Low-dose Computer Tomography Screening For Lung Cancer And The Differentiating Computer Tomography Features Of Early Stage Lung Cancer

Part ?Make a preliminary research and analysis on low-dose computedtomography(LDCT)screening for lung cancerObjective: Make a preliminary research and analysis on the non-calcified pulmonary nodules and lung cancers by low-dose computed tomography(LDCT)screening in asymptomatic participants.Methods: Collect relevant information over the age of 40 asymptomatic healthy participants underwent chest low-dose computed tomography(LDCT)screening for lung cancer.Clinical date and baseline CT result data of participants were investigated.They were divided into two age groups: the middle-aged group(between 40 and 49)and the elderly groups(greater than or equal to 50 years old).According to the smoking history,the population was divided into smoking group(including smokers and former smokers)and non smoking group.According to the previous pulmonary disease,the population was divided into pulmonary disease group and non pulmonary disease group.According to the history of malignant tumor,the population was divided into malignant tumor history group and non malignant tumor history group.According to the family history of lung cancer,the population was divided into family history of lung cancer group and non family history of lung cancer group.At baseline screening,the positive results were identified as at least one solid or subsolid nodule measuring?5 mm in diameter.The negative nodule was identified as at least one solid or subsolid nodule measuring<5 mm in diameter.If none of non-calcified pulmonary nodules was identified the result was negative.All statistical analyses were performed using SPSS 18.0.The measurement data were analyzed by using independent samples t test,count data were compared using chi square test or Fisher exact test.P < 0.05 was considered statistically significant differences.Result: At baseline screening,3,303 participants in Shijiazhuang who met the inclusion criteria were recruited(1,853 men and 1,450 women),the age was from 40 to 91 years old(median,53 years).1,067(32.3%)were in the middle-aged group and 2,236(67.7%)in the elderly group.Of these subjects,982(29.7%)were in the smoking group and 2,321(70.3%)were in the non smoking group.320(9.7%)were in the pulmonary disease group and 2,983(90.3%)were in the non pulmonary disease group.76(2.3%)were in the malignant tumor history group and 3,227(97.7%)were in the non malignant tumor history group.272(8.2%)were in the family history of lung cancer group and 3,031(91.8%)were in the non family history of lung cancer group.At screening,1,298(1,298/3,303,39.3%)participates have at least one solid or subsolid nodule.The result of 655(655/1,298,50.5%)participates had positive nodule.The positive result rate was higher in the elder group than in the middle-aged group(22.4% vs 14.4%,P<0.001).The positive result rate was higher in the pulmonary disease group than in the non pulmonary disease group(26.60% vs19.10%,P=0.001).655 participates were identified as positive at baseline screening,in which the solid nodules were 484(73.9%),nonsolid nodules were 120(18.3%)and part-solid nodules were 51(7.8%).In the positive cases of screening,the solid nodules in male were more than those in female,while the subsolid nodule in male was lower than those in female.The difference was statistically significant(P<0.001).27 cases of lung cancer confirmed pathologically were identified at baseline,they were all adenocarcinoma.There were 25 cases of stage?A and 25 cases of stage?B.Lung cancer cases accounted for 4.12%(27/655)of the positive results and accounted for 0.82% of the total number of participates.The prevalence rate of lung cancer in female was higher than that in males,and the difference was statistically significant(1.2% versus 0.5%,P=0.041).At the same time,the prevalence rate of lung cancer in female exposed to secondhand smoke was higher than the female without secondhand smoke exposure,and the difference was statistically significant(1.83%vs0.47%,P=0.020).The prevalence rate of lung cancer in elderly group was higher than that in middle age group,but the difference was no statistically significant(1.0% versus 0.5%,P=0.183).The malignant rate of part-solid nodule was highest,and the difference was statistically significant(25.5% versus 0.4% versus 10.0%,P<0.001).Conclusion: At LDCT lung cancer screening,the incidence of lung cancer was not significantly different