A Clinical Feasibility Trial for Identification of Exceptional Responders in Whom Breast Cancer Surgery Can Be Eliminated Following Neoadjuvant Systemic Therapy

Abstract

Objective: To determine the accuracy of fine-needle aspiration (FNA) and vacuum-assisted core biopsy (VACB) in assessing the presence of residual cancer in the breast after neoadjuvant systemic therapy (NST).

Summary background data: Pathologic complete response (pCR) rates after NST have improved dramatically, suggesting that surgery might be avoided in some patients. Safe avoidance of surgery would require accurate confirmation of no residual invasive/in situ carcinoma.

Methods: Forty patients with T1-3N0-3 triple-negative or HER2-positive cancer receiving NST were enrolled in this single-center prospective trial. Patients underwent ultrasound-guided or mammography-guided FNA and VACB of the initial breast tumor region before surgery. Findings were compared with findings on pathologic evaluation of surgical specimens to determine the performance of biopsy in predicting residual breast disease after NST.

Results: Median initial clinical tumor size was 3.3 cm (range, 1.2-7.0 cm); 16 patients (40%) had biopsy-proven nodal metastases. After NST, median clinical tumor size was 1.1 cm (range, 0-4.2 cm). Nineteen patients (47.5%) had a breast pCR and were concordant with pathologic nodal status in 97.5%. Combined FNA/VACB demonstrated an accuracy of 98% (95% CI, 87%-100%), false-negative rate of 5% (95% CI, 0%-24%), and negative predictive value of 95% (95% CI, 75%-100%) in predicting residual breast cancer. VACB alone was more accurate than FNA alone (P = 0.011).

Conclusions: After NST, image-guided FNA/VACB can accurately identify patients with a breast pCR. Based on these results, a prospective clinical trial has commenced in which breast surgery is omitted in patients with a breast pCR after NST according to image-guided biopsy.

FIGURE 1

A 44-year-old woman with a palpable triple-negative invasive ductal carcinoma who was enrolled in and completed the study. (A) Craniocaudal and (B) lateromedial left mammograms at diagnosis show a 4.6-cm irregular high-density mass (white arrows) with a ribbon-shaped clip (dashed arrow). C, Corresponding longitudinal gray-scale ultrasound image shows a 4.9-cm hypoechoic lobular mass (arrow). D, Ultrasound image after the completion of NST shows a flattened tumor bed (arrow) with a clip (dashed arrow). Stereotactic biopsy was performed with the removal of the clip. (E) Craniocaudal and (F) lateromedial left mammograms after biopsy demonstrate residual focal asymmetry with a new rod-shaped clip (arrow) at the biopsy site. Specimen radiographs (G) of the core biopsy specimens confirm the removal of the ribbon-shaped clip (dashed arrow). Pathologic evaluation of the core biopsy specimens showed no evidence of residual carcinoma. H, Specimen radiographs from needle-localized segmental mastectomy confirm the removal of the residual focal asymmetry and the clip (arrow). Pathological evaluation of the breast surgical specimen confirmed pCR.