Study Advises Caution For Mesothelioma Blood Test

Australian researchers are warning that a blood test used to help diagnose mesothelioma could indicate the presence of another disease instead.

 

Mesothelin is a protein that occurs naturally in cells of the mesothelium, the membrane that surrounds and protects internal organs. The recent finding that blood levels of mesothelin are elevated in mesothelioma patients was a breakthrough for the asbestos-linked cancer that can be difficult to diagnose.  More than half of the mesothelioma patients tested had significantly elevated serum mesothelin at diagnosis, prompting doctors to begin using serum mesothelin as a diagnostic tool.  

But now a new study suggests that serum mesothelin can also be significantly elevated in people with kidney disease and recommends that doctors take that into consideration when looking for mesothelioma.   The Australian team set out to determine the relationship between mesothelin concentrations and kidney function, so that doctors can more accurately interpret the results of a mesothelioma blood test.

The cross-sectional study included 144 patients with chronic kidney disease (CKD).  The test did not include patients who had had kidney transplants, were on kidney dialysis, or were known to have kidney cancer.  The findings showed that serum mesothelin increased with increasing serum creatinine levels, an indicator of the severity of the CKD. There was also a significant correlation between urine mesothelin-to-creatinine levels and mesothelin levels in the blood.

Although they were approaching the test from a different angle, these researchers reached the same conclusion as those who first revealed the serum mesothelin test to be a mesothelioma diagnosis tool:  When used as part of a multi-factor diagnostic approach that also considers age, symptoms, biopsy results and history of asbestos exposure, serum mesothelin can be valuable. The new study suggests that renal function should also be on the list of considerations when interpreting the test.

Sources:

Boudville, N et al, “Mesothelin and kidney function – Analysis of relationship and implications for mesothelioma screening”, February 16, 2011, Lung Cancer. Epub ahead of print. 

Induced Cancer Malignant Mesothelioma”, June 29, 2010, Cancer Epidemiology, Biomarkers & Prevention.

Power Plants Workers at High Risk for Mesothelioma

A new German study has confirmed what thousands of power plants workers already know: their exposure to asbestos on the job puts them at high risk for malignant mesothelioma.

Because of its heat resistant properties, asbestos was used for many years as an insulator around hot power plants turbines, wires and other sensitive equipment.  Thousands of power plants workers have come in contact with the material on a daily basis, in some cases, for decades.

In the newest study on the risk of mesothelioma among power plant workers, German researchers monitored 8,632 former or current power plant employees between 2002 and 2006 who worked with the large turbines.  The researchers took dust fibers from in and around the plants and found that 96 percent of the samples contained high amounts of chrysotile asbestos fibers, a known risk factor for asbestosis, mesothelioma, and other types of lung cancer.

The results of the analysis showed that up to 94 percent of the study subjects had been exposed to asbestos during their employment, some for as long as 20 years, and were at high risk for mesothelioma. The research team analyzed workers involved in different jobs within the power plant and found that the most intense asbestos exposure happened during the repair or revision of the power turbines. While all the power plant workers were heavily exposed to asbestos, power plant metalworkers and electricians, those most directly involved with turbine repair, tended to have the highest exposure and the greatest risk for diseases such as mesothelioma.

Most strikingly, the study found that, although the air inside the power plants was clearly toxic, 82 percent of the German workers did not have any safety precautions in their workplace to protect them against mesothelioma.  The study’s authors suggest that, because of the findings, metal workers and electricians in the power generating industry should be closely monitored for signs of mesothelioma. 

Although mesothelioma is fast-growing and resistant to traditional therapies, early detection vastly improves a patient’s chances of survival.

Source :

Mesothelioma News

Antioxidants May Help Fight Mesothelioma

New research from a Philadelphia cancer center suggests antioxidants may be another important tool in the fight against malignant mesothelioma.  

Consumers know antioxidants, such as beta carotene, as dietary supplements which can fight oxidative stress at the cellular level.  Certain beans, blueberries, apples, cranberries, strawberries, cherries and plums are just some of the foods that are high in antioxidants.  But there are also several antioxidant-based drugs that have a similar effect on cells and are currently being used to treat conditions such as lung disease, diabetes and malaria. 

Now, researchers at Thomas Jefferson Hospital’s Kimmel Cancer Center in Philadelphia have found evidence that these drugs may also be effective against cancers, such as mesothelioma.  The team showed that the loss of a tumor-suppressing protein known as Caveolin-1 leads to tumor growth and is an important predictor of cancer outcomes.  Breast cancer patients found to be missing the Caveolin-1 protein had only a 10 percent chance of surviving for 5 years, whereas those who did have the protein had a 75 percent chance of survival.

Loss of the Caveolin-1 protein leads to oxidative stress in mesothelioma cells, which produces ‘fuel’ for tumor growth.  Because antioxidants fight this stress, and cut off this fuel supply, the researchers theorize that treating mesothelioma patients with antioxidant medications might be one way to stop the growth of their tumors.  Currently, antioxidants are not typically used to treat mesothelioma and other cancers because it is commonly believed that they could counter the effectiveness of chemotherapy drugs, which cause oxidative stress.

"This study provides the necessary genetic evidence that reducing oxidative stress in the body will decrease tumor growth,” said lead researcher Michael P. Lisanti, M.D., Ph.D., professor of cancer biology at Jefferson Medical College."Now that we have genetic proof that mitochondrial oxidative stress is important for driving tumor growth, we should reconsider using antioxidants… as anti-cancer agents.”

Some of the drugs shown to reduce oxidative stress include the diabetes drugs metformin, a malaria medication called chloroquine and a third agent called N-acetyl cysteine.  In the future they could be used as part of a multi-modality treatment approach to mesothelioma, which is notoriously difficult to treat.

The study’s findings were published in the online February 15 issue of Cancer Biology & Therapy. 

Sources:
  Surviving Mesothelioma