Predictors of invasion in ductal carcinoma in Situ of the breast: The value of a scoring system.

Ductal carcinoma in situ (DCIS) of the breast shows unpredictable association with invasive ductal carcinoma (IDC). Comedo DCIS (CDCIS) is more frequently associated with IDC than noncomedo DCIS (NCDCIS). We studied prognostic variables in 64 cases of DCIS to identify predictors of invasion. These factors included DCIS type and nuclear grade and two counts of the AgNOR silver staining technique for identification of ploidy and proliferative activity (PA) using two counts: mAgNOR for ploidy and pAgNOR for PA. The other factors included immunostaining of the lesions for epidermal growth factor receptors (EGFR), cathepsin-D (C-D), and the c-erbB-2 oncogene. The 34 cases associated with ICD had pAgNOR ranging from 3% to 36% (median 11%), whereas cases not associated with IDC had a pAgNOR range of 0% to 25% (median 5%; P=0.0001). The correlation between mAgNOR and the development of IDC was less statistically significant. The DCIS type and staining pattern for EGFR, C-D, and c-erbB-2 showed no statistical correlation of individual variables with the development of IDC. A scoring system adding the values of the seven variables was used. A score of 1-2 was given to each variable, depending on whether it was positive or negative. Lesions associated with IDC had a median total score of 8 (+/- 1.35 SD), whereas those lesions not associated with invasion had a median score of 4 (+/- 1.45 SD; P=0.0002). We conclude that proliferative activity analysis may play a significant role in predicting the invasive potential of DCIS. The use of a scoring system adding the sum of single prognostic indicators may provide more useful information regarding the prediction of invasive potential of DCIS than single indicators.