An investigation into the diagnostic value of screening all older colorectal cancer patients for defects in cancer's DNA repair function (MMR/MSI testing).

The Clinical Impact of Universal Mismatch Repair Deficiency Screening in Elderly Patients with Resected Colorectal Cancer: A Single-Center, Retrospective Cohort Study - MSI Screening Impact in Elderly CRC

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

JPRN

Registry ID

JPRN-UMIN000059530

Enrollment

750

Registered

2025-11-01

Start date

2024-05-29

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Colorectal Cancer

Interventions

None listed

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Diagnosis and Treatment: Patients diagnosed with Colorectal Cancer (CRC) who underwent surgical or endoscopic resection at Asahikawa Medical University Hospital. Required Test: Patients who have been assessed for high-frequency microsatellite instability (MSI-H) via either MSI testing or Mismatch Repair (MMR) protein Immunohistochemistry (IHC). Age: Patients must have been 20 years of age or older at the time of diagnosis. Observation Period: Patients who underwent surgery on or after January 1, 2013. Exclusions: All stages, disease sites, and genders are included. (i.e., No restrictions on stage, site, or gender.)

Exclusion criteria

Exclusion criteria: Lack of Diagnostic Data: Cases where pathological tissue samples necessary for MMR/MSI status evaluation are unavailable or technically inadequate for testing. Loss to Follow-up: Cases where prognosis data (DFS/OS) cannot be reliably traced, making primary outcome evaluation impossible. Non-Adenocarcinoma: Cases with a pathological diagnosis other than adenocarcinoma (e.g., adenoma, carcinoid, GIST, lymphoma). Non-Colorectal Origin: Cases where the primary tumor site is not colorectal (e.g., metastatic tumor from another organ). Withdrawal of Consent: Cases where the patient or their proxy has formally withdrawn consent (opt-out) for the secondary use of their clinical data.

Design outcomes

Primary

Measure	Time frame
Prevalence of Mismatch Repair Deficiency (MMRd) detection in elderly patients with resected colorectal cancer.	—

Secondary

Measure	Time frame
Implementation rate of universal MMRd screening and associated clinical/systematic factors. Disease-Free Survival (DFS) and Overall Survival (OS) stratified by MMRd status and MLH1 deficiency status. Immune cell infiltration within the Tumor Microenvironment (TME) in MLH1-deficient MMRd tumors. Post-operative treatment strategies considered for elderly colorectal cancer patients, stratified by MMRd status.	—

Measure

Time frame

Implementation rate of universal MMRd screening and associated clinical/systematic factors. Disease-Free Survival (DFS) and Overall Survival (OS) stratified by MMRd status and MLH1 deficiency status. Immune cell infiltration within the Tumor Microenvironment (TME) in MLH1-deficient MMRd tumors. Post-operative treatment strategies considered for elderly colorectal cancer patients, stratified by MMRd status.

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Countries

Japan

Contacts

Public ContactTatsuya Shonaka

Asahikawa Medical University Division of Gastrointestinal Surgery, Department of Surgery

shonaka@asahikawa-med.ac.jp0166-68-2503

Outcome results