CHAPTER

Integrative Oncology: Another Perspective

Yoon Hang Kim, MD, MPH

Board-Certified in Preventive Medicine | Integrative & Functional Medicine Physician

Integrative Oncology: Evidence-Based Strategies to Support Cancer Treatment e-book autor: Yoon Hang Kim - EPUB | Rakuten Kobo Polsce

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Abstract

Integrative oncology is customarily introduced as a list: diets, infusions, repurposed pharmaceuticals, botanicals, devices, mind-body practices. The field is then defended or dismissed on a single question — does anything on the list shrink tumors? This chapter argues that the list is the wrong unit of analysis, and that the question, asked alone, has produced a literature that is simultaneously overclaimed by advocates and undercredited by critics.

The alternative perspective offered here is structural rather than pharmacological. Conventional oncology is organized around the tumor: its histology, its molecular drivers, its measurable burden. Integrative oncology, when practiced rigorously, is organized around the host — the metabolic, inflammatory, immunologic, nutritional, functional, and existential state of the person in whom the tumor is growing and in whom treatment must be tolerated. These are not competing claims about biology. They are different objects of attention, and most of the confusion in this field comes from evaluating a host-directed intervention with a tumor-directed endpoint, or from marketing a host-directed intervention as though it were a tumor-directed one.

Working from that frame, the chapter surveys the domains most often assembled into integrative cancer protocols — dietary and metabolic intervention, circulating tumor DNA and functional laboratory monitoring, pharmacologic ascorbate and other intravenous therapies, drug repurposing, iron and copper homeostasis, hyperthermia and photodynamic therapy, and psychedelic-assisted therapy for existential distress — and grades each against what the human evidence will actually bear as of 2026. It then proposes a four-tier framework that ties the strength of a recommendation, the intensity of monitoring, and the depth of the informed consent conversation to the quality of evidence behind it, together with explicit stopping rules. The argument concludes that the discipline's credibility problem is not the presence of weak evidence in its literature — every young field has that — but the failure to say out loud, at the bedside and in the chart, which tier a given recommendation occupies.

Keywords: integrative oncology; host-directed therapy; pharmacologic ascorbate; circulating tumor DNA; minimal residual disease; drug repurposing; cuproptosis; ferroptosis; hyperthermia; psilocybin; supportive oncology; informed consent

1. Introduction: Why Another Perspective Is Needed

A patient with metastatic pancreatic adenocarcinoma arrives with a printed protocol. It contains a ketogenic diet, high-dose intravenous ascorbate three times weekly, metformin, atorvastatin, doxycycline, mebendazole, melatonin, a copper chelator, and a supplement list running to nineteen items. She has found a clinic that will provide all of it. Her oncologist has told her that none of it works and that some of it may be dangerous. She wants to know who is right.

Both of them are partly right, and neither answer is useful to her, because the question as posed cannot be answered. "Does this work?" collapses at least four distinct questions: will it shrink the tumor; will it extend life; will it make treatment more tolerable; will it make the remaining time more bearable to live through. Different items on her list have different answers to each. Some have credible randomized human data for one endpoint and none at all for another. Some have mechanistic plausibility and a decade of case reports. At least one is a veterinary product with no approved human use anywhere.

The perspective advanced in this chapter is that the practitioner's task is not to render a verdict on the list but to disaggregate it — to sort each element by target, by endpoint, by evidence tier, and by risk, and then to say plainly which is which. This is a more demanding standard than either advocacy or dismissal. It requires knowing the primary literature well enough to distinguish a randomized phase II signal from a retrospective case series, and it requires the willingness to tell a frightened patient that the most mechanistically elegant item on her list has never been tested in a human being under controlled conditions.

It is also, I will argue, the only standard under which integrative oncology can be practiced as medicine rather than as commerce.

2. The Framing Problem

Three words are used interchangeably and should not be. Alternative implies substitution — therapy offered in place of standard care. Complementary implies addition without integration — therapy offered alongside standard care, often without the oncologist's knowledge. Integrative implies coordination — therapy selected, sequenced, monitored, and documented in explicit relationship to the oncologic treatment plan, with the oncology team informed.

The distinction is not semantic. Substitution is the mechanism by which integrative approaches cause death: the patient with an early-stage, curable malignancy who declines surgery or adjuvant therapy in favor of a metabolic protocol. Observational data on this point are consistent and grim, and no argument in this chapter should be read as softening it. Addition without integration is the mechanism by which they cause preventable harm: the antioxidant taken during radiation without discussion, the botanical that induces CYP3A4 and quietly lowers exposure to a targeted agent, the anthelmintic whose transaminitis is attributed to a checkpoint inhibitor and prompts unnecessary cessation of an effective drug.

