[Clinical epidemiology and histological characteristics of patients with lung cancer in West China Hospital of Sichuan University].

OBJECTIVE

To identify changes in patterns of primary bronchogenic carcinoma.

METHODS

We reviewed clinical data of patients with primary bronchogenic carcinoma, who were identified as permanent residents of Sichuan province and were treated in West China Hospital of Sichuan University in 2000 and 2010. The distributions of gender, age, urban/rural residency, smoking history, occupational exposure and histological types of tumor were compared between the 2000 group and 2010 group.

RESULTS

A total of 2 167 patients (616 in 2000 and 1551 in 2010) met the inclusion criteria. Compared with the 2000 group, the 2010 group had a lower proportion of male patients (male/female sex ratio dropped from 2.78:1 to 2.13:1, P = 0.013), more patients from medium and small sized cities (patients from large city decreased from 42.1% to 32.0%, P < 0.001, and patients from medium and small sized cities decreased from 39.9% to 31.7%, P < 0.001), more patients from rural areas (patients from townships increased from 5.5% to 8.1%, P = 0.041, and patients from villages increased from 12.5% to 28.2%, P < 0.001). No significant difference in age was found in the two cohorts of patients. The proportion of squamous cell carcinoma dropped from 44.8% in 2000 to 28.7% in 2010 (P < 0.001). The proportion of adenocarcinoma increased from 43.0% in 2000 to 53. 1% in 2010 (P < 0.001). The proportion of small cell lung cancer increased from 3.7% in 2000 to 11.9% in 2010 (P < 0.001). The proportion of squamous cell carcinoma in male patients was higher than that of female patients (60.7% vs. 36.6% in 2000; 75.8% vs. 42.9% in 2010). The proportion of adenocarcinoma was higher in female patients than that of male patients (60.7% vs. 36.6% in 2000; 75.8% vs. 42.9% in 2010). The proportion of squamous cell carcinoma was higher in elderly patients (> or = 60) than that of young patients (< 45) (50.5% vs. 33.8% in 2000; 30.2% vs. 15.6% in 2010). The proportion of adenocarcinoma in young patients was higher than of elderly patients (54.9% vs. 36.9% in 2000; 57.1% vs. 51.8% in 2010). Squamous cell carcinoma was predominate in smoking patients (55.6% in 2000; 40.9% in 2010). Adenocarcinoma was predominate in no-smoking patients (58.4% in 2010; 75.7% in 2010) and the patients exposed to risk occupations (46.2% in 2000; 60.2% in 2010).

CONCLUSION

Over the past decade, the percentages of female patients, adenocarcinoma and small cell lung cancer increased significantly in the patients with lung cancer. Male gender, old age (> or = 60) and smoking are risk factors of squamous cell carcinoma. Female gender, young age (< 45) and occupational exposure are risk factors of adenocarcinoma.