Screening for breast cancer in women aged 41--60.

All women aged 41--60 (20 644) living in the city of Tampere were invited to attend screening for breast cancer during the period April 1974--March 1975. The breasts and the axillary lymph nodes were examined and palpated by specially trained nurses. The women were instructed in self-examination and given a leaflet for study at home. If anything abnormal was revealed at this stage the subject was referred to a physician for further examination. The women who attended totalled 17 261 (84%), 627 (3.6%) of whom were referred for further examination and 615 attended. Surgical biopsy was recommended for 117 (19%) of these 615. Breast cancer was histologically verified in 27 subjects. Ten further cases of breast cancer were detected outside this screening during the same one year screening period, which made the overall detection rate 1.79 per thousand in this age group. As the expected incidence was 1.20 per thousand, the primary detection excess was 0.59 per thousand or 12 cases. A further advantage of screening of this kind is the instruction given to the subjects, which is expected to result in more cases of cancer being revealed at an earlier stage.