New from USPSTF: Breast cancer risk-reduction recommendations
The US Preventive Services Task Force (USPSTF), in an update of its 2013 recommendations, called on clinicians to offer risk-reducing medications to women who are at increased risk for breast cancer but at low risk for adverse effects.
Unlike the 2013 guidance, the 2019 update includes aromatase inhibitors (AIs) among the medications that can reduce breast cancer risk, along with tamoxifen and raloxifene. The new recommendation applies to asymptomatic women 35 years and older, including those with previous benign breast lesions (atypical ductal or lobular hyperplasia and lobular carcinoma in situ), but not to women with current or previous diagnosis of breast cancer or ductal carcinoma in situ. [JAMA 2019;322:857-867]
The 2019 recommendation is supported by an evidence report and systematic review of 46 studies involving over 5 million participants. In placebo-controlled trials, for example, the use of tamoxifen, raloxifene, and AIs (exemestane and anastrozole) was associated with a lower incidence of breast cancer in women but was also associated with adverse effects that differed between medications. [JAMA 2019;322;868-886].
‘Not for everyone’
“[AIs, tamoxifen, and raloxifene] can be beneficial and can reduce breast cancer risk in women,” said USPSTF member Dr Michael Barry, director of the Informed Medical Decisions Program at Massachusetts General Hospital and professor of medicine at Harvard Medical School, Boston, Massachusetts, US. “But those medications are not for everyone.”
The USPSTF said tamoxifen, raloxifene, or AIs provide at least a moderate benefit in reducing the risk for invasive oestrogen receptor-positive breast cancer among postmenopausal women at increased risk. Women who are not at increased risk for breast cancer (eg, those <60 years old with no additional risk factors for breast cancer or women with a low 5-year risk of breast cancer), should not be routinely offered medications to reduce their risk of breast cancer, because the risk of harms from these medications (venous thromboembolic events, endometrial cancer, and cataracts) likely outweighs their potential benefit, according to the USPSTF recommendation.
Although there is evidence linking tamoxifen and raloxifene – and AIs – to a small-to-moderate harm, the task force said that overall, the net benefit of taking medications to reduce breast cancer risk is still greater in women at heightened risk of developing the disease.
Multiple risk factors influence risk
Aside from the recommendation on which medication to use, the USPSTF also broadens the combination of risk factors clinicians should consider when offering pharmacologic intervention for breast cancer prevention, to include not only the histologic type of benign breast biopsy of the patient, but also the age-specific family history profiles.
“The recognition that multiple risk factors may influence a woman’s risk for breast cancer places a heavy burden on clinicians to interpret the benefits and risks for each woman based on her personal risk profile and tolerance for risk,” commented Drs Mary Daly and Eric Ross from the Fox Chase Cancer Center in Philadelphia, Pennsylvania, US in an editorial. It also places a greater emphasis on the importance of clinician-patient communication regarding the patient’s individual risk profile and personal preferences, they added. [JAMA Oncol 2019;doi:10.1001/jamaoncol.2019.3785]
Speak with your patients
“We all want to find better ways to prevent breast cancer … it’s important for clinicians to speak with their patients about their level of risk and carefully consider the best approach,” added USPSTF member Dr Carol Mangione from the David Geffen School of Medicine, University of California, Los Angeles, California, US.
In a related editorial, Dr Lydia Pace from the Brigham and Women’s Hospital and Dr Nancy Keating from Harvard Medical School and Brigham and Women’s Hospital in the US said understanding which women are most likely to experience benefits and harms is of paramount importance to guide clinician recommendations and patient decisions. [JAMA 2019;322:821-823]
“Ideally, this requires a more accurate risk prediction and studies powered to compare benefits and harms between subgroups. Considering risk-reducing medications for women with a 5-year risk greater than 3 percent seems reasonable, as well as for women with atypical hyperplasia and lobular carcinoma in situ,” they added.
More evidence warranted
“Additionally, we also need more evidence to better understand the lifelong benefits and harms of these medications and how they can reduce risk in specific populations, such as African-American women who are more likely to die of breast cancer, and women who carry harmful BRCA gene mutations,” Barry said.
“It’s also important for women to remember that there are other important ways to reduce breast cancer risk, including reducing alcohol intake and maintaining a healthy weight,” Pace emphasized.