Background: Online interventions can be a fast, cost-efficient, and convenient medium for providing breast cancer patients (BCP) with access to evidence-based interventions that address their emotional needs. As true as that may be, online interventions are still a novel research area that struggles in implementation.

Objectives: This study aims to determine the acceptability, feasibility, and efficacy of Oncovox, an iACT-BC, a guided internet delivered ACT intervention designed to improve psychosocial outcomes in BCP diagnosed within the last two years when compared to treatment as usual. The primary outcomes in this study are health related quality of life, behavioural activation, symptom interference and reward observation. The secondary outcomes are psychosocial distress, anxiety and depression and psychological flexibility.

Methods: A two-arm, parallel, open label, waiting list randomised controlled trial will investigate the effectiveness, feasibility, and acceptability of Oncovox.

Expected results: It is anticipated that Oncovox will show to be effective, feasible and acceptable programme in improving health related quality of life, behavioural activation, symptom interference, reward observation, psychological distress, anxiety, depression, and psychological flexibility in BCP diagnosed in the last two years, as opposing to a waiting list control under treatment as usual.

An exploratory moderator analysis will be employed to the assess the significance of Time x Group as well as Time x Group x Surgery type interactions for all outcome and process variables. A mediation analysis to assess the effect of psychological flexibility on the outcomes will also be applied.

The results of this research will be published in accordance with CONSORT 2010 and CONSORT-EHEALTH guidelines and should be available for publication in September 2022.

Inclusion Criteria:

• Signed written informed consent.
• Age ≥ 18 years
• Ability to read and write in Romanian
• History of histologically or cytologically confirmed breast cancer
• An interval of < 24 months from histologically or cytologically confirmed breast cancer
• Ongoing curative cancer treatment
• Ongoing regular psychoactive medication only accepted if dosage has been stable during the last 3 months
• Daily access to the Internet by computer and/or smartphone
• Ability to use a computer and/or smartphone and the internet
• No participation on any other interventional study or clinical trial

Exclusion Criteria:

• Age ≤ 18 years
• Inability to co-operate and give informed consent
• Breast cancer not histologically or cytologically confirmed
• History of other malignancy within the last 5 years
• Current severe, uncontrolled systemic disease or mental disorder
• Absence of clinically significant symptoms
• Parallel ongoing psychological treatment
• Ongoing regular psychoactive medication if dosage has been changed during the last 3 months
• No access to the internet
• Inability to use a computer and/or smartphone and the internet
• Parallel ongoing participation in other interventional study or clinical trial
• Assessment by the investigator to be unable or unwilling to comply with the requirements of the protocol

Only female BC diagnosis