BREAST CANCER: THE ROLE OF RADIATION THERAPY AFTER TREATMENT BY CONSERVATIVE SURGERY

Abstract

The role of conservative surgery (CS) as definitive treatment of invasive breast cancer has not been established. Previous studies have demonstrated high rates of local tumour recurrence if CS is not followed by radiotherapy (RT). At present, it is impossible to identify subsets of patients who may be at acceptably low risk of recurrence after CS. The treatment of breast cancer by CS alone remains an important research question as this may avoid over-treatment by radiation for some patients. In Australia, a trial has been proposed by the ANZ Breast Cancer Trials Group, comparing CS alone to CS+RT. This paper reviews all available data on CS alone in order to stimulate debate as to the appropriateness of the trial and its end-points. Given that all prospective randomized trials have failed to show a survival disadvantage for CS alone it is essential to consider the value of all outcomes after CS or CS+RT. The conventional end-points proposed in the Australian study (mastectomy rate, disease-free survival (DFS) and overall survival (OS)) are selective. Without the addition of quality of life measures, the utilities of the strategies addressed in the trial cannot be evaluated. Data are presented on the desirability (utility) of the alternative approaches of CS or CS+RT based on data obtained from a questionnaire completed by Westmead Hospital staff. This preliminary study indicates that the majority of respondents to the questionnaire perceived that the strategy of CS+RT to have a higher utility than the strategy of CS alone.