Radiographic screening for breast carcinoma. II. Prognostic considerations on the basis of a short-term follow-up

Prognostic markers were analysed in a randomized screening project for breast carcinoma using mammary radiography as the only screening method. The proportion of small carcinomas (non-invasive carcinoma and invasive at most 10 mm across) was significantly larger among carcinomas detected at screening than that of carcinomas appearing in the control group. Furthermore, the rate of axillary metastasis was lower and the proportion of stage I disease significantly larger. The proportion of highly differentiated tubular carcinoma and intraductal carcinoma in situ was significantly larger in the screened group, while the proportion of less differentiated tubuloductal carcinoma, invasive comedocarcinoma and medullary carcinoma with lymphoid infiltration was larger in the comparison group. The findings strongly indicate that carcinomas found at radiographic screening represent, on the average, an earlier stage compared with carcinomas detected in clinical practice.