Although use of preoperative chemotherapy for breast cancer is increasing, resultant changes in breast architecture have not been described. The purpose of this study was to examine breast architecture changes in response to chemotherapy by the placement of 4 peripheral clips.

In a prospective case-series of breast cancer patients selected to undergo preoperative chemotherapy, 4 clips were placed peripherally to each mass using sonographic guidance. Mammograms documented tumor size and clip locations both before chemotherapy and after chemotherapy. Percentage reduction in area was calculated based on the tumor dimensions and distances between clips.

In 16 participants, 87.5% of lesions had a significant response to chemotherapy. Changes in clip measurements varied widely from significant reduction to significant increase and did not correlate with changes in tumor size. The Pearson correlation coefficient comparing changes in tumor size and clip measurements was .036 (P = .895).

There was no correlation between reduction in tumor size and change in clip measurements. Further research should be conducted using noncompression breast imaging modalities to eliminate possible distortion caused by mammographic compression.