Frequent Use of Antibiotics Is Associated with Colorectal Cancer Risk: Results of a Nested Case-Control Study.
BACKGROUND
Microbiotical dysbiosis induced by a Western diet seems to be associated with an increased risk of developing colorectal cancer (CRC). Few other factors with an effect on the colonic microbiota and their association with CRC have been evaluated.


OBJECTIVE
We investigated whether the use of antibiotics is associated with CRC risk.


METHODS
Data on the use of antibiotics and comedication were extracted from a health insurance database for subjects with a diagnostic-related group for CRC between 2006 and 2011 and four age- and sex-matched controls. Antibiotic use was categorized according to the number of prescriptions during a 5-year follow-up period (1-6 years prior to CRC). Multivariable conditional binary logistic regression analysis was used to estimate odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for different levels of use.


RESULTS
A total of 4029 cases (47 % male, mean age at diagnosis 71 ± 11 years) and 15,988 controls were included. Antibiotics had been prescribed to 2630 (65.3 %) cases and 10,234 (64.0 %) controls (p = 0.13). An increasing use of antibiotics was associated with an increasing risk of CRC [multivariable OR for high (≥8 prescriptions) vs. no prescriptions: 1.26, 95 % CI 1.11-1.44, p-trend <0.01]. For each increase of 5 prescriptions, the OR for CRC was 1.05 (95 % CI 1.01-1.09).


CONCLUSIONS
We found an association between the use of antibiotics, especially when used frequently, and the risk of developing CRC. Further studies are needed to establish under which conditions the use of antibiotics increases the risk of developing CRC.
Department of Gastroenterology and Hepatology, University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands. v.k.dik@umcutrecht.nl.
Vincent K
VK
Dik
Department of Gastroenterology and Hepatology, University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands.|Department of Medical Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Martijn G H
MG
van Oijen
Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.|Achmea Health Insurance, Amersfoort, The Netherlands.
Hugo M
HM
Smeets
Department of Gastroenterology and Hepatology, University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
Peter D
PD
Siersema
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000737:chemistry* / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D016208:Databases, Factual; D064806:Dysbiosis; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
D000900:Anti-Bacterial Agents
Antibiotics; Colorectal cancer; Microbiota; Pharmacoepidemiology