The determinants of lung cancer after detecting a solitary pulmonary nodule are different in men and women, for both chest radiograph and CT

ObjectivesTo determine the factors associated with lung cancer diagnosis and mortality after detecting a solitary pulmonary nodule (SPN) in routine clinical practice, in men and in women for both chest radiograph and CT.Materials and methodsA 5-year follow-up of a retrospective cohort of of 25,422 (12,594 men, 12,827 women) patients aged ≥35 years referred for chest radiograph or CT in two hospitals in Spain (2010–2011). SPN were detected in 893 (546 men, 347 women) patients. We estimated the cumulative incidence of lung cancer at 5-years, the association of patient and nodule characteristics with SPN malignancy using Poisson logistic regression, stratifying by sex and type of imaging test. We calculated lung cancer specific mortality rate by sex and SPN detection and hazard rates by cox regression.Results133 (14.9%) out of 893 patients with an SPN and 505 (2.06%) of the 24,529 patients without SPN were diagnosed with lung cancer. Median diameter of SPN in women who developed cancer was larger than in men. Men who had a chest radiograph were more likely to develop a lung cancer if the nodule was in the upper-lobes, which was not the case for women. In patients with an SPN, smoking increased the risk of lung cancer among men (chest radiograph: RR = 11.3, 95%CI 1.5–83.3; CT: RR = 7.5, 95%CI 2.2, 26.0) but smoking was not significantly associated with lung cancer diagnosis or mortality among women with an SPN. The relative risk of lung cancer diagnosis in women with SPN versus those without was much higher compared to men (13.7; 95%CI 9.2, 20.4 versus 6.2; 95%CI 4.9,7.9).ConclusionThe factors associated with SPN malignancy and 5-year lung cancer mortality were different among men and women, especially regarding smoking history and SPN characteristics, where we observed a relatively high rate of lung cancer diagnosis among female non-smokers.

研究目标：明确临床常规诊疗中检出孤立性肺结节（solitary pulmonary nodule, SPN）后，针对胸部X线摄影（chest radiograph）与计算机断层扫描（CT）两种成像方式，分别探究男性与女性群体中与肺癌诊断及死亡相关的影响因素。材料与方法：对2010—2011年西班牙两家医院收治的25422例年龄≥35岁、转诊接受胸部X线摄影或CT检查的患者（其中男性12594例，女性12827例）开展为期5年的回顾性队列随访。最终893例患者（男性546例，女性347例）检出孤立性肺结节（SPN）。本研究首先估算5年肺癌累积发病率；采用泊松逻辑回归（Poisson logistic regression）分析患者及结节特征与SPN恶性程度的关联，并按性别与成像检查类型进行分层；随后按性别及SPN检出情况计算肺癌特异性死亡率，通过考克斯回归（Cox regression）分析风险比。结果：893例SPN患者中，133例（14.9%）确诊肺癌；24529例未检出SPN的患者中，505例（2.06%）确诊肺癌。发生肺癌的女性患者，其SPN中位直径大于男性患者。对于经胸部X线摄影检出的SPN，若结节位于肺上叶，男性患者发生肺癌的风险显著升高，而女性患者未观察到该关联。在SPN患者群体中，吸烟可升高男性群体的肺癌发病风险（胸部X线摄影组：相对危险度（relative risk, RR）=11.3，95%置信区间（confidence interval, CI）：1.5~83.3；CT组：RR=7.5，95%CI：2.2~26.0），但吸烟与SPN女性患者的肺癌诊断或死亡率无显著相关性。相较于未检出SPN的群体，检出SPN的女性群体肺癌诊断相对危险度显著高于男性群体（女性：13.7，95%CI：9.2~20.4；男性：6.2，95%CI：4.9~7.9）。结论：与SPN恶性特征及5年肺癌死亡率相关的影响因素存在性别差异，尤其体现在吸烟史与SPN特征层面；本研究观察到女性非吸烟者群体中肺癌诊断率相对较高。