People whose parents are diagnosed with cancer have an increased risk of developing the disease themselves, even if their parent's diagnosis came late in life, a new study indicates.

According to German and Swedish scientists, it is already known that early onset cancer carries more hereditary risk - in other words, the relatives of family members diagnosed with cancer at a young age are more at risk of developing the disease themselves.

However, less is known about this hereditary risk when a diagnosis comes at a very old age.

The scientists decided to look into this further. They analysed data from a Swedish family cancer database, which included details about almost eight million people and their parents. They looked at the period 1961 to 2008.

The study found that the highest risk was in the offspring of parents who had been diagnosed with cancer at a younger age.

However, it also found that even if the parents were over the age of 80, and in some cases, 90 years, the risk that the offspring would develop the same type of cancer was still significantly higher compared to people whose parents were not affected.

The scientists said that family members, particularly offspring, may benefit from knowing that they have an increased risk of a specific type of cancer, because they can then attempt to avoid known risk factors.

Details of these findings are published in the British Medical Journal.