The medical community remains deeply divided over the risks and benefits of surgery for malignant pleural mesothelioma, making the decision even more difficult for mesothelioma patients and their families.
But researchers in Canada and Japan believe they have come up with a better way to make the decision process easier.
The team has devised a scoring system based on a blood test to predict which mesothelioma patients are most likely to do well with radical surgery. The test measures the ratio between blood platelets and lymphocytes.
The platelet-to-lymphocyte ratio (PLR) is a way of measuring how effectively a patient’s immune system is responding to a threat like malignant mesothelioma.
When the immune system perceives an “attack”, the body produces more white blood cells (lymphocytes), changing the ratio of platelets to lymphocytes in the blood.
The PLR score is a marker for inflammation and has been linked to poor prognosis in several different malignancies.
Applying PLR to Mesothelioma Treatment Planning
To test the value of the PLR score in mesothelioma patients undergoing surgery, doctors at Toronto General Hospital analyzed the cases of 65 patients who underwent extrapleural pneumonectomy (EPP), the most radical and extensive type of mesothelioma surgery.
Because these patients had blood tests prior to their mesothelioma treatment, researchers could compare the PLR scores and surgical outcomes to see if there was a relationship.
Mesothelioma patients were divided into three group based on their gender and PLR score.
Mesothelioma Prognosis with PLR Scoring
According to the study, patients in high PLR score groups had the shortest survival following their EPP mesothelioma surgery, ranging from a median of 32 months to 19.4 months.
To test how accurate their mesothelioma prognostic score was, the team applied the same process to 32 Japanese patients who underwent EPP for malignant mesothelioma.
Again, mesothelioma patients with the highest PLR scores had a median survival of 14.5 months after surgery while those with the lowest PLR scores had a median post-surgery survival of 45.9 months.
“The new prognostic score using PLR is simple and useful for predicting the prognosis of patients with malignant pleural mesothelioma undergoing EPP,” writes lead investigator Tetsuzo Tagawa of Kyushu University in Fukuoka, Japan.
They recommend further study to see how the new scoring system could be used to optimize mesothelioma treatment.
Tagawa, T, et al, “Clinical role of a new prognostic score using platelet-to-lymphocyte ratio in patients with malignant pleural mesothelioma undergoing extrapleural pneumonectomy”, November 2015, pp. 1898-1906