Cancer of the breast and colon are well known to occur with high frequency in families with certain inherited cancer syndromes. These cancers also occur with increased frequency in families which do not have a recognizable genetic cancer syndrome. The fact of familial occurrence can be used to identify people with increased risk of cancer. In high-risk people methods for early detection can be developed which may reduce morbidity and mortality from these cancers, as has been done for certain inherited cancer syndromes.
Norum, Robert A.
"Family History as a Marker for Increased Risk of Breast Cancer and Colon Cancer,"
Henry Ford Hospital Medical Journal
: Vol. 32
Available at: https://scholarlycommons.henryford.com/hfhmedjournal/vol32/iss1/4