Adjuvant treatment of early breast cancer

This is treatment given to women who have had surgical treatment for early breast cancer and who appear to be well and free of further disease. Adjuvant treatment reduces the risk of breast cancer coming back.

• What types of adjuvant treatment are there?
• How is adjuvant treatment after surgery chosen in early breast cancer?
• What are the names of some of the hormone therapy drugs for early breast cancer?
• What is monoclonal antibody treatment for breast cancer?
• What are the long term disabling effects of treatment for breast cancer?

What types of adjuvant treatment are there?

There are three types of adjuvant treatment:

Chemotherapy – this is intravenous chemotherapy usually given every few weeks over 4-6 months. Women with HER2 positive breast cancers are likely to receive additional chemotherapy using monoclonal antibodies.

Radiotherapy – this is routinely given to women who have had part of the breast removed, it is given daily for 3-5 weeks. It prevents local recurrence at the site of the original cancer. Women who have had the whole breast removed (mastectomy) do not usually need this treatment.

Hormone therapy – these are anti-oestrogen tablets to prevent female sex hormones such as oestrogen triggering growth of remaining breast cancer cells. These are given when breast cancers have oestrogen receptors, when the cells are ‘ER+’. Hormone therapy is usually given for up to 5 years.

How is adjuvant treatment after surgery chosen in early breast cancer?

The pathology report describes the features of the cancer cells and whether the cancer has been completely removed. If the margins of cancer clearance are not wide enough a further operation may be performed to clear them, this can be either a further wide excision of tissue where the tumour was, or a mastectomy.

The second important feature of the report is whether there are cancer cells in the lymph nodes. If cancer cells are present there is a higher chance of secondary cancer developing elsewhere in the body and treatment is needed to prevent this. Treatment is likely to consist of hormone therapy for at least 5 years with or without a course of chemotherapy.

Finally cancer cells are assessed to see if they have oestrogen and progesterone receptors or not and if they over-express a protein called HER2. If oestrogen receptors are present this may be referred to as ER+ in the correspondence, if they are not present this may be written as ER-. If the tumour is ER+ hormone therapy will usually be prescribed for 5 years, this improves survival and prevents the tumour from growing back in the breast. If the tumour regrows at the site of the scar this is called ‘local recurrence’.

If Progesterone hormone receptors are present this may be written as PR+ and PR- if they are absent.

If a tumour is ER- PR- and HER2- no hormone receptors or HER2 protein are present. This type of tumour may be described as 'triple negative breast cancer'. Adjuvant chemotherapy without ongoing hormone therapy is used in this group.

If the cancer over-expresses HER2 then treatment with monoclonal antibody may be possible.

Radiotherapy is given to reduce the chance of local recurrence in the breast, most commonly it is used in women who have only had part of the breast removed, but sometimes it is given after a mastectomy to the chest wall if there were particular features on the pathology report to increase the risk of local recurrence.

What are the names of some of the hormone therapy drugs for early breast cancer?

Anti-oestrogens e.g. Tamoxifen – is a tablet taken once a day for five years. Side effects are menopausal symptoms including hot flushes, weight gain, rarely cancer of the lining of the womb and blood clots e.g. deep vein thrombosis and stroke.

Aromatase inhibitors such as:

• Anastrozole (Arimidex)
• Exemestane (Aromasin)
• Letrozole (Femara)

These tablets are taken every day, they stop the effects of oestrogen by blocking an enzyme called aromatase which converts other hormones into oestrogen. These are sometimes given for the five years or part of the five years instead of tamoxifen. The side effects include hot flushes, bone or muscle pain, osteoporosis, vaginal dryness, headaches and diarrhoea. There is no increased risk of endometrial cancer and blood clots with aromatase inhibitors.

What is monoclonal antibody treatment for breast cancer?

1 in 5 breast cancers express high levels of the protein Her2. This is described as Her 2 positive breast cancer. The drug Trastuzumab (Herceptin) consists of a monoclonal antibody that recognises this protein and a chemotherapy drug molecule. By recognising the abnormal protein and binding to it, the treatment concentrates toxic chemotherapy drug around the cancer cells. This treatment may become routinely used for women with early breast cancer whose cancer expresses Her2. The treatment is used in late breast cancer and is undergoing trials in women with early breast cancer.

What are the long term disabling effects of treatment for breast cancer?

Once treatment is complete it is expected that women will return to full health. Long term problems particular to breast cancer treatment may include:

• Mental health problems related to adjusting to changes in appearance and having cancer
• Debilitating menopausal symptoms related to ongoing hormone therapy
• Lymphoedema of the arm following axillary surgery or radiotherapy
• Any long term side effect related to chemotherapy – (rare)
• Radiation Induced Brachial Plexopathy – RIBP- (rare) symptoms include tingling numbness and paralysis of the hand which spreads up the arm, it is usually associated with severe neuropathic type pains in the shoulder and arm. Pain may resolve when paralysis becomes complete. The condition develops over several years. It is related to radiation induced changes to the nerves supplying the arm – the brachial plexus. The end result of the condition is numbness and paralysis of the affected arm. This will be more disabling if associated with persistent pain.

Amended June 2010