Factors associated with insomnia symptoms over three years among premenopausal women with breast cancer.

PURPOSE

We examined longitudinal trends and factors associated with insomnia over 3 years in a cohort of young breast cancer patients.

METHODS

Women with stage I-III breast cancer at ≤ 45 years were recruited at five institutions from New York, Texas, and North Carolina, within 8 months of diagnosis (n = 836). Participants completed questionnaires every 6 months for 3 years. Linear mixed-effects models were used to examine insomnia over time, using the Women's Health Initiative Insomnia Rating Scale (WHIIRS). We evaluated the relations of insomnia with demographic (age, race, education, income, employment, marital status), clinical (cancer stage, histologic grade, chemotherapy, radiation, hormone therapy, surgery, tumor size, body mass index, hot flashes), and social/behavioral variables (smoking status, social support, physical activity, depressive symptoms).

RESULTS

At baseline, 57% of participants met or exceeded the cut-off for clinical insomnia (WHIIRS score ≥ 9). Insomnia symptoms were most prevalent at baseline (p < 0.0001), but decreased significantly throughout follow-up (p < 0.001). However, 42% of participants still experienced insomnia symptoms 3 years after diagnosis. In multivariable models, older age (p = 0.02), hot flashes (p < 0.0001), and depressive symptoms (p < 0.0001) remained significantly associated with insomnia over time.

CONCLUSIONS

Insomnia symptoms were most frequent closer to breast cancer diagnosis and treatment, but persisted for some women who were older and those reporting higher hot flashes and depressive symptoms. Survivorship care should include assessing insomnia symptoms, particularly during and immediately after primary treatment. Implementing early interventions for sleep problems may benefit young breast cancer survivors and improve their quality of life.