Clinical problems in relation to breast cancer screening with mammography. A preliminary report.

In the mammography screening in Ostergötland county, a shift to more favourable stages of breast tumours has been observed after five years of screening: stage I 71% and stage II 29% in the study group compared with stage I 40% and stage II 60% in the control group. 1 429 women were referred for clinical examination. 418 (29%) turned out to have breast carcinomas. 339 patients (23%) needed more than one clinical examination for definite diagnosis. 49% of the tumours were smaller than 11 mm, and only 32% of the small invasive cancers were suspected of malignancy at the clinical examination.