The Mayo Clinic in Rochester, Minnesota, opened a mesothelioma clinical trial involving intrapleural cryotherapy before surgery to trigger an anti-tumor response.
It is the only cryotherapy clinical trial for mesothelioma conducted in the U.S. Two previous cryotherapy trials for mesothelioma at other cancer centers in 2009 and 2011 were withdrawn or terminated.
Cryotherapy involves dissipating small cancer tumors by freezing them with controlled nitrogen vapors. It has been used with other cancers, but it remains a controversial procedure as an adjuvant therapy for mesothelioma.
The Pacific Meso Center in Los Angeles, whose medical adviser is well-known thoracic surgeon Dr. Robert Cameron, has performed a slightly different form of cryotherapy, or cryoablation, on some patients with much success.
“This is the early, explorative stage where we’re just looking at what it is doing to the body, and how it is stimulating the immune response,” Dr. Shandra Blackmon, Mayo Clinic surgeon overseeing the trial, told CBS News recently.
Clinical Trial Procedure
The cryotherapy in the trial will be conducted during a staging pleuroscopy, a minimally invasive procedure done with a tiny camera in the operating room to better determine the extent of the cancer. It will be done two weeks before major surgery.
The procedure will involve two or three applications of a cryogenic spray within 30 seconds of each other on specific tumor sites. Multiple tumor locations can be treated during the procedure.
The study will better evaluate the safety and effectiveness of cryotherapy. It also should measure the immunotherapy influence on the patient’s cancer.
Doctors hope the cryotherapy may help reduce the aggressiveness of the surgery, preserve more of the lung involved, and lead to a quicker recovery and less recurrence of the cancer.
The cryotherapy is less toxic to healthy tissue when the tumors are closely targeted. It also can be used separately as a palliative measure to control the growth of tumors.
Researchers estimate a trial enrollment of 15 patients who will be measured against a control group undergoing standard of care treatment. The trial is expected to end by January 2017.
Mesothelioma Trials at Mayo Clinic
The Mayo Clinic in Rochester currently is conducting four other clinical trials for mesothelioma patients. Those trials involve:
- High-dose radiation before major surgery: Reverses the standard order of treatment to determine its safety and therapeutic effect. The Princess Margaret Cancer Center in Toronto regularly performs this procedure. It is not currently implemented in the U.S.
- An enhanced, intrapleural measles virus vaccine: Shows an ability to kill cancer cells without harming healthy ones by jump-starting a patient’s own immune system. Safety and dosage levels are being examined.
- Observational study: Evaluation of survival times and response rates for patients who take the trimodal approach to treatment involving chemotherapy, surgery and radiation.
- Early palliative care integrated with standard care: The belief is mesothelioma patients will experience fewer physical and emotional issues from the cancer. Palliative care typically focuses on improving quality of life.