In Finland, organized nationwide breast cancer (BC) screening is biennially offered for women aged 50-69 years. The aim was to estimate, for the first time in Finland, the proportion of women having opportunistic mammography at age less than 50 years and to investigate the role of BC family history and educational level for having opportunistic mammography.
The study material comprises two self-administered, population-based questionnaires from altogether 9845 healthy women; 4666 women in Women's Health and Use of Hormone-study (WHH survey), and 5179 in Breast Cancer Screening, Lifestyle and Quality of Life-study (EET survey). We report the estimated proportions of women with self-reported opportunistic mammography at age?12 years of education than women with?=12 years of education.
Overall, some two thirds of the women reports of having had a mammography before organized screening started. Opportunistic mammography was more likely among women with a positive family history of BC in a first degree relative as well as more than 12 years of education. Regardless of low response activity, the observed popularity of opportunistic mammography before organized screening gives ground for further evaluation of the related health care practices. Screening activity before organized screening also influences the evaluation of the screening program, as women have different, indeterminate histories of pre-organized screening.