Reduction in prostate cancer death risk linked to anticoagulant use

San Diego-Use of anticoagulants, particularly aspirin, substantially reduces the risk of prostate cancer-specific mortality, analysis of a large prostate cancer database showed.

Prostate cancer patients had a 10-year cause-specific mortality of 10% without anticoagulants compared with 4% for patients using anticoagulant therapy (p<.01). Aspirin use accounted for much of the benefit, which was most evident in high-risk patients, according to a presentation at the 2010 American Society for Radiation Oncology annual meeting in San Diego.

Dr. Choe reported findings from a review of the CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) database. The analysis focused on 5,295 men with localized prostate cancer. Of those, 1,982 men reported use of anticoagulants.

In addition to the advantage at 10 years, patients in the anticoagulant group had a 7-year prostate cancer-specific mortality of 1% versus 4% in the control group (p<.01). Subgroup analysis showed that patients with high-risk characteristics had a cause-specific mortality of 8% at 7 years and 22% at 10 years without anticoagulants, compared with 2% and 4%, respectively, among patients who were on anticoagulation therapy (p<.01). Intermediate-risk patients also had a significant cause-specific survival advantage (p=.04).

Use of anticoagulants also was associated with significant reductions in the risk of recurrence (p<.01) and the risk of distant metastasis (p<.01).

The advantages conferred by anticoagulants applied to patients who were treated with surgery or radiation therapy.

Aspirin confers greatest benefit

Analysis by the type of anticoagulant used showed that aspirin alone was associated with a prostate cancer-specific mortality of 1% at 7 years and 2% at 10 years (p<.01 vs. no anticoagulant). Patients on an aspirin-containing combination of anticoagulants had a cause-specific mortality of 0% at 7 years and 5% at 10 years (p<.01). In contrast, use of another anticoagulant without aspirin led to a cause-specific mortality of 2% and 7% at 7 and 10 years, respectively, a nonsignificant difference from no anticoagulant use (p=.06).

In a multivariable analysis, use of aspirin was independently associated with lower risk of prostate cancer-specific mortality (hazard ratio: 0.53, p<.01), along with Gleason score, use of radiation therapy plus androgen deprivation therapy, and initiation of salvage therapy.

Commenting on the results, ASTRO President Anthony Zietman, MD, of Harvard University, Boston, said scientists and clinicians have long suspected that "good old boring, inexpensive aspirin can in some way affect the ability of cancer cells to metastasize. There has been some evidence of a beneficial effect in colon cancer, but in prostate cancer, the data have gone both ways."