Reprimo-like (RPRML) is an uncharacterized member of the Reprimo gene family. Here, we evaluated the role of RPRML and whether its regulation by DNA methylation is a potential non-invasive biomarker of gastric cancer. RPRML expression was evaluated by immunohistochemistry in 90 patients with gastric cancer and associated with clinicopathologic characteristics and outcomes. The role of RPRML in cancer biology was investigated in vitro, through RPRML ectopic overexpression. Functional experiments included colony formation, soft agar, MTS, and Ki67 immunofluorescence assays. DNA methylation-mediated silencing was evaluated by the 5-azacytidine assay and direct bisulfite sequencing. Non-invasive detection of circulating methylated RPRML DNA was assessed in 25 gastric cancer cases and 25 age- and sex-balanced cancer-free controls by the MethyLight assay. Downregulation of RPRML protein expression was associated with poor overall survival in advanced gastric cancer. RPRML overexpression significantly inhibited clonogenic capacity, anchorage-independent growth, and proliferation in vitro. Circulating methylated RPRML DNA distinguished patients with gastric cancer from controls with an area under the curve of 0.726. The in vitro overexpression results and the poor patient survival associated with lower RPRML levels suggest that RPRML plays a tumor-suppressive role in the stomach. Circulating methylated RPRML DNA may serve as a biomarker for the non-invasive detection of gastric cancer.

Gastric cancer (GC) is a heterogeneous disease. This heterogeneity applies not only to morphological and phenotypic features but also to geographical variations in incidence and mortality rates. As Chile has one of the highest mortality rates within South America, we sought to define a molecular profile of Chilean GCs (ClinicalTrials.gov identifier: NCT03158571/(FORCE1)). Solid tumor samples and clinical data were obtained from 224 patients, with subsets analyzed by tissue microarray (TMA; n = 90) and next generation sequencing (NGS; n = 101). Most demographic and clinical data were in line with previous reports. TMA data indicated that 60% of patients displayed potentially actionable alterations. Furthermore, 20.5% were categorized as having a high tumor mutational burden, and 13% possessed micro-satellite instability (MSI). Results also confirmed previous studies reporting high Epstein-Barr virus (EBV) positivity (13%) in Chilean-derived GC samples suggesting a high proportion of patients could benefit from immunotherapy. As expected, TP53 and PIK3CA were the most frequently altered genes. However, NGS demonstrated the presence of TP53, NRAS, and BRAF variants previously unreported in current GC databases. Finally, using the Kendall method, we report a significant correlation between EBV+ status and programmed death ligand-1 (PDL1)+ and an inverse correlation between p53 mutational status and MSI. Our results suggest that in this Chilean cohort, a high proportion of patients are potential candidates for immunotherapy treatment. To the best of our knowledge, this study is the first in South America to assess the prevalence of actionable targets and to examine a molecular profile of GC patients.

Background: Gastrectomy is the main treatment for gastric and Siewert type II-III esophagogastric junction (EGJ) cancer. This surgery is associated with significant morbidity. Total morbidity rates vary across different studies and few have evaluated postoperative morbidity according to complication severity. Aim: To identify the predictors of severe postoperative morbidity. Methods: This was a retrospective cohort study from a prospective database. We included patients treated with gastrectomy for gastric or EGJ cancers between January 2012 and December 2016 at a single center. Severe morbidity was defined as Clavien-Dindo score ≥3. A multivariate analysis was performed to identify predictors of severe morbidity. Results: Two hundred and eighty-nine gastrectomies were performed (67% males, median age: 65 years). Tumor location was EGJ in 14%, upper third of the stomach in 30%, middle third in 26%, and lower third in 28%. In 196 (67%), a total gastrectomy was performed with a D2 lymph node dissection in 85%. Two hundred and eleven patients (79%) underwent an open gastrectomy. T status was T1 in 23% and T3/T4 in 68%. Postoperative mortality was 2.4% and morbidity rate was 41%. Severe morbidity was 11% and was mainly represented by esophagojejunostomy leak (2.4%), duodenal stump leak (2.1%), and respiratory complications (2%). On multivariate analysis, EGJ location and T3/T4 tumors were associated with a higher rate of severe postoperative morbidity. Conclusion: Severe postoperative morbidity after gastrectomy was 11%. Esophagogastric junction tumor location and T3/T4 status are risk factors for severe postoperative morbidity.

Norero E, et al. J Gastric Cancer. 2017 Sep;17(3):267-276. https://doi.org/10.5230/jgc.2017.17.e26

Germline pathogenic variants in the CDH1 gene are a well-established cause of hereditary diffuse gastric cancer (HDGC) syndrome. The aim of this study was to characterize CDH1 mutations associated with HDGC from Chile, a country with one of the highest incidence and mortality rates in the world for gastric cancer (GC). Here, we prospectively include probands with family history/early onset of diffuse-type of GC. The whole coding sequence of the CDH1 gene was sequenced from genomic DNA in all patients, and a multidisciplinary team managed each family member with a pathogenic sequence variant. Thirty-six cases were included (median age 44 years/male 50%). Twenty-seven (75%) patients had diffuse-type GC at ≤50 years of age and 19 (53%) had first or second-degree family members with a history of HDGC. Two cases (5.5%) carried a non-synonymous germline sequence variant in the CDH1 gene: (a) The c.88C>A missense variant was found in a family with three diffuse-type GC cases; and (b) c.1531C>T a nonsense pathogenic variant was identified in a 22-year-old proband with no previous family history of HDGC. Of note, six family members carry the same nonsense pathogenic variant. Prophylactic gastrectomy in the proband’s sister revealed stage I signet-ring cell carcinoma. The finding of 1531C>T pathogenic variant in the CDH1 in proband with no previous family history of HDGC warrants further study to uncover familial clustering of disease in CDH1 negative patients. This finding may be particularly relevant in high incidence countries, such as the case in this report.