UMIN-ICDS Clinical Trial
| Unique ID issued by UMIN | UMIN000063019 |
|---|---|
| Receipt number | R000072142 |
| Scientific Title | Cumulative antibiotic exposure over five years and the incidence of colorectal cancer: a risk-set-matched nested case-control study in a Japanese health insurance claims database |
| Date of disclosure of the study information | 2026/09/22 |
| Last modified on | 2026/09/22 10:02:05 |
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Basic information
Public title
A study of the association between cumulative antibiotic exposure over five years and the subsequent incidence of colorectal cancer, using a Japanese health insurance claims database (risk-set-matched nested case-control study)
Acronym
Antibiotic Exposure and Colorectal Cancer Study (JMDC)
Scientific Title
Cumulative antibiotic exposure over five years and the incidence of colorectal cancer: a risk-set-matched nested case-control study in a Japanese health insurance claims database
Scientific Title:Acronym
Antibiotic Exposure and Colorectal Cancer Nested Case-Control Study (JMDC)
Region
| Japan |
Condition
Condition
Colorectal cancer (colon and rectal cancer, ICD-10 C18-C20, excluding appendix). The exposure is cumulative systemic antibiotic use.
Classification by specialty
| Gastroenterology | Hematology and clinical oncology | Infectious disease |
Classification by malignancy
Malignancy
Genomic information
NO
Objectives
Narrative objectives1
Using the JMDC claims database (2005-2025, restricted to enrollees with a prior systemic anti-infective prescription), to estimate the association between cumulative days of systemic antibiotic coverage during the five years (60 months) ending 24 months before diagnosis and incident colorectal cancer, using a risk-set-matched nested case-control design. Up to five controls per case are matched on sex, birth month, enrollment start month, and age group (under 50 vs 50 or older), and odds ratios adjusted for healthcare use, infections, comorbidities, and co-medications are estimated by conditional logistic regression with person-level cluster-robust variance. Adults under 50 years are also evaluated separately.
Basic objectives2
Others
Basic objectives -Others
Observational study evaluating a risk-factor association. An epidemiological study assessing the association between antibiotic exposure and incident colorectal cancer; it does not aim to establish causality.
Trial characteristics_1
Exploratory
Trial characteristics_2
Pragmatic
Developmental phase
Not applicable
Assessment
Primary outcomes
The primary outcome is a first confirmed (non-suspected) colorectal cancer diagnosis (ICD-10 C18-C20, excluding appendix C18.1, neuroendocrine tumours, sarcomas, GIST, melanoma, carcinoma in situ, and anal cancer). Anchored at the diagnosis month, cumulative days of systemic antibiotic coverage over five years with a 24-month lag are categorized as 0 (reference), 1-7, 8-14, 15-30, 31-60, 61-90, and 91 or more days, and odds ratios relative to 0 days are estimated by conditional logistic regression (95% CI; a 6-degree-of-freedom Wald test).
Key secondary outcomes
Secondary and sensitivity analyses: analysis in adults under 50 years; analyses by tumour site (colon vs rectum); using treatment courses as the exposure metric; oral agents only and WHO J01 only; a 36-month lag with re-matched sets; exclusion of inflammatory bowel disease or hereditary CRC syndromes; restriction to index months from April 2020; alternative handling of missing records; a linear trend per doubling of days + 1; an interaction with age under 50; and a ten-year window with four categories. Balance is described with standardized differences. Reporting follows STROBE and RECORD-PE.
Base
Study type
Observational
Study design
Basic design
Randomization
Randomization unit
Blinding
Control
Stratification
Dynamic allocation
Institution consideration
Blocking
Concealment
Intervention
No. of arms
Purpose of intervention
Type of intervention
Interventions/Control_1
Interventions/Control_2
Interventions/Control_3
Interventions/Control_4
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| Not applicable |
Age-upper limit
| Not applicable |
Gender
Male and Female
Key inclusion criteria
The source population is JMDC claims database enrollees (2005-2025) with a history of systemic anti-infective (EphMRA ATC group J) prescribing. (1) Cases: a first confirmed (non-suspected) colorectal cancer diagnosis (ICD-10 C18-C20, excluding appendix and others). (2) Controls: for each case, enrollees at risk in the diagnosis month, matched on sex, birth month (plus or minus 12 months), enrollment start month (plus or minus 12 months), and age group (under 50 vs 50 or older) at the diagnosis month; up to five controls per case are selected by a reproducible random ordering (controls may be reused and may later become cases). (3) Eligibility: enrollment begins at least 12 months before the exposure window, and the first anti-infective prescription precedes the window start. The exposure window is the 60 months ending 24 months before diagnosis. All ages.
