Gastritis cystica profunda is associated with aberrant p53 and Epstein-Barr virus in gastric cancer: A clinicopathological, immunohistochemical and in situ hybridization study.

Gastritis cystica profunda (GCP) is a lesion characterized by cystic gastric glands within the submucosa. Some studies have reported that GCP is a precancerous lesion. Here, we investigated the association between GCP and gastric cancer. Gastric cancer specimens were taken from 1432 patients undergoing surgery or endoscopic submucosal resection and were classified as GCP or non-GCP. The clinicopathological features, immunohistochemistry and in situ hybridization expression of p53, Ki-67, KCNE2, Epstein-Barr virus (EBV) and programmed death ligand 1 (PD-L1) were compared between the two groups, as well as between GCPs and normal pyloric glands. One hundred and eighty patients (12.6%) had GCPs. In the GCP group, no cancerous lesions were found within the GCPs, but 13% were linked to GCPs and 60.2% were located above or near GCPs. Aberrant p53 expression, EBV-positive cancer cells and PD-L1 scores were significantly higher in the GCP group. The p53 score and Ki-67 labelling index were significantly higher and the KCNE2 score was significantly lower in GCPs than in pyloric glands. Although we suggest GCP is paracancerous, GCP has high proliferation activity and gastric cancer with GCP is associated with aberrant p53 and EBV. GCP is associated with aberrant p53 expression and EBV.

Evaluation of DNA and RNA quality from archival formalin-fixed paraffin-embedded tissue for next-generation sequencing - Retrospective study in Japanese single institution.

Genetic analysis on formalin-fixed paraffin-embedded (FFPE) tissue specimens has become a mainstream method, from conventional direct sequencing to comprehensive analysis using next-generation sequencing (NGS). In this study, we evaluated the quality of DNA and RNA extracted from FFPE sections, derived from surgical specimens of different tumor types. Electrophoresis was performed using a 4200 TapeStation to evaluate DNA and RNA fragmentation. DNA Ct values were higher and significantly increased over a period of 4 years compared with those from cell lines or frozen tissues. The RNA integrity number equivalent (RIN) ranged from 1 to 4.1 and DV200 ranged from 7.3 to 81%. Twelve of the 108 cases were analyzed by NGS using the AmpliSeq Cancer HotSpot Panel v2 on a Miniseq system. A sufficient number of reads and coverage were obtained in all cases. Our results revealed that NGS analysis was sufficient for FFPE-derived DNA within 4 years of preservation. Conversely, approximately 20% of the RNA derived from FFPE within 4 years from the collection could be inappropriate for gene analysis based on RIN and DV200. It was suggested that FFPE would be adequate for genetic analysis, although it is desirable to store frozen specimens for the tumor tissues to be subjected to genetic analysis.