Cannabis and hemp cannabinoids in oncology therapy – new guidelines from the American Society of Clinical Oncology (ASCO 2024)

On March 13, 2024, the American Society of Clinical Oncology (ASCO) published in the "Journal of Clinical Oncology" its first comprehensive guidelines on the use of cannabis and cannabinoids in adult oncology patients (Braun et al., JCO 2024). The document, based on a systematic review of 101 publications and GRADE methodology, changes the way oncologists should talk to patients about medical marijuana. In the United States, 20 to 40% of oncology patients use cannabis, often without the knowledge of the treating team (ASCO, 2024). This article discusses the full range of recommendations, pharmacological mechanisms, interactions with cytostatics, and practical application in the Polish clinical reality, where prescription medical marijuana has been available since 2017.

Author: Michał Waluk | Last updated: April 24, 2026

Oncological disclaimer: Cannabis and cannabinoids are solely a SYMPTOMATIC ADJUNCT therapy, they do NOT CURE cancer. The decision to include them requires written consent from the treating oncologist and consultation with a clinical pharmacist due to numerous interactions with cytostatics (CYP450 system, P-glycoprotein). Never discontinue oncological medications on your own. This article is for educational purposes and does not replace individual medical advice.

What are the ASCO 2024 guidelines and why are they groundbreaking?

The ASCO 2024 guidelines are the first comprehensive document from the American Society of Clinical Oncology regulating the use of cannabis in adult oncology patients, based on a systematic review of 101 publications from 1990-2023 (Braun et al., JCO 2024). A panel of 13 experts applied GRADE methodology, assessing the quality of evidence from "high" to "very low" and formulating strong, conditional, and against recommendations.

The document fills a gap that has lasted for decades. Although medical marijuana is legal in 38 states in the USA, and 20-40% of oncology patients use cannabis according to data from the National Cancer Institute, there has been a lack of uniform clinical recommendations (NCI PDQ Cannabis and Cannabinoids, 2024). The guidelines end an era in which doctors were left alone with patients' questions, without an evidence-based decision-making tool.

ASCO consciously refrains from vague statements like 'more research is needed.' Instead, it presents specific clinical scenarios with assigned recommendations. This is a significant departure from the previous caution of the oncology community.

Citation capsule: The ASCO guidelines from March 13, 2024, published in the Journal of Clinical Oncology by a panel led by Dr. Ilana Braun, are based on a systematic review of 101 publications and GRADE methodology. They represent the first official position of American clinical oncology regarding medical cannabis (Braun et al., JCO 2024).

Composition of the expert panel and GRADE methodology

The ASCO panel consisted of 13 experts: oncologists, pharmacologists, oncology nurses, palliative care specialists, and two patient representatives. They analyzed 13 systematic literature reviews and 81 randomized clinical trials (RCTs). The GRADE methodology (Grading of Recommendations Assessment, Development and Evaluation) allows for the independent assessment of the certainty of evidence and the strength of recommendations.

How do the ASCO guidelines differ from NCCN and NCI PDQ?

The National Comprehensive Cancer Network (NCCN) guidelines on distress and palliative medicine treat cannabinoids marginally, mainly in the context of nausea. In contrast, NCI PDQ Cannabis and Cannabinoids is an informational document, not a recommendation. ASCO 2024 introduces structured clinical recommendations based on GRADE, which has been lacking until now (NCCN Distress Management Guidelines, 2023).

pillar page on medical marijuana in Poland

What are the main ASCO recommendations regarding CINV?

ASCO issued a strong recommendation for the use of cannabinoids as a second or third-line adjunct therapy for preventing chemotherapy-induced nausea and vomiting (CINV) when regimens based on setrons and aprepitant prove insufficient (Braun et al., JCO 2024). A meta-analysis of 23 RCTs showed the superiority of cannabinoids over placebo and comparable efficacy to ondansetron.

Highly emetogenic chemotherapy, such as that based on cisplatin or the AC regimen (doxorubicin + cyclophosphamide), causes vomiting in 90% of patients without prophylaxis (Hesketh, NEJM 2008). The standard three-drug regimen, setron + aprepitant + dexamethasone, controls symptoms in about 70-75% of patients, but the remaining quarter requires escalation.

