DIAGNOSTIC OUTCOME OF REPEATED MAMMOGRAPHY SCREENING

Mammographic screening for breast cancer within health service routine s was evaluated for the years 1987-1992, with special focus on repeate d screening during 1989-1992, The overall attendance rate by women age d 40 to 74 years was 82.8%. During 1989-1992 malignancy was found in 2 .6/1000 screened women, giving a 87.4% positive predictive rate at sur gery and 95.9% efficiency, Among women aged greater than or equal to 4 5, the positive predictive rate was >94%, Fine-needle aspiration (FNA) biopsy showed invasive cancers in 84% and highly suspected cancer in another 15%; 60% of the lesions were nonpalpable. For first-time (prev alence) screening (1987-1988) the positive predictive rate was 86% and the malignancy yield 6.4/1000, In women aged 40-44 years there were f ew surgical referrals (1.6%), but the positive predictive rate at surg ery was only 48.3%, indicating diagnostic difficulties in young women. The median size of all invasive cancers was 12 mm: 84% were classifie d as pT1, and 23% had lymph node involvement. Stage II disease was fou nd in 27% of all malignancies. The use of FNA in the diagnostic workup for breast cancer screening is of crucial importance to the maintenan ce of high positive predictive rates at surgery, Moreover, regular ana lysis is important even when mammographic screening is incorporated in to the routine work of health services.