Efficacy of the MAEva Program (Meditation, Acceptance, and Commitment to Values) Among Patients Treated For Breast Cancer.

The MAEva program combines Acceptance and Committment Therapy (ACT) and mindfulness practices. It is an open and circular intervention, in three sessions (Mindfulness, Acceptance, and Commitment to values). It is designed for cancer patients and was the subject of an initial study that explored its feasibility and acceptability, as well as the initial results on psychological well-being. This randomized, multicenter clinical trial is necessary to demonstrate the efficacy of the MAEva program compared to a discussion group with non metastatic breast cancer patients. Patients will be included and randomized into two arms: * In the first arm, patients will have the opportunity to participate in the MAEva program for nine consecutive weeks. * and the second arm patients will have the opportunity to participate in a discussion group for nine consecutive weeks. The patients will be able to attend one session per week for nine consecutive weeks. Quantitative assessments of quality of life, symptoms of stress, anxiety, and depression, as well as psychological flexibility, will be conducted before the first session, after 3 weeks, 9 weeks, and 12 weeks. Also, a qualitative analysis will be conducted based on satisfaction questionnaire and a semistructured interview performed after the end of the program. The interview analysis will described the extent to which the intervention is adapted to the realities on the ground and the needs of the target population. It will enable to identify how patients appropriate the psychological flexibility processes taught in the program in relation to the conceptual framework of ACT therapy (i.e., contact with the present moment, self-as-context, acceptance, defusion, values, and committed action) and integrate them into their daily lives.