A NEW study has highlighted the potential benefits of breast ultrasound as a supplemental screening tool for women with dense breast tissue, a group at higher risk of breast cancer. Despite its promise, the technology remains largely unavailable in Canada.
The study, conducted between August 2021 and December 2022, assessed the outcomes of ultrasound-guided breast biopsies in asymptomatic women with dense breast tissue (categories C and D). These women had undergone normal screening mammography through the provincial organised screening programme or surveillance diagnostic mammography following a breast cancer diagnosis. Researchers examined risk factors, cancer staging, biopsy rates, and positive predictive values for biopsy (PPV3) to determine the effectiveness of ultrasound screening.
Among the 5,257 women screened, 247 (aged 34-82, with a median age of 56) underwent biopsies for 281 detected masses. Of these, 32 were diagnosed with breast cancer, 27 of which were invasive, and five were cases of ductal carcinoma in situ (DCIS). The study found a PPV3 of 13.0% (32/247) and an incremental cancer detection rate (ICDR) of 6.1 per 1,000 screenings.
Most ductal cancers detected were in the early stages: 15.6% were stage 0, 56.3% were stage 1A, and 6.3% were stage 1B. Additionally, one ductal/lobular cancer was identified at stage 3B. Lobular cancers were also detected, with one at stage 1A, two at stage 1B, and two at stage 2B. A rare case of adenoid cystic carcinoma was found at stage 2A.
Significantly, 62.5% of cancers were detected in women with no personal or first-degree family history of breast cancer, while 84.4% were identified in category C density cases.
The findings suggest that supplemental ultrasound screening in women with dense breasts could enhance cancer detection rates, particularly where access to MRI and contrast mammography is limited. With an ICDR higher than in regions relying solely on annual screening mammography or MRI surveillance, the study underscores the need for wider availability of breast ultrasound in Canada to improve early detection efforts.
Reference
Gordon PB et al. Cancers Detected on Supplemental Breast Ultrasound in Women With Dense Breasts: Update From a Canadian Centre. SAGE. 2025;DOI:10.1177/08465371251318578.
