Henschke C I, McCauley D I, Yankelevitz D F, Naidich D P, McGuinness G, Miettinen O S, Libby D M, Pasmantier M W, Koizumi J, Altorki N K, Smith J P
Weill Medical College of Cornell University and New York Presbyterian Hospital, NY 10021, USA.
Lancet. 1999 Jul 10;354(9173):99-105. doi: 10.1016/S0140-6736(99)06093-6.
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 people at high risk of lung cancer. We report the baseline experience.
ELCAP has enrolled 1000 symptom-free volunteers, aged 60 years or older, with at least 10 pack-years of cigarette smoking and no previous cancer, who were medically fit to undergo thoracic surgery. After a structured interview and informed consent, chest radiographs and low-dose CT were done for each participant. The diagnostic investigation of screen-detected non-calcified pulmonary nodules was guided by ELCAP recommendations, which included short-term high-resolution CT follow-up for the smallest non-calcified nodules.
Non-calcified nodules were detected in 233 (23% [95% CI 21-26]) participants by low-dose CT at baseline, compared with 68 (7% [5-9]) by chest radiography. Malignant disease was detected in 27 (2.7% [1.8-3.8]) by CT and seven (0.7% [0.3-1.3]) by chest radiography, and stage I malignant disease in 23 (2.3% [1.5-3.3]) and four (0.4% [0.1-0.9]), respectively. Of the 27 CT-detected cancers, 26 were resectable. Biopsies were done on 28 of the 233 participants with non-calcified nodules; 27 had malignant non-calcified nodules and one had a benign nodule. Another three individuals underwent biopsy against the ELCAP recommendations; all had benign non-calcified nodules. No participant had thoracotomy for a benign nodule.
Low-dose CT can greatly improve the likelihood of detection of small non-calcified nodules, and thus of lung cancer at an earlier and potentially more curable stage. Although false-positive CT results are common, they can be managed with little use of invasive diagnostic procedures.
早期肺癌行动项目（ELCAP）旨在评估通过低辐射剂量计算机断层扫描（低剂量CT）对肺癌高危人群进行基线筛查及年度重复筛查的情况。我们报告基线筛查的经验。
ELCAP招募了1000名无症状志愿者，年龄在60岁及以上，至少有10包年吸烟史且既往无癌症，身体状况适合接受胸外科手术。在进行结构化访谈并获得知情同意后，对每位参与者进行胸部X线摄影和低剂量CT检查。对筛查发现的非钙化肺结节的诊断性检查遵循ELCAP的建议，其中包括对最小的非钙化结节进行短期高分辨率CT随访。
基线时，通过低剂量CT在233名（23%[95%CI 21 - 26]）参与者中检测到非钙化结节，而通过胸部X线摄影在68名（7%[5 - 9]）参与者中检测到。通过CT检测到27例（2.7%[1.8 - 3.8]）恶性疾病，通过胸部X线摄影检测到7例（0.7%[0.3 - 1.3]），I期恶性疾病分别为23例（2.3%[1.5 - 3.3]）和4例（0.4%[0.1 - 0.9]）。在CT检测出的27例癌症中，26例可切除。对233名有非钙化结节的参与者中的28例进行了活检；27例有恶性非钙化结节，1例有良性结节。另外3名个体违背ELCAP建议进行了活检；均有良性非钙化结节。没有参与者因良性结节接受开胸手术。
低剂量CT可大大提高检测小的非钙化结节的可能性，从而在更早且可能更可治愈的阶段检测出肺癌。尽管CT的假阳性结果很常见，但通过很少使用侵入性诊断程序即可处理。
