Variation in lung cancer survival rates between countries: do differences in data reporting contribute?

Abstract

BACKGROUND: Mortality rates from lung cancer are known to vary considerably between countries. Differences in patients, disease, investigation and treatment are thought to account for some survival shortfalls but it is not known whether differences in collection or processing of data also contribute. METHODOLOGY: We searched recognised sources where information regarding mortality rates have been published for the United Kingdom, Europe and United States (US). Data regarding patient selection, demographics and mortality rates were extracted. RESULTS: Published international 5-year survival for patients with lung cancer varies from 5% to 16%. The survival figures quoted in the literature are based on data which varies widely in its collection and statistical analysis and this information is not always in the public domain. Data from the US suggests an overall 5-year survival rate of up to 16% although this figure covers only a quarter of the general population and excludes patients without histological confirmation. Many European countries report higher mortality rates although in most, data includes patients without proven histology. European datasets have variable population coverage. CONCLUSION: Selective data collection and variable population coverage may account for some of the differences in lung cancer survival between countries. More transparent description of data collection and analysis would be helpful but ideally a uniform method of reporting data is required in order to make valid comparisons in mortality rates.