Backgrounds and objectives: Recent studies have suggested that insulinoma-associated protein 1 (INSM1) is a useful marker for pathological diagnosis of pulmonary neuroendocrine tumors. In the present study, we investigated the association between INSM1 expression and prognosis in patients with pulmonary high-grade neuroendocrine carcinomas (HGNEC) and assessed the usefulness of INSM1 as a prognostic biomarker in these patients.
Methods: Seventy-five consecutive patients with HGNEC who underwent complete surgical resections from January 2000 to December 2018 were enrolled in this study. We classified these patients into two groups: the INSM1-positive group (n = 59) and INSM1-negative group (n = 16). We compared the clinicopathological characteristics, overall survival (OS), and recurrence-free survival (RFS) between the groups. In addition, we performed univariate and multivariate analyses to identify the prognostic factors associated with postoperative survival.
Results: Significant differences in tumor diameter and vascular invasion between the groups were found. OS and RFS were significantly poorer in the INSM1-positive group than in the INSM1-negative group. Univariate and multivariate analyses revealed that INSM1 expression was the strongest predictor of poor prognosis for OS and RFS.
Conclusions: INSM1 expression had the greatest influence on the prognosis in patients with HGNEC and may be a prognostic biomarker in these patients.
Keywords: immunostaining; insulinoma-associated protein 1; large cell neuroendocrine carcinoma; neuroendocrine markers; small cell lung carcinoma.
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