Treatment Outcomes for PET Positive Clinical N3 Breast Cancer Patients after Neoadjuvant Chemotherapy, Surgery, and Regional Lymph Nodes Radiotherapy

Abstract

Materials/Methods: Initially PET positive 55 patients with ipsilateral infraclavicular (ICL) or internal mammary (IMN) or supraclavicular lymph nodes (SCL) without distant metastases were retrospectively analyzed. The clinical nodal stage at diagnosis (2002 AJCC) was cN3a in 14 (25.5%), cN3b in 12 (21.8%) and cN3c in 29 (52.7%) of the patients. All patients were treated with curative intent NEO, mastectomy or breast-conserving surgery (BCS), and radiotherapy (RT). RT was comprised of 60.4 Gy to the ipsilateral breast or 50.4 Gy to chest wall combined with 45-50.4 Gy to SCL for all patients. Additional 5-20 Gy boost RT was done to PET involved SCL. RT coverage of PET involved IMN was performed at physician’s discretion. All hormone receptor-positive patients received hormonal therapy. Results: At a median follow-up of 38 months (range, 9-80 months), 20 patients (36.4%) had developed treatment failures. All treatment failures included distant metastases, among which one ipsilateral breast recurrence (IBR), six regional failures (RF) and one both IBR and RF were combined. Only 3 patients (7.2%) failed at initial PET positive cN3 lymph nodes. The 5-year locoregional relapse-free survival (LRRFS), disease-free survival (DFS), and overall survival rate was 80.1%, 59.6%, and 78.5%, respectively. Estrogen receptor-positive patients showed better 5-year DFS (79.7% vs. 47.4%, p = 0.05). Positive axillary nodes $ 10 after NEO was associated with worse 5-year DFS (69.4% vs. 38.5%, p = 0.009). The SCL dose . 55 Gy for cN3c patients did not affect 5-year SCL-relapse free survival and DFS, as did not those with RT coverage of IMN for cN3b patients (p . 0.05). Conclusions: RT including regional lymph nodes after NEO and surgery achieved excellent locoregional control for patients with PET positive cN3 breast cancer patients. Additional boost RT to PET positive SCL or coverage of PET positive IMN did not show the additional gain in LRRFS or DFS.