Citation capsule: In a meta-analysis of 23 randomized clinical trials published in the Cochrane Database, nabilone and dronabinol showed antiemetic efficacy comparable to metoclopramide and prochlorperazine, but with a higher incidence of psychotropic adverse effects (Smith et al., Cochrane 2015). ASCO qualifies cannabinoids as an adjunct option after the failure of first-line drugs.

Nabilone, dronabinol, and full-spectrum products

The ASCO panel clearly distinguishes synthetic cannabinoids from botanical products. Nabilone (Cesamet) and dronabinol (Marinol, Syndros) have FDA approval for CINV since the 1980s. Their dosing is standardized: dronabinol 5-10 mg/m2 every 2-4 hours, nabilone 1-2 mg twice daily. Full-spectrum products, flowers, and THC:CBD extracts require individual adjustment.

When should an oncologist consider cannabinoids in CINV?

Typical clinical situations include: delayed nausea lasting over 72 hours, anticipatory nausea before the next cycle, chemotherapy with cisplatin derivatives in young patients with high anxiety, failure of the classic three-drug regimen. In practice, Polish oncology centers sometimes see patients starting cannabinoids on their own after the second cycle when delayed nausea becomes unbearable.

Do cannabinoids help with cancer pain?

ASCO issued a conditional recommendation for the use of cannabinoids as an adjunct in cancer pain, particularly mixed and neuropathic pain resistant to opioids (Braun et al., JCO 2024). The review included 13 RCTs, with the largest, Portenoy's study with 360 patients, showing a 30% reduction in pain in one-third of patients on nabiximols compared to placebo (Portenoy et al., J Pain 2012).

Cancer pain affects 55% of patients during active treatment and 66% in advanced stages, according to a meta-analysis by van den Beuken-van Everdingen published in the Journal of Pain and Symptom Management (2016). In 10-15% of patients, classical regimens based on the WHO analgesic ladder do not provide satisfactory control.

Citation capsule: In a randomized, placebo-controlled phase III study by Portenoy et al. published in the Journal of Pain (2012), nabiximols, a THC:CBD 1:1 spray, reduced pain in 30% of oncology patients resistant to opioids compared to 21% in the placebo group. ASCO qualifies this as a conditional adjunct recommendation (Braun et al., JCO 2024).

Pain mechanisms: CB1, CB2, and TRPV1

Cannabinoids exert analgesic effects through multiple mechanisms. CB1 receptors, located mainly in the CNS, modulate pain conduction in the dorsal horns of the spinal cord. CB2, present on immune cells, inhibit neuroinflammation. Additionally, THC and CBD exhibit activity against TRPV1 (vanilloid) channels and 5-HT1A serotonin receptors, explaining their multifaceted effects (Russo, Frontiers in Plant Science 2018).

Comparison with EAPC 2023 guidelines

The European Association for Palliative Care (EAPC) in its 2023 guidelines is more cautious than ASCO. EAPC recommends cannabinoids only after exhausting opioids, co-analgesics (gabapentinoids, antidepressants), physical interventions, and invasive techniques. The European panel emphasizes the risk of cognitive impairment in frail patients weakened by illness (EAPC Opioid Guidelines Update, 2023).

What does ASCO say about cancer cachexia and appetite?

ASCO issued a recommendation against the use of cannabinoids in the treatment of cancer cachexia and as appetite stimulants (Braun et al., JCO 2024). A meta-analysis of 4 RCTs did not show a significant improvement in body weight or body composition compared to placebo, even though dronabinol has FDA approval for AIDS anorexia since 1992.

Cancer cachexia, a syndrome of muscle and fat mass loss unrelated to hunger, affects 50-80% of patients with advanced cancer and directly accounts for 20% of deaths (Baracos et al., Nature Reviews Disease Primers 2018). This is one of the most challenging issues in palliative medicine, lacking effective pharmacotherapy.

The ASCO recommendation may come as a surprise, considering the popularity of cannabis among patients "for appetite." The panel clearly separates the subjective experience of increased appetite from the objective improvement in nutritional status. Simply "eating more" does not translate into an increase in lean mass or prolonged survival.

