Complementary and alternative medicine and musculoskeletal pain in the first year of adjuvant aromatase inhibitor treatment in early breast cancer patients.

Background: Patients with breast cancer (BC) show strong interest in complementary and alternative medicine (CAM), particularly for adverse effects of adjuvant endocrine treatment - e.g., with letrozole. Letrozole often induces myalgia/limb pain and arthralgia, with potential noncompliance and treatment termination. This analysis investigated whether CAM before aromatase inhibitor (AI) therapy is associated with pain development and the intensity of AI-induced musculoskeletal syndrome (AIMSS) during the first year of treatment.
Patients and Methods: The multicenter phase IV PreFace study evaluated letrozole therapy in postmenopausal, hormone receptor-positive patients with early BC. Patients were asked about CAM use before, 6 months after, and 12 months after treatment started. They recorded pain every month for 1 year in a diary including questions about pain and numeric pain rating scales. Data were analyzed for patients who provided pain information for all time points.
Results: Of 1396 patients included, 901 (64.5%) had used CAM before AI treatment. Throughout the observation period, patients with CAM before AI treatment had higher pain values, for both myalgia/limb pain and arthralgia, than non-users. Pain increased significantly in both groups over time, with the largest increase during the first 6 months. No significant difference of pain increase was noted regarding CAM use.
Conclusions: CAM use does not prevent or improve the development of AIMSS. Pain intensity was generally greater in the CAM group. Therefore, because of the risk of non-compliance and treatment discontinuation due to the development of higher pain levels, special attention must be paid to patient education and aftercare in these patients.
Competing Interests: Declaration of competing interest S·Y.B. has received honoraria from Pfizer and Novartis. W.J. has received honoraria and research grants from Novartis. A.D.H. has received honoraria from AstraZeneca, Genomic Health, Roche, Novartis, Celgene, and Pfizer. R.W. has received honoraria and research funds from Novartis. S.K. has received honoraria from Roche, Celgene, Amgen, and AstraZeneca and funding support from Roche. C.T. has received honoraria from Novartis, Pfizer, and AstraZeneca. M.P.L. has participated on advisory boards for AstraZeneca, MSD, Novartis, Pfizer, Genomic Health, and Roche and has received honoraria for lectures from Lilly, Roche, Novartis, Pfizer, Genomic Health, AstraZeneca, medac, and Eisai. P.G. has received honoraria from Novartis and financial support for symposia from Novartis, Roche, and PharmaMar. H.-C.K. has received honoraria from Carl Zeiss meditec, TEVA, Theraclion, Novartis, Amgen, Astra Zeneca, Pfizer, Janssen-Cilag, GSK, LIV Pharma, Roche, and Genomic Health. D.S.-B. has received honoraria from Novartis. M.W.B.‘s institution has received research grants from Novartis. T.F. has received honoraria from Pfizer, Novartis, Roche, and Amgen. P.A.F. has received honoraria from Roche, Pfizer, Novartis, and Celgene. His institution conducts research for Novartis. N.N. has received honoraria from Janssen-Cilag, Novartis and Teva. All of the remaining authors have declared that they have no conflicts of interest.
(Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)