Mammographic bi-dimensional product: a powerful predictor of successful excision of ductal carcinoma in situ

BACKGROUND: The aim of this analysis was to ascertain whether uni-dimensional measurement of mammographic microcalcification, the product of bi-dimensional measurement, calcification morphology, and pathological grade are helpful in predicting successful single therapeutic wide local excision (WLE) of ductal carcinoma in situ (DCIS). METHODS: The study group comprised 505 patients whose mammograms showed the DCIS as calcification, and in whom a non-operative diagnosis had been obtained and WLE attempted. The extents of mammographic calcifications was measured in two planes at 90 degrees on the oblique view, the appearances classified as comedo, granular, or punctate. DCIS was graded using cyto-nuclear characteristics. RESULTS: Three hundred and forty-two patients had a successful first WLE and 163 patients had further surgery. A uni-dimensional measurement of <35 mm and a bi-dimensional product of <800 mm(2) were associated with successful excision (69 versus 54%, p=0.02 and 70 versus 27%, p=0.0001, respectively). Mammographic calcification morphology and histological grade did not influence the likelihood of a successful first WLE. For high-grade DCIS, the upper limit of the bi-dimensional product associated with successful WLE was 800 mm(2) (69 versus 24%, p=0.0003). In contrast, for non-high-grade DCIS, the cut-off was 400 mm(2) (73 versus 33%, p=0.01). Analyses based on mammographic calcification morphology gave similar findings. CONCLUSION: The mammographic bi-dimensional product is a powerful predictor of successful WLE of DCIS when combined with histological grade and/or calcification morphology.