Publication Name	World Journal of Gastrointestinal Oncology
Manuscript ID	123709
DOI	10.4251/wjgo.123709
Country	Japan

Category	Gastroenterology & Hepatology
Manuscript Type	Retrospective Cohort Study
Article Title	Clinical and molecular heterogeneity of microsatellite instability-high colorectal cancer in older adults
Manuscript Source	Unsolicited Manuscript
All Author List	Tatsuya Shonaka, Chikayoshi Tani, Shoichiro Mizukami, Daisuke Koro, Hiroyoshi Iwata, Mizuho Ohara, Hiroki Tanabe, Yoshio Makita, Mishie Tanino and Hideki Yokoo
Funding Agency and Grant Number	Funding Agency Grant Number Akiyama Life Science Foundation
Corresponding Author	Tatsuya Shonaka, DM, PhD, Division of Gastroenterological and Transplantation Surgery, Department of Surgery, Asahikawa Medical University, 2-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan. shonaka@asahikawa-med.ac.jp
Key Words	Microsatellite instability; Colorectal cancer; Mismatch repair; Lynch syndrome; Molecular heterogeneity; Older patients
Core Tip	While microsatellite instability-high colorectal cancer in older adults is widely considered sporadic, our real-world data revealed that 28.6% (6/21) of older adults with microsatellite instability-high exhibited atypical molecular profiles, including BRAF wild-type/MLH1 and MSH2/MSH6 deficiencies. Age-based assumptions can lead to missed diagnoses of Lynch syndrome, as demonstrated in the 72-year-old patient in our study. Therefore, reflex MLH1 promoter methylation analysis should be routinely performed regardless of age to optimize precision medicine and facilitate life-saving cascade screening of family members.
Citation	Shonaka T, Tani C, Mizukami S, Koro D, Iwata H, Ohara M, Tanabe H, Makita Y, Tanino M, Yokoo H. Clinical and molecular heterogeneity of microsatellite instability-high colorectal cancer in older adults. World J Gastrointest Oncol 2026; In press DOI: https://doi.org/10.4251/wjgo.123709
PDF	123709-in-press.pdf

Received	2026-05-27 06:15
Peer-Review Started	2026-05-27 06:15
First Decision by Editorial Office Director
Return for Revision	2026-06-22 03:51
Revised	2026-06-26 20:52
Publication Fee Transferred	2026-07-07 03:40
Second Decision by Editor	2026-07-16 02:41
Second Decision by Editor-in-Chief
Final Decision by Editorial Office Director	2026-07-16 06:35
Articles in Press	2026-07-16 06:35
Edit the Manuscript by Language Editor
Typeset the Manuscript

ISSN	1948-5204 (online)
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