Promising new role for aspirin in cancer

Patients with non-metastatic colorectal cancer can improve their survival by taking regular aspirin as an adjunct to treatment, a study suggests. Overall, the five-year survival rate was 88% for patients who reported any aspirin use, compared with 83% for non-users, according to the study of 1200 patients with stage I, II or III colorectal cancer. The risk reduction was apparent only when aspirin was initiated after the diagnosis, the authors reported in the Journal of the American Medical Association (12 August). Compared with non-users, people who initiated aspirin after diagnosis had a 30% lower risk of death from colorectal cancer, and a 20% lower risk of death from any cause during a 12-year follow-up period, researchers reported. The benefit was similar for all three disease stages and appeared only modestly related to dose, with participants reporting taking at least one aspirin pill weekly for reasons including analgesia and cardiovascular disease prevention. Furthermore, the effect was confined to patients diagnosed with COX-2-positive primary tumours, which were the majority of colorectal cancers, the authors said. It was likely, researchers said, that aspirin lengthened survival time by inhibiting COX-2, which promoted inflammation and cell proliferation. Previous research had suggested aspirin might have a role in colorectal cancer prevention, they said. “These results suggest that aspirin may influence the biology of established colorectal tumours in addition to preventing their occurrence,” they wrote. “Our data also highlight the potential for using COX-2 or related markers to tailor aspirin use among patients with newly diagnosed colorectal cancer.” Professor Terry Bolin, a gastroenterologist and president of the Gut Foundation, said the study suggested a theoretical benefit in establishing the COX-2 status of all colorectal tumours, with a view to determining the benefit of aspirin as adjuvant therapy on a case-by-case basis. The findings were not clear-cut, he said, and at this stage were “food for thought”. Professor Ian Olver, Cancer Council Australia CEO, noted the authors had not been able to analyse side effects, such as GI bleeding, which could negate the benefits shown in the study. JAMA 2009; 302:649-59. Australian Doctor...