Background: Until 1993 postmenopausal women with breast cancer did not receive adjuvant chemotherapy in our institution even if axillary nodes were involved. So in these patients axillary dissection had no diagnostic value for further treatment. Therefore we started a prospective study in which dissection of axillary nodes was replaced by irradiation in postmenopausal cN0 patients.
Patients and methods: From 1986 to 1993 we irradiated 655 patients with breast cancer after breast conserving surgery (BET). In all 144 cN1- and all 209 premenopausal cN0-patients axillary dissection was recommended. Of 302 postmenopausal cN0 patients 129 had breast surgery in our institution. In a total of 129 patients axillary dissection was replaced by irradiation (AxRT-group). They were compared with all 173 patients referred from other hospitals for irradiation after both breast conserving surgery and axillary dissection (AxOP-group). Dissected patients with gross tumor involvement of the axilla or less than eight nodes removed had additional axillary irradiation. Patients age, tumor size, vessel-, muscle- or skin invasion and grading were similar in both groups (Table 1). However, in the AxRT-group there were more patients with negative hormone receptors, multifocal and medial sited tumors. Late complications after dissection and/or irradiation of the axilla were evaluated in 502 patients free of locoregional relapse and with a minimal follow up of 3 years (median 9.5 years).
Results: After 5, 10 and 15 years tumor free survival rates were 90%, 82% and 79% in the AxOP-group vs 91%, 82% and 80% in the AxRT-group, respectively (p = 0.95) (Figure 1). Overall survival (p = 0.98) (Figure 2), local (p = 0.47) and axillary control (p = 0.12) were equal in both groups (Figures 3 and 4). However, serious problems like lymphedema of the arm, pain, mobility impairment occurred in 26% patients following axillary dissection but only in 1% after axillary irradiation. No difference in late sequelae after axillary dissection with or without irradiation could be detected (26 vs 27%) (Table 2).
Conclusion: In postmenopausal cN0-patients axillary dissection should be replaced by axillary irradiation, since it offers the same chance for cure with much lower morbidity.