Breast cancer (BC) is the most prevalent oncological disease worldwide, with an estimated incidence of 2.3 million diagnoses in 2020, representing 11.7% of cancer diagnoses [1].

The diagnosis of BC, the oncological treatment, and the subsequent adaptation to changes experienced during the process can have a negative impact on quality of life (QoL), including physical, emotional, social, and functional areas [2, 3]. Nevertheless, several psycho-oncological interventions have proven their efficacy in reducing emotional distress, the fear of recurrence, and post-traumatic symptoms, while facilitating better psychosocial adjustment to the diagnosis and contributing to an increase in health-related QoL [3,4,5]. A common factor among some of these interventions is the group component [6, 7]; throughout an oncological process, social support emerges as a crucial factor. Studies suggest that patients lacking a social support network undergo more challenging healthcare experiences [8]. Moreover, variables such as emotional distress and post-traumatic growth have been found to be related to social support [9,10,11]. On one hand, as highlighted by Gonzalez‐Saenz de Tejada et al., social support plays a role in reducing emotional distress [11]. On the other hand, prior research has found a positive association between higher levels of social support and increased post-traumatic growth [9, 10].

Within the broader framework of social support, one specific form is “peer support.” Peer support (PS), as defined by Hu et al., is a process in which individuals with the same illness come together to exchange information, share experiences, and provide mutual support and encouragement to face and overcome difficulties [12]. Although research on the impact of PS on oncology patients does not lead to conclusive results, BC patients are often interested in knowing the experience of other patients who undergo similar situations [13, 14]. Some studies suggest that PS can create a safe space leading to emotional support and mutual understanding [15]. Furthermore, interaction among patients beyond the support group can alleviate feelings of loneliness and isolation [16]. The evidence supports the notion that PS may play a significant role in the emotional well-being and QoL of women with BC. Participation in support groups and communities can provide significant benefits, such as improvement in searching, obtaining, and understanding information, a greater perception of social support, an increase in recognition through the sharing of experiences, and even the learning of coping strategies [17, 18]. The symbiotic relationship between improving information-related skills, perceiving increased social support, recognizing shared experiences, and learning coping strategies ultimately leads to a sense of empowerment within the community [17,18,19]. Additionally, empowerment-based interventions in cancer patients have been shown to promote post-traumatic growth [20] while also leading to a decrease in emotional distress through the positive influence of empowerment over autonomy in self-care, perceived control, and feelings of self-efficacy [21,22,23]. It also improves adherence to treatment, an issue of particular significance given that some treatments may be self-administered at home [21, 22, 24]. Furthermore, empowerment has been observed to encourage healthier lifestyles, enhance attendance rates for medical tests, and contribute to improved treatment outcomes [24,25,26]. Empowerment is in fact understood as a multidimensional concept of the awareness of one’s own strengths and the exertion of control over one’s [27].

As Zimmerman (1995) pointed out, it is useful to distinguish between empowering processes and empowerment outcomes, the latter being a consequence of the former. Empowerment processes refer to the actions and experiences that enable individuals to develop skills, manage resources, work as a team, expand social support networks, and strengthen leadership, all with the objective of gaining control and influencing decisions that affect their lives. On the other hand, empowerment outcomes are a product of these processes [28]. As previously found in the study conducted by van Uden-Kraan et al., patients diagnosed with BC and chronic illnesses who participate in online support groups may undergo processes such the exchange of experiences with other participants that contribute to empowerment outcome [19].

Traditionally, communities and support groups have been developed in face-to-face settings, which may not involve a professional facilitator [29] However, for over a decade, the use and development of the internet and social media have given prominence to online support groups and virtual patient communities, not only in the field of oncology but also in mental health and chronic illnesses [19, 29, 30]. Research regarding differences between face-to-face and online PS experiences has identified common factors as well as benefits associated with specific delivery formats [29]. Among the specific benefits, online communities offer the possibility of remaining anonymous, reducing implementation costs, and facilitating accessibility [27, 31]. Finally, it is essential to consider the digital literacy of patients to ensure that their participation is not hindered by difficulties in handling technology [32].

Regarding the potential benefits of PS, in 2019, the Catalan Institute of Oncology established a PS App for BC survivors called Comunitats in Catalonia and Oncommunities in Madrid (from now on in this article, Comunitats). The app aims to provide an accessible, secure, and anonymous space where BC survivors can receive PS. The community operates asynchronously, allowing conversations to extend over time, in contrast to the limitations of face-to-face support groups. Unlike other PS groups, Comunitats involves healthcare professionals such as psychologists, nurses, and social workers, and offers health education resources on topics that patients most frequently seek information about [13]. Given the potential impact of PS reported in previous research, this study aims to investigate whether (1) participation in Comunitats promotes empowerment among BC survivors; (2) empowerment processes within the community defined by Uden-Kraan [19] can predict empowerment outcomes; and (3) empowerment outcomes are related with other variables such as post-traumatic growth and emotional distress.