Effects of Cannabidiol (CBD) in Cancer Patients: Pain Relief and Tumor Response

Einführung

Cannabidiol (CBD) is a non-psychoactive cannabinoid increasingly used by cancer patients for symptom management. CBD has been explored in clinical settings for its potential to relieve pain related to cancer or chemotherapy and even to slow tumor progression. This report reviews human clinical research on CBD in cancer care, focusing on two key areas: pain relief (cancer-related pain and chemotherapy-induced pain) and tumor reduction (changes in tumor size or disease progression). Only studies in human patients are included (excluding preclinical animal or cell studies), emphasizing findings from peer-reviewed clinical trials and observational studies. The current evidence is mixed – some trials suggest benefits in symptom control, while others show no significant improvement, and the anti-tumor effects of CBD in humans remain largely unprovennews.cancerresearchuk.org. Below, we discuss the major findings in each area, followed by a summary table of key studies.

CBD for Pain Relief in Cancer Patients

Cancer-Related Pain

Cancer pain is often severe, and while opioids are the mainstay therapy, a subset of patients experiences refractory pain even on high-dose opioidspubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. CBD and other cannabinoids have been investigated as adjunct analgesics in this context. Several clinical trials have tested CBD-containing medications for managing cancer-related pain:

• THC+CBD Extract vs Placebo (Johnson et al., 2010) – In a landmark multicenter randomized trial of 177 patients with advanced cancer and pain not controlled by opioids, an oromucosal spray containing a 1:1 ratio of Δ⁹-tetrahydrocannabinol (THC) and CBD (nabiximols) was compared to THC alone and placebopubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. After 2 weeks, the THC+CBD group had significantly better pain relief than placebo: average pain scores improved more (−1.37 vs −0.69 on a 0–10 scale) and 43% of patients on THC+CBD achieved >30% reduction in pain vs 21% on placebopubmed.ncbi.nlm.nih.gov. By contrast, the THC-only group did not differ from placebo (≈23% responders each)pubmed.ncbi.nlm.nih.gov. This trial demonstrated that the THC+CBD combination produced clinically meaningful pain reduction in opioid-refractory cancer painpubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov, although mild-to-moderate side effects (e.g. sedation, nausea) were observed more with THC+CBD than placebopubmed.ncbi.nlm.nih.gov.

• Nabiximols in Advanced Cancer Pain (Phase III, 2018) – A larger Phase III RCT (almost 400 patients) evaluated nabiximols (THC:CBD oromucosal spray) as add-on therapy for advanced cancer pain despite opioidspubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. In this trial, nabiximols did not meet the primary endpoint – median pain reduction was slightly greater with THC+CBD but not statistically significant versus placebo (−10.7% vs −4.5%, p = 0.085)pubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. Some secondary quality-of-life measures favored nabiximols, and post hoc analyses suggested patients on lower opioid doses might benefit morepubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. Overall, however, the high-quality evidence from this and other trials led reviewers to conclude that cannabis-based medicines (including THC+CBD extracts) have no clear clinically relevant benefit in moderate-to-severe cancer pain compared to placebo, aside from individual casespubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. Der American Society of Clinical Oncology (ASCO) guidelines currently recommend against routine use of cannabinoids for cancer pain outside of clinical trials, given inconsistent efficacy and known side effectspubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov.

• Pure CBD Oil in Palliative Cancer Care (Hardy et al., 2023) – To isolate CBD’s effect, a placebo-controlled trial in 144 patients with advanced cancers examined purified CBD oil (without THC) as an adjunct to specialist palliative carepubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. CBD was titrated up to 600 mg per day orally over 28 days. The results showed no significant improvement in pain or overall symptom distress scores compared to placebopubmed.ncbi.nlm.nih.gov. By day 14, symptom scores had improved modestly in both groups (due to palliative care), with no difference between CBD vs placebo (58.7% responders on placebo vs 44.8% on CBD, p = 0.13)pubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. There were also no differences in opioid usage or quality-of-life, and adverse effects were similar in both armspubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. The investigators concluded that CBD oil provided no additional benefit beyond standard care in alleviating cancer symptoms or painpubmed.ncbi.nlm.nih.gov. This high-quality trial underscores that pure CBD has not proven effective for cancer-related pain when tested rigorously.

• Recent Developments: Interestingly, very recent data suggest that adding THC might be key to analgesic effects. A 2024 clinical report from an ASCO meeting found that a THC:CBD (1:1) oral cannabis oil did yield a statistically significant improvement in cancer pain versus placebo – however, this came at the cost of increased psychotropic side effects from THCascopubs.org. This reinforces the notion that THC (with its direct agonism of cannabinoid receptors) is likely the primary driver of pain relief, whereas CBD alone has a more limited analgesic role. Overall, current evidence indicates mixed results for cannabinoid-based pain management in cancer: some patients derive relief, but consistent benefits of CBD (especially in isolation) have not been confirmed in large trialspubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov.

