Last updated: April 25, 2026
Most cancer patients use some form of complementary or alternative therapy during their treatment – yet the majority never mention it to their oncologist. This communication gap is not just a missed conversation. It is a patient safety issue with measurable medical consequences. Understanding why patients stay silent, and how to bridge that silence, can lead to safer, more personalized cancer care.
How Common Is Complementary and Alternative Medicine Use Among Cancer Patients?
Complementary and alternative medicine use among cancer patients is widespread, with research showing that 70.2% of cancer patients incorporate some form of CAM into their care (Cancer Therapy Advisor, 2023). This high prevalence spans geographic regions and cancer types, making the gap between CAM use and physician disclosure a systemic healthcare challenge rather than an isolated patient behavior.
The scale of CAM adoption means that oncologists are routinely treating patients whose full therapeutic picture remains partially hidden. From herbal supplements and high-dose vitamins to acupuncture and energy healing, the range of therapies patients pursue is broad. A 2025 review published in PMC confirmed that CAM use among cancer patients is a global phenomenon, with inadequate communication between patients and oncologists identified as a major clinical concern (Balogun et al., 2025).
As spring 2026 brings renewed interest in wellness routines and supplement regimens, understanding the scope of this issue becomes especially timely. Many patients begin new complementary practices in the spring months, often without informing their cancer care teams.
What Percentage of Cancer Patients Use Complementary Therapies?
According to a 2023 survey reported by Cancer Therapy Advisor, 70.2% of cancer patients use CAM as part of their cancer care, excluding mind-body interventions. This figure captures therapies used alongside conventional treatment. A smaller but significant group – 8.8% – use CAM as a complete replacement for conventional cancer treatment. Among those using CAM as a replacement, 31.3% did not disclose this decision to their oncologist (Cancer Therapy Advisor, 2023).
The distinction between complementary use and alternative use is clinically critical. Patients who supplement conventional treatment with yoga or acupuncture face different risk profiles than patients who forgo chemotherapy in favor of herbal protocols. Both groups, however, share one common problem: a significant portion never tell their doctors.
How Often Do Melanoma Patients Specifically Use Alternative Therapies?
A multicenter study of 1,089 melanoma patients found that 41% used complementary and alternative medicine (Huebner et al., 2017). Among melanoma patients who used CAM, 56.8% reported feeling better as a result. The primary motivations were strengthening the immune system (63.4%) and gaining a sense of personal empowerment (53.7%).
The sources of CAM information for melanoma patients are notable. Family and friends were the primary source for 41% of users, while print media informed 41.7%. Oncologists were not a leading source of CAM information, reinforcing the disconnect between clinical teams and patient decision-making. Melanoma patients considering alternative melanoma treatment approaches benefit from understanding these patterns in the context of their own care.
Why Do Up to 70% of Cancer Patients Hide CAM Use From Their Oncologists?
Up to 70% of cancer patients do not disclose complementary and alternative medicine use to their oncologists, driven by fear of judgment, belief that physicians lack CAM knowledge, and a perception gap in clinical communication (Davis et al., 2023). This non-disclosure is a two-sided problem rooted in both patient hesitancy and systemic healthcare limitations.
The evidence reveals a striking disconnect. In a Singapore-based study cited by Davis et al. (2023), 51% of CAM-using cancer patients reported that they had told their physician about their CAM use. However, only 15% of physicians recalled being informed. This gap suggests that even when patients attempt disclosure, the information is not being captured, documented, or retained in clinical settings.
An Australian study found that 61.1% of cancer patients never discussed CAM with a physician at all (Balogun et al., 2025). The communication failure is not confined to one healthcare system or culture – it is a global pattern.
What Are Patients Afraid Will Happen If They Tell Their Doctor?
Research identifies three primary barriers to CAM disclosure among cancer patients. First, patients believe their physicians lack knowledge about complementary therapies. Second, patients fear physician disapproval or judgment for pursuing non-conventional options. Third, patients assume their oncologist will dismiss or fail to understand their choices (Davis et al., 2023).
Kathrin Wode, MD, of the Department of Radiation Sciences and Oncology at Umea University in Sweden, has noted that many cancer patients do not disclose CAM use to cancer care professionals, often due to an assumed lack of knowledge about CAM among their providers (Wode et al., The Oncologist, 2023). This fear is not entirely unfounded – oncology training has historically included limited CAM education, which contributes to the patient perception.
