LONDON (Reuters Health) – The accuracy of core-cut biopsies in determining breast cancer grade increases as the number of needle passes increases, but at four passes it begins to plateau, according to a report published in the January issue of the British Journal of Surgery.
Dr. C. McIlhenny and colleagues, from the Western Infirmary in Glasgow, UK, performed core-cut biopsies on 20 mastectomy specimens from patients undergoing breast cancer surgery. Of the 200 cores performed, 15 showed no discernible histologic features and were considered inadequate.
In terms of providing a histologic diagnosis, two or more needle passes achieved an accuracy of 95%. Furthermore, the diagnostic accuracy was directly related to the tumor size, the investigators note.
In contrast, the accuracy in predicting tumor grade continued to increase until four samples were obtained. Four passes were 74% accurate in predicting tumor grade.
"Accurate grading on preoperative core biopsies is necessary to establish the true grade of the tumor in patients given neoadjuvant chemotherapy," the researchers state. Based on the current findings, they recommend that "at least four core biopsies are taken in the breast clinic."