GSTM1、GSTT1基因多态性和吸烟与膀胱癌关系的病例对照研究

目的:应用全人群为基础的病例对照研究探讨GSTM1、GSTT1基因多态性和吸烟与膀胱癌危险性的关系。方法:采用多重PCR方法对404例正常对照和414例膀胱癌病例的基因组DNA进行GSTM1和GSTT1基因分型,应用非条件logistic回归分析方法进行统计分析。结果:与携带GSTM1( )基因型者比,GSTM1(-)基因型的男、女性患膀胱癌危险性分别为1.66(95%CI:1.18～2.33)和1.08(95%CI:0.59～1.98)。同样携带GSTM1(-)基因型,吸烟者比不吸烟者患膀胱癌的危险性更加明显。与不吸烟且携带GSTM1( )基因型男性比,GSTM1(-)基因型的目前吸烟者的OR值为2.99(95%CI:1.56～5.74),而携带GSTM1(-)基因型同时吸烟年限≥40年者OR为4.33(95%CI:2.14～8.73)。尽管女性吸烟例数较少,但携带GSTM1(-)基因型的吸烟女性患膀胱癌危险性显著高于不吸烟的GSTM1( )基因型者,OR值为6.72(95%CI:1.69～26.80)。与不吸烟且携带GSTT1( )基因型男性相比,携带GSTT1(-)基因型的吸烟者患男性膀胱癌危险的OR值为1.38(95%CI:0.79～2.42)。携带GSTT1(-)基因型的吸烟女性患膀胱癌危险性是不吸烟的GSTT1( )基因型者的3.04倍(95%CI:0.77～12.01)。结论:GSTM1(-)基因型能显著增加男性患膀胱癌的风险,该基因型与吸烟可能有一定的联合作用。GSTT1基因型可能与上海市区男、女性膀胱癌无关。     

GSTM1和CYP2E1基因多态性与肺癌遗传易感性关系的研究

背景与目的肺癌是中国人群恶性肿瘤死因的首位，其发病可能与肺癌人群中某些肺癌相关基因的遗传多态性有关。本研究旨在探讨细胞色素P4502E1(CYP2E1)基因RsaⅠ／PstⅠ多态性和谷胱甘肽转移酶M1(GSTM1)基因多态性与肺癌易感性之间是否存在相关性。方法应用PCR-RFLP和PCR法检测99例人非小细胞肺癌患者和66例同期住院的肺良性疾病患者CYP2E1基因的RsaⅠ／PstⅠ多态性和GSTM1基因多态性，并分析其与肺癌遗传易感性的相关性。结果(1)CYP2E1基因RsaⅠ／PstⅠ多态性的三种基因型在肺癌组和对照组的频率差异没有统计学意义(χ^2=1．374，P=0．241)。(2)肺癌组GSTM1(-)基因型频率显著高于对照组(分别为57．6％和40．9％)(χ^2=4．401，P=0．036)。(3)携带GSTM1(-)基因型的个体患肺癌的危险性显著高于GSTM1( )基因型的个体(OR=1．96，95％CI=1．042～3．689，P=0．037)。(4)与携带c1／c2或c2／c2基因型的不吸烟个体比较，携带c1／c1基因型的吸烟者患肺癌的风险显著增加(OR=3．525，95％CI=1．168～10．638，P=0．025)。(5)联合分析CYP2E1基因RsaⅠ／PstⅠ多态性和GSTM1基因多态性，携带有c1／c1和GSTM1(-)基因型的个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的个体(OR=3．449，95％CO=1．001～11．886，P=0．050)。按照吸烟因素分层，携带有GSTM1(-)和c1／c1基因型的不吸烟个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=11．553，95％CI=1．068-124．944，P=0．044)，携带有GSTM1(-)和c1／c2或c2／c2基因型的不吸烟个体患肺癌的风险同样显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=13．374，95％CI=1．258～142．166，P=0．032)。结论(1)GSTM1(-)基因型增加人群患肺癌的风险；(2)CYP2E1的c1／c1基因型和GSTM1(-)基因型的联合可增加吸烟和不吸烟人群患肺癌的风险。     