The result is a cycle of silence. Patients withhold information because they expect a negative response, and physicians remain unaware of CAM use because patients do not bring it up. Neither side initiates the conversation.
Do Oncologists Actually Know When Their Patients Use Alternative Medicine?
The evidence suggests that oncologists significantly underestimate CAM use among their patients. The perception gap documented in the Singapore study – where 51% of patients said they disclosed CAM use but only 15% of physicians recalled being told – reveals a structural failure in clinical communication (Davis et al., 2023).
Several systemic factors contribute to this gap. Oncology appointments are typically time-constrained, leaving little room for extended conversations about supplements or complementary practices. Most oncology intake forms do not include structured questions about CAM use. Additionally, as noted in the ASCO Post, provider awareness gaps mean that even when disclosure occurs, physicians may not recognize the clinical significance of certain therapies or supplements (Frenkel, ASCO Post, 2018).
The following table summarizes the key disclosure gap findings across studies:
| Study / Source | Key Finding | Year |
|---|---|---|
| Davis et al. (Singapore cohort) | 51% of patients said they disclosed; only 15% of doctors recalled | 2023 |
| Balogun et al. (Australian cohort) | 61.1% of cancer patients never discussed CAM with a physician | 2025 |
| Cancer Therapy Advisor survey | 31.3% of patients using CAM as replacement did not tell their oncologist | 2023 |
| Davis et al. (global review) | Up to 70% of cancer patients do not disclose CAM use | 2023 |
What Are the Real Medical Risks of Not Telling Your Oncologist About Supplements and CAM?
Non-disclosure of complementary and alternative medicine use creates direct medical risks for cancer patients, including dangerous herb-drug interactions, reduced treatment efficacy, and amplified side effects. The National Cancer Institute advises patients to tell their cancer care team about any complementary health approaches, giving providers a full picture of all therapies being used.
When oncologists are unaware that a patient is taking specific supplements or herbal remedies, they cannot assess potential interactions with chemotherapy agents, immunotherapy drugs, or radiation protocols. This blind spot can compromise treatment outcomes in ways that neither patient nor physician may recognize until significant harm has occurred.
Can Herbal Supplements Interfere With Cancer Treatment?
Yes. Research on melanoma patients found that 37.2% of those using biological CAM were at risk of herb-drug interactions (Huebner et al., 2017). Herbal supplements can alter drug metabolism, reduce the concentration of cancer drugs in the bloodstream, or intensify toxic side effects.
Common examples include St. John’s Wort, which is known to reduce the effectiveness of numerous pharmaceutical agents through liver enzyme induction, and high-dose antioxidant supplements, which may interfere with the oxidative mechanisms that certain chemotherapy drugs rely on to destroy cancer cells. The NCI recommends that patients prepare a complete list of all supplements – including dosages and frequency – and share this with their oncology team before and during treatment.
What Happens When Patients Use Alternative Therapies Instead of Conventional Treatment?
Among cancer patients who use CAM, 8.8% use it as a complete replacement for conventional treatment (Cancer Therapy Advisor, 2023). This approach carries serious risks, including treatment delays that allow cancer progression. A U.S. survey found that 39% of Americans believe cancer can be cured through alternative practices alone (Wode et al., The Oncologist, 2023) – a belief that is not supported by clinical evidence.
The 2024 SIO-ASCO joint guidelines explicitly distinguish between complementary therapies used alongside conventional treatment and alternative therapies used as replacements. The guidelines support integration, not substitution. Patients who understand the role of integrative oncology in 2026 are better positioned to make informed decisions that do not compromise their treatment outcomes.
What Does the Latest Medical Evidence Say About Integrative Cancer Care?
The 2024 SIO-ASCO joint guidelines represent the most authoritative endorsement of integrative cancer care to date, recommending specific complementary therapies alongside conventional treatment based on rigorous evidence review. These guidelines formalize that mainstream oncology now supports integrative approaches when delivered with proper medical oversight and patient-provider communication.
