Pathological classification of ductal carcinoma in situ of the breast correlates with surgical treatment and may be predicted by mammography

In order to assess the correlation of pathological and radiological features of ductal carcinoma in situ (DCIS) of the breast and their association with surgical outcome, a consecutive series of 150 patients was retrospectively examined. Pathological slides from all patients were divided into three categories according to the pathological EPWG (European Pathologist Working Group) and DIN (Ductal Intraepithelial Neoplasia) classifications, which showed very good inter-correlation (r=0.99) (whole series). Mammographic images from 46 of these cases were blindly classified into five categories according to the level of radiological suspicion (R), morphology of calcifications (Ca) and preoperative results of needle biopsy (C/B) (limited series). No significant differences in the distribution of clinical and pathological variables were detected among whole and limited series. The lesions were grouped into two (low versus high) pathological (PRG), radiological (RRG and CaRG) and needle biopsy (C/BRG) risk groups. PRG was associated with both RRG (p=0.002) and CaRG (p=0000), but not with C/BRG. Correlations with surgical outcome were also explored, with lesions of high PRG being more likely to undergo re-excision for inadequate first wide local excision [odds ratio (OR)=2.1], mastectomy (OR=2.6) and nodal staging procedures (OR=3.8) in the whole series. Conversely, no significant correlation was found between PRG, RRG, CaRG and C/BRG with surgical outcome in the limited series. We suggest that pathological features of DCIS are associated with surgical outcome and may be predicted by mammography.