CYP1A1和GSTM1基因多态性与内蒙古人群肺癌易感性的关系

背景与目的 肺癌是严重危害人类健康的恶性肿瘤之一，其发病与肺癌人群中某些肺癌相关基因的遗传多态性有关。本研究旨在探讨细胞色素P4501A1（CYP1A1）基因多态性和谷胱甘肽硫转移酶M1（GSTM1）基因多态性与内蒙古人群肺癌易感性的关系。方法 用PCR-RFLP技术分析了原发性肺癌组和住院对照组（各163例）的CYP1A1、GSTM1基因的多态性、基因型分布频率和交互作用。结果 CYP1A1突变型和GSTM1基因缺陷型EGSTM1（-）]频率分布分别为36．8％、65．0％（病例组）和19．0％、48．9％（对照组），二者经χ^2检验差异有显著性（χ^2=12．82，P=0．000；χ^2=9．78，P=0．002）。CYP1A1突变型患肺癌的风险显著增加（OR=2．48，95％CI为1．51～4．08）。GSTM1（-）者患肺癌的风险也显著增加（OR=2．03，95％CI为1．30～3．17）。基因突变的协同分析发现CYP1A1突变型／GSTM1（-）在肺癌组和对照组中的分布频率分别为28．8％和8．0％，二者经χ^2检验有显著性差异（χ^2=23．883，P=0．000）。CYP1A1突变型／GSTM1（-）患肺癌的风险显著增加（OR=4．90，95％CI为2．50～9．83）。无论是在肺癌组还是在对照组，CYP1A1突变型／GSTM1（-）和CYP1A1非突变型／GSTM1（-）在性别间分布频率的差异均无显著性（肺癌组χ^2=0．797，P=0．372；对照组χ^2=0．670，P=0．761）。吸烟与肺癌易感性的统计学分析，结果显示吸烟与肺癌易感性有关（χ^2=14．197，P=0．000），吸烟者患肺癌的风险显著增加（OR=2．33，95％CI为1.50～3．62）。CYP1A1突变型与吸烟关系的协同分析发现，携带CYP1A1突变型基因的吸烟者较携带CYP1A1突变型基因不吸烟者易患肺癌（OR=4．44，95％CI为2．40～8．32，χ^2=23．843，P=0．000）。GSTM1（-）与吸烟关系的协同分析中也发现，携带GSTM1（-）的吸烟者患肺癌的风险显著增加（OR=7．32，95％CI为3．39～15．50，χ^2=36．708，P=0．000）。结论 CYP1A1突变型和GSTM1（-）是内蒙古地区肺癌的易患因素，二者对肺癌的发生有协同作用，吸烟与肺癌的易感性也有关，CYP1A1突变型、GSTM1（-）与吸烟在肺癌的发生上也有相互促进作用。     

叶酸还原载体基因RFC1 G80A多态性与胃癌易感性关系的分子流行病学研究

目的：探讨中国华东汉族人群叶酸还原载体（reduced folate carrier，RFC1）基因G80A多态与胃癌易感性的关系。方法：本组为病例对照研究，经组织学确诊的宜兴高发区胃腺癌病例261例，并选择与病例年龄和性别频数匹配的人群对照295例，以PCR内切酶片段长度多态性方法，比较不同基因型与胃癌风险的关系，并探讨吸烟、饮酒等因素在其中的影响。结果：与携带80GG基因型者比较，携带80AA基因型者胃癌风险增加1．79倍（校正OR=2．79，95％CI：1．77～4．39）；以携带80GG和GA基因型者为参照（隐性模型），80AA变异基因型者胃癌风险增加1．59倍（校正OR=2．59，95％CI：1．77～3．80），且这一显著的相关性在60岁以上（校正OR=2．96，95％CI：1．63～5．37）、女性（校正OR=8．28，95％CI：2．95～23．26）、非吸烟者（校正OR=3．68，95％CI：1．94～6．98）和非饮酒者（校正OR=3．08，95％CI：1．76～5．41）中更为显著。结论：RFC1G80A多态可能与中国汉族人群胃癌遗传易感性有关，值得进一步进行功能学探讨及大样本人群验证。     

