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

Abstract

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/111 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.