Does Sleep Mediate Improvements in Functional Adaptation After a Stress Management Intervention For Women With Breast Cancer?

The time of cancer diagnosis and treatment may be marked by an increase in stressors, which may be associated with poorer psychosocial and physical adaptation and increased sleep difficulty. Prior work has shown that psychosocial interventions that teach stress management skills can improve indicators of psychosocial and physical adaptation in women with breast cancer, mostly in cancer survivors who have completed treatment. The extant literature does not examine the effects of stress management on sleep, or the role that sleep plays in mediating psychosocial and physical adaptation outcomes, among women in the midst of treatment for non-metastatic breast cancer (BCa). Two hundred forty (240) women, recruited post-surgery from oncology practices, were randomly assigned to a 10-week group-based cognitive behavioral stress management intervention (CBSM; n = 120) or 1-day psychoeducation (PE) control (n = 120). The intervention consisted of didactics, CBSM techniques, and relaxation exercises, but did not specifically target sleep or sleep quality (SQ). Women assigned to the PE condition attended a one-day group seminar where they learned some of the material covered in the CBSM intervention, without the therapeutic group environment, role play techniques, and home practice. Participants completed self-report questionnaires at baseline, and at 6- and 12-month follow-ups. After controlling for days since surgery, participants in the CBSM group reported improved SQ, as well as increased positive states of mind, decreased disruption in social recreational functioning, and reduced fatigue-related daytime dysfunction for up to 8 - 12 months after baseline. There were marginally significant improvements in functional well-being and social functioning. CBSM was not associated with improvements in fatigue intensity. Improvements in SQ mediated CBSM-associated improvements in positive states of mind, social disruption, and fatigue-related daytime dysfunction. Thus, the CBSM intervention had beneficial effects on several indicators of functional adaptation that were in part explained by improvements in the quality of sleep. Future work should test the combined effects of stress management and sleep management interventions for women initiating treatment for BCa.