代谢酶CYP2D6基因多态性与肺癌易感性的病例对照研究

背景与目的外源性化合物代谢酶参与环境致癌物在体内的代谢，代谢酶基因多态性被认为与肺癌的易感性相关。本研究的目的是探讨代谢酶细胞色素2D6酶(CYP2D6)基因多态性在四川汉族正常人群和肺癌患者中的分布，以及CYP2D6基因多态性与肺癌易感性的关系。方法应用PCR-RFLP技术检测152例正常人和150例原发性肺癌患者的外周血CYP2D6ch基因型；应用病例对照研究分析CYP2D6ch基因多态性与肺癌易感性的关系。结果(1)CYP2D6ch基因的C和T等位基因在正常人群中分布频率分别为39．5％和60．5％，而肺癌患者中分布频率分别为46．3％和53．7％；两组间C和T等位基因频率比较无显著性差异(P=0．089)。(2)CYP2D6ch等位基因型C／C、C／T、T／T在正常人群中分布频率分别为18．4％、42．1％和39．5％，而在肺癌患者中分布频率分别为22．7％、47．3％和30．0％，两组间比较无显著性差异(P=0．215)。(3)携带CYP2D6ch非T／T等位基因型的个体患肺鳞癌风险是携带T／T等位基因型的2．084倍(95％CI 1．024～4．244，P=0．043)。(4)携带CYP2D6ch非T／T等位基因型的轻度吸烟者患肺癌风险是携带CYP2D6ch T／T等位基因型轻度吸烟者的2．92倍(95％CI1．087～7．828，P=0．033)。结论CYP2D6ch非T／T等位基因型与肺鳞癌风险升高相关，在轻度吸烟人群中，非T／T等位基凶型与肺癌风险升高相关。     

GSTM1、GSTT1基因多态性与四川北部地区肺癌易感性关系的研究

目的:探讨谷胱苷肽硫转移酶M1(GSTM1)和T1(GSTT1)基因多态性与四川北部地区汉族人群肺癌易感性的关系。方法:采用病例对照研究和聚合酶链式反应(PCR)技术检测四川北部地区肺癌病人125例和健康对照组125例中GSTM1(-)和GSTT1(-)的频率,评价两基因型及两基因的交互作用与肺癌易感性的关系。结果:GSTM1(-)在肺癌组和对照组分布频率分别为58.4%和56.8%,单因素回归分析未见统计学差异(OR=1.06,95%CI:0.639-1.757,P=0.822);GSTT1(-)在肺癌组和对照组分布频率分别为45.6%和44.8%,单因素回归分析未见统计学差异(OR=0.968,95%CI:0.588-1.593,P=0.899),GSTM1(-)和GSTT1(-)联合并未增加肺癌风险(OR=1.084,95%CI:0.536-2.192,P=0.823)。结论:GSTM1及GSTT1各基因型单独或联合作用都不是四川北部地区汉族人群肺癌的风险因素。     

DNA修复基因XPC PAT遗传多态与肺癌的关系

目的 探讨DNA修复基因XPC Poly(AT)多态与肺癌的关系。方法 以PCR方法分析597例肺癌患者和509例正常人XPC PAT基因型分布,并比较不同基因型与肺癌风险的关系。结果 正常人群中,XPC PAT ／ 、PAT ／-和PAT-／-基因型频率分别为12．4％、49．7％和37．9％,肺癌患者中分别为11．2％、46．7％和42．1％,差异无显著性(P=0．37)。与携带至少一个XPC PAT等位基因比较,携带PAT ／ 基因型个体患肺癌的风险并未增高(校正OR=0．8;95％ CI为0．55-1．16)。该基因多态与吸烟无联合作用。结论 中国人肺癌风险与DNA修复基因XPC PAT多态无关。     

XPD基因多态性与非吸烟女性肺癌易感性的关系

背景与目的 着色性干皮病互补基因D（xeroderma pigmentosum group D，XPD）是一种重要的DNA损伤修复基因，其常见的多态是位于751密码子的A→C多态。本研究旨在探讨XPD基因751位点单核苷酸多态性与非吸烟女性肺癌易感性的关系，并探讨油烟暴露与基因多态性交互作用对肺癌风险的影响。方法 采用病例-对照研究方法，纳入非吸烟女性肺癌患者105人和对照105人。以聚合酶链反应-限制性片段长度多态性方法分析XPD基因Lys751Gln多态基因型。结果 携带至少1个751Gln等位基因者患肺癌的风险显著增高，调整OR为2．80（95％CI为1．21～6．48）。携带等位基因751Gln又有油烟暴露的个体患肺癌的风险较两个危险因素单独作用时更高，校正OR为6．85（95％CI为1．69～27．67，P=0．007）。结论 XPD基因Lys751Gln多态是非吸烟女性肺癌的遗传易感因素。携带XPD751Gln等位基因又有油烟暴露的非吸烟女性患肺癌的风险明显增高。     

