Researchers Discover New Mesothelioma Blood Biomarker
July 7, 2016
An international team of scientists recently identified a new blood biomarker for mesothelioma that should help with early diagnosis, prognosis accuracy and the personalization of treatment.
Researchers identified activin A, a protein complex found in the blood, as a potential target for future therapies.
“Blood derived biomarkers are important because they can be noninvasively measured, even at multiple stages,” Dr. Balazs Hegedus, at the Medical University of Vienna in Austria, told Asbestos.com. “They can help make the best personalized therapeutic decisions.”
In addition to Hegedus, cancer specialists from Hungary, Switzerland and Australia participated in the study published in the latest issue of European Journal of Cancer.
They measured the activin A levels of 129 patients in four locations, 16 patients with nonmalignant pleural diseases and 45 healthy people for a comparison.
Researchers found significantly higher activin A levels in patients with mesothelioma and increased tumor volume correlated directly with the higher levels of the circulating protein. They also discovered patients with lower levels of activin A at diagnosis lived significantly longer.
Activin A Helps with Histology
The patients with nonmalignant diseases had only a slight increase in activin A, which also helped determine the histological classification of mesothelioma. Those with sarcomatoid and biphasic mesothelioma — the two toughest types to treat — had significantly higher levels of activin A than the epithelioid type.
Activin A is the first mesothelioma biomarker to better identify histological differences. Other biomarkers, such as fibulin-3, are unable to make the distinction.
Mesothelioma, a rare and aggressive cancer, is caused by inhalation or ingestion of asbestos fibers. It is difficult to diagnose, and it often metastasizes before doctors can positively identify it.
An earlier diagnosis, which is possible with a biomarker like activin A, would make it more treatable and provide a better chance of survival. The majority of patients now live less than 15 months after diagnosis.
Biomarker Could Personalize Mesothelioma Treatment
The most effective treatment approach is a multidisciplinary plan that includes a combination of surgery, chemotherapy and radiation. It has led to survival times of two or three years or beyond.
Too often, though, the aggressive treatment approach still leads to a decline in quality of life without significantly extending survival time.
The problem: Accurately advising which patients truly would gain from the aggressive approach. This biomarker should make it easier for physicians to advise their patients.
“The multimodal treatment can be very demanding and should only be offered to patients who can really benefit from it,” Balazs said. “Any marker that can help identify patients with dismal or better prognosis can help with those decisions.”
Study results showed patients diagnosed with lower levels of activin A had an average survival time of 735 days. Those with higher levels survived an average of 365 days, regardless of treatment decisions.
The prognostic benefit of activin A is most effective in patients younger than 66, according to the study. The authors also said the biomarker was more effective for those with the epithelioid histology.
While the diagnostic and prognostic benefits may be immediate, therapeutic gains may take years. Previous preclinical in vitro studies have shown mesothelioma tumor cells potentially use activin A signaling to support growth, but more studies are needed to confirm how.
“If this signaling becomes [treatable] with targeted therapy, it might have therapeutic relevance,” Balazs said. “But we are not there yet.”