This exploratory, cross-sectional, topic-modeling study was conducted from December 2022 to February 2023 and aimed to explore how patients with breast cancer describe toxic relationships with their partners and immediate family members on Reddit. As of February 2023, the public r/breastcancer subreddit, established in 2011, included 13,900 subscribers and self-identified as a support and information group for people who have been diagnosed with breast cancer and their caregivers and loved ones. While Reddit generally attracts young White men of high socioeconomic status [38], demographics vary by subreddit and r/breastcancer is hypothesized to be largely composed of women [40].

This study was deemed exempt from oversight by the author’s institutional ethics review board because all data were gathered from the public domain (per Article 2.2 of the Tri-Council Policy Statement on Ethical Conduct for Research Involving Humans). The subreddit at the center of this study was public at the time of data collection and writing, meaning that any person could access its content at any time. It was therefore determined that r/breastcancer users had no expectation of privacy, negating the need for oversight by an ethics review board.

This subreddit was scraped for textual data from posts and comments using the Python Reddit application programming interface wrapper. No date limits were imposed. An iterative approach to keyword-based searching extracted posts (n=187) related to toxic relationships with partners and immediate family members. Two keyword strings were combined to scrape data: String 1 included words associated with a toxic relationship (eg, narcissist, boundaries, abuse, violence, assault, unsupportive, cheater, affair, divorce, toxic, abandon, and manipulate) and string 2 included words that identified people of interest in the immediate family of the user (eg, abuser, spouse, partner, marriage, significant other, parent, and sibling). To be scraped, posts were required to include a minimum of 1 keyword from both string 1 and string 2 (see Textbox 1).

The scraped posts were then screened for eligibility by one of the authors (CAD), such that posts were ineligible if they addressed anyone other than a partner or immediate family member, were of an administrative nature posted by a moderator, were posted by a user who did not have breast cancer, aimed to exclusively seek or share medical information, or described toxic relationships outside of the context of breast cancer. After screening, 36 posts were eligible for inclusion. Eligible posts were scraped for comments (n=601), of which 98 were relevant (as determined by CAD using the eligibility criteria described above used to filter posts). Textual data were compiled into packets, where 1 packet represented the total relevant contributions (ie, posts and comments) from a single user, with an average of 260 words per packet. The final data corpus included 96 unique users with 36 posts and 98 comments (see Figure 1).

Reddit users have no expectation of privacy in public subreddits and have agreed to the platform’s end user license agreement; all Reddit user content is subject to use by third parties at any time [41]. However, recommended ethical practices aim to protect participant privacy by censoring usernames and avoiding direct quotes through exclusion or paraphrasing to prevent reverse-searching [38,42]. Accordingly, within this study, users were assigned an original poster (OP) number, and reported quotes were reworded to convey their original meaning and style but protect the OP’s identity. For example (fictitious), “My mom has never bothered checking on me” could become “My mother doesn’t ever ask how I’m doing.”

Seven distinct but related themes emerged from descriptions of toxic relationships by patients with breast cancer on Reddit, presented in order of explained variance proportion (highest to lowest) as follows: (1) contextualizing storytelling with lymph nodes, (2) toxic behavior and venting emotions, (3) abandonment and abuse following diagnosis, (4) toxic relationships and social-related fears, (5) inner strength and navigating breast cancer over time, (6) assessing social relationships and interactions, and (7) community advice and support. The overall corpus sentiment score was –4, indicative of very negative sentiment. Theme-specific sentiment scores () reflect the average valence of retained content words within each component.

The first theme was classified as neutral (=0.00) and included lymph, node, and pick as key content words. Lymph nodes functioned as context indicators in users’ stories about toxic relationships to highlight their temporality within cancer treatment. For example, one user was undergoing chemotherapy while navigating a toxic relationship with their mother. This OP prefaced their post by sharing, “After a lot of treatment, my cancer went from grade 3 to grade 1. My lymph nodes shrunk as well” (OP 66).

They then went on to disclose unsupportive behavior from their mother, stating, “My mom doesn’t think I’m capable of making my own decisions–but I am. I’ve picked excellent physicians and made it to all of my appointments” (OP 66).

