As much as 45 to 60% of patients treated with hormonotherapy (HT) for breast cancer (BC) suffer from osteoarticular pain during treatment. Secondary effects have become a real issue because of their consequences on the patients' quality of life, but also on treatment efficacy and survival when they induce dose reduction or premature withdrawal of treatment.

Additional medicines (acupuncture, hypnosis, yoga) have become more and more popular these last years. 48 to 80% of patients with BC eventually choose them. A review comparing efficacy of various therapies to decrease osteoarticular pain concludes to a highest efficacy of anti-inflammatory treatments, paracetamol and yoga.

With this project, the investigators will assess the feasibility of a therapeutic yoga program with home practice for patients with breast cancer treated with hormonotherapy. The investigators will measure adhesion of the patients to perform yoga postures in an autonomous manner. Our study will also allow collection of data on the effect of such a program on quality of life, in view of setting-up an intervention study.

Numerous initiatives have started in France, often associative. It is essential to evaluate in a rigorous manner, these therapies before making them part of the patient's care pathway.

Yoga has shown a real benefit in terms of pain reduction in patients with BC treated with HT. These osteoarticular pains are the secondary effect on which a physical therapeutic care can have a real benefit.

It thus appears innovative to complete this care with a therapeutic education program (TEP) in postural yoga which will enable patients to practice yoga postures at home by themselves. Yoga allows a large adaptation to pains expressed by each patient. It will favor the development of the feeling of control that they have in particular on their pain. participants will so improve the self-efficacy, the quality of life, and will reduce their fatigue and their pain. The patients involved have already lived major body transformations because of the disease and treatments. Yoga will help them put their lives together again, both physically and psychologically, and reclaim their body.

Studies have shown the short-term effects of yoga practice on anxiety, stress, pain and quality of life. Few rare studies have suggested that patients could add yoga practice at home to the supervised sessions, but these studies lacked therapeutic patient education. To date, to our knowledge, no data on the effect of the realization of yoga postures at home on increase of the patients' self-competency feeling are available in France. Also, the long-term effects of such programs need to be assessed.

The Montpellier Cancer Institute (ICM) has set-up 8 years ago yoga sessions for women with breast cancer, together with an association located in Montpellier.

With this study, the investigators will assess the feasibility of an educational yoga program given by a trained physical therapist in patients with beast cancer treated with hormonotherapy.

Inclusion Criteria:

• Age ≥ 18 years
• Non metastatic breast cancer
• Ongoing hormonotherapy, with no treatment modification in the 30 days before inclusion
• Osteoarticular pain ≥ 4 (resting or moving) on the VAS (Visual Analogue Scale)
• Previous treatment (surgery, chemotherapy or radiotherapy) ended at least 2 months before inclusion
• Informed patient and signed informed consent received
• Affiliation to a social security category

Exclusion Criteria:

• Chronic rheumatologic pain with specific care needed
• Yoga practice in the 3 months before inclusion
• Contra-indication or clinical state not allowing physical practice