Lung cancer screening by low-dose spiral computed tomography

Abstract

The poor prognosis of lung cancer has barely changed in the last decades, but the prognosis is better when the disease is detected earlier. Lung cancer screening by chest radiography did not lead to a decrease in lung cancer mortality, presumably because the chest radiograph is a poor screening tool with low sensitivity.With the advent of the low-dose spiral computed tomography (CT) scan it has become feasible to detect early invasive stage I lung cancer in 80-90% of cases. This technique could possibly decrease lung cancer mortality, but the extent of this effect is as yet unknown, and whether lung cancer screening will be cost-effective is yet to be determined. These questions can only be resolved in a randomized controlled trial with lung cancer mortality as an unbiased end-point.In this review, the initiatives to evaluate low dose spiral CT screening for lung cancer in Japan, USA and Europe are presented. In the USA and Japan, evaluation is in onearmed studies, whereas in many European countries randomized trials are now being planned and several one-armed studies have been initiated. A formal collaboration among these countries has now been set up.It is strongly recommended that lung cancer screening be evaluated in randomized trials in order to allow evidence-based health policy decisions to be made on this subject.

Limited value of shape, margin and CT density in the discrimination between benign and malignant screen detected solid pulmonary nodules of the NELSON trial

“…In conclusion, in solid non-calcified nodules larger than 50 mm 3 , size and to a lesser extent lobulated or spiculated margin and irregular shape increased the likelihood that the nodule was malignant. Nodule density had no discriminative power.…”

“…From April 2004 until July 2006, 7310 participants underwent baseline screening. For this particular study a subgroup of 405 participants with 387 indeterminate solid pulmonary nodules between 50 and 500 mm 3 (≤0 mm in diameter) and 82 screen-positive solid pulmonary nodules with a volume > 500 mm 3 (>10 mm in diameter) have been selected. The nodules had to be located purely intra-parenchymal without pleural-, fissure-attachment or juxtavascular location.…”

“…Indeterminate nodules (Category III) were defined as nodules with volumes between 50 and 500 mm 3 , and screen-positive nod-ules (Category IV) as nodules larger than 500 mm 3 . In this study, all solid nodules were further classified based on shape (round/oval, polygonal or irregular) [13], margin (smooth, lobulated or spiculated/irregular) [14], and mean CT density in Hounsfield units (HU) (≤0, 0-100 or >100 HU).…”

“…More than two-thirds of these patients are diagnosed with locally advanced or metastatic disease, and their poor prognosis is due to late diagnosis and lack of effective treatment of metastatic disease. Less than 15% of the patients are surviving 5 years, and in several European countries the 5-year survival is far less [3]. Despite the optimal use of therapeutic resources, overall improvement in survival during the last decades has only 0720-048X/$ -see front matter © 2007 Elsevier Ireland Ltd. All rights reserved.…”

Highlights in lung cancer

“…The place of screening with CT and the clear need to take this topic forward with proper large scale randomized trials is discussed by VAN KLAVEREN et al [13] in the second article. The third paper will present the new World Health Organization International Association for Study of Lung Cancer (IASLC) Lung Cancer Classification [14].…”