A lung cancer patient who shunned conventional treatment and self-medicated with cannabis oil saw her tumour shrink.
The unidentified woman, in her 80s, took cannabidiol (CBD) oil two to three times a day after being diagnosed with lung cancer three years ago.
But despite continuing to smoke and declining standard NHS treatment – which can include surgery, chemotherapy and radiotherapy – her tumour shrunk to a quarter of its original size.
Doctors who treated the patient at Mid and South Essex NHS Foundation Trust said her case justifies thorough research into whether cannabinoids – chemicals derived from cannabis – work as a cancer treatment.
But writing in the BMJ Case Reports, they admitted it is not clear the CBD oil caused her cancer to improve.
And experts said the case is not robust enough evidence that cannabis products can alter the progression of cancers.
The graph shows the diameter of the tumour in millimetres from June 2018 to February 2021, which shrunk from 41mm to 10mm after she self-medicated with CBD oil purchased abroad
The scans show the woman's tumour in the middle part of her right lung (identified by red arrow), which shrunk by 76 per cent over two and a half years. From top left: June 2018, September 2018, November 2018, February 2019, June 2019, October 2019, August 2020 and February 2021
The patient took 0.5ml of CBD oil – that she had purchased outside of the UK – two to three times a day since August 2018 on the advice of a relative. Pictured: shop-bought cannabidiol (CBD) oil
There are hundreds of cannabinoids, but tetrahydrocannabinol (THC) – the chemical that gets you high – and CBD – which is non-psychoactive – are the two which have been most researched.
Both of the chemicals interact with the body's endocannabinoid system, which helps regulate nerve function, emotion, energy metabolism, pain and inflammation, sleep and immune function.
Chemically similar to these molecules, experts claim cannabinoids can interact with signalling pathways in cells — including cancer cells.
Dr Bernard Yung and colleagues said it is 'widely believed' cannabinoids can provide benefits to people suffering pain, anxiety and sleep disorders.
But studies examining whether they can be used alone as a cancer treatment have not established a robust link.
Lung cancer is the second most common cancer in the UK and just 15 per cent of people live for five years after they are diagnosed.
Average survival without treatment is just seven months.
The woman, who smoked more than a pack of cigarettes a week, went to her GP in February 2018 after suffering a cough for a few months.
She was initially given antibiotics after a chest X-ray didn't pick up any problems.
But she was diagnosed with cancer that June after her cough persisted and a follow-up scan showed a lesion on her right lung.
Because there were no signs that it had spread, she qualified for standard surgery to remove the cancer, as well as chemotherapy and radiotherapy.
But she refused the treatment, after watching her husband struggle with the side gruelling effects of radiotherapy.
