Lung cancer circulating tumor cells isolated by the EpCAM-independent enrichment strategy correlate with Cytokeratin 19-derived CYFRA21-1 and pathological staging

BackgroundCytokeratin 19-derived CYFRA21-1 is an acceptable lung cancer biomarker. However, whether CYFRA21-1 correlates with lung cancer circulating tumor cells (CTCs) remains unclear.MethodsCTCs in 42 lung cancer patients and 10 nonmalignant pulmonary disease patients were isolated by means of an EpCAM-independent enrichment strategy. Correlation of lung cancer CTCs with serum concentration of CYFRA21-1 and pathological staging was investigated.ResultsAmong lung cancer patients in this study, 39% (7/18) of those with normal CYFRA21-1 (≤ 3.3 ng/ml) and 62% (13/21) of high CYFRA21-1 (> 3.3 ng/ml) patients were found to have ≥ 3 CTCs/7.5 ml blood. The CTCs-positive rate of stage I to IV lung cancer patients was 20% (2/10), 45% (5/11), 54% (6/11) and 70% (7/10), respectively. Comparing M0 vs M1 patients, the CTCs-positive rate was 43% (13/30) and 70% (7/10), respectively. All M1 patients (10/10) had one or more CTCs detected, whereas none of the nonmalignant pulmonary disease patients had detectable CTCs.ConclusionLung cancer CTCs isolated by the EpCAM-independent enrichment approach correlate with CYFRA21-1 and TNM staging. Correlation of CTCs and CYFRA21-1 in lung cancer patients is of potential clinical utility in terms of early diagnosis and predicting prognosis.

► CTCs in 42 lung cancer patients were enriched by means of a novel strategy.
► Lung cancer CTCs can be efficiently enriched and detected by this strategy.
► Lung cancer CTCs correlate with TNM staging.
► Elevated serum concentration of CYFRA21-1 correlates with positive CTCs.