SAN ANTONIO – Physicians tend to broadly overestimate their own breast cancer patients’ compliance with adjuvant aromatase inhibitor therapy, according to a large observational German study.
Among 2,313 postmenopausal breast cancer patients who were enrolled in the ongoing COMPACT (Compliance and Arthralgias in Clinical Therapy) study, 80.5% stated that they took all or nearly all of their prescribed anastrozole tablets during their first year on adjuvant endocrine therapy.
In contrast, 93.2% of their oncologists indicated they believed those same patients had taken all or nearly all of their medication, Dr. Peyman Hadji reported at the San Antonio Breast Cancer Symposium.
Among COMPACT participants, 11.9% indicated that they experienced pre-existing arthralgias within 4 weeks prior to going on the aromatase inhibitor. Another 17% reported new-onset arthralgias after starting on anastrozole, according to Dr. Hadji of the University Hospital of Giessen and Marburg (Germany) GmbH.
Session chair Dr. Thomas J. Smith said that these initial data from the COMPACT study contain a key take-home message: "I think it certainly behooves me as a breast cancer doctor to ask every time, ‘Are you having trouble with these drugs?’ because people do have trouble with these drugs, and they don’t want to bother us."
Another take-home point is that although roughly 12% of breast cancer patients have pre-existing arthralgias, the prescription of an aromatase inhibitor increases the population of affected individuals by close to an absolute 20%, added Dr. Smith, director of palliative care and professor of oncology at Johns Hopkins University, Baltimore.
Dr. Peyman Hadji
Dr. Hadji said that going forward, COMPACT will assess the frequency and severity of aromatase inhibitor–associated arthralgias in real-world clinical practice, will chart rates of arthralgia-related treatment noncompliance, and will document the effectiveness and costs of various treatments.
Dr. Smith observed that to date there is a noteworthy lack of good-quality, randomized trial data to guide treatment of aromatase inhibitor–associated arthralgias. Dr. Hadji concurred. He said he and his colleagues have had favorable experiences using NSAIDs, but that’s anecdotal experience. Regarding high-quality data, he cited what he termed a "wonderful" double-blind study showing benefit for acupuncture (J. Clin. Oncol. 2010;28:1154-60).
"The data were really fascinating, but we couldn’t find anybody in our clinic to start doing it. For whatever reasons, oncologists don’t like putting needles into patients," he quipped.
The COMPACT study is sponsored by AstraZeneca. Dr. Hadji serves as a consultant to the company.