What is breast cancer?
	Symptoms and diagnosis
	Breast cancer types
	Early breast cancer
	Possible treatment pathways for early breast cancer
	Advanced breast cancer

What is breast cancer?

Cancer is characterised by the uncontrolled growth and spread of abnormal cells. The most common cancer in women in the UK is breast cancer. Although the exact cause of breast cancer is unknown, a person’s chances of developing breast cancer can be affected by a number of factors. Age, heredity, early puberty, taking hormone replacement therapy (HRT), being overweight and drinking alcohol can all increase the risk of developing breast cancer, while breastfeeding and the more children a woman has can lower the risk.1

Breast cancer itself consists of a complex variety of cancers, which begin in different types of cells. The variation in cancer and cell type means that breast cancer can be sensitive to some treatments and not others. Tumour growth varies in speed which means that breast cancer can be discovered at an early or advanced stage of development. The growth pattern taken by the cancer is also difficult to predict, and may be dependent on age and other factors.

Breast cancer can spread through the lymphatic system and blood vessels in the breast, allowing the cancer cells to be carried around the body, invading other organs and establishing new secondary tumours known as metastases. Not all cancers look the same. It is important to understand that cancer originating in one body organ maintains its characteristics even when it spreads to another part of the body. For example, metastatic breast cancer in the lungs continues to behave like breast cancer when viewed under a microscope and looks like cancer that has originated in the breast.2

Symptoms and diagnosis

When breast cancer first develops there may be no symptoms at all. The appearance of a lump is the first symptom in the majority of cases. Other symptoms include changes to the skin of the breast and nipple area, such as flaking, dimpling or discharge, and differences in shape or feel of the breast.

Diagnosis is made through a variety of tests, including mammographic screening and removal of cells or tissue from the lump (aspirate or biopsy). Laboratory tests are then performed on the fluid or tissue to determine whether the lump is cancerous, and if it is, to find out more about the features of the cancer. For example, a hormone receptor analysis helps identify whether the tumour is sensitive to the hormones oestrogen or progesterone. A positive test means that the cancer will respond to hormonal therapy. These patients are most likely to receive an anti-oestrogen treatment.

Breast cancer types

There are different types of breast cancer and the classifications of breast cancer are becoming more specific. The term "breast cancer" describes a variety of cancers that occur within the breast. The different breast cancer types are generally categorised by two factors - where the cancerous cells are located and whether the cancer is prone to spreading. 3

Breast cancer that occurs in the milk ducts of the breast is called ductal carcinoma. The breast cancer that forms in the lobules where breast milk is made is called lobular carcinoma.

Carcinomas that do not spread outside of the duct or lobule are called in situ cancers, which means "in place." If ductal or lobular carcinoma spreads into nearby tissue, it is said to be invasive, or infiltrating.

Breast cancer is classified as either early stage or advanced (secondary) disease; the staging indicates the overall extent of the cancer in the body. The prognosis for patients depends largely on the stage of the disease at diagnosis and the pathological characteristics of the primary tumour.

Understanding breast cancer types, size and spread will help the oncologist select a breast cancer treatment option that is most appropriate. Oncologists take many different factors into account when deciding on the right treatment including:

• Whether menopause has happened
• The type of breast cancer
• The breast cancer’s stage
• The size of the tumour
• The grade of the tumour
• The test results from the tumour
• General health

Many tests are carried out to determine the best treatment for your particular cancer and these will be discussed before having surgery or starting any treatment. Tests carried out on a tumour might check its "hormone receptor" status, for example its oestrogen and progesterone status. The tumour may be then classified as oestrogen receptor positive/negative, sometimes called ER positive/negative or progesterone receptor positive/negative (PR positive/negative). Tests might also be done to see if you have high levels of HER 2, a protein that allows cancer cells to multiply.

Depending on all of these factors, treatment may include:

• Surgery
• Chemotherapy
• Radiotherapy
• Hormone therapy e.g. tamoxifen or an aromatase inhibitor

Early breast cancer

Early breast cancer is confined within the organ of origin and has not invaded other neighbouring cells. In general, early breast cancer is first treated with surgery often followed by radiation.

The type of surgery required can vary from lump removal and breast-conserving therapy to mastectomy, where a substantial part or all of the breast is removed. The decision will depend on the size of the tumour in relation to the breast, the position of the tumour and the patient’s preference. It may be possible to take treatment to help shrink the tumour (neoadjuvant treatment). To prevent the cancer form returning, additional therapies (adjuvant treatment) such as hormonal (endocrine) treatments and/or chemotherapy are then prescribed according to tumour type and extent, and whether tumour cells have spread to the lymph nodes.

Possible treatment pathways for early breast cancer

When breast cancer is found and treated early, the chances for survival are greater. The prognosis for patients at this stage can be encouraging, and following treatment, many patients either never experience relapse or live for years without a recurrence. Sadly however, one third of women do experience a relapse of their disease after surgery, and over half of these relapses occur once standard adjuvant therapies have ceased.

Advanced breast cancer

Advanced breast cancer is cancer that has grown or travelled beyond its cells of origin into other neighbouring tissues. Even when cancer progresses, or is diagnosed at the advance stage, patients can live for years following treatment. Nonetheless, the risk of the cancer recurring in other parts of the body as metastases remains high, although this can sometimes be slowed with appropriate treatment. Treatment typically involves removal of the primary tumour where possible, followed by a regimen of chemotherapy and/or hormone therapy, and sometimes radiation therapy.