Tomosynthesis ‘A Likely Advance’ for Digital Mammography

Tomosynthesis reduces digital mammography screening recall while increasing tumour detection

medwireNews: The addition of tomosynthesis to digital mammography may help improve the benefit-to-harm ratio for women undergoing breast cancer screening, suggests research published in JAMA.

The study indicates that tomosynthesis - an image reconstruction technique to increase the visibility of malignant tissue - significantly boosted breast cancer detection while reducing the likelihood of patient recall for invasive testing.

“[T]he association of implementation of tomosynthesis with simultaneous improvement in both of these fundamental metrics of breast cancer screening indicates a potential advantage of incorporation into screening”, write lead author Sarah Friedewald, from Advocate Lutheran General Hospital in Park Ridge, Illinois, USA, and team.

The researchers compared data for 281,197 digital mammograms conducted at 13 breast centres before the introduction of tomosynthesis and 173,663 digital mammograms conducted after the technique was incorporated.

The model-adjusted rate of recall per 1000 patients screened was 107 for digital mammography versus 91 for digital mammography plus tomosynthesis, a significant 16-screen difference in favour of tomosynthesis.

The adjusted rate of biopsy was 18.1 and 19.3 per 1000 patients screened, respectively, representing an increased likelihood of biopsy with tomosynthesis.

However, the cancer detection rate was also higher with the extra technique, with rates per 1000 screens for digital mammography and mammography plus tomosynthesis of 4.2 versus 5.4 for any cancer and 2.9 versus 4.1 for invasive cancer, respectively.

Moreover, including tomosynthesis significantly increased the positive predictive value for recall from 4.3% to 6.4%, and the positive predictive value for biopsy from 24.2% to 29.2%, report Sarah Friedewald et al.

Etta Pisano, from the Medical University of South Carolina in Charleston, USA, and Martin Yaffe, from the University of Toronto in Ontario, Canada, agree in an accompanying editorial that “tomosynthesis is likely an advance over digital mammography for breast cancer screening”.

Nevertheless, they caution that there is no clear consensus concerning the optimal breast cancer screening strategy with regard to available technologies, timing of screening and management of screen-detected tumours.

“Only an appropriately powered multisite clinical trial of modern technology can answer the remaining questions definitively”, the editorialists write.

“The time is now for the National Institutes of Health to fund such a much-needed trial to address many of the remaining issues about breast cancer screening.”

References

Friedewald S, Rafferty E, Rose S, et al. Breast cancer screening using tomosynthesis in combination with digital mammography. JAMA 2014; 311(24): 2499–2507. doi:10.1001/jama.2014.6095

Pisano E, Yaffe M. Breast cancer screening. Should tomosynethsis replace digital mammography? JAMA2014; 311(24): 2488–2489. doi:10.1001/jama.2014.6421

medwireNews (www.medwireNews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2014