sometimes, cancer cells spread from where the cancer first started (the primary site) to other parts of the body. They can travel through the blood or lymphatic system. When this happens, the cancer that develops in another part of the body is called a secondary cancer or metastasis.

Back to Understanding stomach cancer

The stomach

The stomach stores food and breaks it down so our bodies can absorb the nutrients we need for energy.

The lymphatic system

The lymphatic system protects the body from infection and includes lymph nodes (glands). There are lymph nodes near the stomach.

Types of stomach cancer

The most common type of stomach cancer is adenocarcinoma. We also have information on less common cancers of the stomach.