Breast cancer patients likely to skip follow-up therapy if not treating other chronic ills
Researchers at Columbia University's Mailman School of Public Health and Columbia University Medical Center found that patients who did not adhere to their medication schedule for chronic conditions, such as hypertension, diabetes, and thyroid disease, prior to a breast cancer diagnosis were twice as likely to skip oral adjuvant hormonal therapy. Patients who skipped medications for their chronic conditions had a 23 percent non-adherence rate to hormone treatment, compared with 10 percent for those who took one or more drugs for their conditions prior to a breast cancer diagnosis.
The study is among the first to associate prior medication adherence patterns and subsequent adherence for breast cancer drug therapy. Findings are published online in JAMA Oncology.
This large population-based study was based on data from the Truven Health Analytics MarketScan, a medical and pharmacy insurance claims database. The researchers identified 21,255 women 18 years or older who were diagnosed with breast cancer in 2010-2012 and had filled two or more prescriptions for tamoxifen and/or an aromatase inhibitor. Overall, 16 percent were non-adherent to their hormone replacement therapy.
"Given the fact that medications used in oncology are potentially life-saving or life-prolonging, it is surprising that non-adherence to these medications is common," said Alfred I. Neugut, MD, PhD, Myron M. Studner Professor of Cancer Research and Professor of Epidemiology at Columbia University's Mailman School of Public Health and lead author of the study.
Age had a strong association with adherence versus non-adherence. Compared to women with breast cancer between the ages of 55 and 64, women younger than 45 years and those between the ages of 45 to 54 were more likely to be less adherent, as were those 75 years of age or older. Women who were African-American, being treated by a specialist other than a medical oncologist, as well as those who had poor belief in the treatment's efficacy, lower financial resources, and higher co-payments for the drug, were also less likely to adhere to the treatment. As the 30-day out-of-pocket costs rose from $5, there was a gradual increase in non-adherence.
Having a greater number of chronic conditions and a history of non-adherence to chronic medications in the year prior to a patient's breast cancer diagnosis–regardless of the number of medications a woman was taking–was also associated with not taking the medications. "This finding revealed that those who are non-adherent to chronic medications are at increased risk for non-adherence to hormone therapy and could benefit from vigilance and possible future interventions," noted Dr. Neugut.
Of the women studied, 62 percent initially used aromatase inhibitors, while 38 percent started with tamoxifen. Almost two-thirds (63 percent) used at least one prior medication for a chronic condition. These included common drugs for six chronic conditions: diabetes, hypertension, hyperlipidemia, thyroid disease, osteoporosis, and gastroesophageal reflux disease (GERD). The average rates of non-adherence in the year prior to the hormone therapy were substantial: 37 percent for diabetes; 28 percent, hypertension; 30 percent, hyperlipidemia; 21 percent, thyroid disease; 32 percent, osteoporosis; and 38 percent, gastroesophageal reflux disease.
"Non-adherence to hormone therapy for breast cancer can have significant impact on survival outcomes," said Dr. Neugut. "The hope is that by identifying patients at highest risk for non-adherence and having a detailed history of medication use, interventions can be developed and targeted at higher- risk groups."
Co-authors: Xiaobo Zhong, MS; Jason D. Wright, MD; Melissa Accordino, MD; Jingyan Yang, MHS; and Dawn L. Hershman, MD, MS.
The study was supported by the Department of Defense (grant BC043120), the American Medical Association, Breast Cancer Research Foundation, the American Society of Clinical Oncology, and the Witten Family Foundation. Dr. Neugut has served as a consultant to Pfizer, Teva Pharmaceuticals, Takeda Pharmaceuticals, United BioSource Corporation and serves on the Medical Advisory Board of EHE, Intl. No financial conflicts are reported.
About Columbia University's Mailman School of Public Health
Founded in 1922, Columbia University's Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Mailman School is the third largest recipient of NIH grants among schools of public health. Its over 450 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change & health, and public health preparedness. It is a leader in public health education with over 1,300 graduate students from more than 40 nations pursuing a variety of master's and doctoral degree programs. The Mailman School is also home to numerous world-renowned research centers including ICAP (formerly the International Center for AIDS Care and Treatment Programs) and the Center for Infection and Immunity. For more information, please visit http://www.mailman.columbia.edu
Columbia University Medical Center provides international leadership in basic, preclinical, and clinical research; medical and health sciences education; and patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Columbia University Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest faculty medical practices in the Northeast. For more information, visit cumc.columbia.edu or columbiadoctors.org.