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

Immune System May Help Fight Mesothelioma

Proteins and toxins produced by the body’s own immune system could prove to be powerful weapons in the fight against malignant mesothelioma. 

 

Manipulating the immune system to fight cancer is known as immunotherapy.  One type of immunotherapy is utilizing natural immunotoxins, or cell killers, produced by the white blood cells to attack tumors.  Preliminary data shows that a protein produced by these cells called interleukin-4 or IL-4, may have potent cancer-fighting properties.  Researchers with the Pacific Heart Lung & Blood Institute in California are planning studies to test the toxin’s value as a way to combat mesothelioma. 

Their first challenge will be to produce enough IL-4 to conduct tests.  When enough of the immunotoxin can be synthesized according to FDA standards, the researchers plan to test it in combination with chemotherapy, hyperthermia and interferon therapy using mesothelioma cells grown in the laboratory.  If the results of the laboratory studies (in vitro) show promise, the teams will conduct studies of IL-4 in animals (in vivo) and eventually in human subjects.  

Mesothelioma, a rare cancer that attacks the tissues surrounding the lungs and other organs, is extremely difficult treat and survival beyond one year is uncommon.  According to the PHLBI website, if these planned trials prove the efficacy of IL-4, it ‘could be a key to significant progress toward a cure for this dreaded disease’.

Another substance produced by the immune system, interferon, has also shown promising results against mesothelioma in studies conducted at UCLA.  Interferons are messenger proteins that are normally produced to fight certain kinds of infections.  PHLBI researchers believe that, like immunotoxins, interferons may also play a role in fighting abnormal cells like cancer cells, by inhibiting their ability to form blood vessels.  In high does, they have already been shown to help keep melanoma cancer from recurring. 

Plans are in place for upcoming trials to combine interferon with other therapies such as hyperthermia and immune stimulating cytokines to treat mesothelioma cells in the laboratory. Eventually, interferon may even be combined with a COX-2 inhibiting drug such as Celebrex as a ‘maintenance therapy’ to keep mesothelioma tumors in check.  As with IL-4, success in the lab may lead to animal and eventual human testing at UCLA and other centers around the country.

Source:
  Mesothelioma

Worldwide Mesothelioma Rate Higher Than Expected

The global rate of the asbestos-related cancer mesothelioma is probably much higher than was previously thought.

A new study published in the National Institute of Health’s (NIH) environmental health sciences journal, Environmental Health Perspectives, estimates that for every four or five cases of mesothelioma worldwide, there is at least one more case that goes unreported.   

Malignant mesothelioma is an aggressive form of cancer that usually develops 20 to 50 years after exposure to asbestos, a mineral used for many years in a wide variety of products and applications.  The popularity of asbestos declined after it was associated with mesothelioma and other serious health problems in the 1980’s, but there is still no asbestos ban in the USA.  In addition, because it is cheap and plentiful, asbestos is especially popular in developing countries, many of whom continue to import and use it today, despite the risks.

To arrive at their numbers, the Environmental Health Perspective study’s authors looked at the correlation between asbestos use and mesothelioma deaths in 89 countries, which accounted for more than 82 percent of the world’s population in the year 2000.  The study assessed each country’s level of asbestos use between 1920 and 1970 and compared it with each country’s mesothelioma deaths between 1994 and 2008.  The United States, Russia, United Kingdom, Germany and Japan were the largest users of asbestos. Because many of the smaller, poorer countries that also use asbestos tend to have less reliable reporting practices, the authors cautioned that the actual numbers of mesothelioma cases may be even higher than the study suggests.  

“Our most important finding is the magnitude of unreported mesothelioma in countries that use asbestos at substantial levels but report no cases of the disease,” study co-author Ken Takahashi said in a press release. Takahashi says any country that uses asbestos is certain to have mesothelioma cases and countries whose use has increased, rather than decreased, since 1970 are likely to see a rise in cases in the coming decades.

Takahashi and his co-authors call on all countries to stop mining, using and exporting asbestos in order to prevent mesothelioma. The new study is the first to provide a global estimate of unreported mesothelioma cases based on asbestos use and reported mesothelioma cases. The prognosis for mesothelioma is usually poor.

Source:
  Mesothelioma