Is postoperative radiotherapy after breast conserving surgery always mandatory? A review of randomised controlled trials.

BACKGROUND AND AIMS: Breast-conserving surgery followed by radiotherapy, in order to prevent local recurrence, has been the treatment of choice ever since breast conserving surgery was introduced in clinical practice. Patient selection, type of surgery, dose and type of radiotherapy, however, may have an impact on the risk of local recurrence. The aim of this review is to synthesise the results from randomised trials and try and define a subgroup of patients in whom postoperative radiotherapy could be omitted.
METHOD: A literature search of Pub Med and The Cochrane randomised trials registry identified six trials comparing patients randomised to surgery alone or surgery plus radiotherapy, two trials comparing different radiotherapy modalities and one trial comparing different types of surgery.
RESULTS: Addition of postoperative radiotherapy reduce the risk of local recurrence by 2/3. The dose-intensity of radiotherapy and surgery has a positive impact on local control. Patients at low risk of local recurrence are patients > 55 years of age, with stage I tumours and favourable histology treated with adequate resection margins. No trial showed any positive effect of radiotherapy on survival.
CONCLUSION: In most patients postoperative radiotherapy is an integral part of breast-conservation. Radiotherapy can be omitted in selected low risk patients.