A woman in her forties should be encouraged to make up her own mind whether breast screening is best for her, rather having people tell her what to do, say two American experts in the British Medical Journal, this week’s issue.
According to new guidelines issued by the American College of Physicians, women between the ages of 40 and 49 should make an informed choice after learning about the pros and cons of mammography – rather than recommend universal screening.
According to Lisa Schwartz and Steven Woloshin, reaction to the guidelines was subdued. This suggests that doctors and the general public increasingly recognize that screening for cancer has both benefits and harms.
The writers express hope that perhaps we have moved further than discussing what a woman should do, and focusing more on how to inform women so that they can make the best decision for themselves.
The problem is that no right option really exists. Screening for some women may save their lives, while in other cases they may be harmed by needless treatment. Therefore, say the authors, the next step must be to make sure women are aware of what will probably happen if they undergo screening or decide not to.
According to US data, for every thousand women screened over the period of one decade, less than one life will be saved for younger women and approximately three lives will be saved for older women.
The biggest problem with screening is the number of false positives. Something wrong is detected, so the woman has to have another test, and often a biopsy. The woman goes through all the anxiety, stress and inconvenience to then later on find out that there is nothing wrong with her.
Overdiagnosis is a major problem with screening; it is when lesions are detected, they meet the pathological criteria for cancer – however, they would not cause symptoms or death. Treating women who are overdiagnosed as if they had breast cancer harms them – as no treatment was needed there are absolutely not benefits. The women might have to go through disfiguring surgical procedures, radiation injury, plus the nausea, hair loss and fatigue that come with hormonal therapy and/or chemotherapy.
The authors calculate that during the next ten years for every 1000 women aged 40-49 five will be overdiagnosed, while nine out of every 1000 women screened over 50 years of age will be overdiagnosed.
Most women say they would factor in the overdiagnosis risk when deciding about screening.
The authors approve of the new guideline as it incorporates informed decision making into policy recommendations. Rather than being told what to do, women are given the necessary information so that they can decide for themselves.
“Participation in mammography screening Women should be encouraged to decide what is right for them, rather than being told what to do”
Lisa M Schwartz, Steven Woloshin
BMJ 2007;335:731-732 (13 October), doi:10.1136/bmj.39350.590625.80
Written by: Christian Nordqvist