JAMA. 2004 Feb 18;291(7):880-1.
Antibiotic use in relation to the risk of breast cancer.
Velicer CM, Heckbert SR, Lampe JW, Potter JD, Robertson CA,
Department of Epidemiology, University of Washington, Seattle,
CONTEXT: Use of antibiotics may be associated with risk
of breast cancer through effects on immune function, inflammation,
and metabolism of estrogen and phytochemicals; however, clinical
data on the association between antibiotic use and risk of breast
cancer are sparse. OBJECTIVE: To examine the association between
use of antibiotics and risk of breast cancer.
SETTING, AND PARTICIPANTS: Case-control study among 2266
women older than 19 years with primary, invasive breast cancer
(cases) enrolled in a large, nonprofit health plan for at least
1 year between January 1, 1993, and June 30, 2001, and 7.953
randomly selected female health plan members (controls), frequency-matched
to cases on age and length of enrollment. Cases were ascertained
from the Surveillance, Epidemiology, and End Results cancer
registry. Antibiotic use was ascertained from computerized pharmacy
OUTCOME MEASURE: Association between extent of antibiotic
use and risk of breast cancer.
Increasing cumulative days of antibiotic use were associated
with increased risk of incident breast cancer, adjusted for
age and length of enrollment. For categories of increasing use
(0, 1-50, 51-100, 101-500, 501-1000, and > or =1001 days),
odds ratios (95% confidence intervals) for breast cancer were
1.00 (reference), 1.45 (1.24-1.69), 1.53 (1.28-1.83), 1.68 (1.42-2.00),
2.14 (1.60-2.88), and 2.07 (1.48-2.89) (P<.001 for trend).
Increased risk was observed in all antibiotic classes
studied and in a subanalysis having breast cancer fatality as
the outcome. Among women with the highest levels of tetracycline
or macrolide use, risk of breast cancer was not elevated in
those using these antibiotics exclusively for acne or rosacea
(indications that could be risk factors for breast cancer due
to altered hormone levels), compared with those using them exclusively
for respiratory tract infections, adjusted for age and length
of enrollment (odds ratio, 0.91; 95% confidence interval, 0.44-1.87).
Use of antibiotics is associated with increased risk of incident
and fatal breast cancer. It cannot be determined from this study
whether antibiotic use is causally related to breast cancer,
or whether indication for use, overall weakened immune function,
or other factors are pertinent underlying exposures. Although
further studies are needed, these findings reinforce the need
for prudent long-term use of antibiotics.
PMID: 14970061 [PubMed - indexed for MEDLINE]
Originalquelle (Journal Watch)