PURPOSE: Malignant mesotheliomas arise in the pleura and peritoneum as a result of asbestos exposure. We present a comparative descriptive patho-epidemiological analysis of pleural and peritoneal mesotheliomas occurring in men and women.
METHODS: All patients with mesothelioma of the pleural and peritoneal surfaces were identified using NCI’s Surveillance, Epidemiology, and End Results (SEER) database from 1973 through 2007. For both genders, there were 10,248 and 915 cases of pleural and peritoneal mesotheliomas, respectively. Data were analyzed for age, incidence rates, and their respective log-log plots. Mesothelioma and ovarian serous carcinomas of the peritoneum were also analyzed and compared.
RESULTS: Since 1973, the incidence of pleural mesothelioma increased (1.2% annual percent change), while peritoneal mesothelioma decreased (1.0% annual percent change). Mean age at diagnosis for peritoneal and pleural mesotheliomas were similar across genders, although peritoneal mesotheliomas present earlier. In women, there were 3,603 peritoneal malignant tumors of all types reported of which 2,749 (76%) were ovarian-type histology. The mean age at diagnosis for ovarian-type carcinoma arising from the peritoneum was 66.6 compared with 62.1 for mesothelioma. Log-log plots of age specific incidence rates of mesotheliomas for men and women in both peritoneal and pleural cavities revealed parallel slopes. Log-log plots of incidence rates for mesotheliomas and ovarian type carcinomas arising from the peritoneum revealed non-parallel slopes.
CONCLUSION: Epidemiologic data support a common carcinogenic pathway for peritoneal and pleural mesotheliomas in men and women based on parallel slopes in log-log plots. In both men and women mesotheliomas of the peritoneal cavity present earlier than in the pleural cavity. Non-parallel incident rate log-log plots suggest that ovarian carcinomas arising in the peritoneum have a different carcinogenic pathway than peritoneal mesotheliomas.
CLINICAL IMPLICATIONS: Asbestos exposed individuals, though less likely to develop peritoneal mesotheliomas, are more likely to develop these malignancies earlier. Different carcinogenic pathways for ovarian type relative to mesothelial type peritoneal tumors support differing therapeutic approaches.
DISCLOSURE: Arnold Schwartz, No Financial Disclosure Information; No Product/Research Disclosure Information