Integration is the only defensible mode, and it imposes obligations. It requires that the integrative clinician know what the oncologic plan is, what its intent is (curative, adjuvant, palliative), and where in the treatment arc the patient sits. It requires a written record shared with the treating team. And it requires that the integrative clinician be prepared to withdraw a recommendation when the oncologic plan changes.

3. A Host-Directed Frame

3.1 Two objects of attention

Oncology has spent forty years becoming extraordinarily good at the tumor. Molecular profiling, targeted inhibition, immune checkpoint blockade, antibody-drug conjugates and ctDNA-based residual disease detection all represent refinements of a single logical structure: characterize the malignant clone precisely, then attack it precisely. This structure has produced most of the survival gains of the modern era, and any account of integrative oncology that does not begin by acknowledging that is not serious.

What that structure does not address, by design, is the host. The same tumor in two different hosts behaves differently, is tolerated differently, and is treated differently — not because the biology of the clone differs, but because insulin resistance, sarcopenia, systemic inflammation, microbiome composition, micronutrient status, sleep, physical capacity, and psychological state differ. These host variables influence treatment delivery (dose intensity actually received), treatment toxicity, treatment tolerance, quality of life, and in several cases measurable oncologic outcomes.

The host-directed frame proposes that this is integrative oncology's proper domain. It reframes the field's central question from "what else can we give that kills cancer?" to "what state should this host be in so that the definitive treatment works as well as it can, is tolerated as fully as possible, and is undergone by a person who can still find the experience meaningful?"

3.2 What the frame licenses, and what it does not

The frame licenses a large amount of confident, evidence-based practice. Exercise during and after adjuvant treatment, nutritional repletion, management of treatment-related symptom burden, sleep restoration, psychological and existential support, and structured survivorship care all have real evidence bases and are chronically under-delivered in routine oncology. A clinician who does nothing more than deliver these well is practicing legitimate and valuable integrative oncology.

The frame does not license the reverse inference. That an intervention improves a host parameter does not establish that it improves an oncologic outcome. Lowering fasting insulin is not the same as prolonging disease-free survival; the MA.32 trial, discussed below, is the cleanest available demonstration of exactly that gap. Nor does the frame license the use of host-directed language as cover for tumor-directed claims — describing a chelator as "supporting metal balance" when the patient understands it as anticancer therapy is a consent failure regardless of how the sentence is worded.

4. The Metabolic Terrain: Diet as Host Intervention

4.1 Mechanistic background

The metabolic reprogramming of malignant cells — aerobic glycolysis, glutamine dependence, altered lipid handling, and mitochondrial adaptation — is well characterized and has generated a durable hypothesis: that manipulating substrate availability and the insulin/IGF-1 axis can create a systemic environment less permissive to tumor growth. The relevant host-level levers are insulin and IGF-1 signaling, mTOR activity, autophagic flux, adipose-derived inflammation, and the gut microbiome, the last of which now has credible links to immune checkpoint inhibitor response.

The mechanistic case is strong. The clinical case is more modest, and the honest summary is that dietary pattern has better evidence for cancer risk reduction and for survivorship outcomes than for altering the trajectory of established disease.

4.2 What the human data support

Diets high in whole plant foods, fiber, and unsaturated fat and low in refined carbohydrate, processed meat, and alcohol are associated with lower incidence of several malignancies and with better outcomes in colorectal and breast cancer survivorship cohorts. These are observational associations with the usual confounding, but they are consistent, biologically coherent, and carry essentially no downside. This is the strongest ground in the dietary chapter and should be where counseling starts.

Ketogenic and time-restricted approaches occupy weaker ground. Feasibility and safety have been demonstrated in small trials across several tumor types; short-term fasting or fasting-mimicking around chemotherapy has shown reductions in some toxicity measures and encouraging effects on markers of response in early-phase work. What has not been demonstrated is a survival benefit, and the trials that would demonstrate one are small, heterogeneous in protocol, and inconsistently controlled. A ketogenic diet is a reasonable option for a metabolically appropriate, well-nourished patient who wants it and can be monitored. It is not a treatment, and in a cachectic or sarcopenic patient it is a hazard.