Citation capsule: The ASCO 2024 review showed no statistically significant improvement in body weight, body composition, or quality of life in patients with cancer cachexia receiving dronabinol, nabilone, or botanical THC:CBD extracts compared to placebo (Braun et al., JCO 2024). ASCO actively discourages this indication.

Why is subjective improvement in appetite not enough?

Cancer cachexia has an inflammatory basis. Cytokines, TNF-alpha, IL-6, IL-1, cause muscle proteolysis regardless of calorie intake. Therefore, appetite increase induced by THC does not reverse catabolism. More effective are anamorelin, megestrol acetate, and nutritional interventions combined with resistance training (Fearon et al., Lancet Oncology 2011).

When should cannabinoids still be considered?

In individual cases, when a patient reports suffering from lack of appetite that worsens quality of life, cannabinoids may be considered as part of symptomatic care, regardless of the lack of evidence for prolonged survival. Such a decision should be consulted with the palliative care team.

Can cannabis help with anxiety and depression in oncology patients?

ASCO states that there is insufficient scientific evidence to issue a recommendation regarding anxiety, depression, and sleep disorders in oncology patients (Braun et al., JCO 2024). Existing studies are small, short, and heterogeneous in terms of methodology and products used. Large RCTs with standardized doses of CBD and THC:CBD ratios are needed.

Depression occurs in 16.3% of oncology patients, and anxiety disorders in 10.3%, according to a meta-analysis by Mitchell in Lancet Oncology (2011). This is three times more than in the general population. Insomnia affects up to 60% of patients, especially during periods of active treatment.

Citation capsule: ASCO 2024 does not issue recommendations for anxiety and depression due to insufficient evidence. CBD in doses of 300-600 mg showed anxiolytic effects in small phase II studies in non-oncological populations, but there are no dedicated RCTs in cancer patients (Zuardi et al., Journal of Psychopharmacology 2017).

What do we know about CBD in anxiety disorders?

A systematic review by Skelley in the Journal of the American Pharmacists Association (2020) describes the anxiolytic effects of CBD in mixed populations, but the authors emphasize the weakness of the quality of evidence. The mechanism involves agonism of the 5-HT1A receptor, inhibition of FAAH, and increased levels of anandamide, as well as GABA-ergic modulation. Therapeutic doses range from 25 to 600 mg daily.

CBD interactions with psychiatric medications in oncology patients

CBD inhibits CYP2C19 and CYP3A4, which may increase the concentrations of sertraline, citalopram, and benzodiazepines. In oncology patients already taking SSRI antidepressants or anxiolytics, this risk compounds with interactions with cytostatics. Any modification of pharmacotherapy requires consultation with a clinical pharmacist.

What are the most important cannabinoid interactions with chemotherapy?

CBD and THC inhibit key metabolic enzymes CYP3A4, CYP2C9, CYP2C19, and the P-glycoprotein transporter, which affects the pharmacokinetics of many cytostatics (Alsherbiny and Li, Medicines 2019). Particular risks concern paclitaxel, vincristine, vinblastine, doxorubicin, etoposide, and oral tyrosine kinase inhibitors like imatinib, erlotinib, pazopanib.

Paclitaxel, a first-line cytostatic in breast, ovarian, and non-small cell lung cancer, is metabolized by CYP3A4 and CYP2C8. Concurrent use of strong CYP3A4 inhibitors, including high doses of CBD, may increase its concentration and exacerbate neurotoxicity and myelosuppression (Vaclavik et al., Cancer Chemotherapy and Pharmacology 2015).

An observational study from the Israeli Oncology Center published in Annals of Oncology (Bar-Sela et al., 2020) found that patients with melanoma and lung cancer using cannabis during immunotherapy with nivolumab had a 21% lower clinical response rate (37.5% vs 58.9%) compared to patients without cannabis. However, the difference in overall survival and progression-free survival did not reach statistical significance.

Citation capsule: Cannabinoids inhibit isoenzymes CYP3A4, CYP2C9, CYP2C19, and P-glycoprotein, modulating the pharmacokinetics of paclitaxel, vincristine, doxorubicin, imatinib, and other key cytostatics. ASCO recommends a full history of cannabis use for every oncology patient and pharmacological consultation (Braun et al., JCO 2024).