The second theme was classified as neutral (=0.00) and described toxic relationships that the user experienced a strong emotional reaction to, which prompted them to vent their emotions on Reddit. Key content words included boundary, effort, vent, upset, and stress. Users reported a variety of toxic behaviors, such as boundary violations and disrespectful or abusive actions. Venting was commonly used to cope with powerful negative emotions associated with toxic relationships.

Users felt unsupported when their partners or families reacted to their diagnosis by becoming detached or distressed to the extent of relying on the patient for support. To illustrate, one user expressed disappointment in their father’s silence after diagnosis, stating, “My dad isn’t there for me. I guess I shouldn’t be surprised, he’s always been like this” (OP 45).

Other users were frustrated with bearing the emotional burden for others regarding their cancer. For example, one OP resented their husband for expecting them to manage his emotions, sharing, “I did my best to explain that I needed him to be my rock. He got upset... he wanted us to be mutually supportive. But he doesn’t have cancer.... I do!” (OP 62).

Some OPs described being disrespected and emotionally abused following their diagnosis. For instance, one OP shared that their partner told them, “Lately, you aren’t sexually desirable to me without your natural breasts. I miss them and how they felt... probably even more than you do” (OP 65).

Similarly, another OP disclosed experiencing emotional and verbal abuse from their partner both before and after their breast cancer diagnosis. This OP shared feeling extremely upset that just 2 weeks after their diagnosis, their partner asked them, “How long are you going to pull the breast cancer card?” (OP 85).

Toxic relationships described within this theme were strongly associated with venting, that is, posting negative, emotionally charged content. For example, an OP trying to cope with being isolated by their family prefaced their story by writing, “Heads up that this is a massive, sad vent post. Sorry but I feel like I need to shout into the void” (OP 34).

Theme 3 was classified as slightly negative (=–1.00) and captured how patients in toxic relationships were abandoned or emotionally abused by their partners following their diagnosis. Key content words included devastate, experience, and abuse. Patients who navigated abandonment or abuse concurrently with a breast cancer diagnosis reported feeling emotionally devastated.

Abandonment was especially common after disclosing a breast cancer diagnosis. For example, one OP shared that their husband abandoned them on the way home from their diagnosis appointment, stating, “He said he won’t look after the kids and plans on leaving” (OP 9). Other users were abandoned as treatment began. Many users who shared stories of abandonment described emotional whiplash, characterized by a sudden, unexpected transition from feeling secure in their relationship to feeling betrayed following abandonment. As illustrated by one user, “He made me feel cared for, loved, and safe... until I said I was considering a mastectomy. Then he shut me out” (OP 12).

The emotional impacts of betrayal were devastating. An OP whose long-term partner unexpectedly broke their promise to stick by them during treatment shared, “I am completely devastated. I am infuriated. He and my body betrayed me. I am so furious” (OP 86).

Of partners who stayed following a diagnosis, many subjected the patient to emotional abuse. One OP was told that they deserved their cancer, recounting, “He used my cancer against me by saying I got it because I’m weak and that’s just natural selection at work. He told me not to bother with treatment and to just let nature run its course” (OP 76).

Other experiences involved infidelity, threats of child abandonment, accusations of faking symptoms, and coercion in treatment choices. Emotional abuse was repeatedly described as devastating. For example, an OP whose spouse had been emotionally abusive for years posted, “What can I do to stop feeling devastated that my husband feels I should be punished all the time?” (OP 40).

The fourth theme was classified as slightly negative (=–0.75) and focused on social-related fears associated with breast cancer. Key content words included biopsy, tchp, and scare. Patients’ fear stemmed from anticipating or experiencing a negative reaction to their breast cancer by a toxic family member or partner. For example, an OP who disclosed a toxic family shared dreading their reaction to their cancer, expressing, “The fear of how my family will react to my breast cancer diagnosis is nearly as overwhelming as the actual diagnosis” (OP 81).

