Identifying pathologic complete response of the breast after neoadjuvant systemic therapy with ultrasound guided biopsy to eventually omit surgery: Study design and feasibility of the MICRA trial (Minimally Invasive Complete Response Assessment). (August 2018)

• Record Type: Journal Article
• Authors: van der Noordaa, M.E.M.; van Duijnhoven, F.H.; Loo, C.E.; van Werkhoven, E.; van de Vijver, K.K.; Wiersma, T.; Winter-Warnars, H.A.O.; Sonke, G.S.; Vrancken Peeters, M.T.F.D.
• Is Part Of: Breast. Volume 40(2018)
• Page Start: 76
• Page End: 81
• Publication Date: 2018-08
• Subjects: Breast cancer -- Neoadjuvant systemic therapy -- Pathologic complete response -- Minimally invasive -- Response prediction; Breast -- Diseases -- Periodicals; Breast -- Tumors -- Periodicals; Breast -- Periodicals; Electronic journals; Periodicals; 616
• DOI: 10.1016/j.breast.2018.04.015
• Languages: English
• ISSNs: 0960-9776

Abstract

Abstract: Purpose: Improvements in neoadjuvant systemic therapy (NST) for breast cancer patients have led to increasing rates of pathologic complete response (pCR). The MICRA trial (NTR6120) aims at identifying pCR with post-NST biopsies. Here, we report the study design and feasibility. Methods: The MICRA-trial is a multi-center prospective cohort study. Patients with a pre-NST placed marker and radiologic complete (rCR) or partial response on MRI after NST are eligible for inclusion. Ultrasound guided biopsy of the original tumor area is performed. Pathology results of the biopsies and surgery specimens are compared. The primary endpoint is false-negative rate of biopsies in identifying pCR. Results: During the first year of the trial 58 patients with rCR were included. One patient was a screening failure and excluded for analysis. Twenty-one percent had hormone receptor (HR)+/HER2- tumors, 21% HR+/HER2+ tumors, 18% HR-/HER2+ tumors and 40% TN tumors. Overall pCR was 68%. In seven patients biopsies could not be obtained: in 6 patients, the marker could not be identified on ultrasound in the OR and in 1 patient there were technical difficulties. A median of eight biopsies was obtained (range 4–9). The median of histopathological representative biopsies was 4 (range 1–8). Conclusion: Ultrasound guided biopsy of the breast in patients with excellent response on MRI after NST is feasible. Accuracy results of the MICRA trial will be presented after inclusion of 525 patients to determine if ultrasound guided biopsy is an accurate alternative to surgical resection for assessment of pCR after NST. Highlights: PCR rates after NST in breast cancer patients are increasing. High pCR rates enable de-escalation of local treatment. Imaging methods are not sufficiently accurate to identify pCR to replace surgery. The MICRA trial investigates the value of biopsies of the breast in identifying pCR. If biopsies accurately identify pCR, breast surgery could be omitted in patients with pCR.