4.3 The clinical failure mode

The dominant nutritional risk in oncology is not excess carbohydrate. It is inadequate protein and total energy intake in the setting of treatment-related anorexia, mucositis, taste change, and nausea, compounded by restrictive dietary advice. Cancer cachexia is a recognized, independently prognostic syndrome, and dietary restriction offered without nutritional assessment can accelerate it.

The practical rule follows: assess before restricting. Weight trajectory, grip strength or another functional measure, serum albumin and prealbumin interpreted in the context of inflammation, and a validated screening tool such as the Malnutrition Universal Screening Tool or the Patient-Generated Subjective Global Assessment should precede any restrictive prescription. In a patient losing weight, the intervention is repletion, not restriction, and this is true even when the metabolic argument for restriction is elegant.

5. Precision Monitoring: ctDNA and the Functional Laboratory

5.1 What ctDNA is and where it now stands

Circulating tumor DNA analysis detects tumor-derived fragments in plasma. Tumor-informed assays are built from sequencing of the patient's resected tumor and track variants private to that tumor, which sharply reduces background noise from non-tumor cell-free DNA and gives strong specificity in the postoperative minimal residual disease setting, where target concentrations are extremely low. Tumor-agnostic assays use fixed panels or methylation signatures and trade some sensitivity for the ability to proceed without tissue.

The prognostic validity is not in dispute. Detectable ctDNA after curative-intent resection is among the strongest available predictors of recurrence across colorectal, breast, bladder, lung, and pancreatic cancer, and it frequently precedes radiographic recurrence by a substantial interval — reported lead times cluster in the range of several months to roughly a year, varying by tumor type, assay, and sampling schedule. Clinicians should quote these as ranges rather than as a fixed figure; a single confident number is a signal that the underlying heterogeneity has been flattened.

5.2 The distinction that matters: validity versus utility

Prognostic validity means the test predicts an outcome. Clinical utility means that acting on the test improves an outcome. These have come apart in the ctDNA literature in an instructive way, and 2025–2026 has clarified the picture considerably.

De-escalation has the strongest support. The DYNAMIC trial in stage II colon cancer showed that a ctDNA-guided strategy allowed substantially fewer patients to receive adjuvant chemotherapy without compromising recurrence-free survival, a finding subsequently confirmed at longer follow-up. Current guideline framing treats this de-escalation pathway as the setting in which a specific therapeutic action based on a ctDNA result rests on level I randomized evidence.

Escalation has fared worse. DYNAMIC-III, which tested ctDNA-guided treatment escalation in locally advanced colon cancer, did not establish a practice-changing benefit. The randomized, double-blind phase III ALTAIR trial within the CIRCULATE-Japan platform enrolled patients who became ctDNA-positive after completing standard therapy and randomized them to trifluridine/tipiracil or placebo; median disease-free survival was 9.30 months versus 5.55 months, a hazard ratio of 0.79 that did not reach statistical significance. Signals from CIRCULATE-US and the GALAXY cohort reported in 2026 are biologically plausible and directionally supportive of escalation in selected settings, but they have not met level I statistical rigor. A comprehensive 2026 ASCO guideline review reached a similar conclusion, identifying essentially no studies demonstrating that acting on MRD results improved patient outcomes, with the notable exception of MRD-positive muscle-invasive bladder cancer.

The implication for integrative practice is direct and somewhat deflating. A positive ctDNA result in most settings tells the clinician that the risk of recurrence is high. It does not yet tell anyone what to do about it. Ordering the test therefore obligates the clinician to have answered, in advance and out loud with the patient, the question: what will we do if it is positive? If the honest answer is "intensify surveillance and feel worse," that should be said before the blood is drawn, not after.

5.3 Practical parameters

• Draw the postoperative MRD sample approximately four weeks after surgery; earlier sampling risks confounding from surgical release of cell-free DNA.
• Surveillance intervals of three to six months are typical, aligned to the recurrence hazard curve of the specific disease.
• Clonal hematopoiesis is a recognized source of false-positive results in tumor-agnostic assays; paired white blood cell sequencing distinguishes it.
• A negative result is not proof of cure. Assay sensitivity in the MRD range remains imperfect — one 2026 report noted sensitivity near 31%, well below the roughly 50% seen in much of the published literature — and sensitivity varies with tumor shedding biology.
• Interpret alongside imaging, tumor markers, and clinical findings, never in isolation.

5.4 The functional laboratory

Functional and metabolic testing occupies a different evidentiary position and should be described accordingly. High-sensitivity CRP, IL-6, fasting insulin and HOMA-IR, 25-hydroxyvitamin D, ferritin with transferrin saturation, serum copper with ceruloplasmin, comprehensive metabolic panel, and body composition assessment are all measures of host state. Several are prognostic in cancer populations. None constitutes a cancer test, and none should be presented as one.

