UCLA

Background

Adherence to adjuvant endocrine therapy (ET) influences breast cancer survival. Because ET side effects are frequently cited as reasons for nonadherence, understanding how perceptions and motivations in relation to ET are associated with symptom attribution can help promote timely symptom management.

Materials and methods

Participants were 2,086 breast cancer survivors recruited through the Army of Women registry who were current tamoxifen or aromatase inhibitor (AI) users. Participants reported whether they were bothered by each of 47 symptoms during the past month and whether they thought each symptom was related to taking ET. Frequencies of overall symptoms and symptoms attributed and misattributed to ET were calculated, and linear regression was used to assess sociodemographics, emotions, and illness perceptions as predictors of symptoms attributed to ET.

Results

Women attributed a mean of 8.9 symptoms and misattributed a mean of 1.5 symptoms to ET. In the multivariable analysis, younger age, a more recent diagnosis, AI use (vs. tamoxifen), anxiety, depressive symptoms, more ET-related negative emotions, more concern about long-term ET use, and greater perceived ET necessity were independently associated with attribution of more symptoms to ET. More perceived ET necessity was associated with correctly attributing symptoms to ET, whereas higher depressive symptoms and more concern about ET use were associated with misattribution of symptoms to ET.

Conclusion

Given that many women perceive a range of symptoms as a consequence of ET, attention to these symptoms may reduce symptom burden and improve quality of life, potentially improving ET adherence and optimizing survival.

Implications for practice

Many breast cancer survivors on endocrine therapy (ET) experience a range of side effects while taking ET. Targeting potentially modifiable factors associated with attributing a greater number of symptoms to ET, including perceived need for ET, concerns about long-term ET use, negative emotions toward ET, and symptoms of anxiety and depression, may reduce symptom burden and improve quality of life.