Telephone Support for Metastatic Breast Cancer Patients

This trial tests the effect of telephone-based Acceptance and Commitment Therapy (ACT) on fatigue interference in metastatic breast cancer (MBC) patients (Aim 1) as well as secondary outcomes (Aim 2). This trial also examines increases in psychological flexibility as a hypothesized mediator of ACT's effect on fatigue interference (Aim 3). Finally, two core aspects of psychological flexibility (i.e., mindfulness/acceptance and commitment/behavior change processes) are examined as exploratory mediators of ACT's effect on fatigue interference. The study team will recruit MBC patients receiving care through Eskenazi Health or Indiana University (IU) Health. Potentially eligible patients will be mailed an introductory letter signed by their oncologist and the PI along with a consent form. The letter will have a number to call if they do not wish to be contacted further. A research assistant (RA) will call all prospective participants who do not opt out approximately 1 to 2 weeks after the letter is mailed. The RA will describe the study as outlined in the consent form and answer any questions. Then the RA will administer an eligibility screening to those who consent to participate. Eligible and consenting patients will complete a 35-minute baseline phone assessment. Following baseline assessments, MBC patients (N = 250) will be randomly assigned in equal numbers to ACT or education/support using a stratified block randomization scheme to balance the groups by age (\<65 yrs. vs. 65+ yrs.) and performance status (patient-reported Eastern Cooperative Oncology Group \[ECOG\] scores 0 or 1 vs. 2). Patients in both study conditions will complete six weekly 50-minute telephone sessions with the first session occurring one week after baseline. For ACT participants, adherence to home practice during the past week will be assessed and recorded during each session. Blind interviewers will assess outcomes and potential mediators during 30-minute follow-up phone assessments at 2 weeks, 3 months, and 6 months post-intervention.