McWilliams Annette M, Mayo John R, Ahn Myeong Im, MacDonald Sharyn L S, Lam Stephen C
British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
J Thorac Oncol. 2006 Jan;1(1):61-8.
Thoracic computed tomography (CT) for lung cancer screening is sensitive for the detection of early peripheral lung cancer but is not sensitive for detecting central preinvasive and microinvasive cancer. Our hypothesis is that the use of a two-step strategy, using a sputum biomarker, may increase the detection rate of lung cancer by identifying individuals at highest risk.
We completed a pilot study of 561 volunteer current or former smokers 50 years of age or older, with a smoking history of more than or equal to 30 pack years. All subjects received induced sputum examination and low-dose thoracic CT scan and were offered autofluorescence bronchoscopy.
CT detected 2408 pulmonary nodules, 80% of which were less than or equal to 4 mm in diameter. During 2-year follow-up, 95% of these nodules were stable or resolved, with only 4% showing growth at any time. A total of 28 cancers were detected in 22 subjects: 21 by CT scan and seven by autofluorescence bronchoscopy. Overall, 0.9% nodules were malignant, but growth on more than or equal to two CT scans increased the malignancy rate to 75%. The mean diameter of malignant nodules on detection was 12.8 mm (range, 3 to 36.4 mm). However, 18% of malignant nodules were less than or equal to 4 mm in diameter when first seen.
Multi-detector row CT scanners found multiple small nodules in most subjects screened, but most were stable over the 2-year follow-up. Persistent interval growth increases the probability of malignancy from less than 1% to 75%. One quarter of detected cancers were CT occult and only seen with autofluorescence bronchoscopy. Prescreening using a sputum biomarker improved the detection rate of lung cancer from 3 to 5%.
用于肺癌筛查的胸部计算机断层扫描（CT）对早期周围型肺癌的检测很敏感，但对中央型癌前病变和微浸润癌的检测不敏感。我们的假设是，采用两步策略，即使用痰液生物标志物，可能通过识别高危个体来提高肺癌的检出率。
我们对561名年龄在50岁及以上、吸烟史大于或等于30包年的现吸烟者或既往吸烟者志愿者进行了一项初步研究。所有受试者均接受诱导痰检查和低剂量胸部CT扫描，并接受自发荧光支气管镜检查。
CT检测到2408个肺结节，其中80%的直径小于或等于4毫米。在2年的随访期间，这些结节中有95%稳定或消失，只有4%在任何时候出现生长。22名受试者共检测到28例癌症：21例通过CT扫描发现，7例通过自发荧光支气管镜检查发现。总体而言，0.9%的结节为恶性，但在两次或更多次CT扫描上出现生长使恶性率提高到75%。检测到的恶性结节的平均直径为12.8毫米（范围为3至36.4毫米）。然而，18%的恶性结节在首次发现时直径小于或等于4毫米。
多排CT扫描仪在大多数筛查的受试者中发现了多个小结节，但在2年的随访中大多数结节是稳定的。持续的间隔期生长将恶性的概率从不到1%提高到75%。四分之一检测到的癌症在CT上隐匿，仅通过自发荧光支气管镜检查才能发现。使用痰液生物标志物进行预筛查将肺癌的检出率从3%提高到5%。
