Currently, up to 40 percent of patients undergoing breast-conserving surgery to treat cancer require re-operation because of a failure to remove all of the cancerous tissue during the initial operation. Brigham and Women’s Hospital (BWH) researchers, however, have successfully tested an innovative tissue imaging approach that accurately distinguishes cancerous breast tissue from normal breast tissue and precisely defines the margins between the two – an advance that could significantly decrease the need for follow-up surgery.
The tool the researchers used for their study is called desorption electrospray ionization (DESI) mass spectrometry imaging, a technology that allows physicians and researchers to promptly evaluate human tissue. It works by electrically charging (ionizing) molecules in a tissue sample through the application of a microscopic stream of solvent. The mass of these ionized molecules is then measured and their distribution within the tissue is mapped.
This technique is particularly well-suited for characterizing fatty acids (lipids) within breast tissue samples, and the researchers found that several fatty acids, such as oleic acid, were more abundant in cancerous breast tissue as compared to normal tissue. Thus, by focusing on the evaluation of these fatty acid molecules, the researchers were able to reliably discriminate between cancerous tissue and healthy tissue. They also were able to do it quickly, the other significant advantage to this approach.
“Our findings demonstrate the feasibility of classifying cancerous and normal breast tissues by using DESI mass spectrometry imaging,” says Nathalie Agar, PhD, Director of the BWH Surgical Molecular Imaging Laboratory and the study’s senior author. “The results may help us to move forward in improving this method so that surgeons can use it to rapidly detect residual cancer tissue during breast cancer surgery, hopefully decreasing the need for multiple operations.”
While her team works on further validating their findings, Dr. Mehra Golshan, Director of Breast Surgical Services at Dana-Farber/Brigham and Women’s Cancer Center and co-author of the study, is eager to continue collaborating with Agar to start the next phase of research – clinically testing the new diagnostic approach in the Advanced Multimodality Image Guided Operating (AMIGO) suite. Designed to improve the precision of surgery through the use of imaging, the AMIGO suite has proven to be an ideal setting for testing and refining such advanced, intra-operative (during surgery) imaging techniques.
During this second phase, Dr. Golshan’s surgical team will test the effectiveness of using mass spectrometry to evaluate breast tissue during surgery, and the results will be compared to those of a final pathology report (the current gold standard). If testing is successful, as a similar use recently was for brain tumor removal, this new technique could become the next significant advance in care for patients with breast cancer – potentially saving tens of thousands of women from returning to the operating room.
The study was published in the online edition of Proceedings of the National Academy of Sciences.