Prostate cancer may increase risk of blood clots
Men with prostate cancer, particularly those receiving hormone therapy, may face an increased risk of blood clots or 'thromboembolism', scientists at King's College London have found.
Cancer is already known to increase the risk of blood clots, but the underlying reasons for this effect are unclear.
Mieke Van Hemelrijck, a PhD student at King's, explained that little is known about the specific association between prostate cancer and blood clots, although previous research had shown men to face an increased likelihood of thromboembolic disease after receiving hormone therapy.
In order to study the link, the researchers analysed data on a large group of Swedish men between 1997 and 2007, including both prostate cancer patients and men with no history of the disease.
Of those with prostate cancer, 30,642 men received hormone therapy; 26,432 curative treatment; and 19,526 surveillance.
During the ten-year study period, a total of 1,881 blood clots were reported and the researchers observed that the problem was more common in men with prostate cancer than in those who were cancer-free.
Prostate cancer patients had an increased risk of deep vein thrombosis (DVT) and pulmonary embolism, regardless of the type of treatment they were receiving.
However, the researchers noticed that men receiving hormone therapy were particularly likely to develop venous thromboembolism.
Overall, those receiving hormone therapy were 2.5 times more likely to have a DVT than those without prostate cancer, and nearly twice as likely to have a pulmonary embolism.
Younger men and those with advanced prostate cancer were particularly at risk.
According to the researchers, whose findings are published in the Lancet Oncology, the increased risk of blood clots is probably due to the cancer itself, but may also be affected by the type of treatment administered and a patient's age.
They wrote: "Our findings indicate that it is important to consider thromboembolic side-effects when treating patients with prostate cancer, especially those who require endocrine (hormonal) treatment."
Josephine Querido, Cancer Research UK's senior science communications officer, said: "We know that cancer patients are at an increased risk of developing blood clots and this large study highlights the importance of monitoring men with prostate cancer in particular. We advise any cancer patient who is concerned about their risk of developing blood clots to discuss it with their GP."