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New Chemotherapy Promising for Asbestos Lung Cancer
LONDON (Reuters Health) - The results of a preliminary study suggest that a new chemotherapy combination may be a promising treatment for mesothelioma, British researchers reported on Tuesday.
Mesothelioma is a type of lung cancer thought to be triggered by long-term inflammation where asbestos fibers come into contact with the lung surface. It affects 1,700 people in the UK each year and is normally resistant to chemotherapy.
But the combination of a new drug called pemeterxed, developed by Eli Lilly, and an existing drug called carboplatin, could be an effective treatment for the hard-to-treat condition, according to Dr. Hilary Calvert from Newcastle General Hospital and colleagues.
The researchers administered the two drugs to 27 patients with malignant pleural mesothelioma in a range of doses. They report their results in the August 13th issue of the Journal of Clinical Oncology.
"The drug combination showed remarkable activity in mesothelioma," Calvert said. "Indeed, our study provided the first convincing demonstration that pemeterxed (and) carboplatin could be useful in the treatment of the disease."
Of 25 patients who completed the study, 8 showed a partial response, while 70% of patients noticed an improvement in symptoms, often after just two courses of chemotherapy.
The median survival time in the study was 451 days, or over 14 months. A handful of patients have survived for 3 years or more. Previously, people diagnosed with mesothelioma could expect to survive for 6 to 8 months, the University of Newcastle researchers said.
The chemotherapy was toxic to the blood cell system, causing mainly neutropenia, a drop in infection-fighting white blood cells known as neutrophils. However, this side effect was usually short-lived and "caused few clinical problems," the researchers write.
More advanced trials have since been completed, showing an improvement of survival and symptoms, Calvert noted.
"Mesothelioma is a serious condition that is difficult to treat so this is an important development," said Dr. Lesley Walker, director of cancer information at Cancer Research UK.
"We now need to look closely at the drug's performance in the next stages of clinical trials to see how it compares to other anti-cancer drugs."
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Gemcitabine/carboplatin "a valid option" for mesothelioma therapy
Reuters Health
Posting Date: May 30, 2003
Last Updated: 2003-05-30 12:59:25 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Due to its acceptable toxicity profile and good response rate, the combination of gemcitabine and carboplatin appears to be a useful treatment for malignant pleural mesothelioma, according to a report published in the June 1st issue of Cancer.
In a multicenter phase II study, Dr. Adolfo G. Favaretto, from the University Hospital in Padova, Italy, and colleagues assessed the outcomes of 50 patients with mesothelioma who were treated with gemcitabine/carboplatin therapy between July 1996 and September 2000. Most of the patients had early stage disease and most had never received any treatments.
Although no complete responses were observed, 26% of patients did experience a partial response, with a median response duration of 55 weeks, the authors note. Disease progression was noted in 24% of patients.
Treatment was often associated with improvements in clinical symptoms. For instance, 46% of patients had improved dyspnea, 40% were able to gain weight, and 26% experienced less pain.
Eleven percent of chemotherapy cycles were associated with grade 3-4 leukopenia and 15% of cycles were associated with severe thrombocytopenia, the investigators note. Anemia, by contrast, was only noted in 5% of cycles. No severe nonhematologic toxicities were observed.
The 1-, 2-, and 3-year survival rates were 53%, 30%, and 20%, respectively. The median overall and progression-free survival periods were 66 and 40 weeks, respectively, the researchers state.
"The combination of gemcitabine/cisplatin has become a common off-protocol treatment for patients with diffuse malignant pleural mesothelioma," Dr. Favaretto's team notes. "Based on our experience, we conclude that the gemcitabine/carboplatin combination is a valid option in the treatment of malignant pleural mesothelioma."
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Asbestos Related Cancers On the Rise
BERLIN, Germany, September 24, 2001 (ENS) - Industrialized as well as developing countries are under threat of asbestos exposure in the workplace, said researchers at the 11th Annual Congress of the European Respiratory Society today in Berlin. The scientists called the pulmonary effects of asbestos exposure a "time bomb in the lungs."
The European Respiratory Society (ERS) devoted one of its Monday symposia to the consequences of asbestos exposure. While the symposium's aim was to discuss in greater depth how to improve the management of workers who had suffered occupational exposure, participants also discussed the global problem caused by the mineral.
The symposium took on special meaning in the wake of the September 11 terrorist attacks in the United States. The collapse of the World Trade Center buildings has released measurable amounts of asbestos in the air in New York City, and some fear rescue workers and other emergency personnel may have suffered significant exposures.
In general, increasingly strict exposure standards have helped reduce the number of cases of asbestos related lung disease worldwide, as have bans on asbestos production and use in several countries.
