Incidence and time of occurrence of regional recurrence in stage I-II breast cancer: Value of adjuvant irradiation

Purpose: The value of adjuvant radiation therapy (RT) of the axilla and sup raclavicular fossa is controversial in early-stage breast cancer. This retr ospective study was undertaken to identify pathological risk factors that w ould predict which subsets of patients would benefit from regional nodal ir radiation (RNI), Methods and Materials: A total of 1309 women with Stage VII breast cancer u nder,vent full axillary dissection and either mastectomy (n = 894) or breas t-conserving surgery (n = 415), Of these, 712 patients received RNI, The me dian axilla/supraclavicular fossa dose was 50 Gy, Results: The 10-year actuarial rate of axillary failure (AXF) was 0.5% in N 0 and 2.8% in N1 patients (p 0.0014), The number of retrieved nodes, less t han or equal to 5 vs. > 5, also correlated with AXF; the respective rate wa s 4.3% vs. 1.2% (p = 0.0142), Neither the incidence of,AXF nor the time to AXF was affected significantly by the use of RNI, but in N1 patients with r etrieved nodes I 5, the rate of AXF was 8.3% without RNI vs. 0% with RNI (p = 0.2340), The 10-year actuarial rate of supraclavicular failure (SCF) was 1.2% in N0 and 6.3% in N1 patients (p ;0.0000), SCF was also associated wi th the extent of nodal involvement (p = 0.0031), The incidence of SCF was n ot significantly affected by the use of RNI, However, when the results of N 1bii and N1biv patients were evaluated as a single group, the effect of RNI was significant (p = 0.0358), The rates of SCF without RNI were high in pa tients with N1bii or N1biv stage: 10% and 37.5% and, with RNI, 3.2% and 18. 2%, respectively, These findings were reinforced by the various combination s of T- and N1-stage, The mean time to SCF was 53.6 months in the irradiate d and 24.9 months in the nonirradiated patients (p = 0.0007). Conclusions: After a complete axillary dissection, only N1 patients with re trieved nodes less than or equal to 5 may be considered for axillary RT, El ective supraclavicular RT is suggested for patients with N1bii or N1biv sta ge. Supraclavicular irradiation decreases the incidence and delays the appe arance of SCF. (C) 1999 Elsevier Science Inc.