南京市人群NQO1、CYP1A1、mEH基因多态性与肺癌易感性研究

目的：探讨南京市人群人NQO1，CYP1SA1，mEH-exon3,mEH-exon4基因多态性与肺癌易感性的关系。方法：用病例－对照研究方法，收集南京市区原发性肺癌患者84例，其中鳞癌35例，腺癌49例，同时选择对照84例，采用PCR技术，对样本NDA进行NQO1，CYP1A1，mEH-exon3,mEH-exon4基因的检测，并分析各基因型与肺癌易感性的关系。结果：南京市区人群NQO1，CYP1A1和mEH-exon4与肺癌易感性没有明显关系。mEH-exon3基因型与肺鳞癌发生有关，野生型个体可降低肺鳞癌发病的风险（OR＝0．32，95％CI：0．0078－0．63），杂合型和突变型个体患肺鳞癌的危险性明显高于野生型个体（OR＝3．1，95％CI：0．08－6．12），考虑吸烟因素后，mEH-exon3基因型与吸烟者肺癌发生有关，野生型个体可使肺癌发病风险性降低（OR＝0．18，95％CI：0．06－0．29），杂合型和突变型个体患肺癌的危险性增高（OR＝5．66，95％CI：2．01－9．30）。结论：南京市人群中NQO1，CYP1A1，mEH基因的分布情况与国内外的相关报道存在一定差异；种族差异，地域不同可能是造成上述基因分布不同的重要原因，南京市人群中mEH-exon3基因杂合型和变型与肺鳞癌发生有关，与吸烟者肺癌发生关系更为密切。     

GST基因多态性与儿童急性淋巴细胞白血病关联Meta分析

目的：探讨2个常见谷胱甘肽硫转移酶（glutathioneS-transferase,GST）GSTM1和GSTT1基因多态性与儿童急性淋巴细胞白血病（acutelymphoblasticleukemia,ALL）易感性的关系。方法：检索PubMed、EMBase、CBM、CNKI、VIP和万方数据平台从建库到2013-10-02的文献,提取相关数据。应用Stata11．0,选用合适的模型计算合并OR及95％CI,并进行发表偏倚检验。结果：共纳入17篇文献,21项研究。其中关于GSTM1与儿童ALL的研究21项,包含病例组2365例,对照组3885例。关于GSTT1与儿童ALL的研究20项,其中病例组2263例,对照组3744例。GSTM1纯合缺失基因型及GSTT1纯合缺失基因型合并0R分别为1．13（95％CI：1．03～1．23）和1．07（95％CI：0．94～1．22）。亚组分析发现,在亚洲人群及黑种人中GSTM1纯合缺失基因型增加儿童ALL的发病风险,OR分别为1．25（95％CI：1．07～1．45）和1．43（95％CI：1．03～1．23）;在白种人中GsTMl纯合缺失与儿童ALL．无明显相关性（OR=1．05;95％CI：0．94～1．18）;在亚洲人群中GSTTl纯合缺失增加儿童ALL的发病风险（OR=1．32;95％CI：1．08～1．60）;在白种人及黑种人中GSTTl纯合缺失与儿童ALL无明显相关（OR=0．92,95％CI：0．77～1．10;OR=0．95,95％CI：0．55～1．63）。结论：GSTM1纯合缺失基因型增加儿童ALL的发病风险,GSTT1纯合缺失基因型可增加亚洲儿童ALL的发病风险。GSTM1与GSTT1基因多态性与儿童ALL的易感性关联受人种影响。     

Irradiation of mouse lungs causes a dose-dependent increase in lung weight

The lungs of Balb/c mice were irradiated with doses of 200 to 1300 rad and excised and weighed three days to 20 weeks later. In all cases the wet weights were increased relative to unirradiated controls. The weight increases were dose-dependent up to 1000 rad. The largest weight increase was 28%. Comparison of the wet and dry weights of irradiated and control lungs indicated that the material responsible for the weight increase was intermediate in water content between normal lung tissue and plasma, whereas the water content of pulmonary edema fluid produced by adrenalin injection was similar to plasma. Protection of the mediastinum during irradiation did not affect the weight increase appreciably.     

Optimal anatomic coverage for CT in staging lung cancer: lessons from PET-CT correlation

Objective

To determine the optimal anatomic coverage at CT that would provide the most accurate staging for patients with non-small cell lung cancer.

Methods

We reviewed lung cancer staging PET-CT scans and correlated them with staging chest CT scans performed within 50 days of the PET-CT study. There were 113 patients who underwent both studies within our time frame. We reviewed the results of subsequent imaging studies and surgical and biopsy procedures to determine the final stage for each patient. This study was approved by the local institutional review board.

