Breast-conserving surgery removes just the cancer and a little of the normal tissue around it, leaving behind as much healthy tissue as possible. A few cancer cells may, however, also be left behind. Doctors already knew that giving patients breast radiotherapy soon after they recover from surgery reduce the chances of local recurrence. The new study shows that the chances of dying from breast cancer are also reduced by breast radiotherapy soon after surgery. On average, for every four local recurrences avoided by radiotherapy, about one breast cancer death is avoided. The main effect of radiotherapy on local recurrence is seen during the first few years after treatment, but the main effect on mortality is seen in later years. The effects of radiotherapy add to the known improvements in long-term survival produced by chemotherapy and hormone therapy (see EBCTCG, Lancet 2005; 365:1687).
Although guidelines in America and Europe already recommend radiotherapy after breast-conserving surgery they are not always followed. This is partly because of the side-effects of radiotherapy, and partly because recurrence in a conserved breast can usually be removed by further surgery, but it may also be because there was no definite evidence on survival.
Professor Sarah Darby, who helped co-ordinate the collaboration, states: "We already knew that radiotherapy to a conserved breast substantially reduces the chances of local recurrence of breast cancer, and now we know that it also reduces th
Contact: Joe Santangelo