Landscape of Microsatellite Instability Across 39 Cancer Types
Russell Bonneville, Melanie A Krook, Esko A Kautto, Jharna Miya, Michele R Wing, Hui-Zi Chen, Julie W Reeser, Lianbo Yu, Sameek Roychowdhury, Russell Bonneville, Melanie A Krook, Esko A Kautto, Jharna Miya, Michele R Wing, Hui-Zi Chen, Julie W Reeser, Lianbo Yu, Sameek Roychowdhury
Abstract
Purpose: Microsatellite instability (MSI) is a pattern of hypermutation that occurs at genomic microsatellites and is caused by defects in the mismatch repair system. Mismatch repair deficiency that leads to MSI has been well described in several types of human cancer, most frequently in colorectal, endometrial, and gastric adenocarcinomas. MSI is known to be both predictive and prognostic, especially in colorectal cancer; however, current clinical guidelines only recommend MSI testing for colorectal and endometrial cancers. Therefore, less is known about the prevalence and extent of MSI among other types of cancer.
Methods: Using our recently published MSI-calling software, MANTIS, we analyzed whole-exome data from 11,139 tumor-normal pairs from The Cancer Genome Atlas and Therapeutically Applicable Research to Generate Effective Treatments projects and external data sources across 39 cancer types. Within a subset of these cancer types, we assessed mutation burden, mutational signatures, and somatic variants associated with MSI.
Results: We identified MSI in 3.8% of all cancers assessed-present in 27 of tumor types-most notably adrenocortical carcinoma (ACC), cervical cancer (CESC), and mesothelioma, in which MSI has not yet been well described. In addition, MSI-high ACC and CESC tumors were observed to have a higher average mutational burden than microsatellite-stable ACC and CESC tumors.
Conclusion: We provide evidence of as-yet-unappreciated MSI in several types of cancer. These findings support an expanded role for clinical MSI testing across multiple cancer types as patients with MSI-positive tumors are predicted to benefit from novel immunotherapies in clinical trials.
Conflict of interest statement
AUTHORS’ DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The following represents disclosure information provided by authors of this manuscript. All relationships are considered compensated. Relationships are self-held unless noted. I = Immediate Family Member, Inst = My Institution. Relationships may not relate to the subject matter of this manuscript. For more information about ASCO’s conflict of interest policy, please refer to www.asco.org/rwc or po.ascopubs.org/site/ifc. Russell Bonneville No relationship to disclose Melanie A. Krook No relationship to disclose Esko A. Kautto No relationship to disclose Jharna Miya No relationship to disclose Michele R. Wing No relationship to disclose Hui-Zi Chen No relationship to disclose Julie W. Reeser No relationship to disclose Lianbo Yu No relationship to disclose Sameek Roychowdhury Stock and Other Ownership Interests: Johnson & Johnson (I) Research Funding: Takeda, Ignyta
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Source: PubMed