Chemotherapy-Induced Pain (Neuropathy)

Certain chemotherapy drugs (e.g. platinum compounds, taxanes) cause peripheral neuropathy, leading to tingling, numbness, and neuropathic pain in cancer patients. Preclinical studies suggested CBD might protect nerves or reduce neuropathic pain. Early clinical research has explored CBD for chemotherapy-induced peripheral neuropathy (CIPN):

• CBD to Prevent CIPN (Nielsen et al., 2022) – A Danish pilot study evaluated oral CBD (300 mg/day) given prophylactically around chemotherapy to prevent acute nerve damagepubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. Fifty-four patients receiving oxaliplatin-based (for colorectal cancer) or paclitaxel/carboplatin chemotherapy (for cancers like breast or ovarian) were given CBD oil (150 mg twice daily for 8 days, starting one day before chemo) and compared to a similar cohort without CBDpubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. Results: Patients who took CBD showed attenuated neurologic symptoms in the first week after chemo – in the oxaliplatin group, CBD users reported significantly less cold sensitivity and discomfort swallowing cold liquids than controlspubmed.ncbi.nlm.nih.gov. Objective tests of nerve function (vibrometry at 250 Hz) also showed smaller sensory changes in the CBD group, especially in the paclitaxel group, suggesting less nerve impairmentpubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. No serious side effects emerged, leading authors to conclude CBD appeared to reduce early neuropathy symptoms without major safety issuespubmed.ncbi.nlm.nih.gov. They noted this as preliminary evidence that CBD might protect against chemotherapy-induced neuropathic pain, warranting larger randomized trialspubmed.ncbi.nlm.nih.gov.

• CBD for Established CIPN Pain (D’Andre et al., 2024) – In contrast to prevention, another trial tested CBD for treating chronic CIPN that was already established. In this Mayo Clinic pilot RCT, 40 cancer survivors with persistent chemotherapy-induced neuropathic pain were randomized to a topical CBD cream vs a placebo cream, applied to painful areas for 2 weeks, then crossed overpubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. Outcome: Unfortunately, no significant difference was found – neuropathy scores (EORTC-CIPN20 questionnaire) were similar with CBD and placebopubmed.ncbi.nlm.nih.gov. Pain and tingling did not improve more with the CBD-infused cream than with the dummy cream, although both were well-tolerated with minimal side effectspubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov. This small trial did not support topical CBD as an effective treatment for established CIPN pain. It is possible that CBD’s benefit, if any, is greater in preventing nerve damage (as in the prior study) rather than reversing chronic nerve injury.

In summary, human trials on CBD for chemotherapy-related neuropathic pain have yielded mixed findings. A prophylactic oral CBD regimen showed promising reduction in acute nerve symptomspubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov, but treating existing CIPN pain with CBD (topical or oral) has not shown clear benefitpubmed.ncbi.nlm.nih.gov. More research is ongoing to clarify if timing, dosing, or formulation (and the presence of THC) influences efficacy in this setting. Overall, current evidence does not conclusively support CBD alone as an effective analgesic for cancer or chemotherapy-related pain, especially in comparison to standard therapiespubmed.ncbi.nlm.nih.govpubmed.ncbi.nlm.nih.gov.

CBD and Tumor Reduction in Cancer Patients

Beyond symptom control, there is significant public interest in whether CBD can directly affect tumor growth. Preclinical studies have shown CBD can induce cancer cell death and slow tumor growth in lab models, but clinical evidence in humans remains very limitednews.cancerresearchuk.org. Unlike conventional anticancer drugs, cannabinoids are not an established cancer treatment. Here we review the few human studies and observations that have reported tumor-related outcomes with CBD or CBD-containing cannabis products:

CBD Availability in Prague and the Czech Republic

In the Czech Republic, CBD is fully legal and widely accessible. Thanks to progressive cannabis laws, you can easily find a wide range of CBD products across Prag and other cities. These include:

🌿 Common CBD Products Available:

CBD oils and tinctures (various concentrations, often full-spectrum or broad-spectrum)

CBD gummies and edibles

CBD-infused cosmetics and skincare

CBD vapes and e-liquids

CBD capsules and softgels

CBD flower and pre-rolls (with <0.3% THC, legally compliant)

CBD for pets (treats and tinctures)

🛍️ Where to Buy CBD in Prague:

Specialized CBD shops (e.g., CBD Star, Canatura, HempPoint)

Pharmacies and wellness stores (many stock CBD oils and creams)

Vape shops (for CBD e-liquids and vaporizers)

Online retailers based in the Czech Republic (fast domestic shipping)

🇨🇿 Legal Note:

CBD products must contain less than 1.0% THC, which is the legal limit in the Czech Republic—higher than most EU countries (typically 0.2–0.3%). This means full-spectrum products are more potent and still legal in Czechia, giving consumers a broader selection.

So, whether you’re a tourist or resident, CBD is legal, easily available, and part of a growing wellness market in Prague and the Czech Republic.