A Pill a Day to Keep Breast Cancer Away
A Pill a Day to Keep Breast Cancer Away
Editor's Note: The American Society of Clinical Oncology (ASCO®) issued the latest update to its guideline on pharmacologic interventions for breast cancer risk reduction in July 2013. The guideline focused on the risks/benefits of pharmacologic intervention vs no pharmacologic intervention, the comparative efficacy of breast cancer chemoprevention agents, and how physicians should communicate issues regarding breast cancer risk reduction in women with increased risk (ie, a 5-year projected absolute risk of ≥ 1.66%). The basis for the update was new evidence from randomized controlled trials and meta-analyses published since the previous update in 2009. This evidence led to strengthened recommendations to consider using tamoxifen (20 mg per day for 5 years) in pre- and postmenopausal women who are at increased risk for invasive breast cancer, specifically estrogen-receptor (ER)-positive breast cancer, and raloxifene (60 mg per day for 5 years) or exemestane (25 mg per day for 5 years) as an option in postmenopausal women. No recommendation is made for the use of other selective estrogen receptor modulators (SERMs) or other aromatase inhibitors to lower breast cancer risk outside of a clinical trial. The guideline strongly encourages healthcare providers to discuss the option of chemoprevention, including the specific risks and benefits associated with each agent, with women at increased breast cancer risk.
Co-chair of the guideline panel, Kala Visvanathan, MD, MHS, spoke to Linda Brookes, MSc, for Medscape, about the ASCO guideline and how it aims to increase awareness and uptake of chemoprevention in women at high risk for breast cancer. Dr. Visvanathan is Associate Professor, Johns Hopkins University School of Medicine, and Director of the Clinical Cancer Genetics and Prevention Service, Johns Hopkins Hospital, Baltimore, Maryland.
Medscape: Why did ASCO decide to issue an update to this guideline?
Dr. Visvanathan: New evidence had emerged. There were data on the aromatase inhibitor exemestane, longer-term data on tamoxifen, longer-term data comparing tamoxifen and raloxifene, and additional data on net health benefits with both raloxifene and tamoxifen within specific patient groups. All of those studies are reasons why we thought it was a good time to update the guideline.
Medscape: The US Preventive Services Task Force (USPSTF) issued its own recommendation statement on medications for risk reduction of primary breast cancer in women. Do the guidelines differ in any major way?
Dr. Visvanathan: They are similar. One difference is in the cut-off for what is considered to be higher risk. The USPSTF concluded that for an estimated 5-year breast cancer risk -- on the basis of Freedman risk/benefit indices -- the threshold for likely benefit over risk from using tamoxifen or raloxifene is 3% or greater. Our committee thought a lot about what defines higher risk and decided that it is very difficult to assign a single cut-off; it really is a matter of an individual's discussion of risks and benefits. It is hard to say that you are at increased risk only if your risk is 3% or greater but not 2.5%. I think it will become easier to assign a cut-off point as we become better at identifying those women at high, intermediate, and low risk. That is probably the biggest difference between the 2 guidelines, but the rest is quite similar.
Weighing the Individual Risk for Breast Cancer
Editor's Note: The American Society of Clinical Oncology (ASCO®) issued the latest update to its guideline on pharmacologic interventions for breast cancer risk reduction in July 2013. The guideline focused on the risks/benefits of pharmacologic intervention vs no pharmacologic intervention, the comparative efficacy of breast cancer chemoprevention agents, and how physicians should communicate issues regarding breast cancer risk reduction in women with increased risk (ie, a 5-year projected absolute risk of ≥ 1.66%). The basis for the update was new evidence from randomized controlled trials and meta-analyses published since the previous update in 2009. This evidence led to strengthened recommendations to consider using tamoxifen (20 mg per day for 5 years) in pre- and postmenopausal women who are at increased risk for invasive breast cancer, specifically estrogen-receptor (ER)-positive breast cancer, and raloxifene (60 mg per day for 5 years) or exemestane (25 mg per day for 5 years) as an option in postmenopausal women. No recommendation is made for the use of other selective estrogen receptor modulators (SERMs) or other aromatase inhibitors to lower breast cancer risk outside of a clinical trial. The guideline strongly encourages healthcare providers to discuss the option of chemoprevention, including the specific risks and benefits associated with each agent, with women at increased breast cancer risk.
Co-chair of the guideline panel, Kala Visvanathan, MD, MHS, spoke to Linda Brookes, MSc, for Medscape, about the ASCO guideline and how it aims to increase awareness and uptake of chemoprevention in women at high risk for breast cancer. Dr. Visvanathan is Associate Professor, Johns Hopkins University School of Medicine, and Director of the Clinical Cancer Genetics and Prevention Service, Johns Hopkins Hospital, Baltimore, Maryland.
Medscape: Why did ASCO decide to issue an update to this guideline?
Dr. Visvanathan: New evidence had emerged. There were data on the aromatase inhibitor exemestane, longer-term data on tamoxifen, longer-term data comparing tamoxifen and raloxifene, and additional data on net health benefits with both raloxifene and tamoxifen within specific patient groups. All of those studies are reasons why we thought it was a good time to update the guideline.
Medscape: The US Preventive Services Task Force (USPSTF) issued its own recommendation statement on medications for risk reduction of primary breast cancer in women. Do the guidelines differ in any major way?
Dr. Visvanathan: They are similar. One difference is in the cut-off for what is considered to be higher risk. The USPSTF concluded that for an estimated 5-year breast cancer risk -- on the basis of Freedman risk/benefit indices -- the threshold for likely benefit over risk from using tamoxifen or raloxifene is 3% or greater. Our committee thought a lot about what defines higher risk and decided that it is very difficult to assign a single cut-off; it really is a matter of an individual's discussion of risks and benefits. It is hard to say that you are at increased risk only if your risk is 3% or greater but not 2.5%. I think it will become easier to assign a cut-off point as we become better at identifying those women at high, intermediate, and low risk. That is probably the biggest difference between the 2 guidelines, but the rest is quite similar.
