A simple blood test may have the potential to replace the more costly and burdensome CT scan for monitoring post-treatment recurrence and progression of pleural mesothelioma.
Researchers at the University of Bristol in the United Kingdom recently found that the changing levels of the protein mesothelin in blood often mirrored CT scan results in patients who already had completed treatment.
BMC Cancer published results of their study — a first of its kind — which included the long-term monitoring of 41 patients with mesothelioma who had either completed chemotherapy or other supportive care.
“With this study alone, we can’t confidently say that a mesothelin test can replace the CT scan, but there may be a potential role for it within this group of patients,” Dr. Duneesha de Fonseka, lead researcher of the study, told Asbestos.com. “We would need a larger, more extensive study, but this is a good start.”
Researchers believe the recent emergence of potential second-line and non-chemotherapy treatment options have made more accessible disease monitoring a key to follow-up care for this cohort of patients.
Mesothelioma, the rare and aggressive cancer caused by asbestos exposure, has no definitive cure and often a poor prognosis.
Measuring mesothelin levels in the blood has been used in the past to assist with diagnosis and with gauging treatment effectiveness.
The U.K. study is the first to focus on mesothelin levels for long-term monitoring of disease progression.
Soluble mesothelin is found in the pleural fluid and blood of mesothelioma patients. Levels often correlate with tumor bulk and stage.
After chemotherapy treatment or other supportive care ended, patients in the study began three monthly blood tests for at least a year to measure mesothelin levels. Those tests were paired with less frequent CT scans at three, six and 12 months.
Researchers found a 10 percent change in mesothelin levels matched similar findings on a CT scan with 96 percent accuracy for patients with epithelial mesothelioma, the most common cell type.
For those with the less common sarcomatoid mesothelioma, the accuracy rate was just under 80 percent.
The blood test was 74 percent accurate for patients whose disease had not progressed.
The study also showed mesothelin levels provided a good predictor of survival times.
Patients whose levels remained steady or dropped at the six-month mark had an average survival of 448 days, compared to just 175 days for those whose levels were rising.
De Fonseka believes the convenience and accuracy of post-chemotherapy mesothelin blood tests could play a key role in extending survival times.
Patients who know their mesthelin levels are on the rise could enroll in a clinical trial or start second-line treatment.
“It could be a form of more pro-active monitoring — identifying progression of disease before [patients] start to deteriorate,” she said. “What we don’t want to do is wait too long, then miss the boat for treatment. We could potentially pick it up earlier.”
De Fonseka did caution against any overreliance on mesothelin protein levels because of the study’s small number of patients.
“Our study was not strong enough to make any firm determinations,” she said. “We need further studies. This was the pilot.”