Results

In 86 (76%) of 113 patients, staging by PET-CT and by CT from the lung apices through the lung bases was identical. PET-CT upstaged 21 patients (19%) compared with CT findings; in 13 of these patients the PET-CT noted disease that was either outside of the anatomic range of any lung cancer staging CT or was within the area scanned by CT, but was not evident by CT. In the other 8 upstaged patients, extending the anatomic scope of the CT scan to the supraclavicular region (5), adrenal glands (2) or abdomen (1) would have resulted in correct staging.

Conclusions

CT scanning from the supraclavicular region through the caudal adrenal glands improves the accuracy of CT staging of lung cancer compared with scanning from the lung apices through the lung bases. Anatomic coverage beyond the adrenal glands has a low yield for improved staging, at the cost of requiring administration of oral contrast to all patients.

Summary

To determine the optimal anatomic coverage at CT that would provide the most accurate staging for patients with non-small cell lung cancer, we reviewed lung cancer staging PET-CT scans and correlated them with staging chest CT scans performed within 50 days of the PET-CT study. CT scanning from the supraclavicular region through the caudal adrenal glands improves the accuracy of CT staging of lung cancer compared with scanning from the lung apices through the lung bases. Anatomic coverage beyond the adrenal glands has a low yield for improved staging, at the cost of requiring administration of oral contrast to all patients undergoing lung cancer staging.     

肺癌患者弥散功能特点及临床意义探讨

目的：探讨肺癌患者弥散功能特点及临床意义。方法：用复重呼吸法对138例原发性肺癌患者的弥散功能进行测定。结果：弥散量（DLCOrb）、校正弥散量（DLCOrbc）在不同类型和不同程度及通气功能障碍的组间及不同大体类型间均无显著性差异（P＞0．05），但是肺通气功能正常的肺癌患者弥散系数（DLCOrb／VA）略降低，限制型组校正弥散系数（DLCOc／VA）降低（P＜0．01），阻塞型组和混合型组弥散系数降低（P＜0．05）。肺通气功能轻度减退和显著减组的肺癌患者校正弥散系数降低（P＜0.05).中心型肺癌患者校正弥散系数降低且与周围型组间有显著性差异（P＜0．01）。术后呼衰组弥散量、校正弥散系数低于无呼衰组，有显著性差异（P＜0．05）。校正弥散系数＜80％和弥散系数＜70％预测术后呼衰诊断正确率和诊断指数较高。结论：肺癌患者存在弥散功能减退，主要表现在弥散系数和校正弥散量的异常，肺癌的大体类型和患者的肺通气功能状态对肺弥散功能均有影响，应选择校正弥散系数＜80％和弥散系数＜70％预测术后呼衰。     

肺癌患者结核菌感染状况

目的　探讨肺结核与肺癌的相关性。方法　运用经典抗酸染色 (ZN法 )、改良抗酸染色(IK法 )、免疫组织化学染色 (ABC法 )及TB PCR方法对 3 3 0例肺癌患者结核菌感染状况进行了前瞻性研究。结果　全组 3 3 0例纤维支气管镜刷检结核菌阳性率为 2 7.88% ;93例肺癌组织标本IK法结核菌阳性率 3 8.71% ,ABC法阳性率 5 1.6 1% ;14例手术切除标本结核菌培养阳性率 5 7.14 % ;2 0例肺癌组织切片TB PCR阳性率 6 0 %。结论　肺癌患者结核菌特别是它的L型有较高的感染率。提示肺结核与肺癌之间可能有一定的相关性。     