Other users felt scared because they had already experienced an unsupportive reaction by a toxic family member or partner to their cancer. For example, one OP felt scared and hopeless after being gaslit by their partner about their diagnosis, sharing, “He was trying to tell me that my breast cancer was all in my head, despite having seen my biopsy results and meeting with multiple members of my medical team” (OP 3). Similarly, an OP whose family neglected to support them after learning of their diagnosis expressed, “My family doesn’t care about me or my breast cancer. It makes me feel scared and alone” (OP 34).

Theme 5 was classified as slightly positive (=1.00) and highlighted how breast cancer was disruptive to the lives of patients. Key content words included future, matter, and strength. Users described how health and social adversity influenced their inner strength. Toxic relationships that emerged after diagnosis were especially trying for patients. For instance, one OP expected their partner’s support as they began cancer treatment (as their partner had promised). However, the OP’s partner abruptly took back their commitment, leaving the OP to navigate cancer alone: “They sent me a message the next day and said they don’t want anything to do with me” (OP 12).

Inner strength emerged as a dynamic construct that was both challenged by experiencing a breast cancer diagnosis and toxic relationships and enhanced by surviving these adverse experiences. Many users believed that surviving breast cancer concurrently with exposure to toxic relationships was a testament to their inner strength. For example, one OP attributed their inner strength to recovering from breast cancer while navigating a lack of empathy and support from their spouse. This OP stated, “I feel 100% confident that I am a strong, intelligent woman who can face almost anything” (OP 64), while sharing that they had received a new cancer diagnosis. Inner strength also enabled users to regain a sense of control over how they were going to navigate living with a breast cancer diagnosis. For example, an OP who was abandoned by their partner after being diagnosed stated, “I finally felt strong enough to delete his contact information because I couldn’t stop myself from calling him–it was the best choice I could have made” (OP 47).

The sixth theme was classified as marginally positive (=0.20) and described how OPs assessed their social relationships and interactions. Key content words included conversation, response, listen, regret, and grateful. Users assessed the quality of social support from family based on whether they felt judged, subjected to toxic positivity, or made to listen to unsolicited advice. For example, an OP with an emotionally unsupportive family shared, “I think a lot of family think it’s helpful when they shove positivity down our throats. What we really need is support and someone to listen without trying to solve all our problems” (OP 82).

For some users, responses to breast cancer unveiled toxic relationships that they regretted having to face. For example, an OP with unsupportive parents shared, “I regret that my breast cancer forced me to confront that my parents never have and still don’t support me how I need them to” (OP 4). However, OPs who discovered both toxic and supportive relationships during cancer expressed gratitude for the sources of support they did have. As one OP stated, “Sometimes I get jealous of people whose parents love and support them, but then I remember the rest of my friends and family who showed up for me when I needed them, and I’m grateful” (OP 32). The subreddit community was repeatedly praised by users because it was such a valuable source of support. For instance, one OP shared, “I am endlessly grateful for the knowledge and resilience of this community” (OP 53).

The seventh theme was classified as marginally negative (=–0.17) and characterized a core function of r/breastcancer: providing advice and support. Key content words included money, quit, and follow. The subreddit facilitated advice regarding various topics, especially related to navigating financial matters and treatment options in the context of a toxic relationship.

Numerous users offered money-related advice to OPs facing difficult financial situations because of toxic relationships. Situations included financial coercion, exploitation, and manipulation following cancer disclosure and managing finances during separation from a toxic partner. For instance, one OP was abandoned by their partner during a joint real estate purchase. A community member with self-professed real estate expertise strongly advised the OP against continuing with the investment, writing, “I’m begging you... please do NOT sign anything else! Lose your money... that’s not important... please do not continue with this purchase” (OP 89).

Members also counseled OPs about postmastectomy reconstruction by offering advice on how to reduce social pressure and prioritize personal preferences. For example, one OP shared how they resisted their partner’s pressure to follow reconstruction, stating, “I made him look at photos of reconstruction to show him that it’s not a free boob job and can be ugly. He changed his tune real quick” (OP 39).

