01. Origins of Mesothelioma
When Was Mesothelioma First Discovered?
In the 1960s, doctors and researchers began looking into the causes of mesothelioma. Although its cause has since been confirmed, researchers continue to learn more about mesothelioma. The medical community continues to make advances in mesothelioma diagnosis and treatment.
The first known cases of pleural tumors were in 1767. These cases were diagnosed by Joseph Lieutaud. In a study of 3,000 autopsies, Lieutaud reported two cases of pleural tumors. This publication may be the first reference to pleural mesothelioma.
Further studies on pleural tumors took place in the decades following. In 1819, Dr. Rene Theophile Hyacinthe Laennec hypothesized pleural tumors could be malignant. Later, Professor Karl Freiherr von Rokitansky stated pleural cancer was always secondary. He theorized the tumors arose from another primary cancer that existed elsewhere in the body.
By the early 1900s, doctors generally accepted malignant tumors could originate in the pleura. With more research throughout the following decades, the medical community learned more about the rare cancer, including its connection to asbestos.
Timeline of Important Mesothelioma Historical Events
- 1767: Joseph Lietaud reports the first cases of pleural tumors, which are possible cases of mesothelioma.
- 1943: H.W. Wedler reports a connection between asbestosis and pleural cancer.
- 1964: Dr. Irving J. Selikoff announces findings that members of New York-area asbestos workers unions have a higher-than-expected mortality rate from lung and pleural cancers.
- 1989: The EPA issues a partial ban on asbestos and asbestos-containing products.
- 2019: The EPA further restricts the use of asbestos products that were not previously regulated.
- 2020: The EPA’s Final Risk Evaluation for Asbestos, Part 1: Chrysotile Asbestos reports uses of chrysotile asbestos pose an unreasonable risk to workers’ and consumers’ health. The agency will need to determine a risk management plan to prevent exposure.
02. Historical Mesothelioma Studies
Historical Asbestos and Mesothelioma Studies
Pleural tumors were discovered more than two centuries ago, but researchers only made clear connections between asbestos and mesothelioma in recent decades.
Since the first discovery of these tumors, scientists and physicians have conducted pivotal treatment research about this cancer. These studies have helped the medical community understand how mesothelioma develops and its connection to asbestos. With the help of this research, asbestos is recognized as a known carcinogen that causes mesothelioma. This research also helped establish mesothelioma as a distinct diagnosis.
Linking Asbestosis and Cancer
In 1943, researcher H.W. Wedler reported a connection between asbestosis and pleural cancers. His research focused on German asbestos workers. In his study, about 20% of workers developed cancer. While most developed lung cancer, several were diagnosed with mesothelioma.
Making the Connection Between Asbestos and Mesothelioma
In 1960, a paper by researcher J.C. Wagner and physician Chris Sleggs was published in the British Journal of Medicine. It documented the connection between mesothelioma and asbestos. In this paper, the authors provided details of 33 cases of diffuse pleural mesothelioma that occurred in residents of South Africa’s Cape Province. All but one of these patients were definitively exposed to crocidolite asbestos.
Studying Asbestos Workers’ Health Risks
In 1964, American physician Dr. Irving Selikoff studied more than 600 workers from New York-area asbestos unions. He determined the mortality rate from lung cancer was 6.8 times that of the general population. Selikoff also described the incidence of pleural mesothelioma in this group as “strikingly high.”
In 1972, physician Molly Newhouse studied mesothelioma cases in individuals who worked in an asbestos factory in London. She attributed their higher rates of cancer and respiratory disease deaths to asbestos exposure.
03. History of Mesothelioma Treatment
History of Mesothelioma Treatment
Although research is continually conducted on mesothelioma, a cure for mesothelioma has not yet been found. However, researchers have made advancements in mesothelioma treatment options through continued clinical trials. Depending on the individual’s case, treatments such as surgery may help decrease the number and size of tumors and/or alleviate symptoms.
