The Urgent Need for Cannabis as a Cancer Treatment
By: Justin Kander
Tags: Cannabis Medical, Cannabis, Thc, Cbd, Cancer

Many innovative treatments for cancer have been developed in the last half-century. Despite advancements in medical technology, prognoses are still poor for patients diagnosed with Stage IV cancer, and even survival times for patients diagnosed with some early-stage cancers are low. For example, 56% of patients diagnosed with an early-stage lung cancer live for at least five years after diagnosis, which means that for patients who catch the cancer early, 44% still die in the near-term. The five-year survival rate for metastatic lung cancer is only 5%. Cancer cases are expected to increase all across the world over the next decade, most starkly in low-income countries. As the World Health Organization notes, “Between 2008 and 2030, the number of new cancer cases is expected to increase more than 80% in low-income countries, which is double the rate expected in high-income countries (40%).” Global cancer deaths are also projected to increase substantially. In 2008, 7.6 million people died from cancer; in 2030, that number is expected to be 13 million. The traditional route of focusing exclusively on chemotherapy, radiation, surgery, and even immunotherapy clearly is not enough. Society must contemplate the potential of plants to help significantly reduce the cancer death burden.

One plant in particular holds immense promise as a cancer treatment — cannabis. While there are many plants which possess compounds that inhibit cancer cells, the scope and quality of the evidence surrounding cannabis is truly extraordinary. To start, the primary unique phytocannabinoids in cannabis, tetrahydrocannabinol (THC) and cannabidiol (CBD), have been shown in preclinical studies (using cell cultures and animals) to exert a wide variety of anticancer effects against virtually every major type of cancer. Forms of brain, breast, colon, liver, lung, prostate, pancreatic, and skin cancers, as well as leukemia and lymphoma, are susceptible to phytocannabinoids. Both THC and CBD cause cancer cells to undergo programmed cell death, or apoptosis; the cells neatly break down into small parcels to be cleared by the immune system or neighboring cells. Phytocannabinoids also slow the reproduction of cancer cells, prevent their migration to distant tissues, and interfere with the development of blood vessels to solid tumors. Importantly, these inhibitory effects are almost always selective for cancer cells, and phytocannabinoids are generally shown to be inert against or protective of regular, healthy cells. This property contributes to the safety of using high doses of phytocannabinoids. Photographic documentation from a preclinical study is included below.

Animal Study of Breast Cancer Shrinking in Response to THC or a Synthetic Cannabinoid

There is more reason to believe that plant-derived phytocannabinoids would inhibit cancers in humans because of research into our own self-made endogenous cannabinoids, called endocannabinoids. The primary ways that THC and CBD work against cancer cells is through activation of CB1, CB2, and TRPV1 receptors on the surface of the cells. Likewise, our primary endocannabinoids anandamide and 2-arachidonoylglycerol (2-AG) exhibit anticancer effects via the same receptors. For example, 2-AG mitigates prostate cancer cell invasion via CB1 receptor activation, and along with anandamide it inhibits proliferation of breast cancer cells. In addition, anandamide induces apoptosis in cervical cancer cells via TRPV1 receptors. Since both phytocannabinoids and endocannabinoids inhibit cancer growth through similar mechanisms, it is not surprising there are so many successful reports of humans experiencing anticancer effects after using cannabis. It is worth noting that beyond THC and CBD, other phytocannabinoids like cannabichromene (CBC) and cannabigerol (CBG) possess anticancer properties.

The Connection Between Cannabis for Epilepsy and Cancer

Before discussion of human cases, there is another line of logical reasoning that greatly bolsters the argument for cannabis as a cancer treatment. It is now completely accepted that CBD-rich cannabis products can treat rare forms of epilepsy like Dravet syndrome and Lennox-Gastaut syndrome. When these reports started getting substantial attention in 2013 due to Charlotte Figi’s positive response to CBD, few doctors took them seriously. How could a compound from a federally illegal plant treat seizures that literally no pharmaceuticals were effective against? Genetic conditions like Dravet syndrome are extremely complex, which is why it has been exceptionally difficult for companies to develop proper treatments. Yet what started as “anecdotal evidence” quickly became confirmed by double-blind clinical trials using CBD for Dravet syndrome and Lennox-Gastaut syndrome. Ultimately, in some cases where pharmaceuticals could not decrease seizures at all, CBD-rich oil was effective at reducing seizures by 100%. Due to data like this, the Food and Drug Administration approved a naturally-derived CBD oil called Epidiolex in 2018.

Just as with cancer, there is preclinical evidence suggesting that CBD could treat seizure disorders. For example, a 2012 study found that CBD administration reduced seizures and improved memory in rats with chemically-induced seizures. These types of seizures are far less complex than the ones associated with genetic conditions like Dravet syndrome, so it would have been reasonable not to expect CBD to work in Dravet patients. Yet as we now know from clinical trials, CBD unquestionably delivers therapeutic efficacy for multiple complex seizure disorders.

