β-Blocker usage and colorectal cancer mortality: a nested case-control study in the UK Clinical Practice Research Datalink cohort.
BACKGROUND
Epidemiological and laboratory studies suggest that β-blockers may reduce cancer progression in various cancer sites. The aim of this study was to conduct the first epidemiological investigation of the effect of post-diagnostic β-blocker usage on colorectal cancer-specific mortality in a large population-based colorectal cancer patient cohort.


METHODS
A nested case-control analysis was conducted within a cohort of 4794 colorectal cancer patients diagnosed between 1998 and 2007. Patients were identified from the UK Clinical Practice Research Datalink and confirmed using cancer registry data. Patients with a colorectal cancer- specific death (data from the Office of National Statistics death registration system) were matched to five controls. Conditional logistic regression was applied to calculate odds ratios (OR) and 95% confidence intervals (95% CIs) according to β-blocker usage (data from GP-prescribing records).


RESULTS
Post-diagnostic β-blocker use was identified in 21.4% of 1559 colorectal cancer-specific deaths and 23.7% of their 7531 matched controls, with little evidence of an association (OR = 0.89 95% CI 0.78-1.02). Similar associations were found when analysing drug frequency, β-blocker type or specific drugs such as propranolol. There was some evidence of a weak reduction in all-cause mortality in β-blocker users (adjusted OR = 0.88; 95% CI 0.77-1.00; P = 0.04) which was in part due to the marked effect of atenolol on cardiovascular mortality (adjusted OR = 0.62; 95% CI 0.40-0.97; P = 0.04).


CONCLUSIONS
In this novel, large UK population-based cohort of colorectal cancer patients, there was no evidence of an association between post-diagnostic β-blocker use and colorectal cancer-specific mortality.


BACKGROUND
NCT00888797.
Centre for Public Health, Queen's University Belfast, Belfast, Northern, Ireland.
B M
BM
Hicks
L J
LJ
Murray
D G
DG
Powe
C M
CM
Hughes
C R
CR
Cardwell
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001262:Atenolol / Q000494:pharmacology / Q000627:therapeutic use*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011433:Propranolol / Q000494:pharmacology / Q000627:therapeutic use*; D011446:Prospective Studies; D012042:Registries; D006113:United Kingdom
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D001262:Atenolol; D011433:Propranolol
atenolol; colorectal cancer survival; medication; pharmacoepidemiology; propranolol; β-blockers