The investigator proposes to use the cardiac coherence technique (Cardiac Coherence) coupled with a hypnosis session to reduce pre-operative anxiety.

The perioperative period is recognized as anxiety-provoking for most patients. In oncology, 60 to 80% of patients suffer from stress throughout their treatment. If for some patients, this anxiety is more or less manageable, for others, it is the major concern with regard to their intervention.

For many years, pharmacological premedication, especially with benzodiazepines, has been the gold standard for the treatment of preoperative anxiety, but this systematic prescription is increasingly controversial, especially in populations most exposed to side effects, such as elderly subjects and patients with cardiac or respiratory pathologies.

The aim of this study is to propose an alternative to pharmacological premedication by a non-drug approach.

The two techniques (the Fixed Rate Guided Breathing Technique = cardiac coherence and hypnosis) can potentiate each other and become synergistic. Thus, for patients undergoing oncological surgery, regular practice of cardiac coherence coupled with hypnosis prior to their surgery should enable them to better manage perioperative anxiety and thus significantly reduce their level of anxiety on the day of their surgery.

The association of the 2 techniques combines several advantages:

• It is totally "physiological", free and immediately available for the patient and without any undesirable effect;
• It gives autonomy to the patient to manage his stress, making him independent of chemical molecules, the presence of a third party or expensive equipment.
• It will allow oncology patients to use it throughout their care (invasive examinations, MRI imaging, heavy and complex care such as certain dressings, etc.)

This work will allow:

• To give oncology patients the possibility to be actors of their care by a self-management of their anxiety in substitution or complement of a medicated approach;
• To map anxiety in oncology surgery using a simple scale such as the EVA, which has not yet been done;
• To identify the most anxious patients in order to provide them with the appropriate management (pharmacological and/or NMI) before their surgery;
• To evaluate the correlation between the level of preoperative anxiety and the occurrence of postoperative adverse events;
• To evaluate the correlation between the level of anxiety and the quality of recovery (QoR) and the postoperative experience (EVAN-G).

Patients in the experimental group will be interviewed to explain how to perform the cardiac coherence and hypnosis sessions at home before the surgery.

Inclusion Criteria:

1. Age ≥ 18 years old
2. Patient with a scheduled surgery for a cancer (suspected or declared) with a classic or ambulatory hospitalization
3. Patients requiring general anesthesia with or without associated loco-regional anesthesia or loco-regional anesthesia alone
4. Patient with a smartphone or a tablet or a computer and able to install the application
5. Inclusion of the patient minimum 7 days before the date of the surgery
6. Patient who signed the informed consent
7. Patient affiliated to a French social security system

Exclusion Criteria:

1. Emergency surgery
2. Plastic surgery for reconstruction: lipomodelling
3. Prophylactic surgery: no suspected or existing cancer
4. Bradycardia (< 50 beats/minute) with β-blockers
5. Severe heart failure with ventricular ejection fraction < 40%
6. Uncontrolled chronic pain for more than three months on morphine
7. Patient with unstable epilepsy or respiratory pathology with rest dyspnea
8. Patient used to and having a regular and habitual practice of relaxation techniques such as yoga, hypnosis, sophrology, meditation, music therapy, virtual reality, ...
9. Medical (neurological, psychiatric, etc.) or psychological conditions not allow for participation in the protocol (completion of questionnaires and booklet, compliance with the cardiac coherence program coupled with hypnosis)
10. Deaf patient without hearing aids
11. Patient under guardianship or curatorship

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.