People who are older than 70, have a high white blood cell count, or high levels of a particular protein in their blood may be less likely to survive malignant mesothelioma than other patients.
This is the finding of a group of researchers from the University of Tokyo. The researchers studied 314 patients who had been diagnosed with malignant pleural mesothelioma, a rare and aggressive cancer linked to asbestos exposure. The survival of these patients was tracked using the Kaplan-Meier method, which takes into account the fact that certain patients may drop out of such a study prior to its completion.
In addition to finding that older patients, those with high white blood cell counts, and those with high C-reactive protein levels were at greater risk, the researchers also pinpointed several other factors associated with lower mesothelioma survival rates.
Patients who had a non-epithelioid type of mesothelioma fared worse in the study. Epithelioid mesothelioma is the most common histological type, accounting for more than half of all mesothelioma cases. Non-epithelioid types of mesothelioma include sarcomatoid, in which the cancer cells are more oval in shape with a less visible nucleus, and biphasic, which is a combination of the more boxy epithelioid cells and sarcomatoid cells. Both sarcomatoid and biphasic mesothelioma cancers were linked with lower survival rates.
The other risk factor for lower mesothelioma survival was poor performance status, a term physicians use to characterize the severity of a patients’ symptoms and their ability or inability to function normally.
Of the 314 mesothelioma patients in the University of Tokyo study, 51 were transferred to other hospitals or dropped out of contact before the study ended. Of those whose remained in the study, forty were still alive at the end of the observation period. The median survival for all patients studied was 308 days.
After adjusting the results for other factors, the researchers concluded that, “Some baseline conditions… were determinants of poor survival of patients with malignant mesothelioma.”
Risk factors for mesothelioma include asbestos exposure. As many as 100,000 deaths around the world are attributed to the disease each year.
Nojiri, S et al. “Survival and prognostic factors in malignant pleural mesothelioma: A retrospective study of 314 patients in the West part of Japan”, August 26, 2010. Japanese Journal of Clinical Oncology.
“Epithelioid, Sarcomatoid and Biphasic Mesothelioma Cancer Cell Types” 2005