ABSTRACT
Objective To analyze the incidence and risk factors for regional nodal failure(RNF) and chest wall recurrence(CWR) in T1 or T2 breast cancer patients(median age 44 year-range 26-72) with 1-3 positive axillary nodes treated with postmastectomy radiotherapy limited to the regional nodes.Methods From 1990 to 1999,320 patients were treated with postmastectomy(radical or modified radical) radiother- apy confined to the supraclavicular and internal mammary nodes with a median dose of 50 Gy in 25 fractions over 5 weeks.The median number of nodes examined was 8 (range 1-24).The median lymph nods rate (LNR) was 25% (range 5%-100%).Results The 5-year overall survival rate and disease free survival rate was 89.7% and 83.4%,respectively.The 5-year RNF and CWR was 7.9% and 5.7%,respectively. The 5-year RNF in patients with LNR＜30% and≥30% was 4.4% and 14.0% (P=0.002).The 5-year CWR in the subgroups with LNR＜30% and≥30% was 3.5% and 9.6% (P=0.018).In age≤35 year eld patients with LNR≥30%,the 5-year RNF and CWR was 40.0% and 20.0%.In T2 patients with LNR≥30%,the 5-year RNF and CWR was 15.8% and 12.2%.Age and LNR were independent prognostic factors for RNF+CWR,LNR was the only independent prognostic factor for CWR by multivariate analysis. Conclusions In T1 or T2 breast cancer patients with 1-3 positive axiliary nodes treated with radical or modified radical mastectomy,a relatively high incidence of chest wall recurrence is observed in the subgroup of patients with lymph nods rate of 30% or greater accompanied by a T2 primary tumor or age≤35 years old. Lymph nodes rate is the only significant prognostic factor of chest wall recurrence.For these patients,post- operative lymphatic drainage area and chest wall irradiation should be considered.