Clinical Features and Long-term Survivals of Metastatic Hepatic Neuroendocrine Neoplasms Secondary to Gastro-entero-pancreatic Site: An Analysis by Applying the World Health Organization 2017 Grading Classification

Abstract

Background and Purpose Hepatic neuroendocrine neoplasms (NENs) are very rare, in which metastatic hepatic NENs (MH-NENs) secondary to gastro-entero-pancreatic NENs (GEP-NENs) account for their majority. In 2017, World Health Organization (WHO) redefined GEP-NENs into G1 neuroendocrine tumors (NETs), G2 NETs and G3 NETs and G3 neuroendocrine carcinomas (G3 NECs), which has not been rigorously validated for MH-NENs secondary to GEP-NENs. Method: Data of patients who were surgically treated and clinicopathologically diagnosed as MH-NENs secondary to GEP-NENs at West China Hospital of Sichuan University from January 2006 to December 2018 were retrospectively analyzed by applying the WHO 2017 grading classification. Results We identified 150 patients with MH-NENs secondary to GEP-NENs, including 10 patients with WHO 2017 G1 NETs, 26 with G2 NETs, 33 with G3 NETs and 81 with G3 NECs. The estimated 3-year overall survival for each new grading group was 100%, 79.4%, 49.5% and 20.7%, respectively. Survival of G1 NETs or G2 NETs was significantly better than that of G3 NETs (P = 0.013, P = 0.037; respectively) and G3 NECs (P = 0.001, P < 0.001; respectively). Patients with G3 NECs present notably worse survival than those with G3 NETs (P = 0.012), while survival comparison between G1 NETs and G2 NETs wasn’t statistically different (P = 0.131). The WHO 2017 grading classification was effective independent predictor of survival for MH-NENs secondary to GEP-NENs (hazard ratio: 4.234; 95% confidence intervals: 1.984–6.763; P = 0.003). Conclusion Our demonstration revealed that the WHO 2017 grading classification could well stratify MH-NENs secondary to GEP-NENs into prognostic groups and supported its wide use in clinical practice.