Interactions with immunotherapy: a warning signal

Immunotherapy based on checkpoint inhibitors, pembrolizumab, nivolumab, ipilimumab, atezolizumab, is changing the face of oncology in the last decade. Cannabinoids modulate the functions of T lymphocytes, macrophages, and NK cells through CB2 receptors. Observational data suggest a possible deterioration in clinical response with concurrent high cannabis use (Bar-Sela et al., Annals of Oncology 2020).

Hepatotoxicity at high doses of CBD

CBD at doses of 300 mg daily and higher may cause reversible elevations in liver aminotransferases (ALT, AST). This is particularly significant with hepatotoxic cytostatics, methotrexate, 6-mercaptopurine, oxaliplatin, or in patients with liver metastases (Ewing et al., Molecules 2019). ASCO recommends monitoring liver tests every 4 weeks.

P-glycoprotein and bioavailability of oral cytostatics

P-glycoprotein (P-gp) is a membrane pump that removes many drugs, including cytostatics, from cells. CBD and THC inhibit its activity, which may increase the absorption of oral cytostatics (lapatinib, sunitinib, pazopanib) and alter their distribution in tissues, especially in penetrating the blood-brain barrier. This is significant in patients with CNS metastases.

What mechanisms of action of cannabinoids are key in oncology?

Cannabinoids interact with at least four receptor systems relevant in oncology: cannabinoid receptors CB1 and CB2, TRPV1 channels, and serotonin receptors 5-HT1A and 5-HT3 (Russo, Frontiers in Plant Science 2018). This multi-target activity explains their potential antiemetic, analgesic, and anxiolytic effects, but also raises the risk of interactions.

CB1 receptors are primarily concentrated in the central nervous system, particularly in the hippocampus, cerebellum, and cerebral cortex. Their activation by THC is responsible for the psychoactive effect, but also for the antiemetic action in the chemoreceptor trigger zone of the medulla oblongata. CB2 receptors are mainly found on immune cells, explaining the effects of cannabinoids on inflammation and immunity.

Citation capsule: THC acts as a partial agonist of CB1 and CB2, while CBD does not strongly bind to these receptors but modulates them allosterically and inhibits FAAH and MAGL, increasing endogenous levels of anandamide and 2-AG. Additionally, CBD activates 5-HT1A, explaining its anxiolytic effects (Russo, Frontiers in Plant Science 2018).

The entourage effect in full-spectrum products

Full spectrum products contain not only THC and CBD but also smaller cannabinoids (CBG, CBN, CBC), terpenes (myrcene, beta-caryophyllene, limonene, linalool), and flavonoids. Russo described the concept of the 'entourage effect' in a classic publication in the British Journal of Pharmacology (2011), which refers to the mutual enhancement of components. Beta-caryophyllene acts as a CB2 agonist without psychoactive effects.

Why do pure CBD and full-spectrum CBD differ in action?

CBD isolates have a narrow 'therapeutic window' (bell curve), with an optimal dose in the middle. Full-spectrum or broad spectrum products show a more linear dose-response relationship due to the synergy of components (Gallily et al., Pharmacology and Pharmacy 2015). This is one explanation for why practitioners of cannabinoid medicine prefer complex extracts.

What is the availability of medical cannabis in Poland?

In Poland, medical marijuana has been available by prescription since November 1, 2017, following the amendment of the Act on Counteracting Drug Addiction (Journal of Laws 2017, item 1458). In 2024, the number of prescriptions issued for the pharmaceutical raw material Cannabis flos exceeded 390,000, representing more than a tenfold increase compared to 2020, according to data from the Chief Pharmaceutical Inspectorate.

An oncology patient in Poland can receive a prescription for medical marijuana from any doctor with the right to practice, including oncologists, palliative care physicians, and family medicine specialists. The prescription is issued in the eRP system, facilitating fulfillment in pharmacies participating in the trade. The most commonly available products are from Spectrum Therapeutics (Canada), Aurora Cannabis, Tilray, and S-Lab.

In Polish oncology centers, there is an increasing interest in pharmaceutical marijuana among patients with chronic pain after mastectomy and in chemotherapy-induced peripheral neuropathy (CIPN). However, many doctors still do not initiate therapy independently, referring patients to a medical cannabis specialist or pain management clinic.

