The effect of smoking on the development of lung cancer in idiopathic interstitial pneumonia

66例肺癌患者的发病率对11例原发性间质性肺炎（IIP）患者（男54例，女12例）进行了2 ~ 13年的前瞻性随访，并与同期的慢性阻塞性肺疾病（COPD）患者（男16例，女12例）进行了比较。7%）发生肺癌，其发病率明显高于COPD（1/95.1%）组（p<0.01），无论COPD组的平均年龄和平均观察时间较高。除1例肺癌患者外，所有肺癌患者均为男性吸烟者。在临床发现中，与未患肺癌的患者相比，患有肺癌的IIP患者没有接受类固醇治疗，胸部X线片体积减少。在免疫组化研究中，为了验证生长因子在肺癌中的旁分泌机制，我们用表皮生长因子（EGF）和EGF受体（EGF-R）对肺癌组织进行了染色。9例IIP（+）患者中有2例和44例IIP（-）患者中有23例显示EGF染色阳性。在间质细胞中，9例IIP（+）和44例IIP（-）患者中，EGF阳性5例（P<0.05），EGF-R阳性6例（P<0.05），两组间无显著性差异，提示IIP肺癌的发生可能存在旁分泌机制。

The incidence lung cancer in 66 patients (54 males and 12 females), who were originally diagnosed as having idiopathic interstitial pneumonia (IIP), was studied prospectively by following them 2 to 13 years.As controls, sex and smoking history matched patients with chronic obstructive pulmonary disease (COPD) were also surveyed for the same follow up period.Eleven patients with IIP (16,7%) developed lung cancer.This incidence was significantly higher than that of COPD (1 out of 95,1%) group (p<0.01), regardless of the higher mean age and mean observation period of COPD group.All lung cancer patients except one were male smokers.In clinical findings, IIP patients with lung cancer didn't have steroid treatment and volume decrease in chest roentogenogaram when compared with those who did not develop lung cancer.In the immunohistochemical study, we examined the hypothesis that there is a paracrine mechanism of growth factor in the lung cancer with IIP.To validate it, we stained lung specimen with Epidermal growth factor (EGF) and EGF-receptor (EGF-R).Two of 9 IIP (+) patients and 23 of 44 IIP (-) patients showed positive for EGF staining.In stroma cells, 5 of 9 IIP (+) patients and 6 out of 44 IIP (-) patients exhibited positive for EGF straining (p<0.05).For EGF-R,there weren't any significant difference between the two groups.These results suggest that there might exist paracrine mechanism in the growth of lung cancer with IIP.