Social media is both a valuable resource and a challenging arena for cancer patients and their families to navigate. Patients with cancer can find community [1,2], support [3,4], identity [5], and resources [6] across social media groups, pages, and forums. Social media also allows patients with cancer and their families to share updates and appeal for support within their networks [7,8]. Simultaneously, the internet contains widespread misinformation [9-14] about cancer, including its causes, evidence-based cancer treatments, and purported cancer treatments represented as efficacious when little, no, or disproven evidence exists for its use [15,16]. Nonetheless, content and articles with cancer misinformation shared on social media receive more engagement than factual sources [17].

Cancer misinformation reaches patients on social media and may have negative consequences, such as misinformed treatment decisions, worsened clinician-patient dynamics, and damaged caregiver-patient relationships [18,19]. In some cases, cancer misinformation can lead to patients with treatable or early-stage cancers opting out of evidence-based treatments in preference for alternative cancer treatments [20]. In other cases, patients with advanced cancers or limited treatment options may reasonably want to exhaust all options in search of a cure or to prolong life, leading them to try unproven, experimental, or alternative cancer therapies against their medical provider’s recommendation [21,22]. Patients who distrust health care, lack health literacy, do not have their informational needs met [23-25], and those with lower educational attainment are the most susceptible to cancer misinformation [26]. Alternative cancer treatment in patients with treatable or terminal cancer is associated with a reduced time to death than in patients with cancer undergoing scientifically supported treatment [27,28].

Compounding the misinformation difficulties faced by patients with cancer, alternative cancer treatment providers are alleged to actively promote unproven, experimental, and potentially harmful treatments [29,30]. Promotion occurs through various mediums and strategies, including websites and social media. Facebook groups, which can support patients with cancer through community and shared experiences, are targeted by posts advertising alternative cancer treatments or products [31]. Providers make unsubstantiated health claims, share disinformation [32], and distort the scientific evidence supporting their services in promotional activities [15]. The marketing of cancer treatments, especially by alternative providers, is harmful in that it provides false hope, utilizes medical resources inappropriately, and disrupts doctor-patient relationships [33]. The US Food and Drug Administration (FDA) regularly issues warnings to companies and services promoting unproven cancer products and treatments. In 2018, the FDA warned 14 alternative providers for “fraudulently claiming to diagnose, treat, or cure cancer,” with some selling and promoting their products on Facebook and Instagram [34]. However, warnings typically lead to limited negative consequences for providers.

While it is understood that advertising by alternative cancer providers is a source of harmful misinformation, an important area yet to be explored is how alternative cancer treatment providers utilize paid social media advertising products and tools to market their services. As opposed to other types of nondigital direct-to-consumer and nonpaid social media promotional activities or strategies [35-37] (eg, hosting a Facebook page without paid advertisements), targeted advertisements are uniquely effective at reaching specific groups via tailored messaging with little cost. Social media advertisers can target users in a certain age group, gender, geographic area, and income group, as well as people who demonstrate specific interests [38]. Advertisers can also employ advanced targeting features such as “custom” [39] or “lookalike” [40] audiences for further in-depth advertisement audience targeting. Applying social media–targeted advertising strategies for alternative cancer treatments may enable potential advertisers to target demographic groups fitting their target demographic profile, such as groups at a statistically higher risk of cancer or high-income earners. Targeted advertising may also enable advertisers to focus on demographics with “interests” or social activities demonstrating a higher likelihood of receptivity to their services (eg, “natural products”). Meta banned certain detailed terms (eg, “cancer”) to target as interests on January 19, 2022 [41]. However, as an advertiser, it is still possible to target the followers of known proponents of alternative medicine, such as Gwyneth Paltrow [42]. In summary, social media advertisements can reach and track a large, defined audience with little investment and effort.

