Optimal Selection of Breast Cancer Patients for Elimination of Surgery Following Neoadjuvant Systemic Therapy

Innovative Standards in Surgery of the Breast after Neoadjuvant Systemic Therapy

BACKGROUND

The goal of neoadjuvant systemic therapy (NST) in breast cancer is to downstage tumors and downgrade treatment. Indications are constantly evolving. These changes raise practical questions for planning of surgery after NST.

SUMMARY

In this review we discuss current evolving aspects of surgery of the breast after NST. Breast-conserving surgery (BCS) eligibility increases after NST - both neoadjuvant chemotherapy (NAC) and neoadjuvant endocrine therapy. Adequate margin width in NST and upfront surgery are similar - "no tumor on ink" for invasive cancer. Oncoplastic breast surgery after NST is feasible - both for BCS and mastectomy with reconstruction. There is increasing interest in the possibility of omitting surgery in patients with a complete response to NAC. Several trials are being conducted in aim of achieving acceptable prediction of pathological complete response, by combination of imaging and percutaneous biopsy of the tumor bed, as well as assessing the safety of such an approach.

KEY MESSAGES

Surgery of the breast after NST should be determined not only according to biologic and anatomic parameters at diagnosis, but is dynamic, and must be tailored according to the response to therapy. The omission of surgery in exceptional responders after NAC is being explored.

Leveraging the increased rates of pathologic complete response after neoadjuvant treatment in breast cancer to de-escalate surgical treatments

INTRODUCTION

Breast conservative surgery (BCS) and sentinel lymph node biopsy (SLNB) after neoadjuvant treatment (NAT) is safe and effective for selected patients. This aim of this study is to evaluate the impact of anatomic site of response on outcomes and to assess the real population who may benefit from nonsurgical approaches after NAT.

MATERIAL AND METHODS

From a prospectively maintained database, patients with T1-4 N0-2 breast cancer undergoing NAT were identified. Clinicopathological and survival rates were compared in relation to response and anatomic site of response.

RESULTS

Six hundred and forty-six patients were included in the study. Pathologic complete response (pCR) was an independent factor for BCS and SLN. HER2 positive and TN tumors with cN0 achieving a breast pCR remain ypN0 (p = .002). Residual axillary disease was associated with breast residual tumor (p = .05) and subtype (p = .001). With a median follow up of 35.25 months, patients with any pCR had improved survival when compared with partial response, but not significant differences between pCR, axillary pCR, or breast pCR.

CONCLUSION

Achieving a pCR increases BCS and SLN. In selected subgroups, sparing any axillary surgery after NAT maybe feasible. In cN+ patients, any pCR was associated with survival, but not the anatomic site of response.

Disease-Free and Overall Survival Among Patients With Operable HER2-Positive Breast Cancer Treated With Sequential vs Concurrent Chemotherapy: The ACOSOG Z1041 (Alliance) Randomized Clinical Trial

Importance

Pathologic complete response rate (pCR), the primary end point of the ACOSOG (American College of Surgeons Oncology Group) Z1041 (Alliance) trial, and disease-free survival (DFS) and overall survival (OS) in women with operable HER2-positive breast cancer are similar between treatment regimens.

Objective

To assess DFS and OS for patients treated with sequential vs concurrent anthracycline plus trastuzumab.

Design, Setting, and Participants

Phase 3 randomized clinical trial conducted at 36 centers in the continental United States and Puerto Rico. Women 18 years or older with invasive operable HER2-positive breast cancer were enrolled from September 15, 2007, to December 15, 2011, and randomized to 1 of 2 treatment arms. The analysis data set was locked on October 15, 2017, and analysis was completed on December 15, 2017.

Interventions

Patients randomized to arm 1 received 500 mg/m2 of fluorouracil, 75 mg/m2 of epirubicin, and 500 mg/m2 of cyclophosphamide (FEC) every 3 weeks for 12 weeks followed by the combination of 80 mg/m2 of paclitaxel and 2 mg/kg (except initial dose of 4 mg/kg) of trastuzumab weekly for 12 weeks. Patients randomized to arm 2 received the same combination of paclitaxel with trastuzumab weekly for 12 weeks followed by FEC every 3 weeks with weekly trastuzumab for 12 weeks. Women with hormone receptor-positive disease received endocrine therapy, and radiotherapy was delivered at physician discretion.

Main Outcomes and Measures

The primary outcomes were DFS and OS and pCR in the breast and nodes.

Results

Two hundred eighty-two women with HER2-positive breast cancer were enrolled in the trial, and 2 withdrew consent before treatment. Among the remaining 280 women, the median age was 50 years (range, 28-76 years), 232 (82.9%) were white, 29 (10.3%) were black, 8 (2.9%) were Asian, 4 (1.4%) were American Indian or Alaskan Native, and 7 (2.5%) did not report race/ethnicity. There were 22 disease events in arm 1 and 27 in arm 2. Disease-free survival rates did not differ with respect to treatment arm (stratified log-rank P = .96; stratified hazard ratio [HR] [arm 2 to arm 1], 1.02; 95% CI, 0.56-1.83). Overall survival did not differ with respect to treatment arm (stratified log-rank P = .73; stratified HR [arm 2 to arm 1], 1.17; 95% CI, 0.48-2.88).

Conclusions and Relevance

Across a median follow-up of 5.1 years (range, 26 days to 6.2 years), pCR, DFS, and OS did not differ with respect to sequential or concurrent administration of FEC with trastuzumab.

Trial Registration

ClinicalTrials.gov identifier: NCT00513292.