[Analysis of conditional logistic regression for risk factors of lung cancer in Dachang Tin Mine]

An increased risk of lung cancer in Dachang Tin Mine of Guangxi has been reported. To investigate the factors of the excessive risk of lung cancer, the authors conducted a matched pair case-control study in the mine area and analysed the effect of multiple factors, such as condition of living and housing, occupational exposure and smoking by statistical method of conditional logistic regression. The patients group consisted of 69 patients with primary bronchogenic cancer including 55 deceased. The control group consisted of 138 persons also including 55 deceased. The results showed that the factors of the excessive risk of lung cancer in the mine area were mainly related to the occupational exposure. The risk factors with statistical significance in conditional logistic regression analysis were exposure time of smelting, time of underground drilling, and age of beginning mining underground. In the study model of all cases matched against living controls, daily number of cigarette also was a risk factor besides the above three factors. Furthermore, there was a synergic action among the factors. The relationship between the risk factors and lung cancer is discussed.