Interobserver agreement in breast radiological density attribution according to BI-RADS quantitative classification.

PURPOSE: The authors sought to assess interobserver agreement in classifying mammography density according to quantitative Breast Imaging Reporting and Data System (BI-RADS) criteria. MATERIALS AND METHODS: Six expert mammography readers were tested on a set of 100 mammograms. Interobserver agreement was determined according to the kappa statistic, adjusting for chance agreement, on a four-category (D1 vs. D2 vs. D3 vs. D4) or two-category (D1-2 vs. D3-4) basis. Agreement with a panel of 12 readers who had been tested on the same set in a previous study was also assessed. RESULTS: The six readers showed good agreement when compared in pairs [agreement on a four-category basis was substantial (kappa=0.60-0.80) for 13 pairs and almost perfect (kappa>0.80) for two pairs); agreement on a two-category basis was substantial for 12 pairs and almost perfect for three pairs) or compared with the panel (on a four-category basis, agreement was substantial for five of six readers and almost perfect for one; on a two-category basis, agreement was substantial for all readers). CONCLUSIONS: In agreement with previous studies, visual classification of mammography density according to BI-RADS quantitative criteria was highly reproducible among readers; nevertheless, attribution to the "dense breast" (BI-RADS D3-4) category, which might be adopted as a determinant of different screening protocols (such as adjunct ultrasonography or yearly interval) varied among readers (range 6-15%). Controlled studies should be performed comparing visual with computer-density category attribution, the latter possibly being a better alternative due to its absolute reproducibility.

Analysis of proportional incidence and review of interval cancer cases observed within the mammography screening programme in Trento province, Italy.

PURPOSE: The aim of this study was to assess the performance of the mammography screening programme in Trento Province, Italy, by analysing the interval cancers (IC) observed from 2001 to 2008. MATERIAL AND METHODS: IC were identified by linking screening archives with local cancer registry and pathology archives as well as with hospital discharge records. Proportional incidence was determined according to breast cancers expected in the absence of screening, estimated on the basis of patients/year at risk and age-specific incidence. The review of screening mammograms preceding ICs was performed by an external (three radiologists) and an internal (five radiologists) panel and aimed at assessing the proportion of IC reviewed as screening errors. Results were compared with European Community (EC) recommended standards. RESULTS: IC proportional incidence was 15.90% for the first year (EC standard <30%) and 25.77% for the second year (EC standard <50%) of the interval. At external review, 18.4% of cases were reviewed as screening errors (identified by at least two of three reviewers), whereas at internal review (identified by at least three of five reviewers) it was 17.4% (EC standard <20%). No significant difference was observed between external and internal review (mean recall rate 8.3% vs. 9.0%; mean identification rate 19.7% vs 19.6%). CONCLUSIONS: The study confirms good performance of the mammography screening programme in Trento Province, Italy. Comparable results of external and internal reviews suggest that the latter, no doubt easier to be implemented, might be adopted as a routine procedure to assess this early efficacy indicator.

Focal breast lesions with benign appearances. Review of eight breast cancers with initial features of intramammary lymph node.

PURPOSE: The aim of this study was to evaluate whether certain histological types of early breast cancer may share radiographic features with intramammary lymph nodes. MATERIALS AND METHODS: The previous mammograms of patients with histologically proven breast cancer and lesions displaying the morphological features of intramammary lymph nodes were retrospectively reviewed. RESULTS: Retrospective evaluation demonstrated eight breast cancers of varying histological nature--mostly ductal carcinomas not otherwise specified (NOS)--whose early radiographic features were similar to intramammary lymph nodes. CONCLUSIONS: Although uncommon, a lesion with the radiographic features of an intramammary lymph node may hide an early breast cancer. No significant relationship exists between histological type and the presence of such features.