More than 30 percent of patients with epithelioid mesothelioma, the most common cellular strain of this cancer. lived for five years or more after a multidisciplinary treatment approach in England, raising hopes and expectations everywhere for this rare and deadly disease.
The startling success rate stems from a retrospective study of 102 mesothelioma patients who underwent aggressive lung-saving, pleurectomy/decortication (P/D) procedure performed by U.K. thoracic surgeon Dr. Loic Lang-Lazdunski.
All patients also were treated with chemotherapy and post-surgery radiotherapy, along with the controversial hyperthermic povidone-iodine wash of the chest cavity before surgical closure.
“This treatment plan represents an alternative to the classical trimodality approach,” wrote Lang-Lazdunski in a study published last month in the Journal of Thoracic and Cardiovascular Surgery. “Because of the multiple therapies being used in this study, the exact impact of povidone-iodine lavage on outcomes and long-term survival is not possible to precisely know. However, we believe this is a cheap, safe and possibly useful adjunct after P/D.”
A Novel Therapy for Mesothelioma?
Povidone-iodine is a chemical complex popular since the 1950s as a traditional antiseptic often marketed as Betadine and used by doctors as a pre-surgery scrub. Recent laboratory work shows it can suppress and destroy mesothelioma tumor cells.
Although it is part of several clinical trials involving other cancers, it has not been clinically studied specifically with mesothelioma patients. Some surgeons, including Lang-Lazdunski, are using it as an alternative to a chemotherapy wash of the chest cavity after surgery. They believe it could prevent tumoral seeding following surgical resection and slow any future metastasis.
Yet even in his report, Lang-Lazdunski did not fully endorse the treatment without a trial designed to prove its effectiveness.
“We cannot speculate on the impact of povidone-iodine lavage on a patient’s survival in our series,” he wrote.
Lang-Lazdunski did not respond to Asbestos.com e-mail requests to discuss specifics of his latest study.
He has been one of Europe’s most vocal proponents of the intricate P/D surgery for mesothelioma patients and a critic of the more aggressive extrapleural pneumonectomy (EPP) that removes an entire lung. The P/D surgery removes the lining around the lung and all visible tumors throughout the thoracic cavity.
Results of Study Are Impressive
The results of the study, on many levels, were impressive and especially encouraging to medical professionals and patients searching for treatment options.
Mesothelioma is the rare, aggressive cancer with no cure. It is caused by the inhalation of microscopic asbestos fibers, which can become lodged in the lining around the lungs and cause scaring. Years later, those fibers can lead to serious respiratory illnesses, including asbestosis or pleural mesothelioma cancer.
Epithelial mesothelioma, a cellular type of the disease, typically accounts for 50-70 percent of all mesothelioma cases. In this study, it accounted for 73 of the 103 cases, or 71.5 percent. Those generally responded best to treatment.
The one, two and five-year survival rates for epithelial types in the study were 94.5 percent, 76.5 percent and 30.7 percent, respectively.
The patients were from January 2004 to December 2013. Almost half still are alive, according to the study report. Median age of the patients was 64.7 years at time of surgery and 24 patients were older than 70.
The overall median survival was 32 months, considerably longer than the estimated 6-18 months that patients often survive in the U.S. if they don’t find a mesothelioma specialty center.
The overall five-year survival rate in the study was 23.1 percent. The two-year survival was 62.9 percent. Non-epithelial patients had a median survival rate of just 15 months and a five-year survival rate of just seven percent.
No Early Mortality with P/D Surgery
There was no 30-day or 90-day mortality of the study patients, although 30 percent of the patients experienced post-operative complications. All but four patients received from 4-6 cycles of systemic chemotherapy before surgery. Many also received it after surgery.
His most successful patients were among the 46 who had both the epithelial mesothelioma and relatively early diagnosis, allowing for complete macroscopic resection of the disease during surgery. The one, two and five-year survival rates of that group were 97.8 percent, 87.4 percent and 40.2 percent.
One of his earliest patients still was regarded as disease-free after 80 months.
Not Everyone Is Excited
Despite the overall success of the study group, an editorial commentary accompanied the paper in the Journal of Thoracic and Cardiovascular Surgery and cautioned against unrealistic hopes.
“This is a banner time for laboratory and clinical studies in this disease [But it] also illustrated ways in which we can do better in studying MPM,” wrote Dr. Valerie Rusch, from the Department of Surgery at Memorial Sloan-Kettering Cancer Center in New York. “The study evaluated multiple therapies, making it hard to determine which ones might be effective.”
The editorial sounded skeptical about a reliance on povidone iodine as an adjunct therapy.
“It seems unlikely that the povidone-iodine lavage, though well tolerated, was particularly effective. More robust preclinical and initial clinical data should be available before incorporating a novel therapy into a multimodality regimen. The preclinical data supporting hyperthermic povidine-iodine pleural lavage in this study, for example, were scant.”