Corso G, et al. - This monocentric retrospective investigation was carried out to evaluate the factors that create risk for developing ipsilateral breast tumor reappearance (IBTR) and de novo contralateral breast cancer (BC) after primary BC treatment. Compared with low-risk group, for which adjuvant treatments seemed more beneficial, breast surgery continued to be more important in the high-risk group.

Methods

• From June 1994 to December 2006, retrospective enrollment of 15,168 consecutive patients with primary monolateral BC was carried out.
• Statistical analysis was performed on clinicopathological features, follow-up, and survival at 15 years.

Results

• The following factors showed significant associations with increased risk for IBTR: metastatic axillary lymph nodes (HR 1.37 [1.15–1.62], p=0.0004), high tumor grade G2 (HR 1.35 [1.05–1.74], p=0.02) and G3 (HR 1.35 [1.01–1.79], p=0.04), luminal B (HR 1.51 [1.25–1.82],p < 0.0001), and HER2-positive (HR1.66 [1.14–2.41], p=0.008) and triple-negative subtype (HR 1.54 [1.07–2.21], p=0.02).
• The identified risk factors for contralateral BC included older age (HR 1.44 [1.08–1.91], p=0.01) and positive family history (HR 1.85 [1.47–2.32], p < 0.0001).
• Hormonotherapy (HR 0.71 [0.59–0.85], p=0.0003), chemotherapy (HR 0.72 [0.60–0.87], p=0.001), and radiotherapy (HR 0.73 [0.61–0.87], p=0.0005) were identified as significant protective factors for IBTR.
• Findings corroborated hormonotherapy as a protective factor for contralateral second BC (HR 0.43 [0.30–0.60], p < 0.0001).