A high platelet count may not bode well for people battling malignant pleural mesothelioma.
New evidence suggests that people who have a high concentration of platelets in their blood prior to the start of mesothelioma treatment have shorter overall survival than those with normal platelet counts.
The news comes from a Chinese meta-analysis including more than 3,600 mesothelioma patients.
Platelets and Health
Smaller than either red or white blood cells, platelets are the components in blood that facilitate clotting. The normal range for platelet counts is 150,000 to 400,000 platelets per microliter (mcL).
When an unusually high concentration of platelets is caused by a secondary problem (such as cancer-related inflammation), it is known as thrombocytosis. By itself, thrombocytosis usually does not cause symptoms and requires a blood test to diagnose.
Platelet Count for Mesothelioma Prognosis
Researchers with First Affiliated Hospital of Fujian Medical University in Fujian, China analyzed 18 different published studies on the relationship between thrombocytosis and mesothelioma survival. The analysis included mesothelioma studies conducted through April 2016 and published in one of four large online databases.
Although there was significant variability between the studies, a clear correlation was found between platelet counts before the start of treatment and mesothelioma treatment response.
“In conclusion, high pretreatment platelet count resulted in poor overall survival in malignant mesothelioma. Therefore, platelet count could be an adequate and useful factor of prognosis for malignant mesothelioma,” writes Dr. Y. Zhuo of the Thoracic Surgery Department.
A Simple Prognostic Tool
Mesothelioma is rare and difficult to treat. Only about 2,500 people are diagnosed with mesothelioma in the US each year, but the majority of those face a life expectancy of a year or less.
But certain factors can impact outcomes and are valuable for treatment planning, which typically involves a combination of multiple therapies. Because it is fast and easy to measure with a blood draw, platelet count may offer a simple prognostic tool to assist in the mesothelioma treatment planning process.
Another New Tool for Mesothelioma Prognosis
Platelet count is just one possibility for helping doctors predict mesothelioma prognosis. Earlier this year, an international team of scientists conducted a study suggesting that the protein complex Activin A may be another prognostic indicator in malignant mesothelioma.
That study included an analysis of plasma samples from 129 mesothelioma patients at four different European institutions. The results showws that the mesothelioma patients had significantly higher levels of Activin A in their bodies than did the healthy controls.
The mesothelioma patients with the lowest Activin A levels had the highest survival levels. Like platelet count, Activin A can be measured with a blood draw.
Zhuo, Y, et al, “Pretreatment thrombocytosis as a significant prognostic factor in malignant mesothelioma: a meta-analysis”, November 16, 2016, Platelets, Epub ahead of print