Effects of annual vs triennial mammography interval on breast cancer incidence and mortality in ages 40-49 in Finland.

BACKGROUND: The aim of this study was to evaluate the effects of mammography screening invitation interval on breast cancer mortality in women aged 40-49 years. METHODS: Since 1987 in Turku, Finland, women aged 40-49 years and born in even calendar years were invited for mammography screening annually and those born in odd years triennially. The female cohorts born during 1945-1955 were followed for up to 10 years for incident breast cancers and thereafter for an additional 3 years for mortality. RESULTS: Among 14,765 women free of breast cancer at age 40, there were 207 incident primary invasive breast cancers diagnosed before the age of 50. Of these, 36 women died of breast cancer. The mean follow-up time for cancer incidence was 9.8 years and for mortality 12.8 years. The incidence of breast cancer was similar in the annual and triennial invitation groups (RR: 0.98, 95% confidence interval (CI): 0.75-1.29). Further, there were no significant differences in overall mortality (RR: 1.20, 95% CI: 0.99-1.46) or in incidence-based breast cancer mortality (RR: 1.14, 95% CI: 0.59-1.27) between the annual and triennial invitation groups. CONCLUSIONS: There were no differences in the incidence of breast cancer or incidence-based breast cancer mortality between the women who were invited for screening annually or triennially.

Service screening mammography reduces breast cancer mortality among elderly women in Turku.

OBJECTIVES: The aim of this study was to assess the effects of service screening mammography on breast carcinoma incidence and refined mortality among women aged 55-69 at entry in three cities employing different screening policies. METHODS: Since 1987, the city of Turku, Finland, has provided service screening mammography for women aged 55-69 at entry (in 1987), and Tampere provided screening for women aged 55-59 at entry, whereas Helsinki did not screen any of these age groups. The incidence of breast carcinoma during the screening period 1987-97 in women born in 1918-32 (1918-22, 1923-27, 1928-32) was compared with incidence during the pre-screening period 1976-86 in women born in 1907-21 (1907-11, 1912-16, 1917-21) in each city. The follow-up for mortality was four years longer. RESULTS: Breast carcinoma incidence was 31-38% higher in the screening period in all three cities irrespective of screening. In breast carcinoma mortality, no significant changes were seen in Helsinki or Tampere. In Turku, a 36% mortality reduction (relative risk [RR] 0.64; 95% confidence interval [CI] 0.47-0.88; P=0.007) in the whole study population and a 47% reduction in women aged 65-69 at entry (RR 0.53; 95% CI 0.28-0.99; P=0.047) were seen. CONCLUSIONS: The incidence of breast carcinoma increased in all study cities irrespective of screening. The comprehensive screening programme in Turku including women aged 55-69 at entry was associated with a significant reduction in breast carcinoma mortality. The pronounced decrease in mortality in the oldest age group (65-69 years at entry) also indicated that women of this age group greatly benefit from mammography screening.

Customer fee and participation in breast-cancer screening.

Until 1997, breast screening by mammography was free for all women living in Turku, Finland. After this date, women born in certain years had to pay to be screened. We did a retrospective study, using data obtained from Statistics Finland, to ascertain whether or not the introduction of a fee affected attendance. We also assessed the effect of socioeconomic status on attendance. Our findings show that people who had to pay for mammography attended less often than women who were entitled to free screening, irrespective of their socioeconomic status.