Key exclusion criteria
An explicit recurrence code at or before the first colorectal cancer diagnosis, or a code for colorectal-cancer-derived bone metastasis preceding it (excluded as prevalent). Cases with indeterminate exposure due to missing prescription dates or days (the set is dropped), and indeterminate controls (removed individually). Records with only a suspected flag.
Target sample size
32227
Research contact person
Name of lead principal investigator
| 1st name | Satoshi |
| Middle name | |
| Last name | Kutsuna |
Organization
The University of Osaka, Graduate School of Medicine Faculty of Medicine
Division name
Department of Infection Prevention and Control
Zip code
565-0871
Address
2-2, Yamadaoka, Suita city
TEL
0836-6879-5111
kutsuna@hp-infect.med.osaka-u.ac.jp
Public contact
Name of contact person
| 1st name | Satoshi |
| Middle name | |
| Last name | Kutsuna |
Organization
The University of Osaka, Graduate School of Medicine Faculty of Medicine
Division name
Department of Infection Prevention and Control
Zip code
565-0871
Address
2-2, Yamadaoka, Suita city
TEL
0836-6879-5111
Homepage URL
kutsuna@hp-infect.med.osaka-u.ac.jp
Sponsor or person
Institute
The University of Osaka, Graduate School of Medicine Faculty of Medicine
Institute
Department
Personal name
Funding Source
Organization
The University of Osaka
Organization
Division
Category of Funding Organization
Self funding
Nationality of Funding Organization
Japan
Other related organizations
Co-sponsor
None
Name of secondary funder(s)
None
IRB Contact (For public release)
Organization
Ethics Committee for Observational Research, The University of Osaka Hospital (approval no. 25469)
Address
2-15, Yamadaoka, Suita city
Tel
0836-6879-5111
rinri@hp-crc.med.osaka-u.ac.jp
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
大阪大学大学院医学系研究科 感染制御学 / The University of Osaka, Graduate School of Medicine
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 09 | Month | 22 | Day |
Related information
URL releasing protocol
Publication of results
Unpublished
Result
URL related to results and publications
Number of participants that the trial has enrolled
32227
Results
Results date posted
Results Delayed
Results Delay Reason
Date of the first journal publication of results
Baseline Characteristics
Participant flow
Adverse events
Outcome measures
Plan to share IPD
IPD sharing Plan description
Progress
Recruitment status
Completed
Date of protocol fixation
| 2026 | Year | 04 | Month | 14 | Day |
Date of IRB
| 2026 | Year | 04 | Month | 14 | Day |
Anticipated trial start date
| 2026 | Year | 04 | Month | 14 | Day |
Last follow-up date
| 2026 | Year | 09 | Month | 22 | Day |
Date of closure to data entry
| 2026 | Year | 09 | Month | 22 | Day |
Date trial data considered complete
| 2026 | Year | 09 | Month | 22 | Day |
Date analysis concluded
| 2026 | Year | 09 | Month | 22 | Day |
Other
Other related information
This is a retrospective risk-set-matched nested case-control study using the JMDC claims database (January 2005 to May 2025, restricted to enrollees with a history of systemic anti-infective prescribing). The association between cumulative days of systemic antibiotic exposure over the five years ending 24 months before diagnosis and incident colorectal cancer was estimated by conditional logistic regression. Ethics approval: Ethics Committee for Observational Research, The University of Osaka Hospital (approval no. 25469, 14 April 2026); anonymized data were used and consent was waived.
Management information
Registered date
| 2026 | Year | 09 | Month | 22 | Day |
Last modified on
| 2026 | Year | 09 | Month | 22 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000072142
