Active clinical trials for "Microsatellite Instability"

The relationship between Microsatellite instability and efficacy of fluorouracil based adjuvant chemotherapy in gastric cancer after operation.

Investigators would like to assess the efficacy and safety of tegafur-uracil in patients with stage II MSI-L or MSS colon cancer under metronomic setting for one year.

To compare the Idylla microsatellite instability test versus mismatch repair immunohistochemistry (IHC) in gastric adenocarcinoma.

MSI (Microsatellite Instability) colorectal cancer (CRC) show improved survival, are less prone to metastasis and show poor response to chemotherapy (compared to MSS tumors). The underlying reasons for these characteristics are still not understood and no specific therapeutic approach for MSI colon tumours (15% of CRC overall) has yet been developed. The MSI process is oncogenic when it affects DNA repeat sequences that have a functional role, e.g. Small Coding Repeats (SCR). MSI also frequently affects Long Non-Coding Repeats (LNCR) in tumour DNA. In contrast to SCR, only a few LNCR are endowed with biological activity. Consequently, this area has received very little attention. Our group recently identified HSP110 mutant chaperone protein in MSI CRC that was generated by somatic deletion of a LNCR. Of interest, HSP110 mutant (due to exon skipping) have anti-oncogenic properties and the survival of MSI CRC patients receiving chemotherapy is positively associated with HSP110 mutations in tumour DNA. The aim of the current project is to identify additional clinically relevant MSI-associated splicing aberrations due to mutations in LNCR located in splice acceptor sites. The four main steps are as follows: To identify exon/intron sites affected by aberrant splicing events due to MSI in CRC . All RNASeq data will be exploited to identify recurrent splicing aberrations (mostly exon skipping) that occur specifically in MSI colon tumours; To investigate for possible functional links between MSI and any detected aberrant splicing events . All specific aberrant splicing events detected by RNAseq in MSI CRC samples will be first confirmed (quantitative RT-PCR) in order to eliminate false positive cases. For validated exon candidates, the allelic profiles of adjacent intronic LNCR will be analysed (PCR and fluorescence genotyping) in CRC cell lines and primary tumours (MSI and MSS), as well as in matching normal mucosa samples in order to assess their polymorphic status; To identify splicing events and LNCR mutations with clinical relevance in MSI CRC patients . All LNCR with a confirmed role in gene splicing in MSI CRC will be analysed. The clinical relevance of candidate genes will be assessed using multivariate survival regression models for Relapse- Free Survival, with interaction terms (response to chemotherapy); To initiate functional studies on a limited number of clinically relevant, cancer-related genes whose splicing is perturbed in MSI cancer cells, and to develop biological tools to simplify screening in future clinical assays Similar to HSP110, we will focus on 4 or 5 mutant proteins that are promising drug therapeutic targets. Functional assays will be developed to further elucidate their role in the pathophysiology of MSI tumours. We also aim to develop biological tools for these candidate genes, such as the detection of wild-type or mutant proteins by immunohistochemistry.

The method to analyze the microsatellite instability (MSI) status by next-generation sequencing (NGS) has been established to assess the deficiency of DNA mismatch repair (MMR) system. The aim of our study is to evaluate the feasibility and reliability of this NGS method by testing the circulating tumor DNA (ctDNA) in blood sample of advanced colorectal cancer patients. If the result is positive, the MSI status could be easily learned without the acquisition of tissue samples.

Little is known about the characteristics of genetic mutation in a large multi-gene panel in epithelial ovarian cancer. This study is to explore the targeted genetic mutations via a multi-gene panel, which consists of more than 500 hundred genes. The mutation characteristics are to be revealed in single nucleotide variants, copy number variations, insertion-deletion variations, and genomic structural variations. The total mutation burden (TMB) will be calculated. The status of microsatellite instability, expression of PD-1 and PD-L1 antibodies are also tested. These findings will be studies in association with the patients' prognosis and sensitivity to platinum-based chemotherapy.

This study aims to analyze the microsatellite instability (MSI) in the circulatory tumor DNA and in the tumor tissue in the patients diagnosed with uterine endometrial cancer. These data will be used for the study of "Cohort Study of Universal Screening for Lynch Syndrome in Chinese Patients of Endometrial Cancer" (NCT03291106, clinicaltrials.gov).

Little is known about the characteristics of genetic mutation in recurrent cervical cancer. This study is to explore the targeted genetic mutations via a multi-gene panel, which consists of more than 500 hundred genes. The mutation characteristics are to be revealed in single nucleotide variants, copy number variations, insertion-deletion variations, and genomic structural variations. The total mutation burden (TMB) will be calculated. The status of microsatellite instability, expression of PD-1 and PD-L1 antibodies are also tested. These findings will be studies in association with the patients' prognosis and sensitivity to platinum-based chemotherapy and immunotherapy.