In order to find a new effective treatment for mesothelioma, researchers must first identify survival factors in mesothelioma patients. In 2010, researchers in Japan found that patients older than 70-years-old and with the non-epithelioid from of mesothelioma had lower survival rates than other mesothelioma patients. Now, researchers in Netherlands report they have identified a third factor in survival – localization of the cancer.
Researchers from the Netherlands analyzed the medical files of 1,353 patients with a confirmed diagnosis of malignant mesothelioma between 2005 and 2008. One year after diagnosis, 47% of the patients were alive, 20% were alive after 2 years, and just 15% lived longer than 3 years. After closely reviewing overall survival as well as related prognostic variables, the researchers concluded the primary survival of malignant mesothelioma patients is highly dependent on three factors: age, mesothelioma subtype and localization of the cancer.
Nearly half of the patients in the study were 70-years-old or older when they were diagnosed with the disease. Mesothelioma has an extended incubation period before symptoms present themselves, and the researchers found the median latency period after their initial exposure to asbestos was 49 years. The only known cause of mesothelioma is asbestos exposure.
The researchers found that survival was worse for patients where the cancer was no longer confined to the pleura. The pleura is the membrane that lines each lung and the wall of the chest cavity, and is the site where mesothelioma forms. Often, due to the aggressiveness of mesothelioma, cancer cells continue to thrive or regenerate even after treatment. Unfortunately, when the cancer continues to grow and metastasize, or is no longer localized and begins invading other organs, the survival rate drops for patients.
A further distinction in the type of mesothelioma includes the histological subtypes of epithelioid, sarcomatoid and biphasic, or mixed. The researchers found that patients who had the sarcomatoid subtype had lower survival rates. The sarcomatoid and biphasic subtypes combined account for only 30% of all mesothelioma cases and have proven to be the most difficult to treat.
Mesothelioma is diagnosed in close to 3,000 Americans each year. The disease is very aggressive and is resistant to many cancer treatments. Many doctors also attribute stage of mesothelioma, treatment plan, whether the patient has ever smoked, the lifestyle, diet and fitness level of the patient, as well as gender and family traits.
