Investigators from Massachusetts General Hospital, Dana-Farber Cancer Institute and Brigham and Women's Hospital (all in the Boston area) are reporting that regular use of aspirin after colorectal cancer diagnosis may reduce the risk of cancer death. In the August 12 issue of the Journal of the American Medical Association, the study's authors say that the aspirin-associated survival advantage was seen primarily in patients with tumors expressing the COX-2 enzyme, a characteristic of two-thirds of colorectal cancers.
"While previous studies by our group and others showed that aspirin and other non-steroidal anti-inflammatory drugs reduce the risk of developing colorectal cancer, this study is the among the first to show that aspirin can also improve survival in patients who have already been diagnosed with colorectal cancers. Moreover, the benefit appeared to be especially strong among patients with cancers that express COX-2," says Andrew Chan, MD, the study's lead author. "This is an important first step toward developing targeted approaches to improving patient outcomes."
Many previous studies have shown that regular use of aspirin and other non-steroidal anti-inflammatory drugs reduces the risk of developing colorectal cancer. The current study focused on 1,279 study participants who were diagnosed with stage 1, 2 or 3 colorectal cancer during their participation in the studies for whom data was available on aspirin use before and after diagnosis. The benefit was especially strong among patients who began using aspirin after diagnosis. In contrast, patients who were aspirin users before diagnosis did not appear to benefit as much from continuing aspirin use after diagnosis. As expected, the survival benefit appeared restricted to patients with COX-2-positive tumors.
"We believe our results could lead to improvements in the therapy of patient with colon cancer," says Charles Fuchs, MD, of Dana-Farber, the study's senior author. "We're now following up this observational study with a randomized trial to evaluate adding the COX-2 inhibitor celecoxib -- which is less likely to have the gastrointestinal side effects of aspirin -- to standard chemotherapy."