CDX2 Expression and Prognostic Factors of Resectable Pulmonary Large Cell Neuroendocrine Carcinoma

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare neoplasm, and its clinical features and management are still limited. We evaluated the clinicopathological factors, including CDX2 immunohistochemical expression, to predict survival in patients with LCNEC.

In all, 50 patients with LCNEC who underwent surgery at 4 institutes between 2001 and 2017 were included. Clinicopathological characteristics were evaluated for prognostic factors and statistically analyzed by Kaplan-Meier curve with a log-rank test or Cox regression models. We used immunohistochemical (IHC) analysis to determine the expressions of CDX2 and compared them with clinicopathological factors and survival.

Sixteen of the 50 cases (32%) were CDX2 positive. No correlation was found between the CDX2 expression by IHC and clinicopathological factors. Multivariate analysis identified adjuvant chemotherapy (hazard ratio [HR] =2.86, 95% confidence interval [CI] = 1.04-8.16, P = .04) and vascular invasion (HR = 4.35, 95% CI = 1.21-15.63, P = .03) as being associated with a significantly worse rate of recurrence-free survival.

CDX2 was expressed in 1/3 of LCNEC but not associated with prognostic factor. Adjuvant chemotherapy and vascular invasion were associated with a negative prognostic factor of LCNEC.