Mesothelioma clinical trials are ongoing. The goals of these trials are to find a cure and more effective therapies for the cancer.
Advancements in Surgery for Mesothelioma
Researchers continue to advance surgical options for mesothelioma.
For example, one common pleural mesothelioma surgery, called extrapleural pneumonectomy (EPP), was first performed in the 1970s. In a 1976 study, EPP was performed on 29 mesothelioma patients. Three patients achieved prolonged survival, but the mortality rate was 31%. Since then, researchers have improved the EPP technique. Generally, studies report a median survival of 12 – 20 months for pleural mesothelioma patients who undergo EPP.
Other surgeries for mesothelioma, such as pleurectomy/decortication, have also improved with continued research. Researchers continue to test different treatment combinations with mesothelioma surgery, such as radiation before surgery.
Advancements in Chemotherapy for Mesothelioma
Chemotherapy treatment for mesothelioma has progressed over the years. One such advancement is the use of combination therapy to treat patients.
In 2003, a clinical trial reported a response rate of 41.3% in pleural mesothelioma patients treated with the combination chemotherapy. Since then, researchers have continued to test these and other chemotherapy drugs for mesothelioma.
In recent years, physicians have found success in treating mesothelioma with other forms of chemotherapy, including HIPEC and NIPEC. These are chemotherapy washes that are administered directly into the abdominal cavity, typically after surgery for peritoneal mesothelioma.
For instance, some studies have found survival of 10 years or longer for some peritoneal mesothelioma patients treated with surgery and HIPEC. The average survival for peritoneal mesothelioma is 31 months.
Advancements in Radiation for Mesothelioma
Researchers continue to test new applications of radiation therapy for mesothelioma. Researchers have found radiation therapy may extend survival for patients with most forms of mesothelioma.
Researchers have also been testing treatment combinations with radiation. For instance, the SMART protocol consists of administering radiation therapy before surgery. In a recent study of 96 pleural mesothelioma patients, researchers found the SMART protocol improved survival for some patients. The median survival for participants was 24.4 months.
More recent clinical trials have suggested targeted forms of radiation may be an effective option for patients with recurrent mesothelioma or progressive mesothelioma. For instance, one clinical trial tested focal radiation (a highly targeted form of the treatment) for 37 patients with progressive pleural mesothelioma. Researchers found the treatment extended overall and progression-free survival.
Research continues to find new techniques for using radiation for mesothelioma.
Ongoing Mesothelioma Treatment Research
Clinical trials are continually conducted to investigate new therapies and treatment options for mesothelioma. These trials also work to improve existing therapies, including chemotherapy and radiation.
For instance, immunotherapy drugs have shown promise as safe, effective options for mesothelioma. In October 2020, the combination of nivolumab (Opdivo®) and ipilimumab (Yervoy®) gained approval from the U.S. Food and Drug Administration (FDA) for unresectable pleural mesothelioma. The FDA approved the combination after studies showed survival benefits.
Researchers have also seen promise with other emerging treatments, such as photodynamic therapy and tumor treating fields. Some of these treatments have helped mesothelioma patients survive months or years beyond their prognosis.
For instance, a clinical trial tested a tumor treating fields system combined with chemotherapy for 80 patients with unresectable mesothelioma. Participants had a median survival of 18.2 months. These promising results led to FDA approval of the combination, helping it become more widely available.
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04. Mesothelioma Research Today
Current and Future Mesothelioma Research
Advancements in mesothelioma research have helped doctors better understand the rare cancer. Research efforts have also helped advance mesothelioma diagnostic methods and treatment options. Mesothelioma patients have access to specialists who understand this disease and can provide them with the best possible treatments.
Across the U.S., there are now a variety of dedicated mesothelioma research programs and specialized mesothelioma cancer centers, including the International Mesothelioma Program in Boston. These programs and centers help lead continued research efforts to further doctors’ understanding of the rare cancer and work to find a cure.
Thanks to this ongoing research, mesothelioma survival rates have improved in recent years.