Adjuvant post-operative radiotherapy in operable node positive mammary cancer: a comparison of three treatment protocols

Abstract

A retrospective analysis of the results of post-operative radiotherapy in 501 operable node positive patients with mammary cancer was performed on all patients treated in 1965-1967 and in 1976, thus enabling us to judge the impact of the different dose levels used in the protocols valid at that time. Low doses were used from 1965 to 1969 and moderately high doses were used in 1976. No influence of the different treatment schedules was observed on survival or disease-free survival at 5 years. Higher T category, lower grade of differentiation, capsular invasion, and top level axillary involvement all contributed to higher risk of locoregional recurrence. High dose post-operative radiotherapy significantly reduced the rate of axillary recurrences and supraclavicular recurrences. A dose effect relationship was evident. Parasternal node metastasis was observed only once, thus influence of radiotherapy on parasternal node metastases could not be evaluated. Scar area recurrences in high risk patients were insufficiently prevented by these post-operative radiotherapy schedules. Indications for post-operative radiotherapy to axillary and supraclavicular areas in mammary cancer should be limited to high risk patients with the aim of preventing locoregional recurrence.