be deriveds of a Finnish cohort sub...

be deriveds of a Finnish cohort subject of attention showed an association between antibiotic use and breast cancer risk in women younger than 50 years. Given the high prevalence of breast cancer and the widespread use of antibiotics, Velicer and colleagues performed a case-control subject of attention to determine whether an association exists between breast cancer risk and antibiotic use.

Patients with newly diagnosed primary breast cancer were identified, along with matched command patients. Data on antibiotic use were obtained from pharmacy records. pair measures of antibiotic exposure were employed: the cumulative number of days of antibiotic use and the total number of antibiotic prescriptions for each close attention participant. Antibiotic use was categorized as grave moderate, or high. Detailed information about risk factors for breast cancer was available for application of mind enrollees. In a substudy, a chart review allowed investigators to ascertain the indications for antibiotic use.

For all eight antibiotic classes considered, increasing cumulative days of use were associated with increased risk of incident breast cancer. For categories of increasing days of use (i.e., naught one to 50, 51 to 100 101 to 500 501 to 1000 and 1001 or more days), the additionals ratios for breast cancer were 100 145 153 168 214 and 207 Similar conclusions were found when the number of antibiotic prescriptions was the focus of the analysis. In addition, a sturdy association was noted between antibiotic use and death from breast cancer. None of these comes was affected when adjusting for demographic and breast cancer risk variables.

The authors finish that there is an association between increasing antibiotic use as measured according to cumulative number of days and prescriptions, and increased risk of incident breast cancer. The findings apply to pre- and post-menopausal women In a sub-analysis, indication for antibiotic use was not associated with breast cancer risk, if it were not that because of the small size of the subset indication may play a part The study, which controlled for many risk factors, could not ascertain whether the association of antibiotic use and cancer risk is causal, or whether antibiotic use is related to any other cause (such as a weakened immune system) or medical indication.

CAROLINE WELLBERY, MD

Velicer CM et al. Antibiotic use in relation to the risk of breast cancer. JAMA February 18 2004;291:827-35

COPYRIGHT 2004 American Academy of Family Physicians

COPYRIGHT 2004 Gale Group