But the scientists said there has been an alarming increase in asbestos related cancers, and that that trend is likely to continue for some time. This is partly because the effects of asbestos exposure can manifest themselves years or decades after the event - but also because millions of people, largely in poorer countries, continue to suffer daily exposure to asbestos.
RUSSIA, CHINA, CANADA TOP THE CHARTS
Global asbestos production was more than two million tons in 2000. The hands down winner was the Russian Federation, with 700,000 tons, said Antti Tossavainen of the Finnish Institute of Occupational Health in Helsinki, one of the symposium's speakers.
China came in second, with 450,000 tons, and Canada produced 335,000 tons - and exported almost all of it.
Canada produces and exports thousands of tons of chrysotile, a form of asbestos used to make chrysotile cement for pipes, sheets and shingles (Photo courtesy Canadian Asbestos Institute)
The data makes it clear that risks from asbestos are still very much present, and that developing countries may be looking at a bleak future. The respiratory specialists participating in the Berlin meeting emphasized that, in countries that have taken strong measures to reduce exposure, the full scope of the damage inflicted by asbestos became evident long after the exposure took place.
"We know that occupational asbestos exposure in Western Europe, North America, Japan and Australia was at its peak in the 1970s," said Tossavainen. "Now, recent estimates indicate that 30,000 new asbestos related cancers continue to be diagnosed there every year. They include some 10,000 mesotheliomas [cancers of the lung lining] and approximately 20,000 cases of lung cancer."
The introduction of increasingly strict limits for asbestos exposure has helped reduce the number of cases of diseases known as asbestosis, which are disabling lung lesions linked to very high asbestos exposure.
For example, Pascal Dumortier of the Erasmus Hospital in Brussels, Belgium, explained that asbestos imports into Belgium have fallen steadily since 1975, from some 85,000 tons to below 1,000 tons in 1999, and that maximum exposure standards have been tightened several times.
A very slight decrease over time in the average concentration of asbestos was seen in a review of thousands of samples of lung tissues taken from Belgian workers exposed to asbestos between 1983 and 2000.
However, "this reduction is lost entirely if the 27 most heavily exposed individuals are excluded from the calculation," Dumortier emphasized. "While epidemiological studies confirm that the risk of dying from asbestosis as such is now very low, at least in the countries that now have regulations ensuring only a very low exposure rate, we will continue to see new cases of mesotheliomas for years to come."
CANCER RATES TO RISE UNTIL 2020
For other asbestos linked diseases, particularly the cancers of the lung lining known as mesotheliomas, scientists do not know whether exposure over time plays an important role. According to the Berlin speakers, mesothelioma rates in industrialized countries seem to have dropped as they have cut back on the amount of asbestos used each year.
But overall, the risk of developing asbestos related cancers appears to increase over time.
Marc Letourneux of the University Medical Center Côte de Nacre in Caen, France, told the symposium that, "The epidemiological outlook is clear: there will be a steady rise in the frequency of asbestos linked cancers until at least 2010 or 2020 because they take years to manifest themselves."
"The mesothelioma rates are expected to rise in France by as much as 25 percent every three years, with some 150 fatalities every year between 2010 and 2020, almost twice the rate of 1996-1997," Letourneux warned.
The figures make it clear that any level of asbestos exposure can increase the risk of developing a cancer of the lungs, Letourneux added.
Another study, presented at the meeting by Krassimir Mitchev of the Erasmus Hospital in Brussels, found that almost one person in every seven in a randomly chosen urban population bore the scars of asbestos exposure.
HOW TO RESPOND?
"This is the crux of the question, and there are no uniform satisfactory answers at present," commented Paul De Vuyst, co-chair of the symposium and chair of the Occupational and Environmental Health Group in the ERS Occupation and Epidemiology Assembly.
The meeting participants discussed the benefits and drawbacks of systematic screening for the signs of past exposure in all patients who have had contact with asbestos. Pierre Alain Gevenois, co-chair of the symposium and president of the Imaging Group in the ERS Clinical Assembly, warned that annual or even semiannual scans may not catch cancers early enough to improve the chances of survival.
"During the period between two scans, it is perfectly possible for a bronchopulmonary cancer to appear, develop and evolve," Gevenois said.
As there is little hope of curing mesotheliomas once they are detected, the experts recommended focusing screening efforts on other lung cancers, for which an early diagnosis may improve chances of survival.
Dr. Gregory Wagner of the U.S. National Institute for Occupational Safety and Health presented a review of promising new American research into asbestos related lung cancers. The research provides some hope that survival rates may be improved through the use of periodic scans of smokers who have been exposed to asbestos.
The symposium's participants said it is now urgent - more than a century after the health threats of asbestos were first documented - to determine the best ways of dealing with this medical time bomb.
At the close of the symposium, De Vuyst called for the creation of a "European Task Force responsible for centralizing data and defining precisely what groups can benefit most from new types of early screening for serious and potentially curable pathologies."
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