between 40-50 years old and greater than or equal to 50 years old.It may be more reasonable and accurate to define the age of LDCT lung cancer screening persons as greater than or equal to 40 years of age.At screening,we should pay a attention to the non-smoking female who are exposed to second-hand smoke.The malignant rate of positive part-solid pulmonary nodules was highest that should be followd up closely.Part?The differentiating computer tomography features of early stagelung adenocarcinoma appearing as subsolid nodulesObjective: To retrospectively investigate the differentiating computed tomographic(CT)features between preinvasive lesion,minimally invasive pulmonary adenocarcinoma(MIA)and invasive pulmonary adenocarcinoma(IPA)appearing as subsolid nodules in 82 patients.Methods: Clinical and radiographic data of 83 subsolid nodules in 82 patients surgically resected lesions from December 2011 to November 2015 were retrospectively investigated.Clinical features include gender of patient and age of patient.Radiographic features include tumor diameter,tumor attenuation,density type of lesion,the proportion of solid component,speculated,lobulated,bubble lucency and pleural retraction.All surgically resected specimens were reviewed according to IASLC/ATS/ERS classification.All subsolid nodules were divided into nonsolid nodule and part-solid nodule category according to the existence of an internal solid component at CT.Then,according to the pathology of the lesions,the lesions were divided into two groups.One group included preinvasive lesion(AAHs and AISs)and MIAs,the others included IPAs.All statistical analyses were performed using SPSS 18.0.Age of patient,lesion size,density and the proportion of solid component were compared with two independent samples t test if satisfy the normal distribution,otherwise with Mann-Whitney U test.Gender of patients,speculated,lobulated,bubble lucency and pleural retraction were compared with groups using ?2 test and Fisher exact test.To identify the differentiating CT features between preinvasive lesions,MIAs and IPAs and to evaluate their differentiating accuracy,logistic regression analysis and receiver operating characteristic(ROC)curve analysis were performed,respectively.P < 0.05 was considered statistically significant differences.Results: There were 33 nonsolid nodules and 50 part-solid nodules in 83 lesions.In nonsolid nodules,6 cases were preinvasive lesions,17 cases were MIAs and 10 cases were IPAs.Among the preinvasive lesions,5 cases were AAHs and 1 case was AIS.In part-solid GGNs,4 cases were preinvasive lesions,20 cases were MIAs and 26 cases were IPAs.Among preinvasive lesions,1 case was AAH and 3 were AISs.In nonsolid nodules,among the age of patient,gender of patients,density,speculated,lobulated,bubble lucency and pleural retraction,there was no significant differences between preinvasive lesion,MIAs and IPAs(P >0.05).Preinvasive lesions and MIAs were significantly smaller than IPAs(P=0.002).Multivariate analysis revealed that lesion size was the single significant differentiator of preinvasive lesions and MIAs from IPAs(P=0.013).The optimal cut-off size for IPAs was more than 14.7mm(sensitivity,80.0%;specificity,82.6%).That the area under the ROC curve(AUC)for lesion size was 0.802(95% confidence interval: 0.623,0.981).In part-solid nodules,there were significant differences in lesion size,solid proportion,speculated,lobulated and pleural retraction between preinvasive lesions,MIAs and IPAs(P<0.05).The optimal cut-off value for lesion size and solid proportion for differentiating preinvasive lesions and MIAs from IPAs was 20.2 mm or less(sensitivity,57.7%;specificity,79.2%)and 33.8% or less(sensitivity,69.2%;specificity,79.2%),respectively.ROC analysis revealed that the AUC for lesion size and solid proportion was 0.692(95% confidence interval: 0.546,0.837)and 0.774(95% confidence interval: 0.644,0.904),respectively.Multivariate analysis revealed that smaller lesion size and smaller solid proportion were the single significant differentiator of preinvasive lesions and MIAs from IPAs(P=0.042,P =0.006,respectively),with preferably differentiating accuracy(AUC =0.861,95% confidence interval: 0.762,0.959).Conclusion: In nonsolid nodules,a lesion size of less than 14.7 mm can be a very specific discriminator of preinvasive lesions and MIAs from IPAs.In part-solid nodules,preinvasive lesions and MIAs can be accurately distinguished from IPAs by the smaller lesion size and smaller solid proportion.