Early detection and diagnosis of mesothelioma offers you the best chance of effectively fighting the disease. More often than not, patients suffering from mesothelioma will be treated with chemotherapy. Chemotherapy works to attack cancer cells and prevents them from multiplying, however, the science has not bee perfected so healthy cells are often destroyed alongside the cancer cells. This problem is the cause of many of the unpleasant side effects of chemotherapy treatments.
Mesothelioma
Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos. In this disease, malignant cells develop in the mesothelium, a protective lining that covers most of the body's internal organs. Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or have been exposed to high levels of asbestos fibers.
Lung Cancer
Lung Cancer is the leading cause of death for both men and women. According to the American Cancer Society (ACS), in 2007 there will be about 213,000 new cases of lung cancer, and approximately 160,000 deaths. Average five-year survival rates for patients diagnosed with lung cancer are less than 15%. Five year survival rates for patients with advanced stage IV lung cancer are only about 5%. The population at highest risk for lung cancer includes approximately 5 million men and women between the ages of 50 and 69 who are current or former smokers.
Mesothelioma and Lung Cancer Study’s Objective in Evaluating LDCT Screening
December 24, 2007 — According to a recent and promising study in The Oncologist, researchers found that LDCT may be helpful in detecting pleural abnormalities including the early diagnosis of malignant pleural mesothelioma. Researchers evaluated low dose computed tomography (LDCT), i.e., spiral or helical computed tomography, screening of those exposed to asbestos. LDCT proved more effective at early detection of lung cancer than a chest radiograph (x–ray).
The objective of the study was to create a nonrandomized trial to evaluate the feasibility of baseline and annual repeat screening using LDCT for the early diagnosis of lung cancer and malignant pleural mesothelioma in a population that had been exposed to asbestos. 1,045 volunteers, already enrolled in a surveillance program for asbestos–exposed workers and former workers, were recruited for the study. The volunteers, between the age of 40–75, had no history of prior cancer, or other severe, preexisting conditions and no chest CT scan in the last two years. Participants underwent a structured interview regarding their medical and occupational history, including their involvement with asbestos. Researchers determined that the median age was 58 years, with an average amount of time exposed to asbestos of 30 years. Most participants, sixty–six percent, had smoked for almost 20 years.
After participants were screened, blood samples were taken and they were given respiratory tests, a chest x–ray and an initial LDCT screening. All LDCT images were reviewed by two radiologists and their findings were individually recorded, discussed and documented. In many participants, LDCT revealed nodules on their lungs, round or oval–shaped lesions, both benign and malignant. The nodules were identified and classified into categories. Positive baseline results were defined as noncalcified nodules (enlarged nodules that may be malignant) and pleural thickening (a hardening of the lungs). Participants with positive findings received a high–resolution CT–scan and additional diagnostic tests. If the nodule was not benign, it was treated by a CT–guided biopsy and video–assisted thoracoscopic surgery, or by a bronchoscopy—a procedure that allows your doctor to look at your airway through a thin viewing instrument called a bronchoscope.
LDCT Screening Results—Will LDCT Be Helpful in Early Diagnosis of Mesothelioma?
Results of LDCT screening were:
- 834 noncalcified (benign) nodules were detected in 44% of the participants on an initial LDCT compared to 43 noncalcified nodules in 4% of participants by chest x–ray.
- There were nine cases of lung cancer detected by LDCT and none by chest x–ray. Of the nine lung cancers detected, eight lung cancers were Stage I and one was Stage IIA. All were treated with potentially curative surgery.
- In addition, one person had a thymic carcinoid detected by LDCT. There were 11 false positive results.” (The Oncologist, August 21, 2007).
It was determined that annual repeat LDCT screening could provide useful information on the natural history and significance of asbestos–related pleural abnormalities.”" Researchers concluded that LDCT significantly increases the likelihood of detecting small nodules, and thus lung cancer, at an earlier, more curable stage.”" (The Oncologist, August 21, 2007) LDCT was 19 times more likely to detect nodules than the x–ray, and none of the malignant nodules were detected by x–ray.
