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About Breast Cancer

Breast Cancer: you may be familiar with the words, but do you actually know what it is?


All tissues in our body are made from cells, including the breasts. Cancer starts in the cells which make up the tissues.

In normal circumstances, cells grow and divide as our body requires new cells.

When cells get damaged or grow old they are replaced by new cells. Sometimes this natural process goes wrong and new cells appear without our body needing them, while old or damaged cells may build up rather than die. A gradual build up of these cells can form a lump, tumour or mass. Lumps in the breast can be benign (non-cancerous) or malignant (cancerous).

Normally, breast lumps turn out to be non-cancerous and these benign lumps won’t spread.

However, malignant breast cancer cells can spread. They can move beyond the primary tumour and be transported via the lymph or blood vessels to other parts of the body. Sometimes these cells may attach to other tissues in the body and cause further tumours or growths. The spread of cancer in the body away from the primary tumour is called metastasis.

Have you ever given much thought to how our breasts actually work?

The female breast is made up of many lobes. Inside these lobes are smaller sections called lobules. Milk is produced in small glands inside the lobules. When a woman breast feeds her baby milk flows from the lobules through small ducts to the nipple. Estrogen, progesterone and prolactin hormones all play a key role in breast development and function. Estrogen stretches milk ducks and helps them carry more milk, prolactin prepares glands for milk production and progesterone increases the number and size of lobules in preparation for breastfeeding.

Breast cancer develops in the ducts or the lobules of the breast.

Breast cancer develops when there are mutations in genes due to carcinogen (a substance that causes cancer in the body) exposure leading to DNA damage. It can also develop when there are errors in DNA replication, but these mutations can occur quite randomly. In many genes, mutations can occur which have no impact, but mutation in some genes can lead to cancer.

Find out more

Marina Kochetkova, Breast cancer researcher

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