Their legitimate use is to identify modifiable host abnormalities and to track whether interventions aimed at those abnormalities are working. Their common misuse is as a surrogate for oncologic response — the patient whose hs-CRP fell and who is told, or allowed to infer, that the cancer is retreating. Organic acid panels, extensive micronutrient arrays, and oxidative stress markers have limited validation in oncology specifically and should be ordered, if at all, with an explicit statement of what decision the result will change.

Table 1. A suggested monitoring architecture, organized by what each tier is for rather than by test menu.

6. Intravenous Therapies

6.1 Pharmacologic ascorbate

Intravenous ascorbate at gram-level doses achieves plasma concentrations two orders of magnitude above what oral dosing can produce — the pharmacokinetic fact that invalidates the negative oral trials of the 1980s and that is still routinely overlooked when the older literature is cited. At millimolar concentrations ascorbate acts as a pro-oxidant, generating extracellular hydrogen peroxide, with proposed selectivity arising from differences in catalytic metal availability and peroxide-handling capacity between malignant and normal cells. Radiosensitizing and chemosensitizing effects have been demonstrated preclinically.

The human evidence improved materially in late 2024. A randomized phase II trial in metastatic pancreatic adenocarcinoma added high-dose ascorbate (75 g, three times weekly) to gemcitabine and nab-paclitaxel; median overall survival was approximately 16 months versus 8 months for chemotherapy alone (HR 0.46), with progression-free survival roughly doubled and a lower rate of serious adverse events. The trial was stopped early for benefit. Earlier randomized phase I/IIa work in ovarian cancer showed reduced chemotherapy-related toxicity and longer progression-free survival, and phase I data in pancreatic cancer showed radiographic responses in most treated patients.

This is the strongest human dataset integrative oncology currently possesses, and it deserves to be cited accurately rather than inflated. The pancreatic trial enrolled 34 patients. It was phase II, single-institution, and stopped early — and early stopping for benefit systematically inflates effect estimates. Meta-analyses reporting dramatic pooled survival differences are dominated by heterogeneous observational cohorts with substantial selection bias and should not be presented to patients as though they carried the weight of the randomized data. A confirmatory multi-institutional phase III trial is the appropriate next step and has been difficult to fund precisely because ascorbate is unpatentable, a structural feature of the evidence landscape worth naming explicitly when discussing why the literature looks as it does.

Practical administration

• Screen for G6PD deficiency before the first infusion. Hemolysis in G6PD-deficient patients is the principal catastrophic risk.
• Contraindications and cautions: significant renal impairment, oxalate nephropathy risk, hemochromatosis or iron overload, decompensated heart failure given the osmotic and volume load.
• Titrate from 15–25 g upward with monitoring; trial-level dosing has run considerably higher, and dose should be matched to the intent and to the evidence being invoked.
• Ascorbate interferes with several point-of-care glucometers; warn diabetic patients specifically.
• Coordinate timing with the oncology team, and document that coordination.

6.2 Other intravenous agents

Glutathione, alpha-lipoic acid, curcumin, and mistletoe extract are commonly offered. The evidence tiers differ sharply and should not be blended. Alpha-lipoic acid and glutathione have been studied for chemotherapy-induced peripheral neuropathy with mixed and generally modest results. Mistletoe has a substantial European supportive-care literature of variable methodologic quality, plus a completed North American phase I trial establishing dosing and tolerability in advanced cancer; quality-of-life signals are more consistent than antitumor ones. Intravenous curcumin has poor pharmacokinetic and formulation support relative to the enthusiasm it attracts.

One theoretical concern deserves more attention than it receives: antioxidant administration concurrent with radiation or with chemotherapy whose mechanism is oxidative could in principle blunt efficacy. The clinical data are inconclusive rather than reassuring. The prudent default is temporal separation from cytotoxic administration and explicit disclosure to the oncologist, rather than confident assertion in either direction.

7. Repurposed Pharmaceuticals

7.1 The appeal and the trap

Drug repurposing is attractive for good reasons: known safety profiles, low cost, established pharmacology, and in several cases genuine mechanistic rationale. It is also the domain in which integrative oncology has done most damage to its own credibility, and understanding why requires attention to a specific methodological failure.