This shift reflects decades of accumulating evidence. Integrative oncology is no longer a fringe concept – it is a recognized clinical framework endorsed by two of the most influential oncology organizations in the world. The emphasis throughout the guidelines is on shared decision-making, meaning that patient preferences are respected within an evidence-based safety framework.
Which Complementary Therapies Are Now Recommended by ASCO and SIO?
The 2024 SIO-ASCO guidelines recommend several complementary therapies for symptom management during cancer treatment:
- Mindfulness-based stress reduction – for anxiety, depression, and overall quality of life
- Yoga – for fatigue, sleep disturbances, and emotional well-being
- Acupuncture – for chemotherapy-induced nausea, pain management, and fatigue
- Music therapy – for anxiety and mood during treatment
All of these therapies are recommended alongside conventional treatment, not as replacements. The guidelines stress that implementation should occur within a shared decision-making framework where patients and providers collaboratively evaluate options (SIO-ASCO, 2024, PubMed 39052420).
What Is the Difference Between Complementary and Alternative Cancer Treatment?
Complementary cancer therapies are used alongside conventional treatment to manage symptoms and improve quality of life. Alternative cancer therapies are used instead of conventional treatment. This distinction is medically critical because outcomes differ dramatically between the two approaches.
The National Cancer Institute defines complementary approaches as those that are added to standard medical treatment, while alternative approaches replace standard treatment entirely. The 2024 SIO-ASCO guidelines support complementary integration but do not endorse alternative replacement of evidence-based conventional therapies. When patients and providers share a clear understanding of this distinction, conversations about CAM become more productive and safer.
How Should Cancer Patients Talk to Their Oncologist About Complementary Therapies?
Cancer patients can improve communication about complementary therapies by preparing a comprehensive disclosure list before appointments, asking specific questions about potential interactions, and framing the conversation around shared decision-making. The NCI, ASCO, and SIO all support open patient-provider dialogue about CAM as a foundation of safe cancer care.
The goal is not to seek permission but to create a complete clinical picture. When oncologists know everything a patient is using – supplements, herbs, mind-body practices, dietary protocols – they can provide more precise, personalized guidance that accounts for the full range of therapies involved.
What Should You Prepare Before Discussing CAM With Your Cancer Care Team?
The NCI recommends that patients prepare the following before their oncology appointment:
- A complete list of all dietary supplements, including brand names, dosages, and frequency
- All over-the-counter medicines currently being used
- All prescription medications
- Any CAM practices currently in use or being considered, such as acupuncture, massage, or energy therapies
- Product labels or packaging for any supplements, brought to the appointment for review
This preparation transforms a potentially uncomfortable conversation into a structured, productive exchange. Patients who arrive with documented information help their oncologists make faster, more accurate safety assessments.
What Questions Should You Ask Your Oncologist About Integrative Therapies?
Patients benefit from bringing specific, prepared questions to their oncology appointments. The following questions support informed shared decision-making:
- Are any of my current supplements potentially interacting with my cancer treatment?
- Which complementary therapies have evidence supporting their use for my specific cancer type?
- Are there supplements I should stop taking before surgery, chemotherapy, or immunotherapy?
- Can you refer me to an integrative oncology specialist for a comprehensive review?
- What complementary approaches do you consider safe alongside my current treatment plan?
These questions shift the dynamic from disclosure as confession to disclosure as collaboration. They also signal to providers that the patient is seeking evidence-based guidance rather than blanket approval.
How Can Integrative Oncology Specialists Bridge the Communication Gap?
Dr. Moshe Frenkel, MD, writing in the ASCO Post (2018), highlighted the role of integrative oncology specialists in bridging the gap between patient expectations and evidence-based care. These specialists are trained to evaluate complementary therapies within the context of a patient’s full treatment plan, providing the CAM-specific knowledge that many conventional oncologists lack.
Integrative oncology specialists serve as translators between two worlds. They understand the clinical mechanisms of conventional cancer treatment and can simultaneously assess the safety and potential value of complementary approaches. For patients who feel their primary oncologist is unreceptive to CAM discussions, a referral to an integrative specialist can keep the conversation within a medically supervised framework.
Why Is Open Communication About CAM Especially Important for Melanoma Patients?
