Study Investigates Prognosis of Mesothelioma

What Factors Affect the Prognosis of Mesothelioma Patients?

Recent retrospective research from the Department of Thoracic Malignancy at the Osaka Prefectural Medical Center for Respiratory and Allergic Diseases in Osaka, Japan has outlined several factors that dramatically influence the individual prognosis of mesothelioma patients. The study, authored by H Suzuki et al., examined individual incidents of malignant pleural mesothelioma in Japan and uncovered several prognostic factors of MPM. The researchers also reexamined the validity of the European Organization for Research and Treatment of Cancer prognostic score (EPS) system used in past medical reports.

The data they used for the study was collected from the patient records of 68 individuals who were diagnosed with pleural mesothelioma between 1991 and 2010. Researchers then examined the medical history of each patient – including an in-depth analysis of their individual diagnosis – and determined just which factors could be reliably used to “predict” their future prognosis.  Several factors were identified including:

• Histological type (epithelioid, sarcomatoid, biphasic)
• Performance Status (across a variety of tests)
• Type or absence of chemotherapy
• Presence of lactate dehydrogenase (an enzyme that occurs naturally but more so in disease patients as cells breakdown)

These factors were then used to calculate the EPS score in accordance with guidelines created by the European Organization for Research and Treatment of Cancer.

The team of Japanese researchers discovered, not surprisingly, that low-risk groups with EPS scores of 1.27 or less fared significantly better in both survival and quality of life after diagnosis. In fact, the study’s population enjoyed a solid 17 month survival rate – 1.5 times that of the average life expectancy of an MPM patient here in the United States. On the other hand, those who scored high on the EPS (greater than 1.27) fared poorly. Indeed, those patients lived, on average, just 8 months. That is significantly lower than the 12 month average overall.

By far the most predictive of these factors is the histological type of the specific mesothelioma from which the patient is suffering. Epithelioid mesothelioma accounts for roughly 70% of all mesothelioma cases but is also the most treatable. Patients with this form of the disease typically live longer and respond better to various forms of treatment, especially chemotherapy, than patients suffering from the other two histological types, sarcomatoid and biphasic mesothelioma.  Indeed, patients suffering from sarcomatoid mesothelioma fare the worst. That form of the disease is highly resistance to most forms of treatment and not even combined chemotherapy has much of an effect.

Patients suffering from biphasic mesothelioma often express traits and symptoms common to both other subtypes of this disease because their tumors are generally composed of both sarcomatoid and epithelioid cancer cells. As such, their prognosis can often be predicted with a reasonable degree of accuracy by judging the percentage of these other two subsets within an individual’s tumors. Therefore, if the biphasic tumor contains a higher concentration of epithelioid cells, it will likely respond more like proper epithelioid mesothelioma would. And vice versa for tumors with high concentrations of sarcomatoid cells.

In the end, the Japanese team concluded that the EPS scoring system was indeed a valid way to predict the overall prognosis of a recently diagnosed mesothelioma patient even though each individual case must be treated as of unique.