Radiotherapy or tamoxifen after conserving surgery for breast cancers of excellent prognosis: British Association of Surgical Oncology (BASO) II trial

Abstract Background The incidence of local recurrence (LR) after conservative surgery for early breast cancer without adjuvant therapy is unacceptably high even with favourable tumours. The aim of this study was to examine the effect of adjuvant therapies in tumours with excellent prognostic features. Methods Patients with primary invasive breast cancer Findings The actuarial breast cancer specific survival in 1135 randomised patients at 10years was 96%. Analysis by intention to treat showed that LR after WLE was reduced in patients randomised to radiotherapy (RT) (HR 0.37, CI 0.22-0.61 p p Conclusions Even in these patients with tumours of excellent prognosis, LR after conservative surgery without adjuvant therapy was still very high. This was reduced to a similar extent by either radiotherapy or tamoxifen but to a greater extent by the receipt of both treatments.