Citation capsule: In Poland, since November 2017, medical marijuana in the form of pharmaceutical raw material Cannabis flos has been available by electronic prescription. In 2024, over 390,000 prescriptions were filled, most often for strains standardized for THC and CBD from suppliers Aurora, Tilray, and Spectrum Therapeutics (GIF, 2024).

Registered cannabinoid medications in Poland

In addition to the pharmaceutical raw material Cannabis flos, Polish pharmacies offer: Sativex (nabiximols, oral spray THC:CBD 1:1), registered for spasticity in MS, Canemes (nabilone) for CINV resistant to standard therapy, and Epidyolex (CBD) for drug-resistant epilepsy. Canemes is sometimes used off-label for resistant oncology-related nausea.

Over-the-counter CBD products vs. medical marijuana

Full-spectrum or broad-spectrum CBD products available over the counter as dietary supplements are a different category than medical marijuana. They contain up to 0.3% THC, do not have drug status, and cannot be formally recommended by a doctor as part of oncology therapy. They may be considered as symptomatic support after individual consultation with an oncologist and pharmacist.

Which CBD products can support symptomatic care?

In the context of supportive care for oncology patients, with the approval of the attending physician, the choice of CBD product should be based on several criteria: source of raw material, extraction method (supercritical CO2 preferred), confirmed analytical certificate (COA) composition, absence of pesticide and heavy metal residues, batch stability. Use occurs solely as symptomatic support.

The following products available in the u Bucha store may be considered as a supplement to daily care (under consultation with an oncologist):

• SOOL Broad Spectrum CBD 5% 10 ml – moderate concentration oil, broad spectrum extract without THC, 76 PLN.
• SOOL Broad Spectrum CBD 10% 10 ml – higher concentration for users requiring a larger dose, 99 PLN.
• Cannova CBG 15% 10 ml – CBG oil, an alternative cannabinoid with a varied action profile, 240 PLN.
• Mars Dry CBD 9% – CBD hemp flower for vaporization, 59 PLN.

Attention: None of these products is a registered medicinal product and does not replace oncological treatment. Use in a patient with cancer requires consultation with the attending oncologist and consideration of interactions with ongoing pharmacotherapy.

How to safely talk to an oncologist about cannabis?

The ASCO 2024 guidelines explicitly encourage oncologists to make inquiries about the use of cannabis and cannabinoids a routine part of the interview with every patient at every visit (Braun et al., JCO 2024). Between 20 and 40% of adults with cancer in the USA use cannabis, most often without the knowledge of the treatment team, creating a risk of unforeseen interactions with cytostatics and immunotherapy.

The patient should proactively inform the doctor about all forms of cannabis they are using or intend to use: CBD oils, hemp flower, edibles, full-spectrum products, Sativex, Canemes. Key information includes daily doses, THC:CBD ratio, method of administration (oral, sublingual, vaporization, inhalation), frequency.

In clinical practice, a communication barrier may be the patient's fear of moral judgment from the doctor. The ASCO guidelines clearly emphasize that the oncologist should adopt a non-judgmental attitude, even if they do not recommend this form of therapy. The goal is patient safety, not enforcing norms.

Citation capsule: ASCO recommends that inquiries about cannabis become a routine part of every oncology visit, alongside questions about dietary supplements, herbs, and OTC medications. The expert panel clearly emphasizes that the patient should receive reliable information about benefits and risks, not moral judgment (Braun et al., JCO 2024).

Checklist for patients before talking to an oncologist

• What cannabis products am I currently using (names, concentrations)?
• What are the daily doses of CBD, THC, CBG?
• What is the method of administration and frequency?
• How long have I been using them?
• What symptoms do I want to alleviate?
• What side effects have I noticed?
• Am I combining with other supplements or herbal medications?

The role of the clinical pharmacist

In oncology centers, the role of the clinical pharmacist, a specialist in oncology pharmacy assessing interactions and dosing, is growing. In the case of cannabinoids, this is a key consultation, especially with regimens containing tyrosine kinase inhibitors, taxanes, or immunotherapy. In Poland, the role of the clinical pharmacist in oncology hospitals has been systematically developing since 2021.

What are the side effects of cannabinoids in oncology patients?