LDCT’s sensitivity for detecting lung cancer is four times greater than the sensitivity of an x–ray. (American Family Physician, March 15, 2005) The assumption is that a 5– to 10–mm nodule found by LDCT is more curable than a 2– to 3–cm lesion seen on chest radiographs. (American Journal of Respiratory and Critical Care Medicine, March, 2001) . It is reasonable to expect that novel insights into the significance of pleural abnormalities may emerge from novel imaging techniques with higher resolution capabilities than 5–mm collimation CT. (The Oncologist, August 21, 2007)"
Although no cases of mesothelioma were detected in this study using LDCT, a very high number of pleural abnormalities were detected. Imaging is crucial in the diagnosis of mesothelioma. X–rays of the pleura (lining of the lungs) are used to show lung abnormalities such as pleural effusions (excess fluid between the two membranes that envelops the lungs) and pleural thickening which are symptoms of mesothelioma. Further clinical trials are necessary to evaluate the possibilities of using LDCT to detect and diagnose mesothelioma."
resource : Brayton Purcell LLP
Study of the Protein Osteopontin Produced Encouraging Results.
According to a recent article published in the December 2005 New England Journal of Medicine, a recent study of the protein osteopontin produced encouraging results. Comparing patients diagnosed with mesothelioma, patients exposed to asbestos but disease free and healthy control subjects, revealed clear differences in the patients with malignant disease. Although more research is needed to confirm the accuracy of this investigation, a strong correlation between osteopontin levels and mesothelioma was found.
A significantly higher concentration of osteopontin was detected in patients with diagnosed cases of mesothelioma compared to subjects with asbestos exposure. When compared, the levels of osteopontin were not significantly different in unexposed control subjects versus those subjects exposed to asbestos. Nearly 78% of mesothelioma patients showed elevated osteopontin levels. Levels were elevated in both patients with early stage disease (Stage I) and advanced disease. In over 85% of cases, osteopontin levels differentiated patients with mesothelioma versus benign lung conditions.
Definitive detection of mesothelioma in the earlier stages makes surgical removal of tumors possible before the disease has had a chance to spread. Once spread occurs, the effectiveness of surgical treatment drops dramatically. In end?stage disease, surgery is simply a palliative measure to improve breathing capability with little of no curative value.
While it is not clear that this information will lead to longer survival, we do know that the earlier treatment can begin, the better chance for a prolonged life expectancy and with time, hopefully a cure. ( Mesothelioma Web).
Osteopontin is a type of protein that is involved in communication between cells, including signaling involved in the development of cancer. Osteopontin has also been linked to processes involved in cancer progression and spread. Furthermore, it can be found in circulating blood and would therefore be easily measured in individuals at a high risk of developing specific types of cancer.
In order to evaluate osteopontin as a potential marker for mesothelioma, researchers from several institutions conducted a clinical study to compare osteopontin levels in patients diagnosed with mesothelioma and patients with benign (non-cancerous) lung conditions. This study included 76 patients who had been diagnosed with mesothelioma, 69 individuals who had asbestos-related benign lung conditions and 45 healthy individuals who had not been exposed to asbestos. All individuals had their blood drawn and tested for osteopontin levels.
Overall, osteopontin levels were strongly associated with mesothelioma:
* Osteopontin levels were significantly higher in the group of patients diagnosed with mesothelioma compared to those individuals with asbestos-related lung complications (133 ng/ml versus 30 ng/ml, respectively).
* Osteopontin levels were not significantly different between individuals with asbestos-related lung conditions and those who were never exposed to asbestos.
* Osteopontin levels correctly identified nearly 78% of patients with mesothelioma, and accurately distinguished between mesothelioma and benign lung conditions at a rate of 85.5%.
* Osteopontin could accurately identify individuals with stage I mesothelioma (earliest stage - prior to spread), as well as those with advanced disease.
The researchers concluded that osteopontin may be a promising marker for the detection of mesothelioma. Furthermore, osteopontin identified patients with early-stage mesothelioma, a stage at which surgical removal is possible. However, further studies are necessary to confirm these findings, as well as determine whether early detection through osteopontin can improve survival.
Patients who have been exposed to asbestos may wish to speak with their physician regarding the risks and benefits of osteopontin testing or the participation in a clinical trial further evaluating screening measures for this disease. Two sources of information regarding clinical trials include the National Cancer Institute (cancer.gov) and www.cancerconsultants.com
Reference: Pass HI, Lott D, Lonardo F, et al. Asbestos exposure, pleural mesothelioma, and serum osteopontin levels. New England Journal of 
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