It's not clear exactly what causes prostate cancer.
Doctors know that prostate cancer begins when cells in the prostate develop changes in their DNA. The changes tell the cells to grow and divide more rapidly than normal cells do.
A new study, published in BMJ, found an added risk factor for those recently diagnosed with the cancer which includes blood clots.
The researchers found that cancer sufferers had a 50% higher risk of developing serious and potentially fatal blood clots during the five years after their cancer diagnosis compared with men of the same age without prostate cancer.
The research is an added alert for clinicians to be aware of and ensure a timely diagnosis and treatment should a blood clot occur.
The particular blood clot found in the research is venous thromboembolism (VTE) and is a leading cause of death among people with cancer, with the risk higher in those with a more advanced disease.
In the study, men from across Sweden were used with data being collected during 2007 to 2017.
This was then compared against the occurrence of VTE among 92,105 men with prostate cancer and 466,241 men of the same age without prostate cancer (comparison group).
Researchers found that 3.2% of men in the prostate cancer group experienced a VTE within about five years of their cancer diagnosis, compared with 2.1% of men in the comparison group.
They calculated that for every 1,000 men with prostate cancer, around seven would develop a VTE each year, compared with around four among every 1,000 men without prostate cancer.
After taking into account factors that could affect VTE risk in their analysis, the researchers showed that the men with prostate cancer had a 50% higher risk than those in the comparison group over the five-year study period.
They found the biggest risk period for developing VTE was the first six months following the cancer diagnosis.
As prostate cancer is the most commonly diagnosed cancers found among middle-aged and older men, the risk for VTE is therefore much stronger.
Some older studies have suggested that the risk of VTE is two to three times higher in men with prostate cancer than among men of similar age without cancer.
However, the researchers wanted to obtain more recent data in light of the dramatic improvement over the last decade in how men with prostate cancer are managed.
This includes the widespread uptake of newer anticoagulant drugs for other conditions, but which potentially could decrease the risk of VTE.
Anticoagulants are medicines that help prevent blood clots and are given to people at a high risk of getting clots, to reduce their chances of developing serious conditions such as strokes and heart attacks.
Warning symptoms of blood clots
Blood clots can be very serious, and need treating urgently, so it' important to be aware of the symptoms.
Here are some of the common symptoms:
- Leg pain or tenderness of the thigh or calf
- Leg swelling (oedema)
- Skin that feels warm to the touch
- Reddish discolouration or red streaks
PE, or pulmonary embolism, can be fatal and occurs when the DVT breaks free from a vein wall and blocks some or all of the blood supply to the lungs, causing:
- Unexplained shortness of breath
- Rapid breathing
- Chest pain anywhere under the rib cage (may be worse with deep breathing)
- Fast heart rate
- Light headedness or passing out
The study authors concluded: “The magnitude of increased VTE risk among men with prostate cancer seen in our study is lower than that seen for other cancer types as seen in previous studies, and is likely attributable to the high proportion of men with localised disease and at low risk of cancer progression.
“Notwithstanding this, physicians treating men with prostate cancer should be aware of the marked increase in VTE risk in these men, particularly in the first six months following cancer diagnosis, to help ensure timely VTE diagnosis.”
If you think you have a blood clot you should call 111 straight away.
