Cannabis and cancer: anti-tumor research & reality

in , /by
Key points: In vitro and in animal models, cannabinoids inhibit tumor growth, angiogenesis and metastasis. In humans: no clinical evidence for cancer cure. Cannabis in cancer is well documented for symptom control (pain, nausea, appetite).
At a glance:
  • In vitro: Cannabinoids inhibit tumor growth, angiogenesis and metastasis in dozens of cell lines
  • Guzman 2006: Intratumoral THC injection inhibited glioblastoma in 2/9 patients – only clinical experiment
  • No RCTs prove cancer cure with cannabis – symptomatic control is well established

Cannabis and cancer: between hope and evidence

Overview hide
Cannabis and cancer: between hope and evidence
In vitro findings: what happens in cell cultures
Why in vitro data cannot be transferred to humans
Cannabis for cancer: what really works
Important safety information
SHI and cancer
FAQ: Cannabis and cancer
Summary

No topic in cannabis research is as emotionally charged as the question of anti-tumor effects. Reports of cannabis as a cancer cure circulate on the internet – the scientific reality is much more nuanced. There is real, solid in vitro and animal data on anti-cancer cannabinoid properties. There are no human clinical studies proving that cannabis cures or permanently halts cancer in humans.

In vitro findings: what happens in cell cultures

Type of cancer Study Findings
Glioblastoma Guzmán et al. 2006 (Cancer Res) Intratumoral THC injection: tumor cell proliferation inhibited, apoptosis induced in 2 of 9 GBM patients (first human pilot study)
Breast cancer Caffarel et al. 2010 (Mol Cancer) CBD inhibits breast cancer cell migration and invasion via ID-1 gene inhibition in animal models and in vitro
Lung cancer Preet et al. 2008 (FASEB J) THC inhibits lung cancer metastases in a mouse model; reduced tumor cell invasion
Colorectal cancer Aviello et al. 2012 (J Mol Med) CBD inhibits colorectal cancer cell growth via CB1/CB2-independent pathways; apoptosis induction
Leukemia McKallip et al. 2002 (Blood) THC induces apoptosis in leukemia cells via CB2 receptor; no effect on healthy immune cells

Why in vitro data cannot be transferred to humans

The dosages in cell culture experiments are typically 10-100 times higher than can be achieved in humans. What kills cancer cells in the test tube also kills healthy cells in this concentration in vivo. No orally ingested CBD or THC reaches the tissue concentration used in in vitro studies.

Most important point: There is no completed phase 3 study to date that shows that cannabis reduces tumor size or cancer mortality in humans.

Cannabis for cancer: what really works

The clinically well-documented role of cannabis in oncology is supportive and palliative therapy:

Pain: Tumor pain – especially neuropathic pain – responds well to cannabis. CB1-mediated pain modulation in the spinal cord; opioid-sparing effect (Johnson 2010).

Nausea and vomiting (CINV): Best proven indication. Dronabinol approved since 1985. Antiemetic of second choice after ondansetron.

Appetite stimulation/cachexia: THC stimulates appetite via hypothalamus-CB1. Relevant for tumor patients with weight loss (cachexia syndrome).

Anxiety and depression: tumor patients have high psychiatric comorbidity. CBD anxiolytic, THC mood-enhancing – improvement in quality of life.

Sleep disorders: Common in cancer patients; cannabis (THC-dominant in the evening) improves deep sleep and sleep onset latency.

Important safety information

Cannabis as a cancer therapy instead of conventional medical treatment can lead to life-threatening delays. There are documented cases in which patients have missed chemotherapy-ready cancer stages by self-treatment with cannabis. Cannabis as a supplement to oncological therapy is useful and well documented – never as a substitute.

SHI and cancer

Tumor patients have one of the highest SHI approval rates for medical cannabis:
– Tumor pain (nociceptive and neuropathic)
– Chemotherapy-induced nausea after failure of classic antiemetics
– Loss of appetite/cachexia in advanced tumor disease
– Palliative sedation (anxiety, sleep disorders)

Study highlight: Guzmán et al. 2006 (Cancer Res): Intratumoral THC injection inhibited glioblastoma growth in 2 of 9 patients. The only clinical experiment on direct antitumor cannabinoid use – a pilot signal, not proof of cure.
More on the topic:

FAQ: Cannabis and cancer

Summary

Cannabis and cancer – in vitro data show antitumor effects of THC, CBD and CBG in cell cultures and animal models. Human phase 3 studies on tumor therapy are lacking – cannabis is not a cancer cure. The clinically well-documented role is in supportive and palliative therapy: tumor pain, CINV, cachexia, anxiety. Tumor patients have the highest SHI approval rates. Cannabis for chemotherapy nausea and cannabis for tumor pain provide more specific information.

Cannabis prescription online? Our teleclinic comparison shows all 31 providers in direct comparison – with prices, waiting times and real reviews. Free and independent.
FIV Magazine 🔥 More About