Division of Cancer Epidemiology and Genetics, National Cancer Institute, 6120 Executive Boulevard, MSC 7248, Bethesda, MD 20892-7248, USA.
Cancer Epidemiol Biomarkers Prev. 2010 Mar;19(3):716-21. doi: 10.1158/1055-9965.EPI-09-0873. Epub 2010 Mar 3.
Although pneumonia has been suggested as a risk factor for lung cancer, previous studies have not evaluated the influence of number of pneumonia diagnoses in relation to lung cancer risk.
The Environment And Genetics in Lung cancer Etiology (EAGLE) population-based study of 2,100 cases and 2,120 controls collected information on pneumonia more than 1 year before enrollment from 1,890 cases and 2,078 controls.
After adjusting for study design variables, smoking, and chronic bronchitis, pneumonia was associated with decreased risk of lung cancer [odds ratio (OR), 0.79; 95% confidence interval (CI), 0.64-0.97], especially among individuals with three or more diagnoses versus none (OR, 0.35; 95% CI, 0.16-0.75). Adjustment for chronic bronchitis contributed to this inverse association. In comparison, pulmonary tuberculosis was not associated with lung cancer (OR, 0.96; 95% CI, 0.62-1.48).
The apparent protective effect of pneumonia among individuals with multiple pneumonia diagnoses may reflect an underlying difference in immune response and requires further investigation and confirmation. Therefore, careful evaluation of the number of pneumonia episodes may shed light on lung cancer etiology.
虽然肺炎已被认为是肺癌的一个危险因素，但之前的研究并未评估肺炎诊断次数与肺癌风险之间的关系。
基于人群的环境与基因在肺癌病因学（EAGLE）研究纳入了 2100 例病例和 2120 例对照，在入组前 1 年以上收集了病例和对照中肺炎的相关信息。
在调整了研究设计变量、吸烟和慢性支气管炎后，肺炎与肺癌风险降低相关[比值比（OR），0.79；95%置信区间（CI），0.64-0.97]，尤其是在有 3 次或以上诊断的个体中（OR，0.35；95% CI，0.16-0.75）。调整慢性支气管炎后，这种负相关关系更为明显。相比之下，肺结核与肺癌无相关性（OR，0.96；95% CI，0.62-1.48）。
在有多次肺炎诊断的个体中，肺炎的这种明显保护作用可能反映了潜在的免疫反应差异，需要进一步的研究和证实。因此，仔细评估肺炎发作次数可能有助于阐明肺癌的病因。
