Improved Radiation Therapy Extends Lives of Mesothelioma Patients
December 30, 2014
Mesothelioma patients receiving novel radiation therapy following lung-sparing pleurectomy/decortication (P/D) surgery lived almost twice as long as those undergoing the more aggressive extrapleural pneumonectomy (EPP), according to one recent study.
The findings accentuated the recent trend toward the P/D option and away from the EPP, which once was considered the optimal surgical choice because it included a more complete removal of the cancer.
New and improved radiation techniques, including the Intensity Modulated Radiation Therapy (IMRT), have helped reverse the trend. It has allowed more precise and higher doses to the target area.
“This would seem to continue the shift toward the less aggressive surgery,” Daniel Gomez, M.D., assistant professor in the Radiation Oncology Department, MD Anderson Cancer Center in Texas, told Asbestos.com. “The goal is to kill the disease and allow patients to still have high-quality lives.”
Researchers at MD Anderson and at Princeton Radiation Oncology cancer treatment center in New Jersey conducted the study. It included 24 mesothelioma patients at MD Anderson from 2009 to 2013 who received the P/D and IMRT combination.
They were compared with 24 mesothelioma patients, matched by age, nodal status, performance status and chemotherapy, who underwent the EPP-IMRT combination from 2001 to 2011 from a previous study.
The extrapleural pneumonectomy surgery includes complete removal of the diseased lung, the lining of the chest and heart, along with parts of the diaphragm. The pleurectomy/decortication removes the lining around the lung and then meticulously removes any tumor masses growing on the lung or other parts of the chest cavity.
Survival Time Greater with P/D
There has been considerable debate in recent years over which of the two surgical options is the most effective. Both still are being performed for mesothelioma patients in the U.S. This study gives a definitive edge to the P/D procedure.
Median overall survival was 28.4 months for the P/D group compared to just 14.2 months for the EPP group. The progression free survival was 16.4 months for P/D, compared to 8.2 months for the EPP patients.
The over survival and progression free survival at the one-year mark for P/D patients was 76 and 67 percent, respectively. It was 56 and 34 percent at two years. For the EPP patients, the overall survival was 55 percent and the progression free survival was 44 percent at one year.
Radiation Causes Pulmonary Decline
There was one noted downside to the IMRT that has made the P/D more effective. While producing little high-grade toxicity, it did let to progress declines in pulmonary function.
“There is definitely a trade-off,” Gomez said. “This is not a panacea for treatment. The decline in pulmonary function is inevitable because the area being treated.”
Researchers found a 19 percent pulmonary decline from initial baseline to post-surgery analysis. They found a 29 percent decline from baseline to post-IMRT.
“The decline is different than having a lung removed all at once,” Gomez said. “The decline is gradual over an extended period of time. It is relatively modest by comparison.”
The median interval time between the P/D surgery and IMRT was 1.8 months, which was similar to the EPP median. The median follow up between surgery and analysis was 12.2 months, which was four months longer than for the EPP. The authors also said the small number of patients in the study limited the strength of the results.
“Radiation therapy has come a long way,” Gomez said. “In the past, there were very limited options in terms of local control of the disease. I think our results showed that this technique after a pleurectomy can be very beneficial.”