Most experts believe that regular breast cancer screening for women 40 and older means more breast cancer is diagnosed earlier, when it's more treatable. This means lives are saved. Still, doctors continue to discuss and study the effect screening for breast cancer has on public health, as well as the best time to start screening.
In a study, researchers question the value of regular screening mammograms because routine mammography seems to have had little effect on reducing the number of women who die from aggressive forms of breast cancer. The researchers also question the value of routine prostate cancer screening (the PSA test) in men.
The researchers analyzed the results of seven earlier studies that evaluated the effect routine screening mammograms had on the diagnosis and outcomes of breast cancer. After accounting for changes in breast cancer treatments (hormonal therapy, for example), the researchers found that regular mammograms:
- increased the total number of breast cancer diagnoses; most were early-stage, less aggressive forms of breast cancer
- decreased deaths related to breast cancer by 7% to 21%
Based on these results, it might seem reasonable to conclude that current breast cancer screening recommendations make sense. But the researchers also said:
- The increase in the number of women diagnosed with early-stage breast cancer has NOT resulted in a decrease in the number of women diagnosed with aggressive, advanced-stage disease.
- Routine mammograms haven't really lowered the risk of dying from aggressive, advanced-stage disease.
The researchers think that regular screening mammograms detect more early-stage breast cancers that won't become aggressive, advanced-stage disease. But regular screening mammograms aren't translating into better detection of aggressive, advanced-stage breast cancers. The researchers also suggest that some of the very early-stage breast cancers detected by screening mammograms may never grow, and so are over-treated because they've shown up on a mammogram.
Many women have had breast cancer diagnosed early and undergone successful treatment because of screening mammograms. So it might be hard to understand how experts could question the value of regular screening. It helps to look at the issue from both a large, public health viewpoint and a smaller, individual health viewpoint.
Looking at breast cancer screening from a public health perspective means looking at the effect that screening has on the entire population, including weighing the outcomes brought about by the screening against the cost. Public health experts also look at whether the money spent on screening could be used in other ways that might offer more benefits. From a public health perspective, the hope is that increasing early-stage breast cancer diagnoses through regular mammograms would decrease diagnoses of aggressive, advanced-stage breast cancer. This study suggests this hasn't happened. So it's reasonable to ask if routine screening as currently recommended makes sense.
From an individual health perspective, if you or someone you know had early-stage breast cancer diagnosed and treated because a screening mammogram detected an area of concern, it's likely that you consider regular mammograms extremely valuable. Questioning the value of screening mammograms may seem senseless to you.
Based on all of the evidence available today, Breastcancer.org continues to believe that current standards recommending routine screening mammograms for women age 40 and older with an average risk of breast cancer make sense. We also believe that the debate sparked by this research is healthy and makes doctors and health policy experts look critically at what's being done to improve the health of all people -- and ask whether it could be done more effectively.