Recommendations on screening for breast cancer in women aged 40–74 years who are not at increased risk for breast cancer
Cet article présente une mise à jour des recommandations 2011 de la "Canadian Task Force on Preventive Health Care" concernant le dépistage chez les femmes âgées de 40 à 74 ans ne présentant pas un risque accru de développer un cancer du sein
Breast cancer mortality rates among Canadian women have declined from 41.7 per 100 000 in 1988 to an estimated 23.2 per 100 000 in 2017, while age-standardized incidence has remained relatively stable, at around 130 per 100 000 since 2004.1 Declining mortality with stable incidence could reflect improvements in breast cancer treatment, timely detection of symptomatic cancer, screening programs, or all of these.1 Breast cancer screening programs have been in place in most regions of Canada since the early 1990s. In 2014, 54% of women aged 50 to 69 years had been screened in the previous 30 months via a screening program, and an unknown number of women were screened outside of programs.2 Screening may identify breast cancer earlier and lead to more effective and less invasive treatment; however, it may also lead to overdiagnosis and subsequent treatment of cancer that, left untreated, would not have become apparent or caused harm.3 Examples of adverse sequelae of treatments (e.g., surgical intervention, radiotherapy, chemotherapy) include pain, disfigurement and distress. In addition, false-positive screening results may have a psychological impact and can lead to adverse physical effects from further testing.3 The systematic review4 that informed task force recommendations in 2011 5 reported a reduction in breast cancer mortality with mammography screening for women aged 40 to 74 years. However, net benefit for women younger than 50 years was equivocal, given their lower absolute risk as well as their higher probability of being overdiagnosed and having false-positive screens compared with women aged 50 to 74 years.4 Current recommendations are informed by an updated evidence review of benefits and harms of breast cancer screening, as well as a new systematic review of women’s values and preferences about screening.
Canadian Medical Association Journal , article en libre accès, 2017