Confused about mammogram recommendations? It is not hard to understand why.
The American Cancer Society (ACS) states, “Yearly mammograms are recommended starting at age 40 and continuing for as long as a woman is in good health,” as does the American College of Obstetricians and Gynecologist (ACOG).
The United States Preventative Service Task Force (USPSTF) “recommends biennial screening mammography for women aged 50 to 74 years … [and] concludes that the current evidence is insufficient to assess the additional benefits and harms of screening mammography in women 75 years or older.” The Kaiser Permanente Care Management Institute (KPCMI) has similar recommendations.
The guideline for breast cancer screening can be a frustrating one for patients and a challenge for healthcare providers.
How did we end up in this tangle of contradicting recommendations? There are several organizations that have a particular interest in cancer, particularly breast cancer. And with breast cancer affecting one in eight women, that makes sense. For years the ACS and ACOG led the fight against breast cancer recommending yearly screening mammograms starting at age 40. However, recently massive research studies have been conducted and raised some statistical evidence that challenged this recommendation. In light of this evidence the USPSTF and KPCMI is offering differing guidelines. Note: both guidelines are based on “inconsistent and limited scientific evidence” and “consensus and expert opinion”.
Why not frequently screen everyone, screening is good? While screening identifies cancer that may otherwise go undiagnosed, it can also “over-diagnose” breast findings. This over-diagnosis on mammograms, particularly in younger women with dense breast tissue (i.e. women under the age of 50) has been found to lead to further testing, biopsies, and intervention. On the other hand, although women in their 40s have a lower overall incidence of breast cancer compared with older women, the window to detect tumors before they become symptomatic appears to be shorter (two year versus four years). As a society, we are left hanging in the balance of providing the very best health care while being conscience of the potential harms to the masses and the overall cost-benefit of the screening. Interestingly, Canada is often heralded as a global leader in preventive healthcare, and yet their guidelines for breast cancer screening recommends mammograms for women ages 50 – 69 every two to three years.
Clear as mud, right? There is no one-size-fits-all recommendation (so stop looking for one, and you’ll not find it here). Screening depends on many factors, to include your own comfort level. For women over the age of 35 with average risk, there is a breast cancer risk tool that may help you decide which guideline is best for you. Comparisons between the guidelines are also available. Remember, these recommendations are for the average-risk woman. Take what you learn and talk with your healthcare provider (bear in mind they may be biased toward one of the guidelines, or are unaware of the conflicting recommendations). And with that, I will leave you with my own bias on breast cancer screening from the moderately-positioned American Academy of Family Physicians (AAFP):
“Breast cancer is the most common non-skin cancer and the second leading cause of cancer death in North American women. Mammography is the only screening test shown to reduce breast cancer-related mortality. There is general agreement that screening should be offered at least biennially to women 50 to 74 years of age. For women 40 to 49 years of age, the risks and benefits of screening should be discussed, and the decision to perform screening should take into consideration the individual patient risk, values, and comfort level of the patient and physician. Information is lacking about the effectiveness of screening in women 75 years and older. The decision to screen women in this age group should be individualized, keeping the patient’s life expectancy, functional status, and goals of care in mind. For women with an estimated lifetime breast cancer risk of more than 20 percent or who have a BRCA mutation, screening should begin at 25 years of age or at the age that is five to 10 years younger than the earliest age that breast cancer was diagnosed in the family. Screening with magnetic resonance imaging may be considered in high-risk women, but its impact on breast cancer mortality is uncertain. Clinical breast examination plus mammography seems to be no more effective than mammography alone at reducing breast cancer mortality. Teaching breast self-examination does not improve mortality and is not recommended; however, women should be aware of any changes in their breasts and report them promptly.”