A family history of a particular cancer increases the risk of other members of the family developing not only the same cancer but also of getting cancers at different sites in the body, research published this morning suggests.
Researchers from Italy, Switzerland and France looked at some 12,000 cases of cancer occurring in 13 different body sites and then matched these with a control group of 11,000 people without cancer. The results confirmed known associations such as the increased risk of developing the same cancer as a first-degree relative.
But the study also found a 3.3 - fold increased risk of developing oral cancer for someone with a close relative who had been diagnosed with cancer of the larynx (voice-box) and a four-fold increased risk of cancer of the oesophagus (gullet) in a person with a first-degree relative who had oral cancer. And family members had 3.4 times the risk of developing prostate cancer if a first - degree relative had bladder cancer.
The research, published in the European cancer journal Annals of Oncology provides a comprehensive picture of the risk of developing various different types of cancer in families where there is a history of the disease; it also takes into account other factors, such as individual characteristics and lifestyles, that could affect the degree of risk as well.
Dr Eva Negri of the Mario Negri Institute for Pharmacological Research, Milan, Italy, said: "We have also found that if a patient was diagnosed with certain cancers when they were younger than 60, the risks of a discordant (different) cancer developing in family members were greater. "
She added that some of the associations between cancers at different sites were probably due to shared environmental factors such as family habits of smoking and drinking but that the possibility of a genetic link would also need to be explored in future research.
