Early detection of breast cancer: benefits and risks of supplemental breast ultrasound in asymptomatic women with mammographically dense breast tissue. A systematic review

Abstract

BackgroundMammographic screening alone will miss a certain fraction of malignancies, as evidenced by retrospective reviews of mammograms following a subsequent screening. Mammographic breast density is a marker for increased breast cancer risk and is associated with a higher risk of interval breast cancer, i.e. cancer detected between screening tests. The purpose of this review is to estimate risks and benefits of supplemental breast ultrasound in women with negative mammographic screening with dense breast tissue.MethodsA systematic search and review of studies involving mammography and breast ultrasound for screening of breast cancer was conducted. The search was performed for the period 1/2000-8/2008 within the data source of PubMed, DARE, and Cochrane databases. Inclusion and exclusion criteria were determined prospectively, and the Oxford evidence classification system for diagnostic studies was used for evidence level. The parameters biopsy rate, positive predictive value (PPV) for biopsy, cancer yield for breast ultrasound alone, and carcinoma detection rate by breast density were extracted or constructed.ResultsThe systematic search identified no randomized controlled trials or systematic reviews, six cohort studies of intermediate level of evidence (3b) were found. Only two of the studies included adequate follow-up of subjects with negative or benign findings. Supplemental breast ultrasound after negative mammographic screening permitted diagnosis of primarily invasive carcinomas in 0.32% of women in breast density type categories 2-4 of the American College of Radiology (ACR); mean tumor size for those identified was 9.9 mm, 90% with negative lymph node status. Most detected cancers occurred in mammographically dense breast ACR types 3 and 4. Biopsy rates were in the range 2.3%-4.7%, with PPV of 8.4-13.7% for those biopsied due to positive ultrasound, or about one third of the PPV of biopsies due to mammography. Limitations: The study populations included wide age ranges, and the application to women age 50-69 years as proposed for mammographic screening could result in less striking benefit. Further validation studies should employ a uniform assessment system such as BI-RADS and report not only PPV, but also negative predictive value, sensitivity and specificity.ConclusionSupplemental breast ultrasound in the population of women with mammographically dense breast tissue (ACR 3 and 4) permits detection of small, otherwise occult, breast cancers. Potential adverse impacts for women in this intermediate risk group are associated with an increased biopsy rate.

Comparative sonographic review of benign and malignant breast masses

“…Repetition of breast ultrasound with high frequency transducers coupled with sound anatomic and pathologic knowledge will complement (other imaging modalities) in confirmatory declaration of masses as benign or malignant. This in agreement with Nothacker et al, [13] with a summarized cohort study on the role of ultrasound in the framework of malignant cancer screening. Our observations are parallel with Abe et al [14] in which not all breast masses were declared cancerous.…”

Interpretation of automated breast ultrasound (ABUS) with and without knowledge of mammography: a reader performance study

“…Screening with HHUS has found significantly more early-stage breast cancers (4)(5)(6)(7)(8)(9)(10). A limitation is that HHUS is time-consuming.…”

The TOMMY trial: a comparison of TOMosynthesis with digital MammographY in the UK NHS Breast Screening Programme – a multicentre retrospective reading study comparing the diagnostic performance of digital breast tomosynthesis and digital mammography with digital mammography alone

“…81 It has been suggested that population mammographic screening might be more effective if screening strategies were tailored according to mammographic breast density 79 with more frequent screening or use of magnetic resonance imaging (MRI) or adjunctive ultrasound to improve detection in women with dense breasts. 99,[116][117][118][119] In this context, a campaign to include breast density in mammography reporting is currently being debated in the USA. 120 Legislation has been passed in several states mandating that breast density be reported using the Breast Imaging Reporting and Data System (BI-RADS) scale, with women with > 50% breast density offered supplemental screening.…”