Microsatellite Instability of Colon adenocarcinomas in India comprises multiple molecular subtypes (original) (raw)

Expression analysis of colon adenocarcinoma in the South Indian population reveals novel signals of pathogenesis

2020

High throughput somatic expression analyses of colon adenocarcinoma conducted so far were mostly in the western population, and no major studies are currently available in the Indian population. We have performed Nanostring PanCancer pathway panel assay in Stage II colon cancer (n = 11) and compared against normal colon tissues (n = 4). Differentially expressed (DE) genes were identified and superimposed on the Cancer Genome Atlas (TCGA) data, from the Genome Expression Profiling Interactive Analysis (GEPIA) and Tumor Immune Estimation Resource (TIMER).83 out of 730 genes were significantly different (p-value < 0.01), 19 of which had a fold-change |FC(log2)| ≥ 2. A comparison of these signals on TCGA COAD data revealed four common (MET, MCM2, ETV4, and MMP7) and15 uncommon genes. On group comparison, ETV4 expression was significantly higher in microsatellite stable (MSS). Significant DE genes, unique in the study, were INHBA, COL1A1, COL11A1, COMP, SFRP4, and SPP1, which were clu...

Low-level microsatellite instability in most colorectal carcinomas

Cancer research, 2002

Twelve to 16% of colorectal cancers (CRCs) display a high degree of microsatellite instability (MSI-H), whereas most are believed to be microsatellite stable (MSS). The existence of a low degree of instability (MSI-L) group has also been proposed. By using the Bethesda panel of microsatellite markers, the microsatellite instability (MSI) status of CRCs can be determined. This set is recommended to distinguish between MSI-H and MSI-L/MSS. No definition for MSI-L has emerged. Most reports on MSI-L rely on the Bethesda panel, using 5-15markers. Tumors with more than 30% MSI are designated as MSI-H, but the lower limit for MSI-L is ambiguous. We hypothesized that if many markers are studied, almost all CRCs would show some MSI. It would be necessary to establish a cutoff level for MSI-L by showing that, above this cutoff level, tumors display molecular and/or clinical features different from those under the cutoff level. To perform this task, we analyzed 90 BAT26 stable CRC samples with...

Implication of Microsatellite Instability Pathway in Outcome of Colon Cancer in Moroccan Population

Disease Markers

Background. Tumors with microsatellite instability (MSI tumors) have distinct clinicopathological features. However, the relation between these tumor subtypes and survival in colon cancer remains controversial. The aim of this study was to evaluate the overall survival (OS) in patients with MSI phenotype, in FES population. Methods. The expression of MMR proteins was evaluated by immunohistochemistry for 330 patients. BRAF, KRAS, and NRAS mutations were examined by Sanger sequencing and pyrosequencing methods. The association of MSI status with a patient’s survival was assessed by the Kaplan–Meier method and log-rank test. Results. The mean age was 54.6 years (range of 19-90 years). The MSI status was found in 11.2% of our population. MSI tumors were significantly associated with male gender, younger patients, stage I-II, right localization, and a lower rate of lymph node and distant metastasis. The OS tends to be longer in MSI tumors than MSS tumors (109.71 versus 74.08), with a di...

Impact of microsatellite status in early-onset colonic cancer

British Journal of Surgery

Background The molecular profile of early-onset colonic cancer is undefined. This study evaluated clinicopathological features and oncological outcomes of young patients with colonic cancer according to microsatellite status. Methods Anonymized data from an international collaboration were analysed. Criteria for inclusion were patients younger than 50 years diagnosed with stage I–III colonic cancer that was surgically resected. Clinicopathological features, microsatellite status, and disease-specific outcomes were evaluated. Results A total of 650 patients fulfilled the criteria for inclusion. Microsatellite instability (MSI) was identified in 170 (26.2 per cent), whereas 480 had microsatellite-stable (MSS) tumours (relative risk of MSI 2.5 compared with older patients). MSI was associated with a family history of colorectal cancer and lesions in the proximal colon. The proportions with pathological node-positive disease (45.9 versus 45.6 per cent; P = 1.000) and tumour budding (20....