Most repurposing enthusiasm rests on observational pharmacoepidemiology — cohorts of patients already taking a drug for another indication who appear to have better cancer outcomes. These designs are vulnerable to confounding by indication, healthy-adherer effects, and immortal time bias, the last of which can manufacture an apparent survival benefit out of nothing more than the requirement that a patient survive long enough to fill a prescription. When these signals have been tested prospectively, they have frequently evaporated.

7.2 Metformin: the instructive negative

Metformin activates AMPK, inhibits mTOR signaling, and lowers circulating insulin and IGF-1 — a mechanism that maps cleanly onto the host-directed frame. Observational data suggested reduced cancer incidence and improved outcomes. The MA.32 trial then tested it properly: 3,649 patients with high-risk non-metastatic breast cancer without diabetes, randomized to metformin 850 mg twice daily or placebo for five years, with follow-up through 2020. Metformin did not improve invasive disease-free survival. Subsequent analyses found that BMI and obesity-associated blood variables failed to predict metformin benefit across immunohistochemically defined subtypes, with the authors concluding that the results do not support an important indirect metabolic effect on breast cancer outcomes.

This result should be taught, not buried. Metformin did what it was supposed to do metabolically — it improved weight and circulating metabolic factors — and that improvement did not translate into oncologic benefit in this population. It is the single clearest demonstration available that host-metabolic improvement and oncologic outcome are separable, and it is a standing caution against every argument of the form "this improves insulin sensitivity, therefore it should help the cancer."

7.3 The remaining candidates, honestly graded

Statins have plausible mechanisms via the mevalonate pathway and mixed observational support; prospective oncology data remain thin. Doxycycline at sub-antimicrobial dosing inhibits mitochondrial protein synthesis with preclinical activity against cancer stem cell populations and small window-of-opportunity human studies; it is not established therapy. Itraconazole and disulfiram have early-phase human data of varying quality. Melatonin has a reasonable supportive-care literature for sleep and possibly for toxicity mitigation, and a weaker antitumor one.

The Care Oncology protocol — metformin, a statin, doxycycline, and mebendazole in combination — is supported principally by retrospective, uncontrolled case series without a matched comparator. Patients who seek out and pay for such a protocol differ systematically from those who do not, in performance status, health engagement, and access. A retrospective series in this configuration cannot distinguish drug effect from selection effect, and describing it as evidence of efficacy is not defensible.

7.4 Benzimidazoles

Benzimidazole anthelmintics disrupt microtubule assembly and interfere with glucose metabolism in malignant cells, and preclinical data have sustained interest in this class for two decades. Mebendazole is an approved human anthelmintic with a long safety record in its licensed indication; early-phase clinical investigation in oncology is ongoing, and it remains investigational for any oncologic use.

Fenbendazole is a veterinary product. It has no approved human use in any jurisdiction. That is the material fact, and the chapter leaves it there.

8. Metal Homeostasis: Iron and Copper

8.1 The biology

Transition metal handling is genuinely dysregulated in malignancy, and the field has been reshaped by two regulated cell death programs. Ferroptosis is iron-dependent cell death driven by lipid peroxidation, restrained by the cystine-glutamate antiporter and glutathione peroxidase 4. Cuproptosis, described in 2022, proceeds through copper binding to lipoylated components of the tricarboxylic acid cycle, causing proteotoxic aggregation and mitochondrial failure. Both are mechanistically distinct from apoptosis and both have generated intense translational interest.

Two clinically important consequences follow. First, tumor cells that have escaped apoptotic death may remain vulnerable through these pathways. Second, the therapeutic logic is genuinely bidirectional — depleting a metal to starve tumor-supporting processes, or loading a metal to trigger the death program. That bidirectionality is the source of most confusion in this area, because both strategies are marketed under similar language.

8.2 Copper: the most developed clinical story

Elevated serum and tumor copper correlate with poorer prognosis across several malignancies. Copper is required for angiogenesis, contributes to lysyl oxidase-mediated collagen crosslinking and premetastatic niche formation, and supports mitochondrial respiration in metastatic subpopulations.

Tetrathiomolybdate is the agent with the most human data. A phase II study in breast cancer at high risk of recurrence maintained ceruloplasmin between 8 and 17 mg/dL for two years; among 75 enrolled patients, event-free survival at a median follow-up of 6.3 years was 90% in adjuvant triple-negative patients and 69% in stage IV patients with no evidence of disease, with reductions in endothelial progenitor cells, lysyl oxidase activity, and collagen crosslinking in parallel preclinical models. Earlier phase II work established that copper depletion targets are achieved far more readily in triple-negative than in luminal disease. The investigators' own conclusion was that biomarker-driven trials were warranted, not that efficacy was established — and no randomized phase II has yet delivered a definitive answer. It is worth noting that tetrathiomolybdate had failed several earlier oncology trials before this line of work.

