Malignant pleural mesothelioma is an uncommon tumor; only about 3000 cases are diagnosed annually in the United States. Cases were described early in the 20th century, but their relationship to asbestos exposure was not documented until 1960. Since then, the incidence has appeared to increase, and numerous epidemiologic studies have confirmed that exposure to asbestos in a variety of settings and occupations is the most significant risk factor for the development of malignant pleural mesothelioma. More recently, the oncogenic virus SV40 has also been implicated as a potential etiologic agent. Surgery, radiotherapy, and chemotherapy have each been used in the treatment of mesothelioma, but generally with little impact on survival. New directions in therapy include aggressive multimodality programs for potentially resectable patients and targeted therapies, including antifolates, antiangiogenesis agents, and drugs directed at epidermal growth factor receptor for the majority of patients presenting with unresectable disease.
Malignant pleural mesothelioma in housewives in the province of Catania
Our study reports pleural malignant mesothelioma (PMM) in seven female patients. All patients were resident in Catania area (Sicily), the median age was 69.2 years and ranged from 59 to 81 years. They were housewife. Their anamnesis was negative for both direct and indirect previous exposure to asbestos; the partners of all patients were also not exposed to asbestos. The exposure to X-rays was also excluded for these patients. Different pathogenetic mechanisms for the appearance of PMM in these patients can be hypothesized, for example, SV40 infection and genetic susceptibility; a minimal domestic exposure to asbestos can be not excluded. Therefore, further studies in a more large number of subjects are necessary to determine whether one or all of these hypothetic pathogenetic mechanisms are more significant for the develop of PMM.
Benign and malignant pleural mesothelioma.
Malignant mesotheliomas have assumed an importance in the medical and lay literature out of proportion to their incidence in the American population, chiefly due to the known association of pleural mesothelioma with asbestos exposure. Data from the Connecticut tumor registry suggest that this tumor is increasing in incidence. Based on exposures between 1940 and approximately 1970, when industrial precautions were first instituted, epidemiologists
At the present time, construction workers who maintain or remove asbestos constitute one of a number of groups with continued exposure. The diagnosis of a malignant pleural mesothelioma is not difficult provided that the physicians caring for such a patient consider mesothelioma in the differential diagnosis. Patients present with chest pain or shortness of breath, or both, and the initial chest x-ray film most often reveals a large unilateral pleural effusion. The tumor characteristically remains localized until late in its course, and thus extensive workup at the time of diagnosis is seldom required. Generally, a large piece of tissue obtained via an open biopsy is required for adequate histologic diagnosis. Investigational approaches include taking numerous needle biopsies with samples sent for electron microscopy as well as for immunoperoxidase staining for keratin and CEA. The treatment of this disease remains unsatisfactory. Occasional patients have remained disease-free for periods in excess of 5 years after intensive treatment, however. The conclusion that mesothelioma is untreatable is clearly untenable since palliation and a response rate of 30 per cent to various chemotherapeutic regimens have been reported by a number of investigators. While many authors have advocated supportive care alone because "current treatments have not demonstrated increased survival," we believe patients with mesothelioma should be offered investigational therapy.
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