The most common side effects of THC in oncology patients include dizziness (32% according to Whiting's meta-analysis), dry mouth (31%), drowsiness (19%), confusion (17%), orthostatic hypotension (13%), and anxiety and dysphoria (Whiting et al., JAMA 2015). In older and frail individuals, the risk of falls and delirium is clinically significant.

The oncology population often consists of elderly patients, with polypharmacy, diabetes, cardiovascular diseases, and peripheral neuropathy. This is compounded by complications from oncological treatment: anemia, thrombocytopenia, neutropenia, mucositis. This increases sensitivity to the side effects of cannabinoids compared to the general population.

Citation capsule: Whiting's meta-analysis in JAMA (2015) based on 79 RCTs showed that cannabinoids increase the risk of side effects threefold compared to placebo (OR 3.03), with the most common neurological and psychiatric symptoms: dizziness, confusion, drowsiness, anxiety, dysphoria (Whiting et al., JAMA 2015).

Cognitive impairment

THC at therapeutic doses can cause attention deficits, short-term memory issues, and psychomotor slowing. In an oncology patient, especially after chemotherapy ('chemobrain') or with brain metastases, this compounds existing cognitive deficits. Therefore, ASCO recommends cautious dose titration 'start low, go slow'.

Cardiovascular risk

Cannabinoids increase heart rate and may induce supraventricular tachycardia and arrhythmias. In patients after cardiotoxic chemotherapy, anthracyclines, trastuzumab, monitoring is particularly important. Absolute contraindications include unstable coronary artery disease and severe heart failure NYHA III-IV.

Interactions with anticoagulants

CBD inhibits CYP2C9, which affects the metabolism of warfarin and may increase INR values. In oncology patients, low molecular weight heparins or oral anticoagulants (DOACs), apixaban, rivaroxaban, are often used, which are metabolized by CYP3A4. Any change in cannabinoid therapy requires reevaluation of coagulation parameters.

When should cannabis NOT be used in oncology patients?

The ASCO 2024 guidelines list several situations in which cannabinoids are contraindicated or require special caution (Braun et al., JCO 2024). Absolute contraindications include: active psychosis, severe cardiovascular disorders, pregnancy and breastfeeding, history of substance abuse. Caution is advised in patients undergoing immunotherapy and with CNS metastases.

Immunotherapy is a particularly delicate area. As mentioned earlier, data from Bar-Sela et al. (Annals of Oncology 2020) suggest a possible deterioration in response to nivolumab with concurrent high cannabis use. Although this signal requires confirmation in prospective RCTs, many oncologists prefer to discourage cannabinoids during active immunotherapy.

A frequently overlooked risk is the self-discontinuation of conventional cancer treatment in favor of cannabis based on unverified claims from the Internet about "curing cancer with RSO oil." ASCO explicitly warns: there is insufficient evidence that cannabis cures cancer. Substituting standard therapy with cannabis is a potentially deadly choice.

Citation capsule: Absolute contraindications to the use of cannabinoids in oncology patients according to ASCO include active psychosis, severe cardiovascular diseases, pregnancy, and breastfeeding. Relative contraindications concern active immunotherapy, history of substance abuse, and severe cognitive impairments (Braun et al., JCO 2024).

Pregnancy, breastfeeding, children of patients

THC crosses the placental barrier and into breast milk, affecting the development of the CNS in the fetus and newborn. ASCO unequivocally advises against cannabinoids during pregnancy and lactation. In oncology patients of childbearing age, especially those undergoing chemotherapy, the topic of contraception and family planning should be discussed separately before starting cannabis treatment.

Active mental disorders

A history of psychosis, schizophrenia, severe bipolar affective disorders are absolute contraindications to products containing THC. CBD has a somewhat better safety profile, but in these patients, strict psychiatric consultation is also required before inclusion.

How do the ASCO 2024 guidelines differ from previous positions?

The ASCO 2024 guidelines are the first GRADE recommendation document on cannabinoids in oncology in the United States, replacing the previous ASCO position from 2020, which was purely informational (ASCO Cannabis Position Statement, 2020). The biggest change is the shift from vague warnings to specific clinical recommendations in clear scenarios.

Internationally, the ASCO 2024 guidelines are comparable to the EAPC 2023 document (European Association for Palliative Care) and the Canadian CFPC 2022 (College of Family Physicians of Canada). The differences concern the emphasis: ASCO focuses on GRADE evidence and interactions, EAPC places greater emphasis on palliative care, and CFPC on family medicine practice.

