Dr Mamounas on Surgical De-Escalation Strategies in HER2+ Breast Cancers

Terry P. Mamounas, MD, medical director, Comprehensive Breast Program, University of Florida Health, Health Cancer Center at Orlando Health, discusses surgical de-escalation strategies in the treatment of patients with HER2-positive breast cancer.

The initial focus of surgical de-escalation strategies in this patient population revolved around de-escalating the primary tumor surgery by inducing a robust response to neoadjuvant chemotherapy, potentially shifting patients from needing mastectomy to being eligible for breast-conserving surgery, Mamounas begins. In some ongoing trials, investigators are exploring the possibility of omitting formal surgical resection, though this is not standard practice yet, he states. Notably, prospective trials are addressing this question by using imaging to identify a strong response to neoadjuvant chemotherapy in the breast, Mamounas says, adding that core biopsies of the tumor bed are employed to confirm the absence of residual disease. In cases without residual disease, there is consideration for avoiding surgery, although this is not the current standard, Mamounas expands. A recent study conducted out of The University of Texas MD Anderson Cancer Center demonstrated promising local control rates with this approach, showcasing its potential, especially as systemic therapy advances, he emphasizes.

In more recent years, another approach aims to de-escalate surgery for axillary nodes, Mamounas states. For patients with subclinically or clinically involved axilla, traditional surgical methods often involve more extensive procedures to determine whether lymph node dissection is necessary, he adds. However, by sterilizing the lymph nodes and ensuring residual disease negativity at the time of surgery, surgeons can perform a sentinel lymph node (SLN) biopsy alone, avoiding a comprehensive axillary dissection, Mamounas continues. This minimizes the risk of lymphedema and reduces axillary morbidity. Notably, investigators have improved false negative rates in SLN biopsy by employing techniques such as clipping nodes that were positive before neoadjuvant chemotherapy and removing them with the clip after treatment, he explains.

This approach has lowered SLN biopsy false negative rates to be comparable with those seen when conducting SLN biopsies in upfront settings, Mamounas says. The goal of this strategy is to decrease the morbidity associated with axillary surgery by adopting an equally effective yet less invasive approach, he concludes.