Tong L, Spitz M R, Fueger J J, Amos C A
Department of Epidemiology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
Cancer. 1996 Sep 1;78(5):1004-10. doi: 10.1002/(SICI)1097-0142(19960901)78:5<1004::AID-CNCR10>3.0.CO;2-6.
A reduction in the risk of lung carcinoma and a lower death rate among former smokers (FS) compared with current smokers (CS) have been documented in numerous U.S. and international studies. The main objective of our study was to compare the differences in demographic and clinical characteristics in groups stratified by smoking status and gender to evaluate the effect of smoking history and cessation on age at lung carcinoma diagnosis and on specific histologic type.
We conducted a cross-sectional study of lung cancer at The University of Texas M.D. Anderson Cancer Center from January 1986 to December 1990 and from January 1992 to December 1993. This study included 1039 patients age 19-88 with confirmed primary lung carcinoma who responded to self-administered risk factor questionnaires. Among them, 497 patients (47.83%) were CS, 444 patients (42.73%) were FS, 98 patients (9.43%) had never smoked (NS), and 840 patients (80.8%) were heavy smokers (more than 20 pack-years).
The median age at lung carcinoma diagnosis for FS was slightly later than that for CS. The histologic type of lung carcinoma for those who had quit smoking more than 20 years previously was not significantly different from that of NS, but was significantly different from that of CS (P < 0.05) and from those who quit smoking fewer than 10 years previously (P < 0.10). CS was a positive predictor for both small cell carcinoma (odds ratio [OR] = 8.79) and squamous cell carcinoma (OR = 2.11) and negatively associated with adenocarcinoma (OR = 0.50), whereas FS was a positive predictor only for small cell carcinoma (OR = 5.50). The variable of pack-years was negatively associated with adenocarcinoma and positively associated with small cell carcinoma in all patients combined and in women, and was also positively associated with squamous carcinoma in all patients after adjustment by smoking status.
These results indicate that smoking cessation or less life-time smoking exposure affects the distribution of specific histologic subtypes of lung cancer, especially for women, and that smoking cessation may postpone the age at which lung cancer occurs.
在美国和许多国际研究中，已证实与现吸烟者（CS）相比，既往吸烟者（FS）患肺癌的风险降低且死亡率更低。我们研究的主要目的是比较按吸烟状况和性别分层的各组在人口统计学和临床特征方面的差异，以评估吸烟史和戒烟对肺癌诊断年龄及特定组织学类型的影响。
我们于1986年1月至1990年12月以及1992年1月至1993年12月在德克萨斯大学MD安德森癌症中心进行了一项肺癌横断面研究。该研究纳入了1039名年龄在19 - 88岁之间、经确诊为原发性肺癌且对自行填写的危险因素问卷作出回应的患者。其中，497名患者（47.83%）为现吸烟者，444名患者（42.73%）为既往吸烟者，98名患者（9.43%）从不吸烟（NS），840名患者（80.8%）为重度吸烟者（超过20包年）。
既往吸烟者肺癌诊断的中位年龄略晚于现吸烟者。戒烟超过20年者的肺癌组织学类型与从不吸烟者无显著差异，但与现吸烟者（P < 0.05）以及戒烟少于10年者（P < 0.10）有显著差异。现吸烟者是小细胞癌（优势比[OR] = 8.79）和鳞状细胞癌（OR = 2.11）的阳性预测因素，与腺癌呈负相关（OR = 0.50），而既往吸烟者仅为小细胞癌的阳性预测因素（OR = 5.50）。在所有患者以及女性中，包年变量与腺癌呈负相关，与小细胞癌呈正相关，在按吸烟状况调整后，在所有患者中也与鳞状细胞癌呈正相关。
这些结果表明，戒烟或减少一生的吸烟暴露会影响肺癌特定组织学亚型的分布，尤其是对女性而言，并且戒烟可能会推迟肺癌发生的年龄。
