A Short Q & A with Dr Shu on Cannabis and Cancer
Article Interview with Dr Shu Ng
Read time: 3 mins
The momentum for medical cannabis as an adjunctive therapy in cancer care has been increasing in recent years, but where does the science currently stand?
In this exclusive Q&A for The Insiders Extract, we sit down with Dr. Shu Ng of Astrid Dispensary & Specialty Clinic to explore the latest insights on medical cannabis in oncology—from its role in symptom management to its potential synergy with conventional cancer treatments.
Are there any national guidelines currently available for prescribing medical cannabis in cancer care?
In Australia, there are no specific national guidelines for prescribing medicinal cannabis in cancer care or other conditions.
However, the Australian Therapeutic Goods Administration (TGA) has provided some guidance documents on the use of medicinal cannabis in the treatment of a small range of conditions, including the prevention or management of nausea and vomiting in cancer or palliative care.
These documents, first published in 2017, provide an overview of the evidence available at that time to support medicinal cannabis use. Additional studies and regulatory changes have since been updated, but these do not constitute clinical guidelines, as we have for other conditions, or standard protocols, as with other cancer treatments.
Other countries, including the USA, Canada and Israel, have a longer history with medicinal cannabis and our practices are often extrapolated from their clinical data and experiences.
How is cannabis currently integrated into conventional cancer treatments, particularly for managing chemotherapy-induced side effects? For which symptoms is it most effective?
Cannabis is increasingly recognised and integrated as an adjunctive therapy in cancer care, particularly for managing chemotherapy or radiotherapy-induced nausea and vomiting. A recent randomised, placebo-controlled Phase II/III trial conducted in Australia showed a combination of THC and CBD was effective in reducing chemotherapy-induced nausea and vomiting (CINV) in patients where previous standard antiemetic prophylaxis had failed.
Beyond CINV, many patients with cancer may also experience other symptoms pre-existing or related to their cancer diagnosis and management, including anxiety, depression, insomnia, fatigue and even period pain or endometriosis, which may also respond to medicinal cannabis treatments.
Patients who have cancer-related pain also report benefits from THC. Cannabidiol (CBD) may be used for its anti-inflammatory and anxiolytic potential. In the majority of cases we manage, a balanced combination of THC and CBD has been shown to help with synergistic effects while maintaining tolerability with minimal to no side effects.
What is the current state of research on cannabinoids acting directly on cancer cells? Have you seen any recent promising findings in in vitro or human clinical studies?
Preclinical studies suggest some cannabinoids may have anti-cancer properties, such as inhibiting tumour growth or promoting cancer cell death (apoptosis). However, evidence from human clinical trials remains limited and inconclusive. Some laboratory and preclinical studies have shown that THC and CBD can influence signalling pathways in cancer cells, but translating these findings into effective treatments for patients has proven challenging.
There is an increasing amount of research exploring the role of cannabinoids as an adjunct to traditional therapies like chemotherapy and radiation and their potential synergistic effects in treating cancer, but more rigorous research is needed to establish their effectiveness and safety.
Currently, cannabinoids are not considered a cure or direct treatment for cancer, but there is research to suggest that it can be helpful in alleviating cancer and cancer-treatment related symptoms and side effects.
Are there specific cancer types where cannabis shows greater efficacy?
Research has been conducted on various cancer types, including brain, breast, prostate, pancreas and bowel cancers. Despite many promising indications - the results are still mixed and inconclusive.
Variations in cancer types and individual responses to cannabinoids make it difficult to demonstrate consistent outcomes across different cancer types.
What are the key differences between THC and CBD in managing cancer symptoms? Do you use both in combination or favour one over the other?
Due to different mechanisms of action and effects of THC and CBD, they can be used for different symptoms.
THC is typically used for nausea, vomiting, appetite stimulation and pain relief, especially in neuropathic pain. CBD is used more for its potential anti-inflammatory and anti-anxiety effects.
Often, a combination of both is used to balance the therapeutic effects while minimising the potentially intoxicating side effects of THC. For example, a patient with cancer-related pain may benefit from a higher THC ratio, while those who require more anxiety relief may benefit from a higher CBD ratio.
