US trumps mammo for eval of symptomatic women in 30s

The American College of Radiology (ACR) should revise its Appropriateness Criteria and recommend ultrasound as the primary imaging modality for diagnostic evaluation of women between 30 and 39 years of age who present with focal signs and symptoms of breast cancer, according to a study published Oct. 22 in American Journal of Roentgenology.

Currently, protocols for evaluation of women ages 30 to 39 who present with localized areas of concern differ in the U.S. and Europe. European guidelines recommend ultrasound as the primary modality in women under 40 years of age. In contrast, ACR guidelines recommend mammography as the primary diagnostic modality for women ages 30 years and older, and reserve ultrasound for women younger than 30. However, the recommendations are based on sparse data.

“Despite the widely accepted practice of ultrasound as an important imaging modality for focal breast concerns in women 30-39 years of age, there have been few studies validating this practice,” wrote Constance D. Lehman, MD, PhD, from the department of radiology at University of Washington School of Medicine in Seattle, and colleagues.

Given recent improvements in ultrasound imaging and variations in practice and guidelines, Lehman and colleagues sought to evaluate the accuracy and value of ultrasound for primary evaluation of women ages 30 to 39 who present with signs or symptoms of breast cancer.

Lehman and colleagues identified all women between the ages of 30 and 39 who underwent ultrasound and mammography between Jan. 1, 2002, and Aug. 31, 2006, for focal signs or symptoms. The cohort included 1,208 cases in 954 patients.

Most cases were assessed as negative or benign, according to Lehman et al. A total of 708 cases were assessed as BI-RADS category 1, and none were malignant with two-year follow-up. One of the 286 BI-RADS category 2 cases was found to be infiltrating ductal carcinoma at surgical excision.  

A total of 64 lesions were assessed as BI-RADS category 3. Tumor registry follow-up showed no breast cancer diagnoses among this group.

Lehman and colleagues reported that 139 cases were categorized as BI-RADS category 4, and of the 135 that were biopsied, 12 were malignant. Ultrasound identified all 12 malignancies. In contrast, mammography detected six of the 12 malignancies.

Eleven cases were assessed as BI-RADS category 5, and 10 of these were malignant. Ultrasound detected the 10 malignancies, while mammography detected two of the 10 malignancies.

Ultrasound provided a sensitivity of 95.7 percent and negative predictive value (NPV) of 99.9 percent, outperforming mammography, which delivered a sensitivity of 60.9 percent and NPV of 99.2 percent. “The high sensitivity and NPV of ultrasound validate its use as an accurate diagnostic tool in younger women,” wrote the researchers.

In addition, Lehman and colleagues emphasized that the lower sensitivity of mammography suggests it offers minimal diagnostic value among this population.

“Overall, our findings in women 30-39 years of age of a high likelihood of negative or benign cause combined with a low malignancy rate and low sensitivity of mammography compared with ultrasound suggest that the current recommendations for mammography in this patient population should be reconsidered,” concluded Lehman et al.

The researchers added that the use of ultrasound as a primary diagnostic tool obviates tissue biopsy and imaging follow-up, which can reduce downstream costs and patient morbidity.