心肺运动试验预测肺癌患者术后呼吸衰竭的探讨

目的　探讨心肺运动试验预测肺癌患者术后呼吸衰竭的临床意义。方法　采用运动负荷递增的方案对 2 60例原发性肺癌患者行术前心肺运动试验 ,测定终止负荷运动时的功率 (W % )、最大摄氧量( VO2 %P)、公斤氧耗量 ( VO2 /kg)、无氧阈 (AT)、代谢当量 (MET)、氧脉搏 (O2 pulse)、潮气量 (VTe)、呼吸频率(BF)、通气量 ( VE)。结果　 ( 1)除VTe外 ,全肺切除术后呼衰组其余八项指标均显著低于非呼衰组 (P <0 .0 5或P <0 .0 1)。肺叶切除术后呼衰组上述所有指标与非呼衰组无显著性差异 (P >0 .0 5 ) ,将肺叶切除患者分为上叶切除和下叶切除组分析时发现 ,仅下叶切除术后呼衰组W %低于非呼衰组 (P <0 .0 5 )。 ( 2 ) χ2 检验显示 ,八项指标不同程度异常与全肺切除术后呼衰的发生率有关 ,logistic回归分析显示O2 pulse <80 %和BF <3 0次 /分与全肺切除术后呼衰的发生密切相关。 ( 3 ) VO2 %P <60 %、BF <3 0次 /分、 VE<3 5L/min预测术后衰竭的敏感性和特异性均 >60 % ,阴性预测值均大于 90 %。结论　心肺运动试验更适于预测全肺切除术后呼衰的可能性 ,由于 VO2 %P是一项反映运动心肺功能的综合指标 ,建议选择 VO2 %P <60 %作为预测术后呼衰、评估手术适应证的指标。     

Efficacy of PET/CT in the characterization of solid or partly solid solitary pulmonary nodules

We aimed to evaluate the efficacy of (18)fluorine fluorodeoxyglucose ((18)F FDG) PET/CT for the characterization of solitary pulmonary nodules (SPNs) compared with the use of PET alone or CT alone. Our institutional review board approved this retrospective study with a waiver of informed consent. We selected 100 patients (M:F=56:44, mean age; 58 years) with a pathologically proven solid or partly solid SPN. Three chest radiologists assessed the nodule characteristics independently and retrospectively. Diagnostic efficacies were compared for three different approaches: consideration of CT findings only, PET findings only, and both PET and CT findings. The McNemar test, kappa statistics, and receiver operating characteristics (ROC) curve analysis were performed. Sixty patients had benign and 40 had malignant nodules. Overall sensitivity values for malignant SPNs for CT, PET and PET/CT were 82%, 88%, and 88%, respectively, whereas the specificity values were 66%, 71%, and 77%, respectively. PET/CT was significantly better in terms of specificity than the use of PET alone or CT alone (P<.05). The areas under curve (Az) values for the ROC analyses of PET/CT and PET alone, respectively, were larger than that of CT alone (P<.05). Interobserver agreement was moderate (kappa=0.46-0.56) for CT, good to excellent (kappa=0.78-0.90) for PET, and good for PET/CT (kappa=0.64-0.78). For the characterization of SPNs, integrated PET/CT provides significantly better specificity than CT alone or PET alone and both integrated PET/CT and PET alone allow more confidence than CT alone.     

Prior lung disease and lung cancer risk in an occupational-based cohort in Yunnan, China

We used the data from a prospective cohort study among tin miners in Yunnan, China to investigate whether prior lung disease is a risk factor for lung cancer. Information on prior lung disease was obtained from baseline questionnaires. The Cox proportional hazards model was used to examine the relationship between prior lung disease and lung cancer risk. From 1992 to 2001, a total of 502 lung cancer cases were confirmed among 9295 cohort participants. Prior chronic bronchitis was associated with an increase in lung cancer risk with an adjusted HR of 1.50 (95% CI: 1.24-1.81). There was an increased risk of developing squamous cell carcinoma in the setting of prior chronic bronchitis and small cell carcinoma in association with asthma with an adjusted HRs of 1.57 (95% CI: 1.19-2.09) and 2.56 (95% CI: 1.38-4.75), respectively. This prospective study provides further evidence that prior chronic bronchitis correlates with increased lung cancer risk, especially for squamous cell carcinoma. Asthma is associated with increased risk of small cell lung carcinoma.     

False-Negative Results in Lung Cancer Screening—Evidence and Controversies

Identifying false-negative cases is an important quality metric in lung cancer screening, but it has been infrequently and variably reported in previous studies. Although as a proportion of all screening participants, false-negative cases are uncommon, such cases may constitute a substantial proportion of all lung cancers diagnosed (up to 15%) within a screening program.This article reviews the impact and causes of false-negative lung cancer screening tests, including those related to radiologic evaluation, nodule management protocols, and management decisions made by multidisciplinary teams. Following a review of data from international screening studies, this article discusses the controversies within the screening literature surrounding the definition and classification of a false-negative lung cancer screening test and how data on false-negative rates should be captured and recorded. Challenges, such as avoiding overly cautious surveillance of lung nodules while minimizing overdiagnosis and investigation of indolent or benign lesions, are considered. Finally, the advantages and disadvantages of different approaches to dealing with false-negative results in lung cancer screening are discussed.