Cancer Treatment News
New cancer treatment developed at VGH freezes tumours
Cancerous tumours are being engulfed within ice balls, then thawed and frozen again until they wither and die as part of a new technique being pioneered at Vancouver General Hospital.
The process involves sending argon gas through long thin hollow needles into tumours, plunging the cancer cells to temperatures of -100 Centigrade, then thawing the cells with helium gas.
“The tumour cells are killed by the combination of freezing and thawing. The freeze, thaw, freeze cycle results in complete tumour cell disruption,” said Dr. Peter Munk, an interventional musculoskeletal radiologist at VGH.
Called percutaneous cryoablation, the technique is being explored as a less painful alternative to some other procedures used to deal with cancer. And because the ice ball that surrounds the tumour is visible to surgeons, they can track what is happening to it as well as avoid injury to surrounding tissue and organs.
A pilot project to evaluate the safety and efficacy of the procedure is expected to begin at VGH in a few months after final approvals from a University of B.C. ethics review panel.
The project will involve up to 15 patients with metastatic disease -cancer that has spread to muscle and bone -who need help to relieve extreme pain, said Munk.
Pain can be severe for such patients and conventional therapy, such as radiation or pain medications, may not be effective, he said. The new technique can also be used to either cure or treat the pain associated with liver, lung or kidney tumours.
“With the cryo method, it’s less painful than other procedures because it involves freezing,” said Munk.
“It has an anesthetic, numbing effect. Patients can get a local freezing before the probes go in, and a sedative, and then they can leave after the procedure.”
He noted that other methods -such as radio-frequency ablation, which uses heat -may require a general anesthetic, requiring patients to stay in hospital for a few days after.
Another major advantage was cited by University of Wisconsin doctors in a 2008 study describing a series of cases involving cryoablation.
They noted the ice ball that surrounds the tumour is visible on CT scanning technology, which means that tumour death can be observed, as can the status of surrounding structures, like nerves and organs. That is important because doctors don’t want to damage such nerves and organs.
The study also said cryoablation appears to be less painful than other methods, not only during the procedure, but in the immediate aftermath.
The process involves using CT scanning technology as an imaging guide to insert needlelike probes through the skin to the targeted tumour.
The insulated probes are connected to a generator box that provides the argon gas that then flows through the steel tubes. Most tumours require the placement of multiple probes positioned at different angles. The temperature at the uninsulated tips of the probes drops to -100 Centigrade.
After a certain length of time, the frozen tissue is then thawed by helium gas passed through the same probes, and then the freezing cycle is repeated.
Although the cost of each case varies, Munk concedes it is expensive because the $1,000 probes are disposable (one use only) and several might be required for each case. Although the capital cost of the generator box is relatively inexpensive ($50,000), other costs, which can add up to many thousands of dollars, relate to the medical and CT technology staff required.
The cost of the Vancouver Coastal Health Research Institute study will be sponsored by Galil Medical, which manufactures the equipment acquired by VGH with donor funds. Munk’s collaborator in the study is Dr. Paul Clarkson, an orthopedic surgeon who specializes in bone and soft tissue cancers.
Dr. Stephen Ho and Dr. David Liu are interventional radiologists at VGH who have also started using the method.
Cryoshock causing death is the most serious adverse effect that has been described in the medical literature about the technique.
But Munk, who is editor of the Canadian Association of Radiologists Journal, said of the 30 patients who have had cryoablation at VGH since the technology was acquired last year, there have been no serious complications during or after the procedures.
The benefit of the trial is that the cases will be documented and the data peer reviewed and published for close examination of the results.
Melbourne dentist wins cancer therapy case
Health and consumer advocates have vowed to continue fighting after a legal case against a deregistered dentist who claimed to successfully treat cancer sufferers failed.
Victoria’s health services commissioner Beth Wilson said better ways must be found to deal with unregistered practitioners who could exploit vulnerable people, after the Victorian Supreme Court challenge brought by Consumer Affairs Victoria (CAV) collapsed.
CAV had alleged that Noel Rodney Campbell made misleading claims that his alternative treatments could kill cancer and extend the life of patients with a terminal diagnosis.
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Mr Campbell offered treatments such as photo dynamic therapy, radio wave therapy, ozone therapy and high doses of vitamin C at his business, the Hope Clinic in Glenroy.
The clinic was promoted via a website which Mr Campbell set up after his Collins Street practice closed two years ago following a damning report by the health services commissioner.
That report found Mr Campbell’s Hope Clinic acted unethically when it failed to inform patients there was no scientific basis for his treatments.
After the case against Mr Campbell was dismissed on Tuesday, Ms Wilson, who said her office had been grappling with unregistered “alternative” health providers for a decade, expressed dismay.
“Getting redress for people who have been harmed physically, emotionally and financially has been very difficult,” she said.
“I was hoping this case would provide us with assistance in that regard.
“We need better ways of dealing with those unregistered practitioners who exploit vulnerable people.”
