Prostate cancer (PCa) among second- and even third-degree relatives contributes significantly to a Caucasian man’s risk of the disease, a new study suggests.
Obtaining an extensive family history provided a wider range of estimates of individual risk that are “potentially more accurate” than those based on typical family health histories. Maternal family history proved just as important as paternal genealogy.
Risk estimates based on a “complete constellation of affected relatives will allow patients and care providers to make more informed screening, monitoring, and treatment decisions,” a research team led by Lisa A. Cannon Albright, PhD, of the University of Utah School of Medicine in Salt Lake City wrote in The Prostate (online ahead of print).
For the study, the researchers analyzed the records of more than 635,000 men within a Utah population database, 18,105 of whom had PCa. The investigators determined the relative risks of PCa by family relationship and age of onset.
Having a first-degree relative with PCa, such as a father or brother, increased an individual’s risk by 2.5 to 7.7 times, depending on the number of relatives affected. When the closest family members with PCa were second-degree (e.g., a grandparent and/or uncle), a man’s risks were 1.5 to 3 times greater. Even when only third-degree relatives had PCa, a man’s relative risk of the disease was 15% to 50% greater than someone with no family history.
Risks were also higher when a family member was diagnosed before age 50 (5.5 times higher with an affected first-degree relative and 2 times higher with an affected second-degree relative).
Family history in combination with genetic data provides more information about disease risk than genetic data alone, the researchers posited. Identifying specific genes linked to the prostate has proven elusive, however.
“In the meantime, individualized PC[a] risk estimates based on a male’s specific family history may prove to be an inexpensive and efficient mechanism to identify males at highest risk,” the investigators suggest.