Members who were ultimately pressured into reconstruction strongly encouraged OPs to follow their instincts. For example, one member who was coerced into reconstruction by their husband advised, “I constantly wish I went flat instead. If I had to do it again I would listen to my gut and go flat” (OP 8).

Similarly, it was common to share advice about treatment adherence. Many OPs struggling with a lack of support expressed wanting to quit treatment. While members empathized with users and understood their feelings, they ultimately encouraged continuing. For example, one OP shared, “I’m just sick of this. I’m pretty sure I’m done with it all” (OP 34).

The community offered empathy, such as, “When I was in the middle of your treatment, I was frustrated too and tried to quit every week” (OP 7), as well as advice, for example, “Don’t stop treatment without a good reason. It’s a gift in spite of tough side effects because it keeps us alive” (OP 48).

This study explored the use of the r/breastcancer subreddit by patients to describe toxic relationships with their partners and immediate family members. Themes highlighted patients’ lived experiences of toxic relationships, emotional impacts, and support from the subreddit community. A key finding was that many people with breast cancer sought out the r/breastcancer subreddit to share their experiences of toxic relationships, often including descriptions of abandonment, isolation, and emotional abuse within this context. Further, this study presented compelling evidence that toxic relationships impart profound emotional consequences for patients and that some patients cope with these strong emotions through online venting. This work also emphasized the value of online communities like Reddit as alternative, complementary sources of support for patients experiencing toxic relationships.

Psycho-oncology care teams play a critical role in optimizing health outcomes for patients with breast cancer, yet the emotional well-being of patients with cancer is often underreported and underexplored [83]. Patient-reported social media data offers real-time insights into patient experiences and needs which can be beneficial for informing clinical practice [33,83].

Clinicians who understand that many of their patients with breast cancer are negatively affected by toxic relationships are better prepared to support their emotional well-being. Acquiring knowledge about practices and resources that foster coping and inner strength, including venting and safety planning, can contribute to improved patient outcomes.

Some clinicians may be unfamiliar with the advantages of online forums for patients, but recognizing the potential benefits could enhance care [84]. Recommending Reddit as a possible source of advice, information, and support could be a valuable addition to clinical practice for patients navigating breast cancer and toxic relationships. However, because digital literacy is often overlooked in breast cancer care [85], clinicians who concurrently promote digital literacy can empower their patients to access online communities and ultimately, improve their health outcomes.

There are limitations to this work. First, the analysis was conducted by a single researcher, which may have introduced bias in data interpretation. The analysis also relied heavily on automated methods that may have been inadequate in fully capturing nuance or interpreting context cues in textual data. Second, these data are self-reported, which may have resulted in biased perspectives. While users in this sample self-identified as patients with breast cancer, it was not possible to validate this. These data may have inadvertently included content from online robots or people without breast cancer, and thus may not accurately reflect the experiences of the target population. Additionally, these data were scraped from a single social media platform and may not be representative of the experiences of patients who use other social media platforms, do not use Reddit to discuss their personal lives, or lack access to an internet-enabled device. No demographic information was available to further contextualize findings. It is important to note that these results only relate to experiences of emotional abuse, as physical and sexual abuse were not represented in the data. Furthermore, all participants could write in English, were digitally literate, and had access to the internet, meaning that the findings may not represent the experiences of patients who are nonanglophone or lack technological access or literacy. Caution should be used when applying these findings to other patients with breast cancer.

This study identified that toxic relationships described by patients with breast cancer on Reddit were common and characterized by abandonment, abuse, and unsupportive behaviors. Patients often experienced profound emotional reactions to this form of social stress and anonymous venting on Reddit was described as an effective coping mechanism. Some patients described breast cancer and toxic relationships as adverse experiences that ultimately enhanced their inner strength. Overall, the r/breastcancer community appeared to be a means of exchanging advice, information, and support for patients experiencing toxic relationships. Clinicians who understand that their patients may be negatively affected by toxic relationships are better prepared to support their holistic well-being. Further investigation of Reddit as a possible source of advice, information, and support has the potential to help inform clinical practice and subsequently, improve patient health outcomes.