Is there still a role for radiotherapy in metastatic breast cancer?

Abstract

The question in the title could be considered rhetorical if the questioner assumes that all the undoubted therapeutic advances – bisphosphonates, cytotoxics, targeted and hormonal therapies – have cured advanced breast cancer (ABC) and no longer fail. That women still die with and from ABC and, in so doing, require palliation is evidence that radiotherapy (RT) still has a role. The most obvious role is in the palliation of bone metastases. These are not restored to normal integrity permanently by any current systemic therapies; fractures threaten or occur; pain is common; and spinal metastases can and do cause cord compression. RT still has a beneficial and proven role in all of these situations. Intracranial secondaries have also been shown to respond to either whole brain RT or stereotactic RT (SRT) or a combination of both and SRT may obviate the need for invasive surgical excision. Soft tissue disease – as seen in skin, compressive lymphadenopathy and the orbit – will also respond to RT. Where RT has always had much less of a role is in the treatment of solid visceral metastases such as in lung or liver. Proponents of the newer RT technologies such as Intensity Modulated RT (IMRT) or extracranial SRT for oligometastatic disease need to be aware that in breast cancer, unlike some other malignancies such as colonic or renal carcinomata or the sarcomata, the disease is seldom oligometastatic even in one organ. Evidence is required of efficacy before such sophisticated and expensive therapies are applied. When RT is prescribed for palliation in ABC, it should be delivered according to best available evidence, of which there is much, in terms of numbers of fractions, dose and technique. This will maximise the palliative effect and minimise not just the toxicity but also the potential socio-economic and psychological stress, impact and inconvenience of a treatment that, while absolutely essential to reduce symptoms, is unlikely to prolong life. Quality of life is unlikely to improve with prolonged therapeutic interventions. And, in delivering a high quality palliative RT service, radiation oncologists must work closely with their other colleagues in the broader palliative multidisciplinary team that includes not only surgical and medical oncologists but also support staff and palliative medicine physicians.