Pure Solid Pattern of Non-Small Cell Lung Cancer and Clustered Circulating Tumor Cells

There are two solid patterns of non-small cell lung cancer (NSCLC) on computed tomography (CT): pure or mixed with ground-glass opacities (GGOs). They predict the degree of invasiveness, which may suggest the presence of clustered circulating tumor cells (CTCs), a predictor of poor prognosis. In this study, we assessed the implications of the solid patterns on CT and the preoperative clustered CTCs in surgically resected NSCLC. CTCs were detected using a size selection method. The correlation between the presence of preoperative clustered CTCs and the solid pattern and the prognostic implications were evaluated using co-variables from the clinical-pathological findings. Of the 142 cases, pure solid lesions (Group PS) and mixed GGOs (Group G) were observed in 92 (64.8%) and 50 (35.2%) patients, respectively. In Groups PS and G, clustered CTCs were detected in 29 (31.5%) and 1 (2.0%) patient (p < 0.01), respectively. The PS appearance was an independent predictor of preoperative clustered CTCs in the multivariable analysis, and preoperative clustered CTCs were an independent predictor of poor recurrence-free survival; the solid pattern was not an independent variable. Thus, the PS pattern of NSCLC on CT is an indicator of preoperative clustered CTCs, which is an independent poor prognosis predictor.