Another interesting research abstract presented at the Genitourinary Cancers Symposium in Orlando Florida this month found that men with prostate cancer who were on chemotherapy who had also received anticoagulant (blood-thinners) medications experienced improved overall survival rates compared to men who did not take anticoagulants drugs.
This retrospective study involved the reviewed of the medical charts of 247 men with metastatic, castrate resistant prostate cancer who had received docetaxel chemotherapy during the time period of January1998 and 1January 2010. The review included the use of blood thinning drugs, including type of drug given, reason for use, and the time period men received anticoagulant drugs.
The researchers found that about 12 percent of the 247 men in their study had received heparin or warfarin, blood thinning drugs. The men receiving the blood thinning drugs had an overall survival time of 20.9 months vs. 17.1 months for men not taking blood thinners.
Of the 29 men taking anticoagulants, 15 were on the drug to treat a deep vein thrombosis (DVT), 9 for a pulmonary embolism (PE), and 5 men had both DVT and PE. Blood thinning drugs carry the risk of serious side effects which one would expect to negatively impact survival such as internal bleeding and stroke, despite this risk they had a statistically significant increase in over all survival.
When the researchers performed statistical adjustments on their study population to account for other factors that might affect overall survival in the men; the overall survival benefit to men on anticoagulants held up.
However, the authors rightfully said that their surprise findings must be validated. Once validated, they would want to see a larger prospective clinical trial to confirm these results.
The study authors did not propose any type of mechanism that could have led to their findings.
Interestingly, and consistent with these findings other research has shown that men with prostate cancer taking a regular dose of aspirin (a mild anticoagulant) live longer and may experience slower prostate cancer growth.
Dr. Emmanuel Antonarakis, senior author on the study and a medical oncologist at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, pointed out that in mice models Heprin (an anticoagulant drug) treated mice the drug has a direct effect on prostate cancer tumors by suppressing the growth of blood vessels thus limiting the tumor’s access nutrients.
We need to remember that this was a retrospective study that needs to be confirmed. We also need to have additional research to help us understand the actual mechanism of action if the results are confirmed.
Abstract: The effect of therapeutic anticoagulation on overall survival (OS) in men receiving docetaxel chemotherapy for metastatic castration-resistant prostate cancer (mCRPC).
Citation: J Clin Oncol 31, 2013 (suppl 6; abstr 28)
Author(s): Caroline F. Pratz, Robert A. Brodsky, Emmanuel S. Antonarakis; Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD; Johns Hopkins Medicine, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Baltimore, MD
Joel T Nowak, M.A., M.S.W