Many people are aware that when an individual develops cancer, especially an early-onset cancer, that event often signals that family members may have a hereditary risk for the malignancy. Now, new research underscores that the appearance of cancer later in life also can indicate a potential hereditary cancer risk in family members.
A study appearing today in BMJ found that for a number of cancer types—colorectal, lung, breast, prostate, and urinary bladder cancers, as well as melanoma, skin squamous cell carcinoma, and non-Hodgkin lymphoma—the development of such cancers, even those diagnosed between ages 70 and 90 years, is associated with a significantly increased risk in the patient’s offspring. Even when parents were diagnosed at age 90 or older, the risk of the same cancer in offspring was still significantly increased for skin squamous cell carcinoma and colorectal, breast, and prostate cancers.
The investigators, from the German Cancer Research Centre in Heidelberg, Germany, and Lund University in Malmö, Sweden, reached their findings using the Swedish Family-Cancer database, which involves all Swedes born after 1931 and their biological parents. The database has information on more than 12.2 million individuals, including more than 1.1 million cases of a first primary cancer.
As expected, early-onset cancers had the greatest association with hereditary risk, but older age–onset cancers also had a familial component. For example, if colorectal cancer was diagnosed in an individual younger than 40 years, his or her child was almost 10 times more likely to be diagnosed with the same cancer before age 60 compared with offspring without an affected parent. If the parent was diagnosed with colorectal cancer when aged 70 to 79 years, the child was still almost twice as likely to be diagnosed with the cancer before age 60 compared with offspring without affected parents.
The researchers suggested that their findings may be used by individuals to remind them of a hereditary risk associated with having a parent diagnosed with cancer at any age and to use that information to address modifiable risk factors for that particular cancer.