Breast cancer, the most common cancer in women, is increasingly managed as a chronic disease thanks to therapeutic advances. However, treatments such as chemotherapy and hormonotherapy often induce premature menopause in younger women, leading to skin aging, atrophy, and distressing symptoms that negatively affect quality of life. These cutaneous effects are frequently overlooked despite their psychological and social impact. Hyaluronic acid injections, already well established in aesthetic and reconstructive medicine, may offer a safe, minimally invasive option to restore skin quality, improve self-esteem, and enhance overall well-being in breast cancer survivors. This study aims to assess their efficacy and safety in this specific population.

Inclusion Criteria:

1. Women ≥ 18 years old and ≤ 50 years old.

2. Non-menopausal status at time of diagnosis of breast cancer (self-reporting).

3. Patient with breast cancer (uni or bilateral):

   1. treated at the Institut Bergonié by chemotherapy (+/- targeted/immunotherapy) and surgical treatment (conservative or not) and/or hormone therapy and/or radiotherapy
   2. who completed their treatment at least 6 months ago including end of treatment with Herceptin but with the exception for ongoing hormone therapy
   3. in complete remission

4. Non-immunosuppressed patient.

5. Voluntarily signed and dated written informed consent prior to any study specific procedure.

6. Patient affiliated to a social security in compliance with Article 1121-11 of the French Public Health Code.

Exclusion Criteria:

1. Patients with a history of or declared autoimmune disease or immune system deficiency or undergoing immunosuppressive treatment. A 6-month washout is required.
2. Patients undergoing or planning to undergo peeling treatment or laser/ultrasound-based or botox treatment or hyaluronic acid injections during the study or having had one of these treatments in the 6 months preceding the study.
3. Patients showing cutaneous disorders, inflammation or infection (acne, herpes labialis, scars…) at the treatment site or near to this site.
4. Patients having a known hypersensibility to lidocaine and/or amide local anaesthetic agents or hyaluronic acid and/or proteins from gram-positive bacteria, or with a history of severe allergy or anaphylactic shock.
5. Patients with a history of streptococcal disease (recurrent sore throat, rheumatic fever)
6. Patients with autoimmune or cardiac diseases (i.e. heart conduction disorders) and/or undergoing treatment for heart diseases (beta-blockers).
7. Patients with hepatocellular insufficiency and/or undergoing treatment for liver disease.
8. Patients suffering from epilepsy not controlled by a treatment or porphyria.
9. Patients with a tendency to develop hypertrophic scars.
10. Patients with severe, ongoing and/or uncontrolled disease that may pose a health risk to the patient during the study and/or may have an impact on the study assessments.
11. Patients receiving or planning to receive high dose Vitamin E, aspirin, anti-inflammatories, or anti-coagulant during the week preceding each injection
12. Patients receiving any long-term medical treatment or any treatment that, in the opinion of the clinical investigator, may interfere with test results or put the patient at undue risk.
13. Patients under guardianship/tutorship.
14. Pregnant women or breastfeeding mothers.

Female