The proposed randomized clinical trial evaluates a diabetes coping skills training (DCST) intervention for improving breast cancer survivors' abilities to manage symptoms and adhere to recommended diabetes self-management. The telephone-based DCST protocol integrates three key strategies to reduce symptoms and improve diabetes self-management: coping skills training for managing symptoms, adherence skills training, and healthy lifestyle skills training. The investigator will test the effects of the DCST intervention by comparing it to diabetes education alone. Physical symptoms, psychological distress, diabetes self-management behaviors, and self-efficacy for managing symptoms and diabetes self-management will be assessed at baseline and 3, 6, and 12 months. Physical activity (i.e., daily steps and distance) will be assessed using wireless activity trackers and data will be obtained from home blood glucose monitoring devices. Glycosylated hemoglobin (HbA1c) will be assessed at baseline, 6, and 12 months.

Together, breast cancer and type 2 diabetes represent a public health crisis. Approximately 20% of the 3.1 million breast cancer survivors in the U.S. have type 2 diabetes, and this number is expected to grow. Breast cancer survivors who have type 2 diabetes are at high risk for cancer recurrence, serious health complications, and premature death. Breast cancer survivors with type 2 diabetes experience more severe, disabling symptoms and psychological distress relative to breast cancer survivors without diabetes. For breast cancer survivors with type 2 diabetes, maintaining glycemic control is critical for decreasing symptoms and preventing serious health problems. Important diabetes self-management strategies include physical activity, dietary modifications, medication, and blood glucose monitoring. Many breast cancer survivors with type 2 diabetes have difficulty maintaining these behaviors and achieving glycemic control. Physical symptoms and psychological distress are often barriers to engaging in diabetes self-management. The proposed study evaluates a novel diabetes coping skills training (DCST) intervention for improving breast cancer survivors' abilities to manage symptoms and adhere to recommended diabetes self-management. The telephone-based DCST protocol is based on our prior work and integrates three key theory-based strategies: coping skills training for managing symptoms, adherence skills training, and healthy lifestyle skills training. The proposed randomized clinical trial (N=230) will test the effects of the DCST intervention by comparing it to diabetes education alone. Physical symptoms, psychological distress, diabetes self-management behaviors, and self-efficacy will be assessed at baseline and 3, 6, and 12 months. Physical activity will be assessed using wireless activity trackers and data will be obtained from home blood glucose monitoring devices. Glycosylated hemoglobin (HbA1c) will be assessed at baseline, 6, and 12 months. The proposed study addresses a critical gap in the care of breast cancer survivors by evaluating a novel behavioral intervention that aims to improve the management of symptoms, adherence, and glycemic control in breast cancer survivors with type 2 diabetes. The findings of this study could lead to significant improvements in clinical care and beneficial outcomes for breast cancer survivors.

Inclusion Criteria:

• diagnosis of Stage I to III breast cancer,
• diagnosis of diabetes mellitus type 2
• completed local definitive treatment (i.e., surgical treatment, chemotherapy and/or radiation therapy),
• physician verification of ability to participate in the intervention,
• English speaking.

Exclusion Criteria:

• <21 years of age,
• severe cognitive or hearing impairment,
• unable to provide meaningful consent (i.e., impairment such that descriptions of the research are not clearly understood),
• presence of a health problem that precludes safe participation in the intervention.