Secular trends in incidence of lung cancer by histological type in Beijing, China, 2000−2016

Objective The objective of this study was to characterize secular trends in the sex-specific, age-standardized incidence of lung cancer by histological type in Beijing, China, from 2000 to 2016 based on data from a population-based cancer registry. Methods Data on the incidence of cancer from 2000 to 2016 were obtained from the Beijing Cancer Registry. We examined trends in the sex-specific, age-standardized incidence of lung cancer by histological type using a Joinpoint regression model. Results A total of 117,409 cases of lung cancer were diagnosed from 2000 to 2016. Overall, 73,062 (62.23%) patients were males. The most common histological type among both sexes was adenocarcinoma; however, the proportion of adenocarcinoma differed significantly between males and females (45.36% vs. 77.14%, respectively, P<0.0001). The age-standardized incidence of total lung cancer increased from 2000 to 2010 with an annual percent change (APC) of 2.2% [95% confidence interval (95% CI), 1.5% to 2.9%] and stabilized thereafter. Among males, the incidence of total lung cancer peaked in 2008 and then decreased slightly, with an APC of −1.1% (95% CI, −2.1% to −0.1%). Among females, the incidence increased continuously during the study period, with an APC of 1.4% (95% CI, 0.9% to 1.9%). The incidence of squamous cell carcinoma decreased significantly in recent years among both sexes, with APCs of −2.6% (95% CI, −4.5% to −0.6%) from 2007 to 2016 for males and −5.4% (95% CI, −7.2% to −3.6%) from 2004 to 2016 for females. In contrast, the incidence of adenocarcinoma increased continuously throughout the study period, by APCs of 4.0% (95% CI, 2.6% to 5.4%) for males and 6.2% (95% CI, 4.8% to 7.6%) for females. The incidence of small cell carcinoma peaked in 2007 and stabilized thereafter among males, whereas it peaked in 2012 and then decreased with an APC of −14.7% (95% CI, −25.3% to −2.6%) among females. The incidence of large cell carcinoma and other specified malignant neoplasm did not change much, whereas the incidence of unspecified type decreased among both sexes during the study period. Conclusions Although the incidence of squamous cell carcinoma decreased significantly among both sexes in recent years in Beijing, China, adenocarcinoma increased continuously throughout the study period among both sexes. Knowledge of differences in trends is useful for surveillance and control of lung cancer. However, the reason for the increase in adenocarcinoma remains unclear and warrants investigation.