How do you decide on the appropriate dosage and form (oils, edibles, dried flowers) of cannabis for your oncology patients?
It depends on the patient’s symptoms and goals for treatment. Oral liquids are popular as they allow for more precise dosing and titration, with a sustained release of cannabinoids for better, longer-acting symptom relief. However, for patients with nausea and vomiting or gut issues, this can be more difficult to tolerate.
Pastilles (or gummies) can be a suitable option in this case. Dried herb/flower for vaporisation can be used if quicker onset relief is needed, such as pain flares or acute nausea.
Importantly, doses should always be started low and gently, then titrated up based on efficacy and tolerance.
Any comments on how you monitor adverse reactions particularly in cases of polypharmacy?
In cancer care, it is common for patients to be on multiple medications, which increases the risks of drug-to-drug interactions. It is essential for clinicians to understand various drug metabolisms and to monitor for adverse reactions such as excessive sedation, dizziness, or altered cognitive function.
Communication with the patient and regular follow-ups are important to ensure that any issues are addressed promptly.
We do a comprehensive medication review before initiating cannabis therapy, and ensure that pathology, especially liver function tests, are within normal limits or at least stable. We often collaborate closely with pharmacists and other treating specialists to ensure that any potential interactions are avoided or carefully managed.
What are the most common contraindications or cautions you consider when prescribing cannabis to cancer patients?
Cannabis is contraindicated generally in patients who have a history of psychosis, unstable mental health, pregnant or breastfeeding. It is carefully considered in patients who have pre-existing cardiovascular conditions or liver dysfunction. Many patients with cancer may also be elderly or frail, and side effects may be more detrimental in this population.
Immunotherapy agents used in treating cancer have also been shown to potentially interact and impact the efficacy of these agents and cancer outcome. Risks versus benefits need to be considered and discussed at regular intervals.
How do you collaborate with other healthcare providers and deliver patient education to ensure integrated care when using medical cannabis in cancer care?
Although many patients are concerned about the stigma of the use of cannabis, we always encourage transparency amongst healthcare professionals to ensure high-quality care. All patients are given a treatment summary after their consultation so that they can show it to their other treating specialists. In many cases, we correspond directly with the patient’s GP and oncologist to update them about the treatment plan, or request their support (or inform us of any concerns) in the use of cannabis therapy.
Education should include dosing, administration methods, potential side effects and interactions with other medications. Patients should also be aware that cannabis is not currently primarily considered a cure for cancer but can help alleviate symptoms and it is important to manage realistic expectations during the consultation.
What do you see as the future role of cannabinoids in oncology treatment? Are there ongoing clinical trials you’re optimistic about?
There is still a lot we don’t know about the use of cannabinoid therapy in cancer treatment - dosage, administration, even strain types and minor cannabinoid profiles. The future role of cannabinoids in oncology presents many challenges in conducting well-designed trials to determine if cannabinoids can potentially enhance the effects of traditional cancer therapies or directly impactimpacting cancer progression.
There are open trials to determine the efficacy of cannabinoid therapies in managing symptoms in advanced cancer. As cannabinoid therapies evolve and become more widely accepted and utilised, I hope that we will see more substantial evidence for use in this patient population.
Dr. Shu Ng is a Melbourne-based physician and clinical entrepreneur who serves as Chief Medical Officer of Astrid Clinic. With a background in Radiation Oncology and a Master of Public Health, she specialises in cannabinoid medicine while integrating holistic care principles. As founder of QuitRx and an active member of multiple professional organisations, including the Australasian Society of Lifestyle Medicine, Dr. Shu is committed to patient advocacy and advancing evidence-based cannabis therapeutics for conditions including chronic pain, cancer-related symptoms, and mental health disorders.
Disclaimer: This information is shared with a global readership for educational purposes only and does not constitute medical or business advice. All patient-related information has been de-identified OR fictional to protect privacy. Nothing in this article is intended to promote the use or supply of medical cannabis to members of the public.