To prevent the misuse of advertising tools, social media platforms require advertisers’ adherence to their platform-specific health-related advertising policies [43]. For example, Meta’s advertising policy states that “ads must not contain deceptive, false or misleading claims…that set unrealistic expectations for users.” Despite policies against misleading or harmful health advertising, Meta advertising tools promote scientifically unsupported public health messages and unproven products or services. Past research has found that paid Meta advertisements disseminated antivaccine [44] and protobacco content [45]. Patients with cancer have shared anecdotes of how they started to see advertisements for fake cancer cures after their diagnosis [18,29]. As recently as June 2022, paid advertisements for scientifically unsupported cancer treatments were reported on Meta platforms [46]. The current context suggests an immediate need to investigate the extent of alternative and unproven cancer treatment advertisements on Meta social platforms.

In this study, we partially address this need by systematically analyzing the advertising activities of prominent alternative cancer treatment practitioners on Meta platforms, including Facebook, Instagram, Messenger, and Audience Network. We specifically sought to determine (1) whether alternative cancer treatment paid advertising occurs on Meta social media platforms, (2) the strategies and messages alternative cancer providers use to reach and appeal to prospective patients, and (3) how the efficacy of alternative treatments is portrayed. Analyzing the advertising activities of alternative cancer treatment providers serves as a useful case study to examine Meta’s advertising infrastructure and its role in the propagation of misinformed cancer treatments.

We identified 310 paid advertisements from 11 alternative cancer clinics on Meta (Facebook, Instagram, or Messenger) marketing alternative treatment approaches, care, and interventions. The clinic profiles of those hosting advertisements are summarized in Table 1. The clinics found in our study were in the United States (n=4, 36.4%), Mexico (n=4, 36.4%), Spain (n=2, 18.2%), and Thailand (n=1, 9.1%). Clinics may offer services in multiple locations. An expanded table detailing the treatments offered at each clinic and their treatment provider qualifications according to their websites is available in Multimedia Appendix 1.

Nearly all (n=289, 93.2%) advertisements featured imagery or text signifying that the provider is a qualified medical expert and may legitimately advise on and administer cancer treatment. Visual cues included images or text mentioning qualified health care providers (eg, doctors, surgeons), reference to interventions (treatment, medications, intravenous administration, therapies), medical imagery and equipment, and labeling the provider location as a “medical treatment center,” “clinic,” or related terms. Many clinics had staff providers with credentials that were not associated with expertise in primary cancer care or were legally barred from recommending primary cancer treatment. This included naturopaths, chiropractors, and other alternative medicine practitioners. Despite representation as a legitimate medical option, certain providers’ websites specify that they do not offer medical advice. Figure 1 displays illustrative examples of clinics presenting themselves as qualified cancer care and treatment providers. Figure 2 depicts an advertisement from Conners Clinic where the primary service provider refers to himself as “Dr” in a medical context giving cancer treatment advice. However, according to the Conners Clinic website [55,56], he practices under a “Pastoral Medical License” and does not offer medical advice.

In 65.5% (n=203) of the advertisements, providers appealed to persons with limited treatment options due to an advanced, aggressive, or terminal cancer prognosis to not give up seeking treatment because other “effective” options exist. Clinic advertisements invoked skepticism regarding noncurable cancer cases and gave examples of their alleged “success” in treating or curing terminal cancer cases. A CHIPSA (Centro Hospitalario Internacional del Pacifico, SA) hospital advertisement states their client “was told it [their cancer] was noncurative. But nearly 2 years after her initial diagnosis, and treatment at CHIPSA, she is cancer free.” Many advertisements invoked direct skepticism toward other health providers labeling a patient’s cancer as noncurative. In other cases, clinics offered examples where past clients were allegedly abandoned by their medical teams once their cancer reached an advanced or noncurative form. For example, an advertisement states, “She [patient] was ‘dropped’ by her doctors, put on hospice, and given only months to live. [Patient] and her husband [names redacted] refused this death sentence and ventured to CHIPSA Hospital in Mexico.” Illustrative screenshots are shown in Figure 3.

