Mesothelioma Arising in the Pleura in the Case of Peritoneal Mesothelioma

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Asbestos seems to have high potency in the carcinogenesis of lung cancer and low potency in carcinogenesis of Mesothelioma.  1 interesting study is known as, "Asbestos and cigarette smoke cause elevated DNA strand breaks and necrosis in bronchiolar epithelial cells in vivo" by Michael Jung, Wendell P. Davis, Douglas J. Taatjes, Andrew Churg and Brooke T. Mossman, - No cost Radical Biology and Medicine - Volume 28, Concern 8, 15 April 2000, Pages 1295-1299.  Here is an excerpt: "Abstract - Coexposures to asbestos and cigarette smoke trigger increased risks of lung cancer in asbestos workers. Though these carcinogens trigger DNA damage to epithelial cells in vitro via generation of reactive oxygen species (ROS), it is unclear regardless of whether they trigger injury to bronchiolar epithelial cells (i.e., the target cells of lung cancers in vivo). We exposed rats to amosite asbestos, cigarette smoke, and the two agents in mixture for 1, two, and 14 d. Numbers of cells exhibiting DNA strand breaks in comparison to sham rats had been then evaluated in lungs making use of the terminal deoxynucleotidyl transferase (TDT)-mediated dUTP-biotin nick finish labeling (TUNEL) approach and by transmission electron microscopy (TEM). Increases in TUNEL-positive, necrotic epithelial cells occurred after exposure to asbestos alone and in an additive fashion immediately after smoke and asbestos in combination. These outcomes indicate that DNA strand breakage and necrosis are prominent mechanisms of injury by asbestos fibers and cigarette smoke in vivo to epithelial cells of the respiratory tract, therefore validating in vitro observations from a number of laboratories."

A second study is called, "Incidence of cancer among anthophyllite asbestos miners in Finland." By L O Meurman, E Pukkala, M Hakama - Occup Environ Med 199451:421-425 - University of Turku, Department of Pathology, Finland.  Here is an excerpt: "Abstract - A cohort of 736 male and 167 female workers of two anthophyllite mines in Finland was followed up by way of the Finnish Cancer Registry for cancer in 1953-91. Compared with the total cancer incidence of the east Finnish population, the men had a raised risk of total cancer (standardised incidence ratio (SIR) 1.7 95% confidence interval (95% CI) 1.4-1.9), mainly attributable to an excess in lung cancer (SIR 2.8 95% CI 2.two-three.6). The risk of lung cancer was somewhat greater among workers classified as heavily exposed (SIR 3.2 95% CI two.4-4.1) than among those moderately exposed (SIR 2.3 95% CI 1.five-three.6) and the risk elevated with increasing smoking and with increasing time of function with exposure. There had been four circumstances of mesothelioma v .1 expected, all in men who smoked and had had a long and heavy asbestos exposure. Amongst women, a non-considerable excess in total cancer (SIR 1.5 95% CI .9-two.4) was located in the subgroup with heavy exposure to asbestos. Anthophyllite asbestos appears to have high potency in the carcinogenesis of lung cancer and low potency in carcinogenesis of mesothelioma in comparison with the other forms of asbestos."

A third study is known as, "Asbestos and mesotheliomas" by M. C. Godwin, and Juraj Jagatic, - Environmental Analysis - Volume three, Problems 5-6, December 1970, Pages 391-416.  Here is an excerpt: "Abstract - Seven selected situations with asbestos in the lungs and a mesothelioma in the pleura or peritoneum were studied intensively employing routine techniques, polarized light, incineration method, and acid digestion.  We discovered that asbestos bodies, fragments, particles, and dust could be located in hilar and mediastinal nodes frequently. We could find asbestos bodies in lymphatics being transported to the nodes. We found asbestos bodies in the spleen, abdominal tumor, and little bowel wall and dust and particles in abdominal nodes and peritoneum. We discovered a smaller mesothelioma arising in the pleura in a case of peritoneal mesothelioma. We identified a squamous cell carcinoma in the proper lung and a mesothelioma of the left pleura.  We have concluded that asbestos is irritating mechanically and chemically and that it is distributed widely in the body by the lymphatics and blood resulting in malignancies of a variety of varieties with the pleura and peritoneum getting specifically susceptible."

We all owe a debt of gratitude to these fine researchers for their vital function.  If you identified any of these excerpts helpful, please read the studies in their entirety.