Circulating Tumor Cells in Diagnosing Lung Cancer: Clinical and Morphologic Analysis

Background. The purpose of this study was to evaluate the value of circulating non-hematologic cells to differentiate benign from malignant lung lesions and their comparison with clinico-histologic features of corresponding primary lesions. Methods. Circulating cells were isolated by sizemethod from peripheral blood of 77 patients with malignant (n = 60) and benign (n = 17) lung lesions. They were morphologically classified as cells with malignant feature; cells with uncertain malignant feature; and cells with benign feature; then statistically correlated with clinicocytopathologic characteristics of corresponding lung lesion. Results. Malignant circulating cells were detected in 54 of 60 (90%) malignant patients, and in 1 of 17 (5%) benign patients; benign circulating cells in 1 of 60 (1%) malignant patients and in 15 of 17 (88%) benign patients; and circulating cells with uncertain malignant aspect in 5 of 60 (8%) malignant patients and 1 of 17 (5%) benign patients. For a malignant circulating cells count greater than 25, sensitivity and specificity were 89% and 100%, respectively. The count was significantly correlated with stage, size, and standard uptake value of primary tumor. In 39 of 54 (72%) cases, the malignant circulating cells allowed a specific histologic diagnosis of the corresponding primary tumor after immunohistochemical analysis. Conclusions. Malignant circulating cells may be a valid marker in the diagnostic workup of lung lesions. However, our resuts should be corroborated by larger future studies especially for patients having small nodules. (C) 2015 by The Society of Thoracic Surgeons