Mesothelioma is a rare and aggressive cancer that originates in the mesothelium, the thin protective layer of tissue lining most of the body’s internal organs, most commonly the lungs and chest wall. The full understanding of mesothelioma, particularly its cause, unfolded over centuries of evolving medical knowledge and industrial change. This historical account details the progression of mesothelioma from its first descriptions to the definitive identification of its link to asbestos exposure.
The Earliest Observations of Mesothelial Tumors
Medical professionals first documented suspicious tumors of the body’s internal linings as early as the 18th century. The French pathologist Joseph Lieutaud is credited with the earliest suspected medical report in 1767, describing tumors found on the pleura, the lining around the lungs, during autopsies.
During the 19th century, other pathologists continued to note these atypical tumors of the serous membranes, the thin linings of the body cavities. In 1854, Karl Freiherr von Rokitansky, a professor in Vienna, identified primary tumors in the peritoneum, the lining of the abdominal cavity. These early physicians, however, generally considered such growths to be extremely rare and often secondary to a primary cancer located elsewhere in the body.
Formal Classification and Naming of Mesothelioma
The tumors of the mesothelium remained largely unclassified until the early 20th century, when medical professionals began to systematically distinguish them from other cancers. The term “mesothelioma” itself was first coined in 1909 by pathologist J.G. Adami to classify this rare form of cancer. This nomenclature was a step toward recognizing the growths as originating from the mesothelial cells themselves, rather than being metastases from other primary tumors.
A more formal definition and characterization of the disease followed in the 1930s. In 1931, American pathologists Paul Klemperer and Coleman B. Rabin published a paper, Primary Neoplasms of the Pleura: A Report of Five Cases, where they provided a detailed description of pleural mesothelioma tumors. Their work established the histological criteria for mesothelioma, clearly distinguishing it from other types of tumors, particularly lung cancer.
Establishing the Definitive Asbestos Link
Despite the formal naming and classification of mesothelioma, its cause remained unknown for decades until studies in the mid-20th century revealed the link to asbestos. Preliminary reports suggesting an association between asbestos and certain lung diseases had appeared as early as the 1930s and 1940s, but the evidence for mesothelioma was not yet conclusive. A German researcher, H.W. Wedler, published a study on asbestos workers in 1943 that showed a connection between asbestosis and an increased rate of pleural cancer.
The definitive epidemiological evidence came in 1960 from South Africa with the publication of a paper by J. Christopher Wagner, C.A. Sleggs, and P. Marchand. Their study documented 33 cases of diffuse pleural mesothelioma among people living or working near a crocidolite asbestos mine in the North Western Cape Province. The research found that most of the cases had confirmed exposure to crocidolite, or blue asbestos, changing the perception of the disease.
This South African study showed that even low-level, non-occupational exposure, such as living near the mines, could lead to the disease, indicating that no safe threshold for asbestos exposure existed. The findings demonstrated a clear causal relationship, transforming mesothelioma from an idiopathic cancer into a recognized occupational and environmental hazard. American physician Dr. Irving J. Selikoff further cemented this link in 1964 by publishing a study of over 600 insulation workers in the New York area, which showed a high incidence of pleural mesothelioma in the group.
The research also highlighted the disease’s long latency period, which can range from 20 to 60 years between the initial asbestos exposure and the appearance of symptoms. This long delay explained why the connection had remained obscure for so long, even as the industrial use of asbestos had expanded throughout the 20th century. By the late 1960s, the medical and scientific communities widely accepted that asbestos exposure was the primary cause of mesothelioma.
From Rare Disease to Public Health Recognition
The establishment of the asbestos link shifted the perception of mesothelioma from an obscure medical curiosity to a public health concern. Following the definitive studies of the 1960s, public and regulatory bodies began to acknowledge the severe health risks posed by asbestos. In 1968, the American Medical Association officially recognized asbestos as a cause of serious health problems, providing institutional validation for the scientific findings.
This recognition spurred the initial regulatory responses aimed at protecting workers and the public. Early occupational safety warnings and regulations were introduced in the 1970s in various countries to limit workplace exposure to asbestos dust. The growing body of scientific evidence provided the foundation for the first legal cases, which began to surface in the 1980s, holding asbestos manufacturers accountable for the resulting diseases.
The increasing number of diagnoses among former workers and people with environmental exposure signaled a looming epidemic, given the long latency period of the disease. This led to the realization that a widely used industrial material, once considered a “magic mineral” for its fire-resistant properties, was responsible for a preventable, aggressive cancer. This transition marked the beginning of a long process to regulate and eventually ban asbestos use in many parts of the world.