Risk of cancer in patients with irritable bowel syndrome: a nationwide population-based study.
OBJECTIVE
The aim of our study was to evaluate the overall cancer risk among patients with the irritable bowel syndrome (IBS) by using a nationwide population-based data set.


METHODS
We obtained data on newly diagnosed IBS patients (age ≥ 20 years) without antecedent cancer from the Taiwan National Health Insurance Research Database for the period between 2000 and 2010. Standardized incidence ratios (SIRs) were calculated for various types of cancer in the IBS patients.


RESULTS
A total of 1,043 people among the 29,838 IBS patients had developed cancer, and the follow-up was 139,185 person-years (median, 4.56 years), leading to a significantly increased SIR (1.18; 95% confidence interval [CI]) = 1.11-1.26) among all cancer types. However, after excluding cancer that developed within the first year after IBS diagnosis, the increased SIR of overall cancer was nonsignificant. In particular, the IBS patients exhibited an increased risk of cancers of the colon and rectum (SIR = 1.51; 95% CI = 1.31-1.73), liver and biliary tract (SIR = 1.40; 95% CI = 1.21-1.62), pancreas (SIR = 1.56; 95% CI = 1.02-2.28), and kidney (SIR = 1.56; 95% CI = 1.10-2.15).


CONCLUSIONS
An increased SIR in IBS patients was observed only within the first year of IBS diagnosis. The findings of this study might have resulted from detection bias, localized symptoms, or paraneoplastic syndromes associated with IBS-like symptoms. Additional prospective studies are necessary to confirm these findings.
Department of Psychiatry, Kaohsiung Veterans General Veterans Hospital, Kaohsiung, Taiwan; Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Li-Yu
LY
Hu
Division of Hematology and Medical Oncology, Department of Medicine, Changhua Show-Chwan Memorial Hospital, Changhua, Taiwan.
Fan-Chen
FC
Ku
Department of Psychiatry, Kaohsiung Veterans General Veterans Hospital, Kaohsiung, Taiwan.
Ti
T
Lu
Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan.
Cheng-Che
CC
Shen
Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Cancer Center, Taipei Veterans General Hospital, Taipei, Taiwan.
Yu-Wen
YW
Hu
Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
Chiu-Mei
CM
Yeh
Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Cheng-Hwai
CH
Tzeng
Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Tzeng-Ji
TJ
Chen
Department of Psychiatry, Yuanshan Branch, Taipei Veterans General Hospital, Yilan, Taiwan.
Pan-Ming
PM
Chen
Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: chiajenliu@gmail.com.
Chia-Jen
CJ
Liu
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D043183:Irritable Bowel Syndrome / Q000150:complications* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D011159:Population Surveillance; D011446:Prospective Studies; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
Cancer risk; Epidemiology; Functional gastrointestinal disorder; Standardized incidence ratio