About Breast Cancer | Breast Cancer Campaign

About Breast Cancer

Breast cancer is the most common cancer in the UK.

Breast cancer is the name given to cancers that have first developed in breast tissue. There are many different types. 

Thanks to research, more people are surviving breast cancer than ever before. Over 80% of women with breast cancer are still alive five years after diagnosis.

But around 50,000 women are still diagnosed with breast cancer each year, and around 12,000 women die of the disease each year. 

Read more about breast cancer statistics


The tissues that make up our bodies are composed of billions of tiny cells. The genetic information (DNA) inside these cells ensures they divide, grow and die in a carefully controlled way. This allows the body to grow new tissues and repair damaged ones. But when this process goes wrong, cells can multiply and grow out of control and form a tumour.

Some tumours are benign (non-cancerous). They tend to grow slowly and be confined to one part of the body. Tumours that are malignant (cancerous) usually grow more quickly than benign tumours, invading and destroying surrounding tissues and potentially spreading to other organs

Non-invasive breast tumours

When we talk about breast cancer we normally mean tumours that grow into the surrounding breast tissue, called ‘invasive breast cancer’.

However, sometimes cancerous changes develop within the lobules (milk-producing glands) or ducts but do not break out into the surrounding tissue.

Cancerous changes that form within ducts are called Ductal Carcinoma In Situ, or DCIS. Cancerous changes that form within lobules are called Lobular Carcinoma In Situ or LCIS.

It is difficult to estimate how often DCIS or LCIS will develop into invasive breast cancer, but it is believed that if left untreated, DCIS will develop into invasive breast cancer in up to 50 per cent of cases

Secondary breast cancer

When cancer spreads from the breast to other parts of the body, such as the bones, lungs, liver and brain, it becomes known as secondary or metastatic breast cancer. Secondary breast cancer can sometimes be treated and controlled, but not cured. Ultimately, this is the main reason why people die from the disease.

Find out more about our research into secondary breast cancer