低剂量CT筛查肺癌之现状和展望

Screening for Lung Vancer with Low-dose Helical CT: Current Dtate and Outlook

肺癌高居全球癌症死亡的首位。遗憾的是,因出现症状而就诊的肺癌多属晚期,预后甚差。肺癌筛查的想法可追溯到上世纪五十年代,摄胸片筛查了6 000名男性志愿者,虽生存期较有症状组稍有延长,但死亡率无明显差异。随着低剂量CT检查技术的开展,于上世纪九十年代中、晚期报道,用低剂量CT筛查有较高的早期肺癌检出率,使肺癌筛查重又燃起希望。但因这些筛查试验缺乏对照组,故不足以确定低剂量CT筛查是否能降低肺癌死亡率。文献中对仍有很多争论。为确定CT筛查是否真正有益,美国全国肺癌筛查试验及NELS0N试验进行之中,预计2010年可得出最终结果。肺癌筛查是一复杂的有争议的问题,通过CT筛查是否能实质性地降低肺癌死亡率,仍不清楚。尽管CT筛查充满希望,但仍存在一些问题有待解决,在采取大面积筛查前须对其有所了解。

Lung cancer remains the leading cause of cancer-related mortality in the world. Unfortunately, most symptom-detected lung cancers are at a late stage with a poor prognosis. The idea of screening for lung cancer goes back to the 1950s, which performed periodic photofluorogram screening on more than 6000 male volunteers. Although survival was slightly better in the screening-detected cancers than in the symptom-detected cancers, no difference was seen in the lung cancer-specific mortality. After the invention of low-dose CT scan, interest in screening was rekindled in the mid to late 1990s with the reports of high rates of early-stage cancers found on low-dose CT screening. Because these trials did not contain a control group, they were insufficient to determine whether LDCT screening could decrease the lung cancer mortality rate. The controversy over CT screening remains in the literatures. Two randomized controlled trials for determining the benifit of CT screening are ongoing by American National Lung Screening Trial and NELSON trial, with final results expected around 2010. Screening for lung cancer is a complex issue. Still unknown is whether CT screening will result in a substantial decrease in lung cancer mortality. Although developments in the field of CT screening are promising, these and other unsolved issues still exist and must be understood before adopting screening on a large scale.