The American Cancer Society calls for MRI as an adjunct to mammography for women with mutations in the BRCA gene and for those with a history of chest radiation (usually for Hodgkin’s disease), as well as a limited number of others.16 If a woman has a first-degree relative with a history of breast cancer, her own lifetime risk of breast cancer doubles; such women are generally counseled to begin screening when they are five to 10 years younger than the age at which their relative was diagnosed. Women with a known genetic risk frequently begin screening between the ages of 25 and 35 years.17 Having a male family member with breast cancer also is a strong risk factor; genetic counseling may be indicated for these patients.
In addition to family history, genetic mutations and history of chest radiation, other components of a woman’s medical history are germane to determining her risk of breast cancer. Table 1 lists more factors related to a woman’s medical history that should be considered in determining her breast-cancer risk.
For women with an elevated chance of contracting breast cancer, the mammography calculus might be more weighted toward earlier screening. Patients should also be carefully counseled about techniques to address modifiable risk factors (i.e., reducing alcohol consumption and maintaining a normal weight).
When placed in context with existing knowledge about breast cancer and mammography, the seemingly radical USPSTF recommendations simply amount to one more step in the ongoing questioning of the reliability of screening mammograms.
Because we currently lack a more sensitive or specific modality for screening in the general population, ACOG, the American Cancer Society, and the American College of Radiology have declined to change their guidelines and still recommend that women begin receiving mammograms at age 40 years. Many health-care providers and experts have spoken out against the new USPSTF document, concerned cancers that might have been detected early will be missed.
Ultimately, the mammography debate can be boiled down to differing valuations of individual and public health and differing calculations of the risks and benefits of testing. Few would dispute the fact that screening women from age 40 years on will catch some cancers earlier. But those who advocate starting screening at a later age emphasize the financial, emotional and physical costs of those hundreds of thousands of tests each year.
While the USPSTF recommendations do represent an evidence-based approach to care, its standards are not yet accepted practice, and most clinicians are apt to delay implementing changes until other professional societies have endorsed such adjustments. Understanding the underlying data will enable us to understand the present debate and advise our patients appropriately.
Although it did not ignite as much controversy as the change in mammogram guidelines, the USPSTF’s questioning of breast self-examination (BSE) also deserves attention. In 2002, a now famous trial by Thomas et al found that BSE instruction did not reduce breast-cancer mortality but did increase the likelihood of a benign breast biopsy.18
One of the limitations of BSE, according to this study and others, is the detection of a transient, nonmalignant mass, which often leads to unnecessary testing, cost and stress. Also, women are likely to check their own breasts incidentally even without specific instructions from a health-care provider. As many argue, BSE may facilitate the detection of a mass, but it is not shown to decrease breast-cancer mortality.
A smaller study focused on a patient population at high risk for breast cancer (approximately 20% average lifetime risk). The researchers found that BSE was effective in detecting cancer between screening tests.19 Based on the divergences between their findings and those of the 2002 study by Thomas and colleagues, the authors proposed that three factors may be crucial to the evaluation of BSE: “(1) the motivation of women to perform BSE, (2) combined CBE [clinical breast examination]/BSE teaching by a highly trained provider, and (3) the ability of women to directly report BSE findings to a provider and receive rapid clinical follow-up.”
Therefore, it was argued, BSE should not be abandoned, particularly by high-risk women. BSE, like CBE, is especially valuable to people in medically underserved areas in which access to mammography is scarce, and to high-risk individuals.
So, what do you tell your patients? As the USPSTF advises, individual patients’ medical and psychological needs should be considered when prescribing screening tests. Women who are adamant about starting mammograms at age 40 can certainly still do so, as long as they understand the true benefits and limitations of the test.
If your patient is at high risk of breast cancer for lifestyle reasons or because of family history, early screening is advisable. And of course any patient with a palpable lump on SBE or CBE needs immediate follow-up with mammogram and/or ultrasound. For patients at average risk, however, delaying the start of screening mammography until age 50 may be considered prudent and justifiable if doing so is in accordance with the woman’s health profile and values.