Despite the promising results, many epileptic patients only respond partially to CBD or even not at all. Benefits will likely continue to improve as further research is conducted, but there will never be 100% efficacy for everyone no matter how far the research gets. It can also take time for patients to find the right dose of CBD, and the right type of oil, that works for them, as there is no one-size-fits-all treatment. The situation is similar for cannabis and cancer. The doses and treatment periods of THC and CBD that patients have used to achieve anticancer effects varies wildly, from only several milligrams of CBD per day to 1000mg of THC and/or CBD per day, and a few weeks of treatment time to several years. The results that patients obtain also vary, including slowing cancer growth, stopping cancer growth, lowering cancer cell markers, shrinking tumors, or achieving full remission from terminally-diagnosed cancers. Of course, many patients do not respond at all no matter what doses they use. There is still so much more to learn, but for now, it is certain that cannabis can produce anticancer effects in at least some patients.

Orphan Drug Designations by the FDA for Phytocannabinoids to Treat Cancer

Even the FDA is taking the potential of cannabis to fight cancer seriously, as they have granted orphan drug designation (ODD) status to numerous phytocannabinoid drugs for the direct treatment of various cancers, mainly brain tumors. ODD is granted to drugs intended to treat diseases affecting less than 200,000 people, and provides financial incentives that facilitate drug development. While ODD is just an early step and not formal marketing approval, it is only granted if there is reasonable scientific evidence that a potential therapy could work. Therefore, the fact that many cannabis-based drugs have ODD for the purpose of treating cancer implicitly supports the strength of the existing evidence. An example of an ODD listing is found below, and you can learn more about phytocannabinoids as orphan drugs here.

Clinical Trial of Cannabis to Treat Glioblastoma

The most conclusive evidence of cannabis fighting cancer in humans comes from a double-blind, placebo-controlled clinical trial using THC and CBD (specifically the whole-plant, 1:1 THC:CBD formulation known as Sativex) for glioblastoma patients. Both the placebo and treatment groups received standard chemotherapy. Median survival time for the placebo group was 369 days; for the treatment group, it was 550 days, about six months longer (a nearly 50% increase in survival time). For an aggressive cancer that even when optimally treated has a median survival of around 15 months, this extension of life achieved with cannabis therapy is particularly impressive and can only reasonably be explained by an anticancer effect. The symptomatic relief afforded by cannabis simply is not strong enough on its own to enable that kind of life extension. The maximum dose used per day was only 32.4mg THC and 30mg CBD per day, and while some patients have reported full remissions from low doses, most seem to need several hundred milligrams per day to potentially obtain remission-level results. In this case, likely due to the aggressiveness of glioblastoma and the doses used, the phytocannabinoids were only effective in extending life. Other case studies using different dosing protocols or describing patients with different cancers have documented better results.

Case Reports of Using Cannabis to Treat Cancer

One of the first case studies published in 2013 concerned a young female patient who resorted to using THC-rich cannabis oil for leukemia after conventional therapy failed. Her leukemic cancer cell count was uncontrolled by conventional therapy, but once the THC-rich oil (referred to as “hemp oil” in the study despite not being CBD-rich) was given, there was a clear decrease in the cell count. While the precise THC doses used in this case are unknown due to lack of lab testing of the THC oil, the volumes of oil given are known and likely correlate to several hundred milligrams of THC per day.

Unfortunately, the patient still ended up passing away, as the result of a gastrointestinal perforation attributed to a side effect of chemotherapy. Although phytocannabinoids have neuroprotective properties, their ability to cause significant regeneration is clearly limited. In this case, if the cannabis extracts had been used earlier and in synergy with conventional treatment, the final outcome may have been avoidable. As the authors Dr. Yadvinder Singh and Dr. Chamandeep Bali noted, “These results cannot be explained by any other therapies, as the child was under palliative care and was solely on cannabinoid treatment when the response was documented by the SickKids Hospital.” Blood tests ruled out the possibility that chemotherapy was still active.

A case series from 2018 published in the journal Anticancer Research examined 119 patients who used a synthetic form of CBD as cancer treatment. Many of them experienced powerful responses, which were summarized in Table II of the paper. One 62-year-old breast cancer patient started on CBD as the only treatment in October 2014, with a blood test showing 10.6 cells / 7.5mL as the circulating tumor cells (CTCs) count at that time. More tests in July 2015, October 2015, November 2016, and October 2017 showed a continuous decline in CTCs, with respective levels of 7.3, 6.8, 5.0, and 3.9 cells/7.5mL. The Table below displays additional cases. Click here for the larger version.

