In the era of fake news, it is difficult to know who to trust. New screening mammography guidelines published this week from the American College of Physicians (ACP) have caused a stir. Since the 1980’s, mammograms were (and still are) the best way to detect breast cancer early.
When breast cancer is caught early, before it spreads, the chances of survivorship are much higher. Today there are 3.5 million women that are breast cancer survivors. That wouldn’t be the case if women in the 80s didn’t march on Washington to get insurance to cover screening mammography. And now, nearly forty years later, some doctors giving away that precious right for women to be screened in the name of public health or saving some dollars for the insurance companies.
The ACP’s new guidelines are only for women with average risk and no symptoms or problems. They endorse screening mammograms for such women starting at 50 and performed every two years until age 74. This is similar to the US Preventative Task Force’s recommendation that caused such confusion in 2009.
Now three large organizations, the American Cancer Society, The American College of Radiology, and the Society of Breast Imaging, still agree that the most lives are saved by annual screening starting at age 40. The ACR and SBI continue to recommend that women start getting annual mammograms at age 40 and continue as long as they are in good health.
Why the differences of opinion?
Different data. Different goals. Different experiences.
There are three main points that the ACP has overlooked in their public health review for early detection. The Society of Breast Imaging discusses them well.
The ACP claims that guidelines recommending that screening start at age 40 ignore the “low incidence of breast cancer for women younger than 60 years.” In fact, the majority of in situ cancer and nearly half of all breast cancers occur in women under 60. Also, the majority of life years lost to breast cancer occur in women diagnosed younger than age 60. Breast cancer is the most common cancer in women and the second leading cause of cancer death in women. It should be taken seriously at all ages.
The ACP also claims, “Every other year mammography screening results in no significant difference in breast cancer mortality.” This is incorrect. There have been no randomized controlled trials to test this ACP claim. In fact, the NCI/CISNET models that were used by the USPSTF and the ACS actually show a major decline in deaths among women screened annually vs. every other year.
The ACP guidelines also fail to address groups who have a greater risk of developing breast cancer at a young age and dying from the disease. For instance, black women have a 30 percent higher breast cancer death rate than white women (DeSantis et al). Also, breast cancer incidence peaks in the late forties in non-white women and in the sixties in white women (Stapleton et al). The ACP approach may exacerbate racial disparities in breast cancer outcomes.
More doctors support annual screening in women 40 and older than screening later in life or less frequently. National Cancer Institute (SEER) data show that, since mammography became widespread in the 1980s, the U.S. breast cancer death rate, unchanged for the previous 50 years, has dropped 43 percent. A recent study in Cancer showed that women screened regularly for breast cancer have a 47 percent lower risk of dying from the disease within 20 years of diagnosis than those not regularly screened. Large studies (Otto et al. and Coldman et al) show that regular mammography use cuts the risk of dying from breast cancer nearly in half.
Screening risks are often overstated due to faulty assumptions, methodology and hyperbole in articles on which such claims are based. Overdiagnosis means finding cancers that will not grow to kill you before something else does. Overdiagnosis will not be reduced by delayed or less frequent screening. These “overdiagnosed” cancers would still be found by the next screening exam and result in the same work-up, biopsy and treatment. If an aggressive cancer goes undiagnosed because of a longer interval between screenings or starting screening at a later age, treatment will be delayed with higher potential morbidity and a lower chance of saving a woman’s life. Screening-detected breast cancers do not disappear or regress if left untreated.
A British Medical Journal study, using direct patient data, shows that breast cancer overdiagnosis is about 2 percent. An article in The Oncologist shows that studies with high overdiagnosis claims are not well-founded. American Cancer Society findings re-confirmed that overdiagnosis claims based on modeling studies are inflated.
A Journal of The American Medical Association (JAMA) study has shown that normal and understandable anxiety from inconclusive mammogram results or false positives is brief and has no lasting health effects. Research shows that nearly all women who have a false-positive exam still endorse regular screening and want to know their status.
Short- term anxiety from test results, a small percentage of women called back to double-check something and overstated overdiagnosis claims do not outweigh the thousands of lives saved each year through annual mammography screening starting at age 40.
So, while the confusion grows over when to start getting your mammogram, I can tell you from 35 years of personal experience that early detection works. The question has and remains a very personal one. Every woman is different, but every woman deserves the right to choose what is right for herself. For all the reasons above and seeing it personally, we recommend getting a baseline mammogram at 40 and continuing annual screening afterwards because the two biggest risk factors in breast cancer are two we can’t control: being a woman and growing older.