Plasma plastin-3: A tumor marker in patients with non-small-cell lung cancer treated with nivolumab

Plastin-3 (PLS3) is a circulating tumor cell marker associated with aggressive cancer phenotypes. The present study aimed to investigate the usability of plasma PLS3 concentration in assessing the diagnosis, prognosis and sensitivity to treatment in patients with non-small-cell lung cancer (NSCLC) treated with nivolumab. A total of 33 patients with recurrent or advanced NSCLC were treated with nivolumab, and 10 healthy volunteers were retrospectively enrolled. Plasma concentrations of PLS3 were determined by ELISA. Plasma PLS3 concentration in patients with NSCLC was significantly higher compared with that in healthy volunteers (median 7.64 ng/ml vs. 3.13 ng/ml, P<0.001). Univariate analysis indicated that PLS3 ≤5.43 ng/ml was a predictor of partial response. Patients with PLS3 >8.55 ng/ml exhibited a poorer prognosis compared with those in the PLS3 ≤8.55 ng/ml group. A high plasma PLS3 concentration was a predictor of poor overall survival. In conclusion, plasma PLS3 concentration was identified as a marker for the diagnosis, treatment sensitivity and prognosis in patients with NSCLC treated with nivolumab. Plasma PLS3 may be a clinically useful tumor marker in patients with NSCLC; future prospective studies may confirm these results and explore its use in other cancers.