Another interesting case was published in the SAGE Open Medical Case Reports journal in February 2019, titled Striking Lung Cancer Response to Self-Administration of Cannabidiol: A Case Report and Literature Review. The report described an 81-year-old man who went to the doctor for breathlessness in October 2016, and subsequent testing revealed a mass that was biopsy-confirmed to be lung adenocarcinoma. Due to his age, he declined chemotherapy and radiation and did not do anything for nearly a year. Scans in December 2016 and July 2017 showed slow progression of the cancer. In September 2017, he opted to begin using remarkably low doses of CBD (upwards of just 12mg per day); after this, the next scan in November 2017 showed a significant decrease in cancer volume.

Pre-CBD October 2016

Post-CBD November 2017

Doctors from the Royal Stoke University Hospital and Guy Hilton Research Centre in the United Kingdom collaborated on this case, and wrote in their conclusion: “In summary, the data presented here indicate that CBD may have had a role in the striking response in a patient with histologically proven adenocarcinoma of the lung as a result of self-administration of CBD oil for a month and in the absence of any other identifiable lifestyle, drug or dietary changes.”

These formally published cases and the aforementioned clinical trial have come alongside substantial media-reported evidence of cannabis directly fighting cancer in humans. For example, a November 2016 story from an NBC affiliate shared the story of a woman named Tammy Levent who used THC-rich cannabis oil to treat her breast cancer. She first received a lumpectomy shortly after diagnosis in May 2015, but refused further treatments. While her decision was questioned, she was pronounced cancer-free sometime in 2016. One of her nurses, Lisa Genovese, stated, “When I looked at Tammy’s blood work the tumor markers were all zero — and I couldn’t explain it.” Doctors were also surprised, saying they were not sure they had seen anything like this in their lives. Other articles from outlets like ABC News, CBS News, BBC, and Al Jazeera tell stories of patients achieving anticancer effects with cannabis medicine. These are just a few of the existing media-reported cases, which have been increasingly published over the past decade. Over 100 are collected in this free eBook, Cannabis for the Treatment of Cancer.

Summary of the Evidence

The preclinical, clinical, media-reported, and logical evidence clearly demonstrates cannabis can produce anticancer effects in humans in at least some cases. The chance that spontaneous remission, other medical factors, or lying alternatively explain the results of every single case report is essentially impossible. To summarize:

1. Phytocannabinoids from cannabis are shown to kill or inhibit most major forms of cancer in preclinical studies, while not affecting healthy cells

2. Endocannabinoids produced by all mammals kill or inhibit many forms of cancer through similar mechanisms as phytocannabinoids

3. Other preclinical evidence suggesting phytocannabinoids may treat severe, complex conditions like epilepsy have translated radically well to humans

4. There are at least seven case reports/series in formal medical journals hosted on PubMed that describe direct anticancer effects from cannabis

5. There is a double-blind, placebo-controlled trial demonstrating THC and CBD can work together with chemotherapy to inhibit glioblastoma progression

6. Numerous stories from various media sources across the world have been sharing stories of patients claiming remission or anticancer effects from cannabis for over 10 years

Even with all this, some people will say that the evidence just isn’t there yet to claim cannabis can definitely fight cancer in humans. This view is no longer tenable in the face of the current evidence. However, it is true that cannabis is not a guaranteed effective treatment for cancer and there is still far more to learn about the extents and limits of cannabis as a cancer therapy. Nobody should forego conventional treatment for cannabis, and anybody who incorporates cannabis into their cancer therapy should be open with their physician. While it is every patient’s right to use the medicine they want, and some have reported success with cannabis as their sole therapy, the safest course involves combining cannabis with conventional therapy.

Skepticism is an extremely necessary part of life, especially when it comes to novel medical treatments. Nobody wants to provide cancer patients with false hope or advocate something that could hurt them. But skepticism can go too far and hurt people as well. Refusal to acknowledge the real medical potential of cannabis has tragically stunted research and reform, so thousands of patients at this very moment are dying when their lives could be saved or extended with cannabis therapy. There is no guarantee cannabis will work for any specific person, but at the population level, there is absolutely no doubt many cancer patients would experience significant results from cannabis therapy. Given the relatively low cost of cannabis compared to conventional treatments, it would be reasonable for governments to institute programs that help cancer patients financially, as sustaining high doses of phytocannabinoids is expensive when paid out-of-pocket. Governments should also support clinical trials to determine the best treatment protocols for different patients with different cancers, as well as find out which factors mitigate the effectiveness of cannabis.

Cannabis for the treatment of cancer is no longer a fringe issue. At the Cannabis for Cancer Declaration, over 30 medical professionals and researchers have signed on agreeing that cannabis can fight cancer in humans in at least some cases. You can show your support by signing this petition, writing your federal and state legislators, and sharing information with as many friends and family as possible. If we all work together, cannabis will become available as an accessible treatment option for cancer patients throughout the world.