Endocrine disruptors are chemicals or man-made toxins which, when absorbed, have been shown to mimic the action of hormones. They can turn on, turn off, or change normal signals. They can alter normal hormone levels, trigger excessive action, or completely block a natural response. Any other bodily function controlled by hormones can also be affected.
Invalid messages about screening mammography can be detrimental to women
JAMA Internal Medicine, the journal of the American Medical Association, published the findings of a brief online survey of middle-aged Americans.Most had previously been screened for either breast or prostate cancer but about half said they would not choose to start screening if the test resulted in more than one overtreated person per one cancer death averted.
Like all early detection strategies, screening mammography involves trade-offs. If women are to truly participate in the decision of whether or not to be screened, they need some quantification of its benefits and harms. Providing such information is a challenging task, however, given the uncertainty—and underlying professional disagreement—about the data. In this article, we attempt to bound this uncertainty by providing a range of estimates—optimistic and pessimistic—on the absolute frequency of 3 outcomes important to the mammography decision: breast cancer deaths avoided, false alarms, and overdiagnosis. Among 1000 US women aged 50 years who are screened annually for a decade, 0.3 to 3.2 will avoid a breast cancer death, 490 to 670 will have at least 1 false alarm, and 3 to 14 will be overdiagnosed and treated needlessly. We hope that these ranges help women to make a decision: either to feel comfortable about their decision to pursue screening or to feel equally comfortable about their decision not to pursue screening. For the remainder, we hope it helps start a conversation about where additional precision is most needed.
Cancer screening involves trade-offs. Screening offers the potential benefit of avoiding advanced cancer and subsequent cancer death. It also produces the harms of false alarms, overdiagnosis, and unnecessary treatment. Because different individuals value these benefits and harms differently, there is no single calculation to answer the question of what to do. Instead, each of us needs information about both the benefits and harms to arrive at our own decision.
Simply knowing that there are benefits and harms to screening is not sufficient to make the decision; information about their relative magnitude is essential. If 100 people benefit by avoiding a cancer death at the expense of the harms of 50 false alarms and 10 overdiagnoses with the ensuing unnecessary treatments, then the decision is easy. However, if for the same harms, the benefit is only 1 person avoiding a cancer death, the decision may be considerably more difficult. In this article we quantify the benefit-harm trade-off for screening mammography.
METHODOLOGICAL APPROACH: GENERAL PRINCIPLES
HOW MANY BREAST CANCER DEATHS ARE AVOIDED BY SCREENING MAMMOGRAPHY?
HOW MANY FALSE ALARMS ARE CAUSED BY SCREENING MAMMOGRAPHY?
HOW MANY WOMEN ARE OVERDIAGNOSED BECAUSE OF SCREENING MAMMOGRAPHY?
PERSPECTIVE AND LIMITATIONS
CONCLUSIONS – ARTICLE INFORMATION – ARTICLE INFORMATION – REFERENCES