Fig. 2: Multivariable-adjusted mean change in breast sound speed (m/s) by treatment-associated endocrine symptoms and endocrine symptom frequency.

a By treatment-associated endocrine symptoms. Treatment-associated endocrine symptoms were defined as either emergent or worsening vasomotor symptoms and/or joint pain after tamoxifen initiation. P-trend for those with symptoms = 0.004, P-trend for those without symptoms = 0.18; P-interaction between endocrine symptom group and time = 0.02. b By endocrine symptom frequency. Endocrine symptom frequency was assessed with a Likert scale for symptom frequency per week (vasomotor and joint pain) and per day (vasomotor only). An endocrine symptom severity score was created by summing the values for each item and categorized into tertiles defined as no symptoms (score = 0), low/moderate (score = 1–5), and high (score=6+). P-trend for those with no symptoms = 0.91, low/moderate symptoms = 0.03, high symptoms = 0.004. P-interaction between endocrine symptom frequency and time = 0.61. All models were adjusted for age, race, menopause status, body mass index, and baseline sound speed. P-trends were calculated by modeling the time interval from tamoxifen initiation (T1, T2, T3) as a continuous variable using the Wald test. P-interactions were evaluated with multiplicative interaction terms using the Wald test. Error bars represent 95% confidence intervals.