Across the advertisements, 54.2% (n=168) featured 1 or more people with cancer who received treatment from a provider and spoke about their experience, either about the impact of alternative treatment on their cancer diagnosis or their experience with the advertiser. Figure 4 displays examples of advertisements depicting supposed clients speaking to services received as improving or curing their cancer. Many contain specific references to being cancer-free after receiving treatment with an alternative provider. An advertisement from Envita Medical Centres includes a statement from a person depicted as a patient stating, “I came in here with stage 4 colorectal cancer, [and] I’m leaving cancer free.” Another advertisement reads, “My oncologist didn’t believe it was possible to cure my cancer. Thanks to Immunity Therapy Center, I proved him wrong!”

Alternative cancer providers marketed holistic approaches to healing in 39% (n=121) of advertisements, including emotional health, addressing trauma, and other factors impacting a person’s ability to treat and fight their cancer. Providers emphasized incorporating psychological wellness into their treatments. For example, a Budwig Medical Centre advertisement states, “It is a treatment for your physical body, but it also a treatment for your soul—it is an emotional and psychological treatment.”

Approximately 26.1% (n=81) of advertisements featured language conveying care about their patients’ well-being, often emphasizing the relationship they want/do build with their patients. For example, an Immunity Therapy Centre advertisement states, “Our knowledgeable and loving team invests time in developing relationships that bless everyone involved.” Other promotions highlight apparent vulnerable, caring moments between staff and patients. A Brio-Medical advertisement reads, “Dr Larry was there [while patient crying], and he hugged me, and I knew after that it was going to be great.” Last, advertisements emphasize treating clients not just as another case. A Budwig Centre ad states: “You are not a chart or diagnosis—you are an individual who deserves the absolute best care.”

Providers sought to support the effectiveness or legitimacy of their treatments or approach by referencing rhetoric or imagery related to science, research, evidence, and well-known science-related organizations or institutions in 23.2% (n=72) of advertisements. Cues for coding included the terms “research-based,” “Harvard medical,” “NASA,” “new research,” “Nobel prize,” “proven,” “published,” “scientific evidence,” “researched,” “scientifically proven,” and related terms. Here, providers gave little to no details about the research mentioned and included images of cells or other biological processes with no context (see Figure 5). In many cases, unproven, disproven, or experimental treatments were represented as being supported by research. For example, Brio-Medical states, “Researchers are using vitamin C and oxygen to kill cancer.” Advertisements also included misleading statements about the research quality or implications for specific treatments.

In 20.3% (n=63) of the advertisements, providers represented themselves as keeping up to date and offering the latest technological advances in their cancer treatments and approach. Providers used terminology signaling major innovation, including “groundbreaking,” “breakthrough,” “new,” “paradigm shift,” “state of the art,” and related terms. In some cases, the clinic’s latest advanced technology was used as an appeal. For example, an advertisement from Conners Clinic links to the clinic founder’s “groundbreaking book” on treating cancer. In other cases, advertisements mention the facilities as a “state-of-the-art center.”

Messaging stating that the key to treating cancer is understanding why it developed in the first place was observed in 13.9% (n=43) of advertisements. Here, clinics argue that treating cancer requires identifying and removing the reasons leading to cancer development. For example, an advertisement from Brio-Medical states, “Stop fighting cancer and address the cause by asking why your body is sick.” Most often, clinics recommend making certain lifestyle or diet changes to prevent reoccurrence and promote healing. For example, Conners Clinic recommends a 4-pronged treatment for healing cancer that consists of “cause, nutrition, technology, diet, and detoxification.”

Across the 310 advertisements analyzed, 25.8% (n=80) included 1 or more direct statements signifying the offered cancer treatments at their facility are effective for curative or life-prolonging purposes or that the treatment offered has cured or prolonged life in patients. Example excerpts of these direct statements are included in Textbox 1; note that these are raw text and have not been edited for grammar. We found 78 cancer treatments mentioned in advertisements (Multimedia Appendix 2). The most mentioned treatments or approaches were alternative (n=191, 61.6%) and natural (n=153, 49.4%). Many clinics do not advertise the full range of treatments they offer.