Prostate cancer risk and family history in a large cohort of Caucasian men


We have long known that having one or more close, male, family relatives who had previously been diagnosed with prostate cancer is a risk factor for prostate cancer. Classically, the degree of that risk has been thought to depend on

  • The closeness of the familial relationship (i.e., father, brother, grandfather, or paternal uncle)
  • The aggressiveness of the cancer of the family member (i.e., low-risk disease as opposed to metastatic prostate cancer that led to prostate cancer-specific mortality)
  • The age at which the family member’s cancer was diagnosed.

A new study from researchers at the University of Utah (Cannon Albright et al.) has now suggested that — at least among families of Caucasian ethnicity in Utah — having even third-degree relatives with a familial history of prostate cancer can increase individual risk for diagnosis. The very detailed familial and genealogical records maintained by many families in Utah probably helped to facilitate this research.

Basically, Cannon Albright et al. were able to access complete data on the family history of prostate cancer and associated ancestral genealogical data for a total of 635,443 males in Utah, and use these data to look at the relative risk (RR) for diagnosis of prostate cancer among these families compared to a baseline risk based on men with no family history of prostate cancer among first-, second, and third-degree relatives.

So here are the basic findings:

  • 18,105/635,443 men (2.85 percent) in the database had been diagnosed with prostate cancer.
  • For men who had at least one first-degree relative diagnosed with prostate cancer
    • RR = 2.46 if there was only one first-degree relative so diagnosed.
    • RR= 7.65 if there were four first-degree relatives so diagnosed
  • For men who had at least one second-degree relative diagnosed with prostate cancer
    • RR = 1.51 if there were 1 to 4 second-degree relatives so diagnosed (but no first-degree relatives).
    • RR = 3.09 if there were 5 or more second-degree relatives so diagnosed (but no first-degree relatives).
  • For men who had at least one third-degree relative diagnosed with prostate cancer
    • RR = 1.15 if there were 1 to 4 third-degree relatives so diagnosed (but no first- or second-degree relatives).
    • RR = 1.50 if there were 5 or more third-degree relatives so diagnosed (but no first- or second-degree relatives).
  • RRs based on age at diagnosis were higher for earlier age at diagnoses.
    • RR = 5.54 for a man with one or more first-degree relatives diagnosed before age 50 years.
    • RR = 1.78 for a man with more than one second-degree relatives diagnosed before age 50 years.
  • Relative risks were not significantly different for equivalent maternal versus paternal family histories.

The authors draw a series of conclusions, as follows:

  • More complete prostate cancer-specific family histories encompassing close and distant relatives and age at diagnosis seem to be potentially more accurate in estimation of relative risk for prostate cancer brief, summary family histories.
  • The presence of prostate cancer in second- and even third-degree relatives contributes significantly to risk.
  • Maternal family history is just as important as paternal family history.
  • A detailed, multi-generational, prostate cancer-specific family history should allow patients and care providers to make more informed screening, monitoring, and treatment decisions.

We would immediately state a caveat. It is generally considered today that something like 1 in every 6 or 7 men will be diagnosed with prostate cancer during their lifetime (i.e., about 15 percent of all men). However, in the Utah database used in this study, only 2.8 percent of the men had been diagnosed with prostate cancer. This information probably correlates closely with the fact that, prior to 1990, in Utah, most men were being diagnosed with clinically evident prostate cancer (and not on the basis of a PSA result), and that many men may have had or even died from prostate cancer without a diagnosis at all. Given these probabilities, we need to be cautious about how we interpret the data presented by Cannon Albright et al.

And then, of course, most of us just don’t have access to this type of family history, complete with the relevant medical information. Even if we have the genealogical information, we may not have the medical and diagnostic information; even collecting this type of information is time consuming. At the most basic level, we all have or had four great-grandfathers (who were third-degree relatives). Do you know who they all were? More importantly, do you know if they had prostate cancer, when it was diagnosed, whether it progressed, and whether it killed them?

In theory, the widespread use of sophisticated personal health databases might make this type of data management and assessment much easier in the future, but in reality the (justifiable) rights of individuals to protect the privacy of their health information may make it extraordinarily difficult for this type of prospective analysis of risk to be practical for the majority of people.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: