As much as 50% 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.

It thus appears innovative to complete this care with a patient educational project (PEP) in postural yoga instructed by a trained physical therapist, which will enable patients to practice yoga postures at home by themselves.

The investigators conducted a pilot study "SKYPE" with 24 algic patients treated with HT after BC, whose results are very promising.

The investigators now propose in the continuity of the pilot study a multicenter randomized controlled study comparing the efficacy of SKYPE care on pain reduction, an educative care combining physical therapy and yoga, to a control group in patients treated with HT for a BC with osteoarticular and/or musculoskeletal pain.

Furthermore, in order to examine whether yoga interventions may influence inflammation through their effects on the level of a wide range of pro- and anti-inflammatory cytokines (30), the investigators will Change in circulating cytokines' level between baseline level (T0) and post-treatment level (T2) in both groups will be analyzed and if so correlation will be established.

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.

Inclusion Criteria:

• Age ≥ 18 years
• Non metastatic breast cancer
• Ongoing hormone therapy, with no treatment modification in the 30 days before inclusion
• Osteoarticular and/or musculoskeletal pain due to HT ≥ 4 on the Numeric Pain Rating Scale (NPRS)
• 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 system

Exclusion Criteria:

• Chronic rhumatologic pain with specific care needed
• Regular Yoga practice in the 3 months before inclusion
• Contraindication or clinical state not allowing physical practice
• Patient whose regular follow-up is initially impossible for psychological, family, social or geographical reasons,
• Pregnant and breastfeeding woman

All data will be available after publication of the results in peer-reviewed revues, and in national and international meetings. It includes all de-identified participants' data, the study protocol, the statistical analysis plan and the clinical study report. The corresponding author will provide data and datasets generated and/or analyzed during the study upon reasonable request.

Access to study data upon written detailed request sent to ICM, from 6 months until 5 years after publication of summary data.

The data shared will be limit to that required for independent mandated verification of the published results, the applicant will need authorization from ICM for personal access, and data will only be transferred after signing of a data access agreement.