Prognostic Significance of Inner Quadrant Involvement in Breast Cancer Treated with Neoadjuvant Chemotherapy

PURPOSE In the present study, we aimed to evaluate the initial tumor location as a prognostic factor in breast cancer patients treated with neoadjuvant chemotherapy (NAC). METHODS Between March 2002 and January 2007, a total of 179 patients with stage II/III breast cancer underwent NAC followed by breast surgery. Using physical and radiologic findings, patients were grouped by their initial tumor location into inner/both quadrant (upper/lower inner quadrant involvement +/- multicentric tumor involving outer quadrant; n=97) and outer quadrant (n=82) tumor groups. All patients received neoadjuvant docetaxel/doxorubicin chemotherapy. One hundred two patients underwent modified radical mastectomy and 77 patients underwent breast-conserving surgery. Adjuvant radiotherapy (RT) and hormonal therapy were administered after surgery when indicated. While 156 patients underwent postoperative RT, 23 did not. The median follow-up duration was 61.1 (12-106) months. RESULTS The 5-year disease-free survival (DFS) and overall survival rates of all patients were 74.8% and 89.9%, respectively. Patients with inner/both quadrant tumors had lower 5-year DFS than those with outer quadrant tumors (67.7% vs. 83.4%, respectively; hazard ratio [HR]=1.941, p=0.034). A nodal ratio >25% was also an independent adverse prognostic factor for DFS (HR=3.276; p<0.001). There was no significant difference in DFS (p=0.592) after RT on the internal mammary node (IMN). Treatment failed in 44 out of 179 patients (24.6%), of which 27 patients had inner/both quadrant tumors. Twenty-one out of 27 patients had distant failures. CONCLUSION Among breast cancer patients treated with NAC, those with inner/both quadrant tumors had lower DFS than those with outer quadrant tumors. More aggressive neoadjuvant and/or adjuvant chemotherapy with IMN RT is required for improved disease control and long-term survival.