London: Men with brothers or fathers who have had prostate cancer are at a higher risk of developing the disease, a new study has found.
"Men with brothers who have had prostate cancer run twice as high a risk of being diagnosed themselves in comparison to the general population," researchers said.
"It is well known that men with prostate cancer in the family have a higher risk of the disease. Prostate cancer is often a rather indolent disease with favourable prognosis that often does not require treatment but there are also aggressive types that can be mortal," said Par Stattin from Umea University in Sweden.
"The ability to differ between these types is therefore important. Up until now, there has been no knowledge about the absolute magnitudes of these risks," said Stattin.
Researchers from Umea and Lund University in Sweden studied the prostate cancer risk in over 50,000 men in Sweden whose brothers and fathers had prostate cancer.
They found that men with one brother with prostate cancer had a 30 per cent risk of being diagnosed themselves before the age of 75, compared with 13 per cent among other men without family history of the disease.
Men with one brother with prostate cancer also had a nine per cent risk of an aggressive form compared with five per cent among other men.
Men with both a father and a brother with prostate cancer had a threefold risk of prostate cancer themselves - a 48 per cent risk of any form of prostate cancer (compared with 13 per cent among other men) and 14 per cent for aggressive cancer (compared with 5 per cent among other men), researchers said.
The risk of an aggressive prostate cancer was typically as high in those whose brothers or fathers had the mildest form as those who had an aggressive prostate cancer in the family, they said.
"We had expected that the risk of aggressive prostate cancer would be particularly lower in men with favourable cancer in the family, but that was not the case," said Ola Bratt from Lund University.
"Men whose fathers or brothers had a favourable prostate cancer do not usually think that increases their own risk of developing aggressive cancer. They might not even know that they have prostate cancer in the family," said Bratt.
The findings were published in the Journal of the National Cancer Institute.