Henschke C I
Department of Radiology, New York Presbyterian Hospital-Weill Cornell Medical Center, New York 10021, USA.
Cancer. 2000 Dec 1;89(11 Suppl):2474-82. doi: 10.1002/1097-0142(20001201)89:11+<2474::aid-cncr26>3.3.co;2-u.
The Early Lung Cancer Action Project (ELCAP) is designed to evaluate baseline and annual repeat screening by low radiation dose computed tomography (low-dose CT) in persons at high-risk for lung cancer. The authors report on the baseline screening experience. For full evaluation of screening, they await the results of annual repeat screening.
Using a novel non-comparative design, enrollment of 1000 asymptomatic persons, 60 years of age or older, with at least 10 pack-years of cigarette smoking, no prior cancer, and who were medically fit to undergo thoracic surgery was initiated in 1993. After a structured interview and informed consent, chest radiographs (CXR) and low-dose CT were obtained on each subject. The diagnostic workup of screen-detected noncalcified pulmonary nodules (NCNs) was guided by ELCAP recommendations which included short-term high-resolution CT (HRCT) follow-up for the smallest NCNs.
On low-dose CT at baseline as compared to CXR, NCNs were detected three times as commonly (23% vs. 7%), malignancies four times as commonly (2.7% vs. 0.7%), Stage I malignancies six times as commonly (2.3% vs. 0.4%). Of the 27 CT-detected cancers, 96% (26/27) were resectable; 85% (23/27) were Stage I, 19 (83%) of the 23 were not seen on CXR. Following the ELCAP recommendations, biopsies were performed on 28 of the 233 subjects with NCNs; 27 had a malignant NCN and one had a benign one. Another three individuals underwent biopsy outside of the ELCAP recommendations, all had benign NCNs. No one had thoracotomy for a benign nodule.
The estimated five-year survival rate of baseline CT-detected malignancies of 60%-80% is a marked improvement over the current rate of 15%. Although false-positive CTs are common, they can be managed with minimal use of invasive diagnostic procedures.
早期肺癌行动计划（ELCAP）旨在评估肺癌高危人群通过低辐射剂量计算机断层扫描（低剂量CT）进行的基线筛查和年度重复筛查。作者报告了基线筛查的经验。为了全面评估筛查效果，他们正在等待年度重复筛查的结果。
采用一种新颖的非对比设计，1993年开始招募1000名无症状的60岁及以上人群，他们至少有10包年的吸烟史，无既往癌症史，且身体状况适合接受胸外科手术。经过结构化访谈并获得知情同意后，对每个受试者进行了胸部X光片（CXR）和低剂量CT检查。筛查发现的非钙化肺结节（NCNs）的诊断检查遵循ELCAP的建议，其中包括对最小的NCNs进行短期高分辨率CT（HRCT）随访。
与CXR相比，基线低剂量CT检查时，NCNs的检出率高出两倍（23%对7%），恶性肿瘤的检出率高出三倍（2.7%对0.7%），I期恶性肿瘤的检出率高出五倍（2.3%对0.4%）。在CT检测出的27例癌症中，96%（26/27）可切除；85%（23/27）为I期，23例中的19例（83%）在CXR上未显示。按照ELCAP的建议，对233例有NCNs的受试者中的28例进行了活检；27例有恶性NCN，1例为良性。另外3例受试者在ELCAP建议之外进行了活检，均为良性NCN。没有人因良性结节接受开胸手术。
基线CT检测出的恶性肿瘤的估计五年生存率为60%-80%，比目前的15%有显著提高。虽然CT假阳性很常见，但通过最少使用侵入性诊断程序即可进行处理。
