Incidence and Survival of Malignant Pleural Mesothelioma in Norway: A Population-Based Study of 1686 Cases

Background: Asbestos-related malignant pleural mesothelioma is one of the most lethal tumor types. The advent of antimetabolite treatment as pemetrexed, introduced in the early 2000s, may have increased survival on a population basis. In this study, we have analyzed population-based incidence and survival data over the last 40 years. Methods: Complete national data on 1686 patients from the Cancer Registry of Norway sampled from 1970 to 2009 are presented, with incidence rates in 5-year periods. Relative survival for 1 year and 3 years and median survival in 5-year intervals were calculated. Results: The incidence of malignant pleural mesothelioma has been significantly and steadily increasing from 1970 until 2009, with 50 patients diagnosed in the period 1970–1974 and 377 diagnosed in 2005–2009. The incidence was highest among men in all time periods. A slight decline was observed in the last period. The 1-year survival rate increased from 20.7% to 44.0% during the period 1970–2009, whereas the 3-year survival rate remained below 10%. Median survival increased from 4.0 months in the first period to 9.3 months in the last period. Conclusions: The incidence of malignant pleural mesothelioma follows the curve of asbestos exposure with a 20- to 40-year lag. There has been a significant increase in survival, most likely because of earlier diagnosis and improvements in cytostatic treatment.