Open communication about CAM is especially critical for melanoma patients because 41% use complementary therapies, 37.2% of biological CAM users face herb-drug interaction risks, and modern melanoma treatments – particularly immunotherapy and targeted therapy – are highly susceptible to supplement interference (Huebner et al., 2017). The stakes of non-disclosure are uniquely high in melanoma care.
Melanoma treatment has evolved rapidly, with checkpoint inhibitors and targeted agents becoming standard of care. These treatments work through precise immune and molecular mechanisms that can be disrupted by herbal compounds, high-dose vitamins, or other biological supplements. A patient taking an immune-modulating herb alongside a checkpoint inhibitor, for example, may experience unpredictable therapeutic outcomes.
What Herb-Drug Interaction Risks Are Specific to Melanoma Treatment?
The Huebner et al. (2017) study found that 37.2% of melanoma patients using biological CAM were at risk of clinically significant herb-drug interactions. This finding is particularly concerning given that the primary motivation for CAM use among melanoma patients is strengthening the immune system (63.4%) – the same system that immunotherapy drugs are designed to modulate.
Notably, CAM users in the melanoma study had higher education levels and greater psychological support needs than non-users. This means the disclosure gap is not an awareness problem. These are informed patients who are actively seeking additional therapeutic tools but are not integrating that search with their clinical care team. Patients exploring melanoma treatment options benefit from understanding that communication with providers is itself a safety measure.
Where Do Melanoma Patients Get Their Information About Alternative Therapies?
According to Huebner et al. (2017), melanoma patients primarily learn about CAM from informal sources:
| Information Source | Percentage of Melanoma CAM Users |
|---|---|
| Family and friends | 41.0% |
| Print media | 41.7% |
| Internet sources | Not specified as primary |
| Oncologists | Not a leading source |
The near-total absence of oncologists as an information source reinforces the central problem. Patients are making CAM decisions based on advice from social networks and media, not from clinicians who understand their treatment protocols. This gap represents both a risk and an opportunity for oncology teams to become proactive sources of reliable CAM guidance.
Frequently Asked Questions About CAM Disclosure and Cancer Care
Is It Safe to Use Supplements During Chemotherapy or Immunotherapy?
Not all supplements are safe during active cancer treatment. Some herbal and biological supplements can interfere with drug metabolism, reduce treatment efficacy, or amplify side effects. Research shows that 37.2% of melanoma patients using biological CAM were at risk of herb-drug interactions (Huebner et al., 2017). The NCI advises that patients disclose all supplements to their cancer care team to enable proper safety assessment.
Can Complementary Therapies Cure Cancer on Their Own?
No complementary or alternative therapy has been proven to cure cancer independently. Despite this, a U.S. survey found that 39% of Americans believe cancer can be cured through alternative practices alone (Wode et al., The Oncologist, 2023). The 2024 SIO-ASCO guidelines recommend integrative therapies for symptom management alongside conventional treatment – not as standalone cures.
Should I Stop Using CAM If My Doctor Doesn’t Approve?
Rather than stopping CAM abruptly or continuing in secret, patients are encouraged to continue the conversation. The 2024 SIO-ASCO guidelines emphasize shared decision-making, where patients and providers work together to evaluate each therapy’s risks and benefits. If a primary oncologist is not receptive, patients may benefit from seeking a consultation with an integrative oncology specialist who can provide a more detailed assessment.
What Percentage of Doctors Actually Know About Complementary Medicine?
Oncology professionals often lack formal training in CAM, contributing to the communication gap. Wode et al. (2023) noted that many oncology professionals have limited CAM knowledge, which patients perceive and which discourages disclosure. The physician recall rate of only 15% – compared to 51% patient-reported disclosure (Davis et al., 2023) – further suggests that even when CAM is mentioned, it may not be meaningfully integrated into clinical decision-making. The SIO-ASCO 2024 guidelines represent a step toward closing this knowledge gap.
Are There Integrative Cancer Treatment Centers That Combine Both Approaches?
Integrative cancer treatment centers formally combine evidence-based complementary therapies with conventional cancer treatment under coordinated medical oversight. These facilities follow frameworks like the SIO-ASCO clinical guidelines to ensure that complementary approaches are safely integrated rather than used in isolation. EuroMed Foundation in Phoenix, Arizona, operates as a holistic cancer treatment center with an integrative model designed to address the full range of patient needs while maintaining clinical safety standards.
