Here's another one - this time from CP...
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ca.dailynews.yahoo.com
Thursday November 25 7:58 PM ET
Cancer light therapy looks for funding boost
TORONTO (CP) - Special light therapy combined with medication is eliminating cancer in patients like William Perdue, who walked naked past his window for weeks after the procedure to rid his body of the drugs. But the Health Canada-approved photodynamic therapy (PDT) is in limited use because it's not covered by most provincial medical plans, Dr. Brian Wilson of Princess Margaret Hospital said Thursday.
More than 200 Toronto-area patients alone, including Perdue of Oakville, Ont., have either had pre-cancerous cells destroyed or tumours zapped with photosensitizing drugs and the light treatment, Wilson told a Canadian Cancer Society news conference.
He said the therapy offers cures for cancers, such as esophageal, that don't respond well to other treatments.
Without PDT, Perdue likely would have had his pre-cancerous esophagus removed, he said. The only inconvenience was "bleaching" the drug Photofrin out of his body by walking nude in front of his home window for brief periods over a number of weeks. Photofrin makes the skin sensitive to sunlight.
"Walking in front of a window naked amused my wife," joked Perdue, a 72-year-old retired engineer who was asked by the society to speak about his treatment.
"Now I have all my body parts, as far as I know, and I feel great. Instead of examining my will, I can relax and lead a normal life."
PDT - which is available at centres in Toronto, Vancouver, Edmonton, and Sherbrooke, Que. - works best on early-stage cancers of the esophagus, skin, lung, brain and bladder, Wilson said.
Although used mostly on its own, PDT sometimes is used with chemotherapy, radiation or surgery.
The only province providing funding for patients treated with PDT is Quebec.
Dr. Roger Deeley, head of research at Cancer Care Ontario, which sets standards for cancer care in the province, said the light therapy is still considered experimental.
"At the moment, the major technical obstacle is to make sure the drugs don't damage normal as well as the (cancerous) tissue," said Deeley.
"I don't think it's very far away (from being included in coverage) to treat many types of cancer," added Deeley, director of cancer research at Queen's University in Kingston.
PDT results in less trauma to the body than standard cancer therapies, said Wilson, who has received nearly $2 million in funding from the cancer society since 1982.
"The drugs activated by light help search for tumours and destroy them."
In a video of Perdue's 1997 procedure, Dr. Norman Marcon of St. Michael's Hospital inserted optical fibres to deliver the light from a laser to the cancer-cell site. Unlike laser which can kill both healthy and diseased cells, PDT only acts on the cancer cells activated by drugs. Patients are up and about the same day.
"The drugs are 'picked up' by cancerous tissue, then they are activated by a light source," Marcon explained. "Once activated, the drugs generate chemicals that kill the cancer cells, either directly or by destroying the blood vessels supplying the tumour."
The intravenous dose of Photofrin needed for the light therapy usually consists of two vials that cost $3,400, said Elayne Wandler, a spokeswoman for the maker, QLT Phototherapeutics Inc (NasdaqNM:QLTI - news)., of Vancouver.
Another obstacle for wider use is only two companies make the machines needed for the light treatment.
"As we start to see this treatment spreading, the pressure will be on (the provinces) to pay for it in Canada," said Wilson.
Kirstin Ring of the cancer society said QLT Phototherapeutics wasn't involved in the news conference, and it wasn't held to pressure governments.
The society simply wanted to educate the public about the therapy which is on the verge of "exploding" into medical use, she said.
Wilson said PDT treatments are approved and covered under medical plans in the U.S.
Some facts about photodynamic therapy, or PDT:
What is it? - A treatment involving the use of certain drugs (photosensitizers) activated by light (usually red) from a laser machine to generate chemicals that kill cancerous and pre-cancerous cells. Optical fibres deliver the light from the laser to the tumour.
What does it involve?- Can be used alone or in combination with other cancer treatment, such as radiation, surgery or chemotherapy. Usually done on an outpatient basis; generally one treatment is needed.
When does it work best?- In early-stage cancers of the lungs, skin, esophagus, brain, bladder, female reproductive tract.
Advantages- Higher cure rate and quicker than some other therapies. Less invasive, with patients up and about in a day or so.
Side-effects - The drugs make the skin extremely vulnerable to sunlight and burning. It can take weeks for the drugs to leave the body.
Other disadvantages - Cost for two vials of the intravenous drug Photofrin is about $3,400, which is covered only in Quebec. Vancouver, Edmonton, Sherbrooke, Que., and Toronto offer PDT.
A look ahead: Several new drugs are under development and clinical trials are under way to test PDT for conditions other than cancer. They include skin diseases, eye problems (macular degeneration), arthritis, women's reproductive concerns, and coronary artery disease. ¸ The Canadian Press, 1999 |
