Radiation Therapy of Invasive Breast Cancer

Overgaard: In principle I regard adjuvant radiotherapy as a standard within breast-conserving treatment of invasive breast cancer. The evidence of the benefit of radiotherapy has clearly been demonstrated in the last Oxford overview analysis published in December 2005. This study also includes several randomised trials comparing breast-conserving surgery with and without radiotherapy. Irrespective of the presence of systemic therapy radiotherapy results in a significant reduction of the local recurrence rate (3-fold) and an improvement in overall survival in the order of 5% (absolute value) after 15 years. However, in selected groups of patients with favourable prognosis the benefit of adjuvant radiotherapy seems to be very small and might not outweigh the risks and costs of such treatment. Therefore, it is necessary to continue defining selection criteria for patients where radiotherapy can be omitted.