What Is the Path Forward for Safer, More Transparent Cancer Care?
The communication gap between cancer patients and their oncologists about complementary and alternative medicine is a solvable problem requiring action from both sides. Patients can prepare comprehensive supplement and therapy disclosure lists following NCI guidance. Providers can implement structured CAM intake questions during appointments. And the healthcare system can continue adopting integrative oncology frameworks like the 2024 SIO-ASCO guidelines.
The evidence is clear: patients who disclose their full range of therapies receive safer, more personalized care. Non-disclosure does not protect patient autonomy – it undermines it by preventing oncologists from accounting for the complete therapeutic picture.
This spring, before your next oncology appointment, take one concrete step. Write down every supplement, herb, over-the-counter product, and complementary practice you currently use or are considering. Bring that list to your care team. That single act of transparency can be the difference between a treatment plan built on partial information and one that truly reflects your whole approach to healing.
If you are a cancer patient seeking a care environment where these conversations are welcomed rather than avoided, EuroMed Foundation in Phoenix, Arizona, provides integrative cancer care that bridges conventional and complementary approaches under coordinated medical guidance. Reach out to begin a conversation about building a treatment plan that honors your full picture of health.
Frequently Asked Questions
How many cancer patients use complementary or alternative medicine during treatment?
Approximately 70.2% of cancer patients use some form of complementary or alternative medicine as part of their cancer care. Among those using CAM as a complete replacement for conventional treatment, 8.8% forgo standard therapies entirely. Studies confirm this is a global phenomenon spanning all cancer types and geographic regions, making non-disclosure to oncologists a widespread patient safety concern.
Why do cancer patients hide supplement and CAM use from their oncologists?
Up to 70% of cancer patients do not disclose CAM use to their oncologists. The three primary reasons are a belief that physicians lack knowledge about complementary therapies, fear of judgment or disapproval, and the assumption that oncologists will dismiss their choices. Research shows that even when patients attempt disclosure, only 15% of physicians recall being informed, revealing a systemic communication failure.
Can herbal supplements interfere with chemotherapy or immunotherapy drugs?
Yes, herbal supplements can significantly interfere with cancer treatment. Research on melanoma patients found that 37.2% of those using biological CAM were at risk of herb-drug interactions. Supplements can alter drug metabolism, reduce cancer drug concentrations in the bloodstream, or amplify toxic side effects. The National Cancer Institute advises patients to disclose all supplements, including dosages and frequency, to their oncology team.
What complementary therapies are recommended alongside conventional cancer treatment?
The 2024 SIO-ASCO joint guidelines recommend mindfulness-based stress reduction, yoga, acupuncture, and music therapy for symptom management during cancer treatment. These therapies are endorsed for issues like anxiety, fatigue, chemotherapy-induced nausea, and sleep disturbances. All recommendations specify use alongside conventional treatment – not as replacements – within a shared decision-making framework between patients and providers.
What is the difference between complementary and alternative cancer therapy?
Complementary cancer therapies are used alongside conventional treatment to manage symptoms and improve quality of life, while alternative therapies replace conventional treatment entirely. This distinction is medically critical because outcomes differ dramatically. The 2024 SIO-ASCO guidelines support complementary integration but do not endorse using alternative therapies as substitutes for evidence-based conventional cancer treatments like chemotherapy or immunotherapy.
How should cancer patients prepare to discuss CAM with their oncologist?
Cancer patients should prepare a complete list of all dietary supplements with brand names, dosages, and frequency, along with all over-the-counter and prescription medications. Patients should also document any CAM practices currently in use or being considered, such as acupuncture or energy therapies, and bring product labels to the appointment. This preparation enables oncologists to make accurate safety assessments about potential interactions.
What results do cancer patients report from using complementary therapies?
Among melanoma patients who used complementary and alternative medicine, 56.8% reported feeling better as a result. The primary motivations were strengthening the immune system (63.4%) and gaining a sense of personal empowerment (53.7%). However, subjective improvement does not guarantee safety – 37.2% of melanoma patients using biological CAM faced herb-drug interaction risks, highlighting the importance of disclosing all therapies to oncologists.