Pinsky Paul F, Gierada David S, Nath P Hrudaya, Munden Reginald
1 Division of Cancer Prevention, National Cancer Institute, 9609 Medical Center Dr, Bethesda, MD 20892.
2 Department of Radiology, Washington University School of Medicine, St. Louis, MO.
AJR Am J Roentgenol. 2017 Nov;209(5):1009-1014. doi: 10.2214/AJR.17.18252. Epub 2017 Sep 12.
As low-dose CT (LDCT) lung cancer screening moves into routine clinical practice, evaluation of nodules identified as new becomes critical. We examine the frequency and clinical outcomes of new lung nodules reported at the two postbaseline annual screening examinations (hereafter referred to as postbaseline time 1 [T1] and time 2 [T2]), compared with those detected at baseline in the National Lung Screening Trial.
Radiologists classified nodules detected at T1 and T2 as new or preexisting on the basis of comparison with findings from prior LDCT screening examinations. Subjects were tracked for lung cancer incidence and mortality. We examined the incidence of new nodules and their associated lung cancer risk by nodule size (i.e., mean diameter).
A total of 25,002 subjects underwent the baseline LDCT screening examination and either a T1 or T2 LDCT screen. At both T1 and T2, 2.6% of subjects had new solid nodules. Of the new solid nodules, 53.0% were < 6 mm, 29.5% were 6 to < 10 mm, and 17.1% were ≥ 10 mm. Lung cancer risk (defined as diagnosis within 2 years of baseline) increased from 1.1% for nodules < 4 mm to 24.0% for those ≥ 20 mm. Compared with solid nodules detected at baseline, the cancer risk was higher for new solid nodules that were 4 to < 6 mm (p < 0.001) and 6 to < 8 mm (p < 0.001) but lower for new nodules ≥ 20 mm (p = 0.03). Cancers associated with new nodules had significantly poorer survival than did those associated with baseline nodules and were significantly less likely to be adenocarcinoma.
The incidence of new nodules was 2-3% annually, with the cancer risk increasing by nodule size. New nodules may convey differential lung cancer risks by size, compared with baseline nodules.
随着低剂量CT（LDCT）肺癌筛查进入常规临床实践，对新发现的结节进行评估变得至关重要。我们研究了在两次基线后年度筛查检查（以下称为基线后时间1 [T1]和时间2 [T2]）中报告的新肺结节的频率和临床结局，并与国家肺癌筛查试验中在基线时检测到的结节进行比较。
放射科医生根据与先前LDCT筛查检查结果的比较，将在T1和T2检测到的结节分类为新出现的或先前已有的。对受试者进行肺癌发病率和死亡率跟踪。我们按结节大小（即平均直径）研究了新结节的发生率及其相关的肺癌风险。
共有25,002名受试者接受了基线LDCT筛查检查以及T1或T2 LDCT筛查。在T1和T2时，2.6%的受试者有新的实性结节。在新的实性结节中，53.0%的直径<6 mm，29.5%的直径为6至<10 mm，17.1%的直径≥10 mm。肺癌风险（定义为在基线后2年内确诊）从直径<4 mm的结节的1.1%增加到直径≥20 mm的结节的24.0%。与基线时检测到的实性结节相比，直径4至<6 mm（p<0.001）和6至<8 mm（p<0.001）的新实性结节的癌症风险更高，但直径≥20 mm的新结节的癌症风险更低（p = 0.03）。与新结节相关的癌症的生存率明显低于与基线结节相关的癌症，且腺癌的可能性明显更小。
新结节的发生率为每年2% - 3%，癌症风险随结节大小增加。与基线结节相比，新结节可能因大小不同而具有不同的肺癌风险。