Copper ionophores — disulfiram, elesclomol — pursue the opposite strategy, driving intracellular copper upward to precipitate cuproptosis. Human oncology data remain early-phase, and most cuproptosis-targeting work published through 2026 is preclinical or nanomaterial-based.

8.3 Iron, and a safety point that is easy to miss

Iron chelation with deferoxamine, deferiprone, or deferasirox has been explored to limit tumor iron availability; the human oncology data are preliminary. Pro-ferroptotic strategies pursue the reverse.

The practical caution is that these strategies are mutually antagonistic and are frequently combined in ad hoc protocols by clinicians who have not noticed. A patient receiving an iron chelator alongside an agent intended to induce ferroptosis is receiving two interventions designed to cancel one another. The same problem arises with copper: chelation plus an ionophore is incoherent. Before any metal-directed intervention, the clinician should be able to state in one sentence which direction is being pushed and why.

Assessment should include serum copper with ceruloplasmin, ferritin interpreted alongside inflammatory markers since it is an acute-phase reactant, transferrin saturation, and hepcidin where available. Prolonged copper depletion carries risks of anemia, neutropenia, and myelosuppression that require monitoring, and these risks are additive to those of concurrent cytotoxic therapy.

9. Energy-Based and Physical Adjuncts

9.1 Hyperthermia

Therapeutic hyperthermia raises tissue temperature to roughly 40–43°C, producing direct cytotoxicity, enhanced perfusion and drug delivery, radiosensitization through impaired DNA repair, and immune activation via heat shock protein expression.

Regional hyperthermia added to neoadjuvant chemotherapy in high-risk localized soft tissue sarcoma has randomized evidence supporting improved local progression-free and overall survival. Deep regional hyperthermia combined with radiotherapy in locally advanced cervical cancer has randomized evidence of improved local control and survival. These are the two strongest indications and both involve integration with definitive treatment rather than standalone use. Head and neck and superficial recurrent breast disease have supporting but weaker data.

Two cautions. First, the trials that generated this evidence used specialized regional or deep hyperthermia equipment with thermometry and quality assurance; infrared saunas and whole-body devices marketed to clinics are not the same intervention and should not borrow the evidence. Second, the technique is technically demanding, and outcomes depend on achieving and documenting target temperature.

9.2 Photodynamic therapy

PDT combines a photosensitizer with light of a matched activation wavelength to generate reactive oxygen species within the illuminated field. It is an approved, established modality in specific settings — cutaneous malignancy and precancer, Barrett's-associated dysplasia and esophageal cancer, selected endobronchial lesions, and 5-aminolevulinic acid-guided resection in glioma. Its advantages are spatiotemporal control, minimal systemic toxicity, and induction of immunogenic cell death; interest in combination with checkpoint inhibition follows from that last property.

The limiting factor is light penetration, which restricts PDT to accessible lesions. Cutaneous photosensitivity following systemic photosensitizer administration requires explicit patient instruction. PDT belongs in the integrative discussion as a modality to know about and to refer for, not as one to improvise.

9.3 Low-level laser therapy

Photobiomodulation has reasonable supportive evidence for prevention and treatment of chemotherapy- and radiation-induced oral mucositis and appears in supportive care guidelines. It is a good example of an integrative modality with a defined indication, a defined endpoint, and no antitumor claim attached — which is precisely why it has been absorbed into mainstream practice with little controversy.

10. The Existential Dimension

10.1 The clinical problem

Roughly a third to a half of patients with advanced illness experience clinically significant psychological distress: depression, anxiety, demoralization, loss of meaning, and anticipatory grief. This distress is independently associated with worse quality of life, poorer treatment adherence, greater caregiver burden, and increased desire for hastened death. Conventional antidepressants perform inconsistently in this population, and the time horizon in advanced disease often does not accommodate a six-week medication trial.

This is arguably the clearest case in the entire chapter for a host-directed frame. Nothing about treating existential distress claims to affect the tumor. The endpoint is the person.

