The anticancer benefits of nonsteroidal anti-inflammatory drugs
(NSAIDs), seen in studies of colon cancer risk, may extend to
human breast cancer as well. A study of NSAID use in breast cancer
patients at the Moffitt Cancer Center, Tampa, Fla, showed that
women who used the drugs regularly had smaller tumors and were
less likely to have lymph node involvement.
"At this point, any recommendations would be premature, but
chemopreventive use of these drugs probably would not be so inappropriate
and might represent a logical step, at least on the basis of these
findings," David V. Schapira, MD, said in an interview at
the San Antonio Breast Cancer Symposium.
Interest in the chemopreventive potential of NSAIDs stems from
evidence that prostaglandin-E (PGE) plays a role in cyclic AMP-regulated
cell proliferation and that some patients with malignancies have
elevated PGE levels. By inhibiting PGE synthesis or activity,
NSAIDs conceivably could have a favorable effect on cancer risk
Dr. Schapira noted that several NSAIDs have been shown to inhibit
the growth of breast and colon tumors induced in rodents. These
studies also demonstrate that indomethacin inhibits bone metastasis
in laboratory animals injected with mouse mammary tumor cells.
At the San Antonio symposium, Dr. Schapira reported data on NSAID
use in 341 consecutive newly diagnosed breast cancer patients.
The data were then correlated with tumor size, lymph node involvement,
estrogen/progesterone receptor status, DNA ploidy, and S-phase
The analysis showed significant associations between the number
of NSAID pills and two prognostic factors: tumor size and lymph
node involvement (see Table on page 544). Almost 60% of the women
who took 10 or more pills monthly had tumors smaller than 2 cm.
In contrast, about 60% of women who reported no NSAID ingestion
had tumors that were 2 cm or larger.
A similar association occurred with respect to node involvement:
63% of women in the 10-pill category had negative nodes and 60%
in the zero-pill group had positive nodes.
"These results are compatible with the earlier findings on
the effect of NSAIDs on the growth and metastatic potential of
breast cancer," said Dr. Schapira, currently director of
the Stanley S. Scott Cancer Center at the Louisiana State University
Medical Center, New Orleans. "The findings suggest that NSAIDs
may favorably affect the prognosis of breast cancer and, additionally,
that the drugs may have a role in breast cancer chemoprevention."
Different NSAIDs may differ in their ability to inhibit prostaglandin
synthesis, but the investigators did not evaluate that issue.
About 75% to 80% of the patients in the study named ibuprofen
as their NSAID of choice.
"The data on colon cancer prevention and regular NSAID use
are quite positive," Dr. Schapira said. "The next logical
step would be to do a randomized, prospective study to see if
these drugs can prevent breast cancer."