OBJECTIVETo describe the incidence trends and pathological characteristics of lung cancer in urban Beijing, China.

METHODSA total of 32 845 medical records of the residents diagnosed as lung cancer in urban Beijing from 1998 to 2007 were retrieved through the cancer registry system of Beijing Cancer Registry. Crude incidence rate, age-specific incidence rate, adjusted incidence rate by world standardized population, annual percentage change (APC) and histological categorized incidence rate by world standardized population were calculated in order to compare the differences of the incidence trends in different time periods, or among different gender and age groups.

RESULTSA total of 32 845 newly diagnosed lung cancer patients between 1998 and 2007 were included in our study. The crude incidence rate was 47.81/100 000 (32 845/68 704 429), increasing by 38.80% from 39.30/100 000 in 1998 to 54.55/100 000 in 2007 with APC at 3.35% in urban Beijing (Z = 9.984, P < 0.001). While it changed to 28.95/100 000 with an APC at 0.27% (Z = 0.846, P = 0.422) when adjusted by world standardized population. For male, the crude incidence rate was 58.28/100 000 (20 342/34 906 580, adjusted rate at 37.03/100 000, APC at 0.38%, Z = 1.008, P = 0.343); while for female, the crude incidence rate was 36.99/100 000 (12 503/33 797 849, adjusted rate at 21.48/100 000, APC at 0.14%, Z = 0.431, P = 0.678). 17 920 lung cancer patients being diagnosed according to histological evidence, accounted for 54.56%. The respective proportion of the patients with histological diagnosis was 43.14% (1095/2538) in 1998 and 65.55% (2641/4029) in 2007, with a 51.95% increase (χ(2) = 859.152, P < 0.001) in decade. In terms of subtypes of lung cancer, the proportion of squamous cell carcinoma decreased annually, from 30.41% (333/1095) in 1998 to 24.16% (638/2641) in 2007; while the proportion of adenocarcinoma increased from 42.83% (469/1095) to 46.80% (1236/2641). As a result, the squamous cell carcinoma to adenocarcinoma ratio declined from 0.71 (333/469) to 0.52 (638/1236) (χ(2) = 50.214, P < 0.001). For women, the ratio declined more significantly and the proportion of the squamous cell carcinoma and adenocarcinoma were 14.77% (925/6262) and 60.83% (3809/6262), respectively in the period between 1998 and 2007.

CONCLUSIONNo significant change was found in the incidence trend of lung cancer after the incidence rate adjusted by world standard population, but the proportion of the subtypes of lung cancer categorized by histological evaluation changed apparently.