Impact of Trastuzumab on Ipsilateral Breast Tumor Recurrence for Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer after Breast-Conserving Surgery

Abstract

Purpose Trastuzumab is effective in early and advanced human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, few studies have reported the effect of trastuzumab on ipsilateral breast tumor recurrence (IBTR), whose incidence is higher in the HER2-positive subtype than in other subtypes. Methods We retrospectively investigated 959 patients who underwent breast-conserving surgery (BCS), chemotherapy, and radiotherapy for HER2-positive breast cancer between 2000 and 2017. IBTR was compared between the patients who received neoadjuvant or adjuvant trastuzumab (Tmab group) for a total duration of 1 year and those who received no trastuzumab (N-Tmab group). Results Propensity score matching designated 426 and 142 patients in the Tmab and N-Tmab groups, respectively. The median follow-up period for all patients after matching was 73.79 months. The IBTR-free survival rate was significantly higher in the Tmab group than in the N-Tmab group (10-year IBTR-free survival rate, 92.9% vs. 87.3%; p = 0.002). The multivariate analysis showed a significant association between the N-Tmab and Tmab group (hazard ratio, 3.03; 95% confidence interval, 1.07–8.59) and IBTR in addition to close or positive resection margin and hormone receptor (HR) positivity. The subgroup analysis showed that adjuvant treatment with trastuzumab significantly reduced IBTR among the patients with HR-negative or lymph node-negative breast cancer. Conclusion Significantly reduced IBTR after BCS was observed in the patients who received 1 year of adjuvant/neoadjuvant trastuzumab treatment for HER2-positive breast cancer.

Survival outcomes of breast cancer patients with recurrence after surgery according to period and subtype

“…Targeted therapy after recurrence was a treatment-related factor that improved survival in HER2-positive patients. This supports the results of previous studies that the development of trastuzumab made a significant difference in the improvement of the survival rate of relapsed breast cancer patients after surgery [20].…”

Updates and Debate Concerning Margin Adequacy and Management following Breast-Conserving Surgery

“…Adjuvant treatments were introduced in the context of a multidisciplinary and personalized management of breast cancer. They were essential to omit a second intervention in some carefully selected cases while obtaining conservative management and an adequate oncological outcome [68,69].…”

“…Finally, the local recurrence rate is inevitably influenced by adjuvant therapies. For example, a significant reduction in the ipsilateral breast recurrence rate after BCS in patients affected by HER2-positive breast cancer has been observed following the administration of 1-year adjuvant/neoadjuvant trastuzumab treatment [68]. Nonetheless, it is important to underscore the issue of elderly patients who should receive the same therapies of younger ones, if their general health status allows it; in the context of multidisciplinary management, it is vital to prevent their risk of local recurrence [69].…”

Neoadjuvant Trastuzumab-Based Chemotherapy and Pathologic Complete Response in HER2-Positive Breast Cancer; A Systematic Review

“…Trastuzumab signi cantly reduces the rate of residual tumors isolated after 48 hours of the rst breast conservation surgery. [28,29] Drainage uid obtained from wounds and serum samples after surgery provides a medium to HER2-positive breast cancer tumor cells, encouraging its in-vitro growth. But, when trastuzumab is added as a chemotherapeutic agent, the in-vitro proliferation of cancer cells is inhibited before adding drainage uid.…”