10.2 The evidence

Two landmark randomized trials published in 2016, at Johns Hopkins and New York University, tested single high-dose psilocybin with psychological support in patients with cancer-related anxiety and depression. Both found large, rapid, and sustained reductions in depression and anxiety, with improvements in quality of life and measures of meaning; long-term follow-up in the NYU cohort found benefits persisting years after a single session. Mystical-type experience intensity correlated with symptom improvement, a mediation finding that has been replicated and that complicates any attempt to treat the compound as a conventional pharmaceutical. Group-delivered protocols have since shown feasibility, and open-label and phase II work continues across advanced cancer populations, caregivers of patients with advanced cancer, and depression comorbid with specific malignancies.

The regulatory picture changed rapidly through 2025 and 2026, though it is important to be precise about what changed. COMPASS Pathways reported positive results from two phase III trials of synthetic psilocybin — COMP005 in June 2025 and COMP006 in February 2026 — with positive 26-week durability data reported in July 2026, and has proceeded to a rolling New Drug Application. An executive order in April 2026 directed federal agencies to accelerate review of psychedelic therapies for serious mental health conditions, and national priority vouchers were subsequently issued to several psychedelic programs. The indication under review, however, is treatment-resistant depression, not cancer-related existential distress. Approval in one indication would not by itself make the cancer indication available, though it would reshape access, scheduling, and the practical possibility of referral.

10.3 What responsible engagement looks like now

Psilocybin remains a Schedule I substance federally. Legal access in the United States is through clinical trials or state-regulated supervised programs in the jurisdictions that have established them. Facilitating access outside these channels exposes patients to legal risk and to unsupervised experiences without screening — the opposite of care.

• Screen rigorously: personal or family history of psychotic disorder or bipolar I, cardiovascular instability, and serotonergic or other interacting medications are the principal exclusions.
• Preparation matters as much as dose. Trial protocols used multiple preparatory psychotherapy sessions before any administration.
• Dosing sessions in trials ran six to eight hours with two trained monitors, a controlled setting, curated music, and eyeshades. The psychological container is not decoration; it is part of the intervention.
• Integration sessions afterward are where durable benefit is consolidated.
• For most clinicians, the appropriate role is competent referral and honest information — knowing which trials are recruiting, which state programs exist, and what the evidence does and does not show.

It should also be said that the well-validated, immediately available interventions for existential distress in advanced cancer — dignity therapy, meaning-centered psychotherapy, managing existential distress through skilled palliative care involvement — remain underused. A clinician excited about psilocybin who has not referred a patient for meaning-centered psychotherapy has the ordering wrong.

11. Synthesis: Practicing Under Uncertainty

11.1 A tiered framework

The recurring failure in integrative oncology is not that weak evidence is discussed. It is that weak and strong evidence are discussed in the same register, so the patient cannot tell them apart. The remedy is to make the tier explicit — in conversation, in the consent document, and in the chart.

Table 2. A four-tier framework linking evidence strength to consent standard, monitoring intensity, and permissible language.

11.2 Sequencing

The order in which an integrative plan is built should follow the tiers rather than the patient's enthusiasm or the clinic's margin. Establish the oncologic plan and its intent first. Address symptom burden and functional capacity next, because these are where Tier I interventions concentrate and where benefit is most reliable. Address nutritional and metabolic state third, assessing before restricting. Address distress and meaning fourth, and early rather than at the end. Only then consider Tier II and III agents, and only with monitoring already arranged.

Curative-intent treatment deserves particular conservatism. During neoadjuvant or adjuvant therapy with curative intent, the downside of an unrecognized interaction is the loss of a cure. This is not the setting for exploration.

11.3 Interaction discipline

Every integrative plan requires a systematic interaction review, repeated whenever either plan changes.

• CYP450 and transporter effects — St. John's wort as CYP3A4 inducer, grapefruit and certain botanicals as inhibitors, with targeted agents and many oral chemotherapies as the exposure at risk.
• Antioxidants concurrent with oxidative cytotoxic therapy or radiation: separate temporally and disclose, given genuinely inconclusive data.
• Immunomodulatory botanicals with checkpoint inhibitors: theoretical risk of altered immune-related adverse event patterns.
• Additive hepatotoxicity from any non-prescribed agent taken during checkpoint inhibitor therapy, where misattributing transaminitis to immune-related hepatitis risks stopping an effective drug.
• Bleeding risk from fish oil, high-dose vitamin E, ginkgo, and others in thrombocytopenic patients or around procedures.
• Antagonistic metal strategies inadvertently combined, as discussed above.

11.4 Stopping rules

Protocols proliferate because nothing is ever discontinued. Every Tier II, III, or IV element should be assigned, at initiation, a defined endpoint, a review date, and a stopping criterion. Write them down. The questions are: what specifically am I expecting to change, by when, measured how, and what result would cause me to stop? An intervention that cannot be assigned an answer to all four should not be started.

