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Aspirin use may
protect against
colon cancer recurrence, reduce risk of death
Colon cancer patients who took aspirin regularly fared better
after surgery, reducing their risk of disease recurrence and death
by half compared to non-users, researchers reported today at the
annual meeting of the American Society of Clinical Oncology.
While previous studies have shown that aspirin use provided a
preventative benefit by lowering the risk of developing colon cancer
and intestinal polyps, the new study is the largest to demonstrate
that aspirin had a potential treatment benefit in people who have
been diagnosed with colon cancer.
Charles Fuchs, MD, MPH, of the Dana-Farber Cancer Institute
in Boston, is lead author on the report by researchers from the
Cancer and Leukemia Group B, a national clinical research group.
“Our data are intriguing because they showed that aspirin use
notably reduced the risk of recurrence in patients with advanced
colon cancer, but more research is needed before any treatment
recommendations can be made about the regular use of aspirin,” says
Fuchs.
The findings emerged from a prospective study of 846 patients
who were enrolled in a randomized trial of two chemotherapy regimens
following surgery for colon cancer. They all had stage III disease
that had spread to lymph nodes but not elsewhere in the body. The
researchers interviewed the patients about medication use and
lifestyle midway through their chemotherapy, and again six months
after therapy was completed.
Regular aspirin use was reported by 75 patients (8.9 percent)
in doses of 81 mg (“baby” aspirin) to 325 mg per day. A total of 41
patients (4.7 percent) reported using COX-2 inhibitor
anti-inflammatory agents, Celebrex or Vioxx.
The researchers found, based on an average follow up of 2.7
years after the second interview, that regular aspirin users had a
55 percent lower risk of colon cancer recurrence and a 48 percent
lower risk of death compared to non-users. The benefit of aspirin
was independent of the dose, as long as the patient consistently
took the painkiller throughout the follow-up period. Those who took
Celebrex or Vioxx had a 53 percent reduction in recurrence risk.
The researchers also assessed the study participants’ use of
acetaminophen – to determine whether the benefits attributed to
regular aspirin and COX-2 inhibitors had a non-specific analgesic
effect – and found no recurrence or survival benefit.
Fuchs, who is also an associate professor of medicine at
Harvard Medical School, says the next step is to conduct more
research to confirm these findings and to determine the mechanism by
which aspirin use produces treatment benefit. He adds that studies
currently are underway to examine the addition of COX-2 inhibitors
to chemotherapy in patients with advanced colon cancer.
In addition to Fuchs, the study’s other authors are Robert
Mayer, MD, Jeffrey Meyerhardt, MD, MPH, and Denise Brady, BA,
Dana-Farber; Donna Niedzwiecki, PhD, and Donna Hollis, MS, CALGB
Statistical Center; Andrew Chan, MD, Massachusetts General Hospital;
Leonard Saltz, MD, Memorial Sloan-Kettering Cancer Center; and
Richard Schilsky, MD, University of Chicago.
Dana-Farber Cancer Institute is a principal teaching
affiliate of the Harvard Medical School and is among the leading
cancer research and care centers in the United States. It is a
founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), a
designated comprehensive cancer center by the National Cancer
Institute.
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