How breasts grow

Breast development

Female BreastDuring puberty the sexual organs mature, the secondary sexual characteristics (such as breasts and body hair) develop and reproduction becomes possible. During this time girls develop milk-producing glands called lobules at the back of the breasts. These lobules are connected to tiny tubes called ducts that can carry milk to the nipple. The lobules, ducts and blood vessels are surrounded by fatty tissue and connective tissue called stroma which is attached to the chest wall (see Figure 1.0).

The male breast

Men have much less fatty tissue in their breasts than women but can still be affected by breast cancer. Men's breast tissue contains ducts, but only a few, if any, lobules.

Lymph nodes

The lymphatic system is an important part of the immune system that helps the body fight infection. It is made up of a network of thin vessels that spread into tissues throughout the body. A clear fluid called lymph circulates around the system transporting infection-fighting cells called lymphocytes that help remove foreign matter and cellular debris. Lymph nodes act as filters and may swell up when a possible threat (such as a bacterium) is identified. Generalised lymphadenopathy (when all the nodes of the body are swollen) may indicate a systemic illness such as an infection or cancer.

Breast Awareness

What to watch for

It is important to know how your breasts look and feel normally so that you can spot any changes as they occur. Early detection of breast cancer increases the chances of effective treatment. There are several changes to watch for:

  • If one breast becomes larger than the other
  • If a nipple becomes inverted
  • Rashes on or around the nipple
  • Discharge from one or both nipples
  • Skin texture changes (puckering or dimpling)
  • Swelling under the armpit or around the collarbone (where the lymph nodes are)
  • A lump that you feel is different to the rest of your breast tissue
  • Continuous pain in one part of the breast or armpit (not a common symptom)

What to do next

If you do notice one or more of these changes then make an appointment to see your GP as soon as you can but try not to worry too much as most breast symptoms do not turn out to be breast cancer. Non-cancerous or benign breast conditions that may cause breast changes include fibrocystic mastopathy, mastitis and fibroadenoma, to name but a few.

Different types of breast cancer

When breast cancer does occur, cells in part of the breast grow in an uncontrolled way. If the cancer is not treated, the cells can spread within the breast or even further, travelling to other parts of the body. If the cancer cells have not spread, it is called non-invasive breast cancer. If the cancer cells develop in the ducts, the cancer is called ductal carcinoma in situ (DCIS), if they occur in the lobules, it is referred to as lobular carcinoma in situ (LCIS). If the cancer cells have spread (metastasised) into the surrounding breast tissue, lymph glands or further within the body, it is called invasive breast cancer.