Breast cancer remains the most common cancer among women and a major cause of death despite advances in screening and treatment. Current screening programs are not personalized and are experiencing declining participation. A promising strategy for breast cancer control would be to implement risk-based prevention and early screening, targeting individuals at high risk of developing breast cancer, in order to improve chances of cure and reduce the need for more intensive treatments. The MyPeBS study was designed to assess whether personalized breast cancer screening (based on an individual's risk of developing breast cancer) is as effective as, or more effective than, current standard screening.

Lifestyle interventions involving changes in diet or physical activity, for example, have been shown to be effective in reducing the risk of developing breast cancer, whether low or high. The MyPeBS study evaluates personalized screening but offers limited information on breast cancer prevention. MyPREV is a project that aims to assess the feasibility and impact of a personalized online program on breast cancer risk reduction measures. This program is offered to women at high risk of developing breast cancer as part of the European MyPeBS screening study.

The main objective is to evaluate adherence to a personalized, online breast cancer prevention program focused on lifestyle and its acceptance among women at high or very high risk of developing cancer who participated in the MyPeBS study.

MyPREV is a prospective interventional cohort study. The study is based on an online educational, medical, and motivational intervention (webinar and online personalized clinical visit) dedicated to promoting and implementing lifestyle-based breast cancer risk-reduction measures among women identified in the MyPeBS trial as being at high or very high risk of breast cancer based on Polygenic risk score (PRS) and clinical scores. In MyPeBS, 34.4% of the women in the risk-based arm were estimated to be at high (33.03%) or very high (1.37%) to develop a breast cancer within 5 years.

The study MyPREV plans to invite 3016 women (1821 in France and 1195 in Italy for the sites CPO and ISPRO). The expected participation rate is 50%, so around 1507 women (910 in France and 597 in Italy for the sites CPO and ISPRO). The intervention consist of a virtual webinar and an online personalized clinical visit where the personalized prevention plan will be created.

Inclusion Criteria:

1. Female (whether born female or not)
2. Women aged 40 to 74 years (inclusive)
3. Women who have participated in, or are participating in the MyPeBS study and who fulfilled all the inclusion and non-inclusion criteria for the MyPeBS study.
4. Women able to express their non-opposition to participate in the intervention
5. Women who were assessed as being at high (≥≥1.67% - 5.9%) or very high (≥≥6%) risk of invasive breast cancer at 5 years in the MyPeBS study

Exclusion Criteria:

1. Women who developed a breast cancer during their follow-up in the MyPeBS study

Unicancer will share de-identified individual data that underlie the results reported.

A decision concerning the sharing of other study documents, including protocol and statistical analysis plan will be examined upon request.

Unicancer will consider access to study data upon written detailed request sent to Unicancer, 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 Unicancer for personal access, and data will only be transferred after signing of a data access agreement.