Diverse 'just-right' levels of chromosomal instability and their clinical implications in neoadjuvant treated gastric cancer.

Background: The Cancer Genome Atlas (TCGA) consortium described EBV positivity(+), high microsatellite instability (MSI-H), genomic stability (GS) and chromosomal instability (CIN) as molecular subtypes in gastric carcinomas (GC). We investigated the predictive and prognostic value of these subtypes with emphasis on CIN in the context of neoadjuvant chemotherapy (CTx) in GC.

Methods: TCGA subgroups were determined for 612 resected adenocarcinomas of the stomach and gastro-oesophageal junction (291 without, 321 with CTx) and 143 biopsies before CTx.

Prognostic implication of molecular subtypes and response to neoadjuvant chemotherapy in 760 gastric carcinomas: role of Epstein-Barr virus infection and high- and low-microsatellite instability.

Epstein-Barr virus positivity (EBV(+)) and high-microsatellite instability (MSI-H) have been identified as molecular subgroups in gastric carcinoma. The aim of our study was to determine the prognostic and predictive relevance of these subgroups in the context of platinum/5-fluorouracil (5-FU) based preoperative chemotherapy (CTx). Additionally, we investigated the clinical relevance of the low-MSI (MSI-L) phenotype.

A microsatellite based multiplex PCR method for the detection of chromosomal instability in gastric cancer.

Chromosomal instability (CIN) is a hallmark of distinct subclasses of tumours with potential clinical relevance. The aim of our study was to establish a time and cost effective method for the determination of CIN in gastric carcinomas (GC). We developed a microsatellite based multiplex PCR assay for the detection of allelic imbalances (AI) using experimentally defined marker specific threshold values for AI.

Colorectal mixed adenoneuroendocrine carcinomas and neuroendocrine carcinomas are genetically closely related to colorectal adenocarcinomas.

Colorectal mixed adenoneuroendocrine carcinomas are rare and clinically aggressive neoplasms with considerable morphological heterogeneity. Data on their genomic characteristics and molecular associations to either conventional colorectal adenocarcinomas or poorly differentiated neuroendocrine neoplasms is still scarce, hampering optimized patient treatment and care. Tissue from 19 colorectal mixed adenoneuroendocrine carcinomas and eight colorectal poorly differentiated neuroendocrine neoplasms (neuroendocrine carcinomas) was microdissected and subjected to next-generation sequencing using a colorectal adenocarcinoma-specific panel comprising 196 amplicons covering 32 genes linked to colorectal adenocarcinoma, and poorly differentiated neuroendocrine neoplasm tumorigenesis.