It is possible to omit postoperative irradiation in a highly selected group of elderly breast cancer patients.

The purpose of this study was the evaluation of the necessity of routinely applied postoperative radiotherapy in a highly selected patient-group after breast conserving surgery. Between 1983 and May 1994, 356 women over 60 years of age with Stage I or II breast cancer were treated by quadrantectomy and axillary dissection followed by either adjuvant irradiation or no radiotherapy. We have analysed our data retrospectively to investigate whether irradiation has any benefit in elderly patients with respect to locoregional recurrence rates. After a median follow-up of 60 months the multivariate model revealed lymph node status (p = 0.002) as highly significant with regard to local recurrence free survival. We were not able to identify a positive effect of adjuvant irradiation in patients with negative lymph nodes and positive receptor status: both patient groups with or without irradiation had similar locoregional recurrence rates of 3%. In a subgroup of patients who were lymph node negative, receptor positive, and received adjuvant tamoxifen therapy, the local recurrence rates were as low as 2% in both groups. Concerning these results it may be possible to avoid the morbidity and potential psychological side effects of radiotherapy in breast cancer patients over 60 years of age treated by breast conserving surgery (T1, N0, positive hormone receptor, adjuvant tamoxifen) without increasing risk of locoregional recurrence. These data have to be confirmed in a prospectively randomized fashion.