THE "NEW" PROSTATE CANCER INFOLINK

A recent study has assessed the risk of bleeding as a consequence of radiation therapy for localized prostate cancer in men being treated with anticoagulants .

Prostate cancer is most commonly identified in men of aged 50 years and older. Many such men are also receiving anticoagulant drugs like warfarin or clopidogrel (Plavix) to prevent heart attacks and associated conditions. Choe et al. have reviewed data from a cohort of 568 patients with prostate cancer who were treated with 3D conformal or intensity-modulated external beam radiotherapy. Of these men, 79 were receiving treatment either warfarin or clopidogrel.

The authors showed that:

• At a median follow-up of 48 months, the 4-year actuarial risk of Grade 3 or worse bleeding toxicity was 15.5 percent for those receiving anticoagulant therapy compared with 3.6 percent for patients not receiving any such treatment.
• On multivariate analysis, anticoagulant therapy was the only significant factor associated with Grade 3 or worse bleeding.
• For patients receiving anticoagulant therapy, the crude rate of bleeding was 39.2 percent.
• Multivariate analysis within the 79 patients receiving anticoagulant therapy showed that a higher radiotherapy dose, intensity-modulated radiotherap, and previous transurethral resection of the prostate  were all associated with Grade 2 or worse bleeding toxicity.
• Androgen deprivation therapy was protective against bleeding, but only with borderline significance.
• Grade 3 or worse bleeding was minimized if , 10 percent of the rectum received ≥ 70 Gy or < 50 percent of the rectum received ≥ 50 Gy.

It is clear from this study that prostate cancer patients taking anticoagulant therapy, for whatever reason, have a significant risk of bleeding as an adverse effect asociated with external beam radiotherapy.

The authors point out that, given this finding, dose escalation or intensity-modulated radiotherapy should be used with care and that strategies are available to minimize the risks of severe bleeding.

We are not aware of any similar risk assessment data in men receiving treatment with brachytherapy, but similar risks may exist in such patients if they are treated with permanent seed implants.

Filed under: Management, Treatment | Tagged: risk, external beam radiation, EBRT, anticoagulant, warfarin, clopidogrel, bleeding