Citation capsule: The ASCO 2024 guidelines introduce the first GRADE-based recommendations in the history of American oncology regarding cannabis. Compared to EAPC 2023 and NCCN 2023, they are more detailed regarding CINV and drug interactions, but equally cautious regarding the treatment of cancers with cannabis (Braun et al., JCO 2024).

The evolution of the position in the last decade

In 2014, ASCO issued a brief informational statement emphasizing the lack of evidence. In 2017, the report by the National Academies of Sciences, Engineering, and Medicine 'The Health Effects of Cannabis and Cannabinoids' provided the first systematic review. In 2020, ASCO clarified its position regarding amendments to state regulations. In 2024, after 10 years of intensive research, comprehensive guidelines were issued.

What will change in the next edition of the guidelines?

The ASCO panel announced an update of the guidelines every 3-5 years. Expected areas of development include: results of large RCTs with CBD in oncological pain, prospective data on interactions with immunotherapy, real-world evidence studies, cost-effectiveness analyses. An expansion of recommendations regarding sleep and anxiety is possible as RCT evidence emerges.

What are the practical implications for Polish oncology patients?

For oncology patients in Poland, the practical implications of the ASCO 2024 guidelines are threefold: first, cannabinoids have a confirmed place in symptom management (CINV, pain), but as an adjunct, not first-line; second, treatment requires the consent and supervision of the attending oncologist; third, both registered medications (Sativex, Canemes, Epidyolex) and pharmaceutical raw material of medical marijuana are available by prescription in Poland.

Practical recommendations include: discussing with the oncologist at every visit, keeping a diary of doses and symptoms, consulting a clinical pharmacist, monitoring liver enzymes every 4 weeks at doses of CBD above 300 mg/day, avoiding cannabis during active immunotherapy and in pregnancy and lactation, and never discontinuing oncological treatment in favor of cannabis.

In Polish practice, the biggest challenge for the patient is finding a doctor aware of the topic and willing to prescribe pharmaceutical marijuana. Palliative care centers and pain management clinics usually have more experience than general oncology.

Citation capsule: A Polish oncology patient interested in cannabinoids should consult with the attending oncologist, clinical pharmacist, and consider consulting a palliative care center or pain management clinic. Both registered medications (Sativex, Canemes) and pharmaceutical raw material Cannabis flos are available by electronic prescription (GIF, 2024).

Reimbursement and treatment costs

In Poland, the pharmaceutical raw material Cannabis flos is not reimbursed. The cost of monthly therapy at an average dosage of 1-2 g of flower daily ranges from 600 to 1500 PLN. Sativex, Canemes, and Epidyolex are reimbursed only for strictly defined indications (MS, CINV resistant, drug-resistant epilepsy). Costs represent a significant barrier to access, especially for oncology patients.

Where to find a doctor aware of the topic?

Databases of doctors issuing prescriptions for pharmaceutical marijuana are maintained by patient organizations (Cannabis Foundation, Polish Drug Policy Network). It is also worth asking in specialized pain management clinics and palliative care centers. Since 2023, the number of teleconsultations in this area has been increasing.

FAQ: frequently asked questions about ASCO guidelines

Do cannabinoids cure cancer according to ASCO 2024?

No. The ASCO guidelines clearly state that there is currently insufficient clinical evidence that cannabis cures cancer in humans. No available RCTs have shown that cannabinoids as monotherapy extend the survival of oncology patients. Cannabis may only be used as a symptomatic adjunct therapy, not a substitute for chemotherapy, radiotherapy, immunotherapy, or surgical treatment (Braun et al., JCO 2024).

When does ASCO recommend cannabinoids for cancer pain?

ASCO issued a conditional recommendation for the use of cannabinoids as an adjunct in chronic cancer pain, particularly mixed and neuropathic pain resistant to opioids. About 10-15% of patients do not achieve satisfactory pain control with the standard WHO analgesic ladder. In such individuals, cannabinoids may be an addition to opioids, gabapentinoids, and antidepressants, after consultation with the pain management team (Braun et al., JCO 2024).

What are the most dangerous interactions with chemotherapy?

