Selective avoidance of postoperative locoregional radiotherapy in breast cancer seems to be justified

Objective: To try and reduce the amount of routine postoperative radiotherapy that we prescribed without causing an unacceptable rise in locoregional recurrences. Design: Retrospective study. Setting: Teaching hospital, The Netherlands. Subjects: 836 women who were treated for breast cancer between January 1980 and December 1989. Interventions: These 836 had been treated by modified radical mastectomy (n = 534), excision of the turnout and axillary dissection (n = 279), lumpectomy (n = 15), or total mastectomy (n = 8). In December 1984 we stopped giving routine postoperative irradiation to women with T₁ or T₂ tumours unless there was any doubt about the operative specimen. Main outcome measures: The rate of locoregional recurrence 1985-9 compared with that from 1980-December 1984. Results: Only 1 patient of 836 had a clinically detectable recurrence in the internal mammary chain. There were only 2 recurrences in the 235 axillas that had not been irradiated. Conclusion: By a process of careful selection of patients for locoregional irradiation, the number of fields of irradiation given to patients with breast cancer can be reduced by up to 80% without causing a rise in the rate of locoregional recurrences.