The Georgia Straight's Grassroots Expo for the Cannabis Curious began today with a riveting discussion about barriers that cancer patients' face in accessing cannabis.

Two panelists, Joanne Crowther and Steven McKee, also shared stories of their journeys battling life-threatening tumours.

In her opening remarks at UBC Robson Square, Crowther recalled being diagnosed with "fatal lymphoma" and being "sent home to die" six years ago.

She then described how her use of cannabis oils "fixed my kidneys and my liver, which were damaged badly by chemotherapy".

"Nobody needs to die from cancer," Crowther insisted. "There's a cure. It's just illegal."

McKee talked about being repeatedly diagnosed with brain tumours, which at one point required two 10.5-hour brain surgeries.

He revealed that two years ago, he was diagnosed with another tumour and endured six radiation scans per day over more than a month.

McKee said that cannabis helped him stay strong and happy throughout his medical ordeal. And he credited his mother for remaining at his side at every step along the way.

"I had everybody on my side rooting me on," McKee said.

At the same time, he said that it's up to the person with cancer to remain positive.

The division head of UBC palliative care, Dr. Pippa Hawley, acknowledged that there are many "wonderful examples" of cannabis helping patients.

"At the end of the day, you can't ignore the anecdotal stories," Hawley said.

But she also offered a cautionary voice on the panel, saying there aren't large studies of anticancer treatments with cannabinoids. Part of the reason is that cannabis has been illegal, making it difficult to conduct clinical trials.

Hawley also pointed out that there are many substances in cannabis plants. Some can offer positive effects, she said, and others can be negative.

"There are many people who don't have the knowledge and don't know where to get that knowledge," Hawley said. "It's not easy to get."

She stated that she's seen people harmed by taking high doses of THC, suggesting that this can cause negative side effects, particularly among elderly patients who aren't used to consuming cannabis.

Crowther took exception to that point of view, saying that she couldn't find cannabis with strong enough legal marijuana to stay alive.

"I had to grow my own," she revealed.

The other panelist, David Hutchinson, is a cannabis consultant and former Royal Air Force member.

He told the audience that his wife died at the age of 46 after being diagnosed with breast cancer. Two weeks before she passed away, their daughter was diagnosed with a brain tumour.

He pointed out that the endocannabinoid system is the largest neurotransmitter system in the body. Yet he stated that this is given short shrift at the vast majority of medical schools across North America.

Hutchinson also said that the delivery method of cannabis is extremely important, noting that it can be taken through suppositories, drops, nasal sprays, and even eye drops.

"I want to see more education," Hutchinson said. "We need to put pressure on medical schools."

He singled out the Canadian Medical Association and the College of Physicians and Surgeons of B.C. as being slow to understand the medical benefits of cannabis.

"I hope and pray that changes in the next five years," Hutchinson said.

Hawley, however, said that there is a great deal of education of physicians about cannabis. She predicted that UBC medical students in family practice who graduate in three years will be far more knowledgeable than their predecessors.

Near the end of the discussion, Hutchinson urged the audience to be wary of vested interests fighting to curb the legal distribution of cannabis.

The liquor and pharmaceutical industries, in particular, could see their bottom lines affected as cannabis use becomes more commonplace.

"Cannabis has a very negative effect on consumption of alcohol," Hutchinson said.