Mr Campbell, who represented himself in court, is not a medical doctor nor is he qualified in oncology, but has practised as a dentist for 30 years.
CAV pointed to 37 claims on his clinic’s website it said amounted to misleading and deceptive conduct and breached the Fair Trading Act.
The case against Mr Campbell was essentially that the therapies provided by the Hope Clinic were not sanctioned by conventional medicine, Justice Tony Pagone said in his judgment.
Justice Pagone said he was not satisfied the statements were false and misleading, because the clinic’s website made the distinction that its treatments were alternative and did not pretend to be orthodox medicine.
Outside court, Mr Campbell continued to insist his clinic did not promote a cancer cure.
“We’ve never claimed to cure cancer,” he said.
“Most of the people we see are at stage four, and they’re going to die within a period of time and our aim with those people is to extend their life.”
Mr Campbell was deregistered as a dentist in Victoria in 1998 after being found guilty of professional misconduct for providing grossly negligent dental treatment.
He remains registered in NSW.
CAV acting director Geoff Browne said the watchdog would now “consider its options” but did not back away from the action taken against Mr Campbell.
“We hope this action will encourage anyone suffering from terminal cancer and their families to thoroughly research any alternative medical treatments before … handing over tens of thousands of dollars,” he said.
Cancer Treatment – Key To Reducing Cancers In Developing Countries Revealed
Administration of human papillomavirus (HPV) vaccine doses over a longer period of time to adolescent girls in Vietnam resulted in antibody concentration levels that were comparable to the standard vaccine schedule, according to a study in the April 13 issue of JAMA, a theme issue on infectious disease and immunology.
Kathleen M. Neuzil, M.D., M.P.H., of PATH, Seattle, presented the findings of the study at a JAMA media briefing at the National Press Club in Washington, D.C.
Cervical cancer is an important cause of illness and death among women throughout the world. “Each year, new cases of cervical cancer occur in approximately 529,000 women and 275,000 women die. An estimated 88 percent of deaths due to cervical cancer occur among women residing in developing countries,” according to background information in the article. Human papillomaviruses are the primary cause of cervical cancer. “Combined with continued strengthening of simple evidence-based screening and treatment approaches, effective HPV vaccine programs could reduce cervical cancer rates in developing countries to the low levels currently observed in many developed countries. One challenge to broadly implementing HPV vaccination programs in developing countries will be delivering the currently recommended 3 doses of vaccine to adolescents within 6 months (dosing schedules at 0, 2, and 6 months or at 0, 1, and 6 months),” the authors write. Even in settings in which such vaccination schedules are feasible, alternative schedules may have advantages, such as lower cost (the vaccine could be delivered with other health interventions) or increased coverage (it may be easier for girls and their families or for vaccinators).
Dr. Neuzil and colleagues conducted a randomized noninferiority trial (predetermined measured outcome of intervention not worse than that of standard dosing schedule) in northwestern Vietnam to determine the immunogenicity (the ability of the vaccine to stimulate an immune response) and reactogenicity (the capacity of a vaccine to produce adverse reactions) of alternative schedules of quadrivalent HPV vaccine. The study, conducted between October 2007 and January 2010, assessed 4 schedules of an HPV vaccine delivered in 21 schools to 903 adolescent girls (ages 11-13 years at enrollment). Intramuscular injection of 3 doses of quadrivalent HPV vaccine was delivered on a standard dosing schedule (at 0, 2, and 6 months) or one of 3 alternative dosing schedules (at 0, 3, and 9 months; at 0, 6, and 12 months; or at 0,12, and 24 months). Of the 903 girls, 809 (89.6 percent) received all 3 doses of vaccine and had a serum sample available for testing after the final dose of the HPV vaccine.
For all 4 vaccination schedule groups and vaccine types, the HPV geometric mean titers (GMTs; a measure of antibody concentrations) were low at the beginning of the study and increased significantly after receipt of 3 doses of the vaccine. For the intention-to-treat population and compared with the standard schedule group at 0, 2, and 6 months, the alternative schedule groups at 0, 3, and 9 months and 0, 6, and 12 months met noninferiority criteria (as gauged by level of antibody concentrations) for the anti-HPV-16 and anti-HPV-18 (HPV types) responses at 1 month after receipt of the third dose. Compared with the standard schedule group, the alternative schedule group at 0, 12, and 24 months met noninferiority criteria for HPV-18 but not for HPV-16.
The vaccine was generally well tolerated in each dosing schedule group. Pain at the injection site was the most common adverse event. No serious adverse events were found.
“The similarity of the immunogenicity and reactogenicity profiles of the HPV vaccine reported from this predominantly ethnic minority population in a low-resource area of Vietnam and other populations throughout the world is reassuring and supports more widespread introduction of the vaccine. The World Health Organization acknowledges that programmatic constraints must be considered in the decision to commence national HPV immunization programs. The option of delivering HPV vaccine on flexible schedules will allow countries to minimize costs and maximize feasibility according to local vaccination practices,” the authors write