Tangential radiotherapy without axillary surgery in early-stage breast cancer: results of a prospective trial.

Purpose: To determine the risk of regional-nodal recurrence in patients with early-stage, invasive breast cancer, with clinically negative axillary nodes, who were treated with breast-conserving surgery, "high tangential" breast radiotherapy, and hormonal therapy, without axillary surgery or the use of a separate nodal radiation field.

Methods And Materials: Between September 1998 and November 2003, 74 patients who were >/=55 years of age with Stage I-II clinically node-negative, hormone-receptor-positive breast cancer underwent tumor excision to negative margins without axillary surgery as a part of a multi-institutional prospective study. Postoperatively, all underwent high-tangential, whole-breast radiotherapy with a boost to the tumor bed, followed by 5 years of hormonal therapy.

Results: For the 74 patients enrolled, the median age was 74.5 years, and the median pathologic tumor size was 1.2 cm. Lymphatic vessel invasion was present in 5 patients (7%). At a median follow-up of 52 months, no regional-nodal failures or ipsilateral breast recurrences had been identified (95% confidence interval, 0-4%). Eight patients died, one of metastatic disease and seven of other causes.

Conclusion: In this select group of mainly older patients with early-stage hormone-responsive breast cancer and clinically negative axillary nodes, treatment with high-tangential breast radiotherapy and hormonal therapy, without axillary surgery, yielded a low regional recurrence rate. Such patients might be spared more extensive axillary treatment (axillary surgery, including sentinel node biopsy, or a separate nodal radiation field), with its associated time, expense, and morbidity.