The following treatment modalities are used in the management of localized breast cancer:
- Systemic treatments:
- hormone manipulation
Radiotherapy following conservative surgery for breast cancer will reduce the risk of local tumour recurrence to a level comparable to that following mastectomy. Completely excised, good-prognosis tumours or preinvasive (ductal carcinoma in situ) changes alone may be treated with surgery alone. The Early Breast Cancer Trialists” Collaborative Group have reviewed the evidence for radiotherapy, the latest update being in 2000. In summary, there were three times fewer recurrences when radiotherapy was added to surgery. Positive surgical margins, high-grade tumour with lymphovascular invasion, large tumour associated with carcinoma in situ, and node involvement all increased the risk of local recurrence, even after radiotherapy is given. Postoperative chest wall and regional lymph node radiotherapy is also indicated post-mastectomy for a selected group of patients at high risk of local relapse. The axilla is not routinely irradiated following surgery to the axilla because of a high risk of morbidity, particularly lymphoedema.
Does radiotherapy actually improve survival from breast cancer, or does it just improve local control? A review of patients treated in the 1970s revealed an increase in cardiovascular mortality thought to be due to induction of ischaemic heart disease by the radiotherapy treatment, offsetting any survival advantage. Modern improved radiotherapy techniques are reducing treatment-related morbidity and recent Danish studies have shown that loco-regional radiotherapy has improved survival rates in appropriately treated high-risk patients, with no increase in cardiovascular events. The debate is ongoing.
Radiotherapy side effects
Radiotherapy typically involves daily treatment over several weeks to the whole breast followed by a short boost of treatment to the original tumour site in selected patients. A number of studies worldwide, including the “START” trial in the UK, are investigating the optimum treatment schedule.
The side effects of radiotherapy vary from patient to patient. Immediate side effects are fatigue and tiredness, almost universally experienced. This may continue for several months following treatment completion. Early side effects are acute skin reactions, varying from a slight reddening of the skin to severe erythema and blistering, which can be mistaken for cellulitis, particularly in women of larger breast size. Antibiotics are rarely required and the erythema and blistering improves with conservative management. Breast pain and discomfort may occur, particularly in the areolar area. Women are advised regarding skin care to minimize the acute toxicity. E45 or aqueous cream can be used. At the end of treatment, the skin can remain thickened and hyperpigmented. It may take up to 6 months for the skin to settle, although the worst effects improve usually within 6 weeks. Late effects of radiotherapy can include breast pain, breast shrinkage or induration, and rib pain (costochondritis), which usually respond to simple painkillers such as ibuprofen. The incidence of lymphoedema ranges from 5 to 25%, depending on extent of axillary irradiation and surgery. Symptomatic pneumonitis, characterized by cough, fever, and shortness of breath, may occur 2 – 9 months after radiotherapy in less than 1% of women. Symptoms usually resolve with conservative management. Brachial plexus damage is now very rare (1 – 2%) with modern planning and avoidance of axillary radiotherapy, but in patients treated with older regimens, symptoms of neuropathic pain, paraesthesia, or weakness should be fully investigated.
Systemic treatments are given in addition to surgery and radiotherapy in early breast cancer to reduce the risk of recurrence and improve survival, by targeting “micrometastatic” disease. Choice of treatments depends on prognostic factors related to the tumour and on the patient’s general health and preferences. (Table Improvements in 10-year survival of node-positive women associated with different treatments).
Table Improvements in 10-year survival of node-positive women associated with different treatments