Discontinue for objective toxicity, for absence of the anticipated effect at the review date, for financial burden disproportionate to demonstrated benefit, and whenever the oncologic plan changes in a way that alters the interaction profile.

11.5 Documentation and consent

The consent conversation for a Tier III or IV intervention should name the evidence tier explicitly, state that efficacy for the oncologic endpoint is unproven, describe known and theoretical risks including interactions, state the cost and the fact that it is not covered by insurance, describe the monitoring plan and stopping criteria, and confirm that this is in addition to and not instead of standard oncologic care. The oncology team should receive a written summary of every agent, dose, and schedule. This last item is not a courtesy. It is the difference between integration and parallel unmonitored treatment.

12. Limitations and the Duty of Candor

Several structural problems shape this literature and should be stated rather than worked around.

Unpatentable agents do not attract confirmatory funding. The pancreatic ascorbate investigators have said as much publicly. This means absence of phase III evidence in this field is weaker evidence of absent effect than it would be in a commercially attractive area — but it does not convert a phase II result into a phase III one, and the argument is frequently abused in that direction.

Publication and reporting practices in integrative oncology are uneven. Case series without denominators, retracted reports that continue to circulate after retraction, and preprints cited as though peer-reviewed are all common. Citation practice in this field requires verification against the primary source rather than reliance on secondary summaries.

Financial conflict is intrinsic. Most integrative oncology is delivered in cash-pay settings where the clinician recommending an infusion also bills for it. This does not invalidate the practice, but it does raise the bar for disclosure and for the discipline of stopping rules, since the structural incentive runs entirely toward continuation.

Finally, there is the asymmetry of hope. Patients facing mortality are not neutral evaluators of probability, and clinicians who care about them are not neutral communicators. The pull toward saying "this might help" about an intervention with no human data is strong and well-intentioned. Resisting it is the substance of professional integrity in this field. The patient who chooses a Tier IV intervention with full knowledge of what it is has exercised autonomy. The patient who chooses it believing it to be Tier II has been deceived, however gently.

13. Conclusion

Integrative oncology will not establish itself by producing a rival cure. Its contribution is a different one: attending systematically to the host in whom the disease is occurring and the treatment is being endured — metabolic state, nutritional and functional capacity, symptom burden, and the distinctly human problem of finding the experience bearable and meaningful. That contribution is real, is supported by evidence that ranges from strong to preliminary depending on the domain, and is chronically under-delivered.

The perspective this chapter argues for is therefore not more permissive than conventional oncology but in one respect more demanding. It asks the clinician to hold two things at once: genuine openness to mechanistically grounded, incompletely proven interventions, and rigorous honesty about exactly how incompletely proven each of them is. Tier I is not Tier IV, a phase II trial stopped early is not a phase III result, a retrospective case series is not evidence of efficacy, and improving a metabolic marker is not treating a cancer. MA.32 taught that last lesson at a cost of 3,649 enrolled patients and a decade of follow-up, and it should not need to be taught again.

The patient described at the opening of this chapter deserves better than a verdict on her list. She deserves to have it taken apart, item by item, and to be told which pieces have randomized human evidence behind them, which have mechanism and hope, which have a documented liver injury signal, and which are simply being sold. That conversation takes forty minutes and cannot be delegated. It is, in the end, what integrative oncology has to offer that nothing else in her care will.

Selected References

References are grouped by section. Clinicians are encouraged to verify each against the primary source before citing, particularly in a literature with documented retractions.

ctDNA and minimal residual disease

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Drug repurposing

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Metal homeostasis

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Hyperthermia and photodynamic therapy

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Psychedelic-assisted therapy

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Nutrition, metabolism, and supportive care

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Author note

Yoon Hang Kim, MD, MPH, is board-certified in Preventive Medicine and practices integrative and functional medicine. He completed a University of Arizona Osher Fellowship under Dr. Andrew Weil and holds UCLA medical acupuncture certification. His prior roles include Medical Director of Integrative Oncology at Miami Cancer Institute and Director of the Integrative Medicine Program at the University of Kansas Medical Center. He is the author of four books, including Integrative Oncology: Evidence-Based Strategies to Support Cancer Treatment, and of more than thiry peer-reviewed articles.

Disclosure: The author operates a cash-pay integrative medicine practice. No industry funding supported the preparation of this chapter.