Distinct molecular phenotype and the potential prognostic value of immune prognostic index and tumor infiltrating lymphocytes in hepatoid adenocarcinoma of stomach

Hepatoid adenocarcinoma of the stomach (HAS) is a particular subtype of Gastric cancer (GC) with distinct pathological characteristics and genetic profile, but most HAS patients were received identical regimens as common GC. To date, only a few studies has been conducted to investigate the molecular characteristics of HAS, which may prevent the rational application of new anticancer strategies. To further obtain the genetic features and potential predictive and prognostic biomarkers of HAS, our current study evaluated the clinical implications of spectrum molecular markers in 36 surgical resection specimens. None Epstein-Barr virus (EBV) positive and/or micro-satellite instable high (MSI-h) tumors occurred in our study implies that the molecular classification of HAS should be mainly categorized into genomic stable (GS) and chromosomal instability (CIN) phenotypes, and wild type P53 status predicts better prognosis. More importantly, although the prognosis and clinical characteristics were independent of programmed cell death-ligand 1 (PD-L1), the presence of tumor infiltrating lymphocytes (TILs) still suggested that a portion of the enrolled HAS patients are potentially appropriate candidates for immune checkpoint blockade therapy. Additionally, the immune prognostic index (IPI) and derived neutrophil to lymphocyte ratio (dNLR) demonstrated their potential as reliable and economic indicators for predicting prognosis of HAS. We hope this first systematic evaluation will help in deciphering the molecular characterization and potential individualized regimens for this particular subtype of GC.