(RxWiki News) The outlook for patients with mesothelioma has often been quite dire, but that may be changing for some patients.
Researchers in a recent study found that giving mesothelioma patients radiation therapy before surgery can extend life significantly.
Patients with a specific type of mesothelioma — epithelial — responded best to pre-operative radiation, these researchers learned.
"If you’ve been exposed to asbestos and have shortness of breath, see you doctor right away."
John Cho, MD, a radiation oncologist at Princess Margaret Cancer Centre in the University Health Network (UHN) in Toronto, Canada, led this study to evaluate the effectiveness of a specialized approach they called SMART (Surgery for Mesothelioma After Radiation Therapy).
The main cause of mesothelioma is exposure to asbestos, a material that’s been banned in the US for years. The disease most often starts in the lining surrounding the lungs, but it can also begin in the lining of the heart and other internal organs. When the lungs are impacted, the disease is known as malignant pleural mesothelioma (MPM).
The most common subtype of the disease is epithelial mesothelioma, a slower growing and more treatable form of the disease, affecting about 70 percent of patients. Sarcomatoid mesothelioma is the most aggressive type. A third form of “mixed” mesothelioma includes both types of the disease and is known as “biphasic.”
Mesothelioma treatments can include surgery, followed by radiation and sometimes chemotherapy.
"Postoperative radiotherapy has been shown to decrease local recurrence after extrapleural pneumonectomy [surgical removal of diseased lung] for mesothelioma,” David Horvick, MD, a radiation oncologist with 21st Century Oncology of New Jersey, told dailyRx News. “The postoperative course of radiation requires 5-6 weeks of daily treatment and can be difficult for patients who have had major surgery to tolerate,” Dr. Horvick explained.
Even with treatment, though, the average lifespan for most mesothelioma patients is 4 to 18 months following diagnosis.
Dr. Cho and team recruited 25 mesothelioma patients for their study. All of the participants were treated with a special type of radiation called intensity-modulated radiation therapy (IMRT), which conforms the radiation around the tumor, while sparing healthy nearby tissues.
Participants underwent five days of radiation and then had surgery to remove the affected lung within a week. Some patients also had chemotherapy following surgery.
“At three years, the cumulative survival reached 84 percent and disease-free survival 65 percent in patients with epithelial histologic subtype,” the authors of this study wrote. These results were seen after a median follow-up of 23 months.
The most common IMRT-related side effects were fatigue, nausea and an inflamed esophagus.
Study co-author Marc de Perrot, MD, professor of surgery at the University of Toronto and head of the Toronto Mesothelioma Research Program, said the SMART approach not only shortened treatment time but also blocked the cancer’s ability to spread and seed itself elsewhere in the body during surgery.
“These research results offer real hope to mesothelioma patients who have too often been told in the past that they may have only six months to live,” Dr. de Perrot said in a statement.
Dr. Horvick said additional study of this approach is needed to confirm these findings. “The preoperative regimen described in this study was very tolerated, required only one week of treatment, and resulted in good survival rates. Further evaluation of the regimen is indicated," he said.
This study was published January 20 in the Journal of Thoracic Oncology.
The research was funded at UHN by The Princess Margaret Cancer Foundation and The Toronto General and Western Hospital Foundation. No conflicts of interest were reported.