US-Guided FNA Cost-Effective Diagnostic Tool for Finding Nonpalpable Breast Lesions

NEW ORLEANS—In selected patients with radiographically identified nonpalpable breast abnormalities, ultrasound-guided fine-needle aspiration (FNA) with follow-up mammograms is effective and offers a cost savings over stereotactic mammotomy (directional vacuum-assisted breast biopsy). S.S. Buchbinder, MD, of the Department of Radiology, Albert Einstein College of Medicine, New York, reported the results at the American Roentgen Ray Society annual meeting.

The study included 228 lesions from 198 consecutive patients with nonpal-pable abnormalities identified by mammography and ultrasound. Women had to have undergone excisional biopsy or have at least 6 months of follow-up with mammography to be included in the study. Women with clustered microcalcifications were excluded.

A cytopathologist was immediately available to prepare slides and assess the adequacy of the specimen. After discussion of the findings, the information was often given immediately to the patient.

Of the 122 cases available for analysis, 88 (72%) were considered to be benign. These women were not subjected to further surgical procedures, but have had mammographic follow-up for an average of 15 months. In one case, the lesion grew in size and was found on excisional biopsy to be malignant. Dr. Buchbinder said that the sensitivity of ultrasound-guided fine-needle aspiration for a final benign diagnosis was, therefore, 99%.

The accuracy for a positive malignant diagnosis was 100%: All 11 women with malignancy on fine-needle aspiration were found to have invasive disease at definitive surgery. Overall sensitivity was 92%. “If these two groups of women are considered together,” Dr. Buchbinder said, “more than 80% of the women in this study would have been spared unnecessary invasive procedures.”

A group of 23 women were considered to have atypical findings. Dr. Buchbinder said that atypical cytopathology is distinctly different from a histopathologic diagnosis of epithelial hyperplasia with atypia. Cytologic evaluation identifies predominantly noncohesive single cells as being atypical, although cells with large nuclei that exhibit pleomorphism and complex cell arrangements would also fall into this category.

In 4 of the 23 cases, the women chose careful mammographic follow-up despite the recommendation for surgery; no malignant changes have been detected at a mean follow-up of 20.7 months. The other 19 women were referred for surgery, and 3 malignancies were detected. Thus, Dr. Buchbinder recommends immediate surgical follow-up for women with atypical cytology on aspiration. He emphasized that this was a small proportion of the entire study population.

A cost-benefit analysis was conducted using 1998 Medicare reimbursement for the Bronx, New York. Cost for routine stereotactic Mammotome biopsy would have been $685.72, or $83,657.84 for the population of 122 patients, excluding any follow-up. Since the researchers wanted to give the most conservative cost estimate, Dr. Buchbinder said, they made the assumption that no additional procedures would be needed, even though the literature suggests that is not the case.

For the 88 women with benign findings, the cost was $288.10—$210.46 for the ultrasound-guided fine-needle aspiration and $77.64 for one unilateral follow-up mammogram. The single case that changed on follow-up cost $454.55, with an additional $166.45 for the needle localization.

For the 11 women with malignancies and the 19 women with atypical findings who underwent surgery, the cost was $376.91—$210.46 for the aspiration and $166.45 for the subsequent needle localization. Thus, the total charges for the fine-needle aspiration population were $37,281.10, a cost savings of 45% compared with mammotomy, he said.

In addition to cost savings, he said, “the emotional savings, physical savings, and scarring savings should be considered equally important.”