Objective: Hot flashes are valuable indicators of physiological condition and drug effect; however, subjective and objective measures do not always agree. No study has examined both subjective and objective hot flashes in women prescribed aromatase inhibitors. The study (1) compared subjective and objective hot flash measures, (2) examined changes in subjective and objective hot flashes over time, and (3) evaluated predictors of change in hot flashes in aromatase inhibitor-treated women.
Methods: Participants (n = 135) were enrolled in a randomized clinical trial comparing exemestane and letrozole for the treatment of breast cancer. Hot flashes were assessed before the start of the drug therapy and 1, 3, and 6 months later. Participants wore a sternal skin conductance monitor for 24 hours or longer at each time point. With each perceived hot flash, women pressed an event button and rated intensity and bother in a paper diary.
Results: Participants had a mean age of 60 years and were mainly white (92%). Across time points, monitor hot flashes were (1) significantly more frequent than diary and/or event button flashes (P < 0.05) and (2) moderately correlated with subjective measures (0.35 < r < 0.56). Monitor hot flashes did not significantly change over time with aromatase inhibitor therapy, whereas both diary and event button frequencies significantly varied but in dissimilar patterns (51% nonlinear). No consistent predictors of hot flashes across measures or time points were identified.
Conclusions: Findings indicated dissimilarities between subjective and objective measures of hot flashes. Despite statistical significance, there was little clinically meaningful change in hot flashes after initiating aromatase inhibitor therapy.
Findings indicated dissimilarities between measures, hot flash frequency and hot flash intensity and bother did not significantly change over time, diary and event button flashes significantly changed but in dissimilar patterns, and few consistent predictors of change in hot flashes were identified.
From the Schools of 1Nursing and 2Medicine, Indiana University, Indianapolis, IN; 3Breast Oncology Program, University of Michigan Comprehensive Cancer Center, Ann Harbor, MI; and 4Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD.
Received January 19, 2009; revised and accepted March 17, 2009.
Funding/support: This work was supported in part by Pharmacogenetics Research Network Grant U-01 GM61373, which supports the Consortium on Breast Cancer Pharmacogenomics; a Clinical Pharmacology Training Grant 5T32-GM08425 from the National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD; Indiana University General Clinical Research Center (GCRC) Grant M01RR00750 from the National Institutes of Health, Bethesda, MD; University of Michigan GCRC Grant M01-RR00042 from the National Institutes of Health, Bethesda, MD; Johns Hopkins University School of Medicine GCRC Grant M01-RR00052 from the National Institutes of Health, Bethesda, MD; the Fashion Footwear Charitable Foundation of New York/QVC Presents Shoes on Sale; and an interdisciplinary training grant from the National Cancer Institute for Research in Behavioral Oncology and Cancer Control NCI R25 CA 117865.
Financial disclosure/conflicts of interest: Dr. Henry is on the Scientific Advisory Board at Otsuka Pharmaceutical and has received research funding from AstraZeneca and Eli Lilly.
The description of the study design can be found on www.ClinicalTrials.gov (NCT00228956).
Address correspondence to: Julie L. Otte, PhD, RN, Indiana University, 1111 Middle Drive NU236, Indianapolis, IN 46202. E-mail: firstname.lastname@example.org