The most dangerous interactions concern cytostatics metabolized by CYP3A4 and CYP2C9, inhibited by CBD and THC: paclitaxel, vincristine, doxorubicin, etoposide, imatinib, pazopanib, erlotinib. The second area is immunotherapy (nivolumab, pembrolizumab), where observational data suggest possible deterioration in response. At doses of CBD above 300 mg/day, there is a risk of hepatotoxicity. Each combination should be evaluated by a clinical pharmacist (Alsherbiny and Li, Medicines 2019; Bar-Sela et al., Annals of Oncology 2020).

Can a patient use CBD without the oncologist's knowledge?

Absolutely not. The ASCO guidelines explicitly recommend that patients inform their oncologist about any form of cannabis, including over-the-counter CBD as a dietary supplement. Undisclosed use of cannabinoids may lead to unforeseen interactions, altered pharmacokinetics of cytostatics, and misinterpretation of adverse symptoms. Open communication with the treatment team is a key element of safety in oncological therapy (Braun et al., JCO 2024).

Is pharmaceutical marijuana reimbursed in Poland?

No. The pharmaceutical raw material Cannabis flos is not covered by NFZ reimbursement, and the patient bears the full cost, usually 600-1500 PLN monthly at typical dosing. Registered cannabinoid medications are reimbursed only for strictly defined indications: Sativex for multiple sclerosis, Canemes for CINV resistant to standard therapy, Epidyolex for selected drug-resistant epilepsies, each only for strictly defined indications. The lack of reimbursement represents a significant barrier to access for oncology patients.

Can hemp flower be vaporized during chemotherapy?

According to ASCO guidelines, inhalation (vaporization, smoking) is not recommended for oncology patients with neutropenia after chemotherapy due to the risk of respiratory infections and potential contamination of the herb (mold, bacteria). The preferred route of administration is oral (oils, capsules) or sublingual. If a patient chooses to vaporize, they should only use pharmaceutical-grade Cannabis flos from a pharmacy, never 'black market' (Braun et al., JCO 2024).

How long does cannabinoid treatment last in oncology?

There is no established length of therapy. In CINV, cannabinoids are typically used for the duration of chemotherapy, 3-6 months, with efficacy assessment after each cycle. In chronic pain, treatment may last for many months or years, with periodic attempts to discontinue. ASCO recommends regular reevaluation, at least every 3 months, including assessment of efficacy, side effects, interactions, and quality of life. Long-term use requires monitoring of liver tests and cognitive functions (Braun et al., JCO 2024).

Summary and Key Findings

The ASCO 2024 guidelines represent a fundamental change in the approach of American clinical oncology to medical cannabis. The document published on March 13, 2024, in the Journal of Clinical Oncology contains the first GRADE recommendations regarding the use of cannabinoids in adult oncology patients, based on a systematic review of 101 publications (Braun et al., JCO 2024).

Key conclusions are clear: cannabis has a place as adjunct therapy in CINV resistant to standard regimens (strong recommendation) and in cancer pain (conditional recommendation), but should not be used in cachexia and anorexia (recommendation against). The lack of sufficient evidence regarding anxiety and depression requires further RCT studies. In every scenario, the oncologist's consent, consultation with a clinical pharmacist, and awareness of interactions with cytostatics and immunotherapy are crucial.

For Polish oncology patients, the ASCO guidelines are a reliable educational tool, especially in the context of the increasing availability of pharmaceutical marijuana and CBD products. However, remember: cannabis does not cure cancer, requires medical consent and supervision, and self-discontinuation of oncological treatment in favor of cannabis is potentially a deadly choice. The safest path is open communication with the treatment team and conscious inclusion of cannabinoids only where scientific evidence supports their use.

category of supportive products

Final disclaimer: This article is for educational purposes only and does not constitute medical advice. The decision to include cannabis or cannabinoids in oncological treatment must be made individually in collaboration with the attending oncologist and clinical pharmacist. Do not modify oncological treatment on your own. Cannabis is solely a symptomatic adjunct therapy, it does not cure cancer.

About the author: Michał Waluk, educator in the field of cannabinoids and cannabis medicine, founder of the u Bucha store. He follows scientific publications regarding the applications of cannabis in medicine and educates Polish consumers based on the current state of knowledge.