NSAID Use Increases Breast Cancer Risk

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Hi All,

The below is a press release and the abstract of the article, which should be

but

seems not to be pdf-available.

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen,

are

associated with greater breast cancer risks.

L. Zielinski

Press Release: Study Examines NSAID Use and Breast Cancer Risk

J Natl Cancer Inst 2005; 97: 785

Ibuprofen use is associated with an increased risk of breast cancer, and

long-term

daily use of aspirin is associated with an increased risk of estrogen

receptor/progesterone receptor (ER/PR)-negative breast cancer, according to a

new

study in the June 1 issue of the Journal of the National Cancer Institute.

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen,

are

used to treat common conditions such as pain and fever and chronic conditions

such

as arthritis and are given prophylactically to reduce the risk of heart attacks

and

stroke. Interest has also been growing in using NSAIDs to prevent cancer.

Studies

have found an inverse association between NSAID use and colorectal cancer, but

studies of NSAIDs and breast cancer risk have had mixed results.

To investigate the association between NSAID use and breast cancer risk,

F.

Marshall, of the University of Southern California in Los Angeles, and

colleagues

analyzed data on 114,460 women in the California Teachers Study cohort who were

ages

22 to 85 and free of cancer at the baseline of the study, 1995 to 1996. During

the

follow-up period, 1995 to 2001, 2,391 women were diagnosed with breast cancer of

known receptor status.

Regular use (i.e., more than once a week) of NSAIDs was not associated with

breast

cancer risk. However, long-term daily use of aspirin was associated with an

increased risk of ER/PR-negative breast cancer, and long-term daily use of

ibuprofen

was associated with an increased risk of breast cancer and particularly

nonlocalized

cancer.

" These observations warrant further exploration because of the public health

impact

such readily available NSAIDs may have on breast cancer, " the authors write.

" Additional large-scale prospective epidemiologic studies may help clarify the

findings by further examining the long-term effects of aspirin and ibuprofen,

especially with regard to ER/PR-negative and nonlocalized breast cancer. A more

detailed understanding of the tissue-specific effects of NSAIDs, particularly in

the

context of the complex biological mechanisms involved in the development of

different cancers, is also needed. "

Nonsteroidal Anti-Inflammatory Drug Use and Breast Cancer Risk by Stage and

Hormone

Receptor Status

F. Marshall et al and K. Ross

J Natl Cancer Inst 2005; 97: 805-812.

.... anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen ... We

investigated the association of NSAID use with risk of breast cancer in the

California Teachers Study cohort, with special attention to risk of specific

breast

cancer subtypes and to type of NSAID used. Methods: We analyzed data on 114 460

women in the California Teachers Study cohort who were aged 22 to 85 years and

free

of breast cancer at baseline in 1995 to 1996. Information on frequency and

duration

of NSAID use was collected through a self-administered questionnaire. A total of

2391 women were diagnosed with breast cancer during the follow-up period from

1995

to 2001. We used proportional hazards regression to estimate relative risks

(RR)

and 95% confidence intervals (CI) of breast cancer subtypes with NSAID use.

Results:

Neither regular use (more than once a week) of any NSAID (aspirin and ibuprofen

combined) nor regular use of aspirin was associated with breast cancer risk (RR

=

1.09, 95% CI = 0.97 to 1.21 for daily versus no regular use of NSAIDs and RR =

0.98,

95% CI = 0.86 to 1.13 for daily versus no regular use of aspirin). However,

long-term (5 years) daily aspirin users had a non–statistically significant

decreased risk of estrogen receptor and progesterone receptor (ER/PR)–positive

breast cancer (RR = 0.80, 95% CI = 0.62 to 1.03). In contrast, we observed a

statistically significantly increased risk of ER/PR-negative breast cancer with

long-term daily use of aspirin (RR = 1.81, 95% CI = 1.12 to 2.92). In this

population, 11 fewer ER/PR-positive breast cancer cases and seven excess

ER/PR-negative breast cancer cases may be due to daily long-term aspirin use

among

2391 breast cancer cases observed over 6 years if the association were proven to

be

causal. Long-term daily use of ibuprofen was also associated with an increased

risk

of breast cancer (RR = 1.51, 95% CI = 1.17 to 1.95), particularly of

nonlocalized

tumors (RR = 1.92, 95% CI = 1.24 to 2.97). If causality were subsequently

proven, 16

of the observed 2391 breast cancer cases and 8 of the 713 non-localized breast

cancer cases would be attributable to long-term daily use of ibuprofen.

Conclusions:

Long-term daily use of NSAIDs was not associated with breast cancer risk

overall.

Ibuprofen use was associated with an increased risk of breast cancer, and

long-term

daily aspirin use was associated with an increased risk of ER/PR-negative breast

cancer. However, it is not clear if the observed association is causal.

Al Pater, PhD; email: old542000@...

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