DALLAS--Fine-needle aspiration (FNA) breast biopsies in women with mammographically apparent, nonpal-pable breast lesions were deemed impractical due to the high rate of insufficient samples in a Radiologic Diagnostic Oncology Group (RDOG) study, and were stopped 19 months into the trial, Etta D. Pisano, MD, said at the American College of Radiology (ACR) National Conference on Breast Cancer.
The multicenter study has to date enrolled 5,000 women with specific mam-mographic abnormalities who would ordinarily have had an open biopsy procedure. The researchers expect to continue to enroll patients in the study for at least one more year.
The women were initially randomized into four biopsy groups, to undergo either stereotactically or sonographically guided core needle biopsy with or without FNA. Some institutions were not equipped to provide ultrasound-guided biopsies, and women at these centers were randomized to stereotactic FNA plus core or stereotactic core biopsy only.
Crossover was allowed if the lesion was inaccessible by the assigned system. "An example might be a cluster of calcifications that could not be seen by ultrasound or a lesion that was inaccessible by stereotactic biopsy by virtue of its location far back in the chest wall or close to the nipple," Dr. Pisano said.
Not a Report of Accuracy
Accuracy was determined by either open surgical biopsy or follow-up mammography at 6, 12, and 24 months. "This is not a report of the accuracy of either FNA or core needle biopsy," Dr. Pisano said, "only the insufficient sample rate seen with FNA."
A preliminary analysis of 398 women undergoing FNA across all institutions showed that 138 samples (35%) were insufficient, said Dr. Pisano, of the University of North Carolina School of Medicine. Sample insufficiency was determined by two expert cytopathologists who reviewed all FNA specimens: Dr. William J. Frable of Virginia Commonwealth University and Dr. Nour Sneige of the University of Texas M.D. Anderson Cancer Center.