The difference between 5 to 4 represents 20%; but only 1 death is avoided for 2000 women screened.
Finally, this mortality reduction only concerns breast cancer mortality. There is no evidence that screening improves women’s life expectancy. It can be postulated that reducing breast cancer mortality should logically improve life expectancy. This assumption becomes false if the screening exposes to other risks. So, screening only leads to one cause of death being exchanged by another, but no obligatory benefit on life expectancy.
Total mastectomies not avoided
Doubts hovering over the efficiency of screening, communication relies on therapeutic alleviation. That is to say that screening for early detection of small tumors, it would be possible to treat these less advanced lesions less heavily: less mutilating surgery, less radiation and chemotherapy. In a study, to be published in the October issue of the journal Médecine , we sought to verify whether the widespread use of screening had led to a reduction in surgical treatments for breast cancer.
In France, since 1997, all surgeries performed in hospitals are listed in a national database. Based on these data, we studied the annual evolution of the number of total mastectomies (surgical removal of an entire breast) from 2000 to 2016. The report is clear: the number of mastectomies has not stopped increase from less than 17,500 in 2000 to 20,000 in 2016. We also compared the number of interventions to the number of new cases of breast cancer and, again, the finding is clear: in 2000, before the generalization of screening, the discovery of 10 new breast cancers led to 4 total mastectomies; in 2012, after widespread screening, the situation has not changed,
Our study thus shows that the generalization of screening has not made it possible to reduce the most mutilating interventions, total mastectomies. It is therefore wrong to claim that screening makes it possible to reduce surgical treatments. This result is consistent with other studies conducted in the United Kingdom, in the United States, and in the evaluation of a group of Nordic researchers (Cochrane Collective).
A problem of overdiagnosis
The act of screening, x-ray and ultrasound of the breasts, the biopsy of a possible tumor, is unpleasant and distressing. But that’s not really the problem. The real problem is overdiagnosis, and the overtreatment it leads to. Overdiagnosis is the discovery of a lesion, cancerous but not aggressive or aggressive and that would never have impacted the life or health of women. First denied and then downplayed in the various official communications and Pink October, the reality of overdiagnosis is now recognized and, according to some recent studies, up to 20% to 50% of tumors discovered by screening could match overdiagnosis.
And overdiagnosis leads to overtreatment. Because, in the current state of knowledge, we do not know how to distinguish, among the tumors revealed by screening, real cancers and overdiagnosis. In doubt, as a precaution, all tumors are treated in the same way. From overdiagnosis to overtreatment, over-diagnosed women suffer double jeopardy: the false announcement of cancer, with all the psychological and social consequences that go with it, and unnecessary treatment, with its share of surgical mutilations and side effects.
Between one side benefits more modest and the other higher risks, balance benefits / risks of screening appears less rosy than what was announced. This finding calls into question current practices. Either maintain the current screening program but inform women completely and honestly. The information should include the risks involved in screening, without minimizing them, and leave women free choice, without feeling guilty if they decide not to participate. Or a moratorium on organized screening is decided and maintained as long as our scientific knowledge does not reduce overdiagnosis