Colorectal cancer risk in relation to use of acid suppressive medications.
OBJECTIVE
Acid suppressants are commonly prescribed medications. Laboratory studies suggest a mechanism by which they could increase colorectal cancer (CRC) risk. A few epidemiologic studies have investigated acid suppressant use and CRC risk; none has documented an overall association. We sought to investigate whether acid suppressants are associated with CRC risk.


METHODS
We conducted a case-control study among members of an integrated healthcare delivery system in Washington State. Cases (N = 641) were diagnosed with CRC between 2000 and 2003; controls (N = 641) were randomly selected from enrollees and matched to cases on age, sex, and length of enrollment. We used conditional logistic regression to estimate the odds ratios (ORs) and 95% confidence intervals (CI) for CRC associated with the use of any acid suppressive medication, proton pump inhibitors (PPIs) only, histamine receptor antagonists (H2 blockers) only, or both PPIs and H2 blockers in relation to the use of neither PPIs nor H2 blockers.


RESULTS
Use of PPIs exclusively was modestly associated with an increased risk of CRC, however this finding was consistent with chance and based on a small number of patients exposed (OR = 1.7; 95%CI = 0.8, 4.0). H2 blocker use alone was not related to CRC risk (OR = 0.8; 95%CI = 0.6, 1.1).


CONCLUSIONS
PPI use may be modestly associated with CRC risk; further research should be conducted in populations with long-term PPI use.
Chubak
Jessica
J
Group Health Center for Health Studies, Seattle, WA 98101-1448, USA. chubak.j@ghc.org
Boudreau
Denise M
DM
Rulyak
Stephen J
SJ
Mandelson
Margaret T
MT
D000368:Aged; D000897:Anti-Ulcer Agents / Q000009:adverse effects; D015179:Colorectal Neoplasms / Q000139:chemically induced* / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006635:Histamine H2 Antagonists / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors / Q000009:adverse effects*; D012042:Registries / Q000706:statistics & numerical data; D012307:Risk Factors
D000897:Anti-Ulcer Agents; D006635:Histamine H2 Antagonists; D054328:Proton Pump Inhibitors