Clinical and histological analysis of malignant mesothelioma - a comprehensive state-wide study

Background: The cancer registry Northrhine-Westphalia (CR NRW) is state-law based, prospective cancer registry, including all state residents with the diagnosis of cancer (NRW counts approx. 18 million residents). Methods: All MM cases diagnosed and collected between 2010 and 2012 in CR NRW were included (n=1199). 232 cases contained incomplete datasets. In 755 of 967 valid cases (78.1%) the original pathology report was visible, in 468 cases (48.4%) including immunohistochemistry. Results: Of 967 patients with MM 796 were male (82.3%) and 171 female (17.7%), 81.8% were already diseased upon last validation date. Based on ICD-codes 885 patients (91.5%) suffered from pleural MM (C45.0), 72 (7.4%) had peritoneal MM, 2 (0.2%) pericardial MM and 8 (0.8%) had various MM locations. Histology showed predominantly epithelioid growing pattern (60.4%), followed by biphasic growth (13.4%) and sarcomatoid growth (9.4%); in 16.8% the growing pattern was not defined. Median overall survival (OS) of pleural MM was 12.4 months (95%KI 11.3-13.4; all histologies), OS of peritoneal MM was 15.1 months (95%KI 4.5-25.7; all histologies). Multivariate analysis revealed gender, age, histological subtype, cell specific growing features (spindle cell type; papillary type), necrosis, hyaline plaques and proliferation marker Ki67 as independent prognostic factors (p Conclusion: The comprehensive, state-law embedded cancer registry NRW ensures the complete area-wide identification and collection of cancer patients’ course out of 18 million residents. In this very large study MM cell specific growing features and proliferation index could be identified as new independent markers of MM outcome.