The disease, which is most commonly caused by exposure to asbestos, is an incurable cancer that affects the lining of the chest cavity. Patients treated with chemotherapy alone, the standard of care, typically live only 12 to 18 months. In the United States, 2,000 to 3,000 patients are diagnosed with MPM each year.
"These are among the best results ever published for patients with an epithelial subtype of pleural mesothelioma, which accounts for about two thirds of all cases," says the lead author, Joseph S. Friedberg, MD, the Charles Reid Edwards Professor of Surgery and Head of the Division of Thoracic Surgery at the University of Maryland School of Medicine and Thoracic Surgeon-in-Chief of the University of Maryland Medical System.
"This is among the most virulent cancers known to man, and we have a long way to go, but it's encouraging to have achieved results we can report in years not months even for these patients with such advanced disease," Dr. Friedberg says. "Although, from a technical perspective, it is more challenging to save the lung than to sacrifice it, it does appear that this technique helps to not only extend life but to also preserve quality of life."
The study followed 73 patients with MPM who had surgery to remove the cancer, followed by a therapy using a photosensitizing agent and light to kill microscopic cancer cells. Ninety-two percent of the patients also received chemotherapy. Overall median survival for all the patients in the study was nearly three years (35 months), the researchers report, but that figure more than doubled, to 7.3 years, for 19 of these patients whose cancer had not spread to their lymph nodes. Median survival is the length of time at which 50 percent of patients are alive after treatment. In addition, researchers also found that overall survival was three times higher than disease-free survival, which is the length of time until the cancer recurs.
For the 73 patients in the study, median disease-free survival was 1.2 years, a third of the overall survival of three years. In the group of 19 patients with overall survival of 7.3 years, disease-free survival was 2.3 years. The majority of the patients had Stage III or Stage IV disease.
"It's unusual to find such a difference in between overall and disease-free survival rates. When this cancer recurs, which it almost always does, patients usually live only a few months," says Dr. Friedberg of the study results, which were published online in November.
While the researchers caution against drawing definitive conclusions based on this non-randomized study, they are intrigued by the findings. Dr. Friedberg and his colleagues are now looking for mechanisms behind the difference, in order to work on improving survival even more.
Dr. Friedberg performed the lung-sparing surgery on the patients in the study while he was at the University of Pennsylvania, where the research was conducted. He has pioneered lung-sparing surgery for mesothelioma and now serves as Director of the Mesothelioma and Thoracic Oncology Treatment and Research Center at the University of Maryland School of Medicine. The center is part of the University of Maryland Greenebaum Comprehensive Cancer Center.
The lung-sparing surgery is a 6- to 14-hour operation to remove detectable cancer from the lining of the chest and spares the lung and as many other normal structures as possible. Dr. Friedberg developed his lung-sparing technique as an alternative to removing the entire lung, diaphragm and sac around the heart.
Dr. Friedberg and his colleagues say that this study shows that the lung-sparing technique can be safely used to achieve a "macroscopic complete resection" -- the removal of all detectable cancer -- while preserving the lung. "The role for lung-sparing surgery for mesothelioma has not been completely defined, but this series demonstrates that it is an option, even in advanced stage cases," they conclude in the journal article.
"The results showing extended overall survival for some patients are very promising and warrant further study," says E. Albert Reece, MD, PhD, MBA, vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor and dean of the University of Maryland School of Medicine. "Under Dr. Friedberg's leadership, our new Mesothelioma and Thoracic Oncology Treatment and Research Center is fast becoming an major center for important scientific discovery as well as highly specialized, multidisciplinary care for patients with mesothelioma and other thoracic cancers."
Materials provided by University of Maryland Medical Center/School of Medicine.
University of Maryland Medical Center/School of Medicine. "Lung-sparing surgery for patients with advanced mesothelioma results in prolonged survival, new study shows." ScienceDaily. ScienceDaily, 14 December 2016. <www.sciencedaily.com/releases/2016/12/161214145608.htm>.