Lung tumor presentation in relation to histology and smoking habit of operable and inoperable patients

In two separate groups of lung cancer patients, the cranio-caudal site of tumor presentation was related to smoking habits. Group I consisted of 47 inoperable lung cancer patients. In this group apical lung tumor presentation was significantly more common in nonsmokers than in smokers (p less than 0.04). The proportion of women and patients with adenocarcinoma was higher for nonsmokers (p less than 0.01 and p less than 0.01, respectively). In order to validate these findings the site of tumor presentation in relation to smoking habits was studied for a separate group of 369 lung cancer patients. All these patients (group II) had operable tumors. In general, these patients were younger and came from more urban areas than the patients in group I. In group II, upper lobe tumor presentation was not more common among nonsmokers compared with tumor presentation in smokers (p greater than 0.05). However, there were more patients with adenocarcinomas and women among nonsmokers (p less than 0.0001 and p less than 0.0001, respectively). The findings indicate that either the tumor site of presentation in operable and in inoperable lung cancer patients has different epidemiological characteristics, or that, due to chance, a difference in the groups has been observed. However, consistently in the two groups, women with adenocarcinomas who were smokers were younger than other women with adenocarcinomas.