Patterns in the incidence, mortality and survival of malignant pleural and peritoneal mesothelioma, New South Wales, 1972-2009.

INTRODUCTION

Malignant pleural mesothelioma (MPM) and malignant peritoneal mesothelioma (MPeM) are often grouped together in descriptive epidemiological analyses, resulting in limited understanding of epidemiological patterns for these tumour types.

METHODS

We studied patterns in the incidence, mortality and survival of people diagnosed with MPM (n=4,076) and MPeM (n=293) in New South Wales (NSW), Australia, 1972-2009. We also calculated 5-year relative survival for people diagnosed 1972-2006 followed up to 2007. We assessed patterns for each tumour type and histological subtype and, where possible, by combination of these categories.

RESULTS

Annual MPM cases steadily increased over time (n=208 in 2009). There was an increasing trend in the MPM age-standardised incidence rate from 1972 up to 1994. This rate increase has levelled off in the past 10 years. Since 1999, 11 cases of MPeM were diagnosed each year, on average. Five-year relative survival remained stable for MPM and MPeM. However, 5-year relative survival in 2002-2006 was substantially higher for people with MPM epithelioid histological subtype (11.7% [95%CI 6.8-18.2%]) compared to all other non-epithelioid histological subtypes (6.9% [95%CI 5.0-9.1%]), a 70% difference. Survival was also greater for women with MPM (13.4% [95%CI 8.5-19.4%]) compared to men (7.0% [95%CI 5.1-9.2%]).

INTERPRETATION: MPM incidence rates have stabilised since the mid-1990s, suggesting that maximum incidence levels have been reached. When more up-to-date data are available, survival estimates should be reanalysed to include people likely to benefit from the wide introduction of combination chemotherapy in 2007, including pemetrexed.