[Trends in incidence of lung cancer according to histological subtype among men and women in Germany : Analysis of cancer registry data with the application of multiple imputation techniques].

Background: Lung cancer can be described by histological subtype, of which small cell, squamous cell and adenocarcinoma are the most common. International data show that adenocarcinoma is becoming the dominant histological subtype of lung cancer although the relative risk due to smoking has been found to be smaller than that for other histological subtypes.

Objective: The aim of the analysis was to describe the time trends in incidence of lung cancer among women and men in Germany according to histological subtype.

Materials And Methods: All lung cancer cases (ICD-10 C33-C34) newly diagnosed between 2003 and 2012 and collected by the epidemiologic cancer registries of the German federal states with average completeness of registration of at least 90% were considered and grouped into histologic subtypes. If data on tumor histology were not microscopically verified or unspecific, multiple imputation techniques were applied to estimate the histologic subtype.

Results: Among women age-standardized lung cancer rates increased considerably between 2003 and 2012 (annual percent change APC = 2.7%), mostly driven by a rising adenocarcinoma incidence (APC = 4.7%). Among men overall lung cancer rates decreased during the same time (APC = -1.7%). Still, a slight increase in adenocarcinoma incidence was also observed in men (APC = 1.0%).

Conclusion: The rising incidence of adenocarcinoma of the lung is alarming. The cancer registry data do not allow risk factor analysis. In the international discussion, the introduction of filter cigarettes as well as the changing composition of cigarettes has been hypothesized as being responsible. Further epidemiologic studies are strongly needed.