[Analysis of the clinical characteristics of 8 081 primary lung cancer]

Objective: To characterize the clinical epidemiological features of primary lung cancer patients based on massive clinical data. Methods: The demographic and histological information of 8 081 primary lung cancer patients who were initially identified from 1 January 2012 to 31 December 2013 in 16 hospitals from 6 provinces were retrospectively analyzed to determine the characteristics of different histological subtypes among different gender, age-group and birth cohort. Results: Among the 8 081 lung cancer patients, 5 422 (67.10%) were male and 2 659 (32.90%) were female, the average age was (60.96±10.14) years. The most common histological subtypes of lung cancer successively were adenocarcinoma (ADC), squamous cell carcinoma (SCC), small cell carcinoma and large cell carcinoma, and the proportions of these subtypes were 53.13%, 24.51%, 14.59% and 0.66%, respectively, which collectively accounted for 92.89%. The current highest smoking rate was observed in SCC patients, which was 62.45%, while lowest in ADC, which was 29.68%. The incidence of lung cancer in male was significantly higher that that of female, with a sex ratio of 2.04∶1. The highest sex ratio was observed in SCC, which was 9.14∶1, while lowest in ADC, which was 1.14∶1. The distribution of histological subtypes in male lung cancer patients was consistent with the general situation.While among the female lung cancer patients, the proportion of ADC was the highest (75.42%), followed by SCC (10.08%), squamous cell carcinoma (7.34%) and large cell carcinoma (0.39%). Analyzed by the birth cohort, the proportion of ADC gradually increased with the age, while the reduced tendency was observed in SCC (P<0.000 1). Conclusion: Adenocarcinoma is the most important histological subtype of lung cancer, and the distribution characteristics of histological subtypes of lung cancer differs among genders, age and birth cohort.