Can aspirin prevent hormone-positive breast cancer?

[Guest guest]

Rheumawire

May 25, 2004

Can aspirin prevent hormone-positive breast cancer?

New York, NY - Results from a new case-control study suggest that

regular use of aspirin may help prevent hormone-positive breast cancer

[1]. However, prospective clinical trials are needed to confirm this

finding and to elucidate the optimal dose/regimen for such

chemoprevention, say the researchers.

" This is the first study, to our knowledge, that examined whether the

protective effect of aspirin may be limited to hormone-receptor-positive

breast cancer, " say epidemiologist Dr Beth Terry (Columbia

University, New York, NY) and colleagues in their report in the May 26,

2004 issue of the Journal of the American Medical Association [1].

In an accompanying editorial [2], Dr DuBois (Vanderbilt-Ingram

Cancer Center, Nashville, TN) says the study found that the inverse

association between aspirin use and breast cancer was " clearly evident

for every patient subgroup except those with negative hormone-receptor

status. These findings are noteworthy. "

Terry et al conducted their case-control study, which included in-person

interviews, between 1996 and 1997. There were 1442 breast-cancer cases

and 1420 controls. They found that ever use of aspirin or other NSAIDs

at least once per week for six months or longer was reported in 301

cases (20.9%) and 345 controls (24.3%), with a 20% lower risk of breast

cancer for ever use vs nonuse.

" The inverse association was most pronounced among frequent users [seven

or more tablets per week]. The results for ibuprofen, which was used by

fewer women on a regular basis, were generally weaker, " they note.

However, use of acetaminophen, an analgesic that does not inhibit

prostaglandin synthesis, was not associated with a reduction in the

incidence of breast cancer.

Most notably, " the reduction in risk with aspirin use was seen among

those with hormone-receptor-positive tumors [26% lower risk] but not for

women with hormone-receptor-negative tumors, " the authors state.

Unfortunately, the researchers did not have data available concerning

the dose of aspirin. " Whether the dose of aspirin required for

cardiovascular prevention will prove to be sufficient for optimal

protection against breast cancer remains uncertain, " they note.

In his editorial, Dubois agrees: " The optimal aspirin dose or regimen

required to achieve a maximal reduction in cancer risk remains unknown. "

Although aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs)

have also been shown to prevent colorectal cancer, senior author of the

study, Dr Alfred I Neugut (Mailman School of Public Health, New York)

told rheumawire, " I think the mechanism for prevention of breast cancer

[with aspirin] is probably entirely different from that for colorectal

cancer. "

DuBois says that this study, together with others, " provides a clear

rationale for a role of COX and prostaglandins in breast cancer. " In

addition, there is evidence from preclinical studies that COX-2

overexpression can cause breast cancer, he notes. But he warns: " The

association needs to be confirmed before clinicians can make any

definite recommendations to patients at risk for breast cancer. "

But Neugut doubts there will ever be a randomized trial of aspirin for

breast-cancer prophylaxis. " The cardiac preventive effects in the

intervention arm would be so profound, they would probably stop the

trial before any putative breast-cancer or other cancer-prevention

benefits could be observed. " There is, however, a study planned with the

COX-2 inhibitor celecoxib (Celebrex®/Pfizer), he says.

DuBois told rheumawire that he is not aware of any planned trials of

aspirin for the prevention of hormone-positive breast cancer, but that a

good trial design would be a placebo-controlled, randomized,

double-blind study looking at both 80 mg and 325 mg of aspirin once

daily. But " The biggest question is which patients should be studied, "

he says. " Should this be focused on primary cancer prevention, or should

it be focused on recurrence of cancer in progesterone- and

estrogen-positive cases? "

Nainggolan

Sources

1. Terry MB, Gammon MD, Zhang FF et al. Association of frequency and

duration of aspirin use and hormone receptor status with breast cancer

risk. JAMA 2004; 291:2433-2440.

2. DuBois RN. Aspirin and breast cancer prevention. JAMA 2004;

291:2488-2489.

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org