Radiotherapy for early and advanced breast cancer

Postoperative radiotherapy (RT) forms an intrinsic part of breast conservation therapy, substantially reducing the risk of breast relapse. It is given 4-6 weeks postoperatively using medial and lateral beams to achieve a near homogeneous dose to the breast while minimising the dose to adjacent structures. Typically, a dose of 40 Gy in 15 daily fractions over three weeks or 50 Gy in 25 fractions over five weeks is given, with a boost of 10 Gy using low energy electrons or superficial X-rays. RT is delivered to the chest wall after mastectomy in patients with large tumours (> 5 cm), close surgical margins, or significant axillary node involvement and may result in an additional 10% survival benefit. Early complications of RT include tiredness, skin erythema and moist desquamation. Late reactions, breast fibrosis, telangiectases and peau d'orange are reduced if more treatment fractions are given. Lung irradiation is minimised by careful treatment planning and < 1% of patients experience radiation pneumonitis or pulmonary fibrosis. Patients with locally advanced breast cancer may be offered a combination of systemic therapy, endocrine, chemotherapy and radical RT. Preoperative systemic and radiation therapy reduces the mastectomy rate but at present does not improve survival. Those who are unfit for radical treatment and have large ulcerating or fixed cancers are offered either endocrine or cytotoxic therapy, depending upon the oestrogen receptor status, followed by RT, which is unlikely to cure but may achieve local control for a variable duration. RT forms part of the multidisciplinary approach to palliative treatment for metastatic disease. Bone metastases occur in 75% of women with metastatic disease and RT provides effective pain relief and reducing risk of pathological fractures. Patients with brain metastases need high-dose steroids followed by cranial RT.