Family History

Familial association of prostate cancer with other cancers in the Swedish Family-Cancer Database.

The Prostate June 9 2005
K Hemminki and B Chen

Study purpose: Families may develop identical, similar or otherwise related cancers. They may also show a tendency to develop certain types or kinds of cancer that occur within or across families over generations. These events may show what physicians call a “true clustering” of cancers among families, and are an important link to the identification of new cancer syndromes. This meta-analysis from Heidelberg Germany looks at family links between prostate cancer and other cancers. A meta-analysis is a statistical method combining results from published studies in order to re-examine the overall evidence.

Study description: The meta-analysis surveyed 22 studies from 1995 to 2001 that looked at the risk of prostate cancer in pesticide-related occupations. The authors then calculated an overall estimate of the ratio of prostate cancer related risk called the “meta-rate ratio estimate.” This was compared to data from three previously published meta-analyses looking at prostate cancer risk for farmers.

Findings: Results showed that the meta-rate ratio estimate, based on 25 estimators or gauges of relative risk from 22 studies, showed an overall increase in relative prostate cancer risk of 1.13. Large differences in rate ratios existed among the different studies. Further analysis identified these as being largely due to geographic location and study methods. Overall, pooled risk estimates for studies from Europe were lower than those from Canada and the USA. A significant increase in risk was observed for men employed as pesticide applicators, whereas no increase was seen for farmers.

Conclusions: Apart from these important findings, the authors note that their analysis is the largest so far and has discovered numerous links between prostate cancer and other cancers within families.

Relative Risk of Prostate Cancer for Men with Affected Relatives: Systematic Review and Meta-Analysis

International Journal of Cancer 107(5): 797-803, December 10 2003
Deborah Watkins, Bruner Dirk Moore, Alicia Parlanti, Joanne Dorgan and Paul Engstrom

Study purpose: This meta-analysis reviews the medical literature in order to analyze a link between prostate cancer within a family and an increase in risk for prostate cancer among healthy male family members. A meta-analysis is a statistical method that combines findings from previous studies in order to re-examine overall results.

Study description: For the purposes of study, a “family history” of prostate cancer was defined as having a father, brother, and any first- or second-degree relative or other relative affected with prostate cancer. A literature search using computerized databases identified 24 relevant studies from 1982 to 2000. The authors then compiled results in order to calculate an overall “pooled relative risk” estimating the raised relative risk of prostate cancer for men with affected family members compared to healthy men in families with no prostate cancer.

Findings: The pooled prostate cancer relative risk estimates derived from the results of all 24 studies show that a healthy man with one family member with prostate cancer has a relative risk of prostate cancer 1.93 times higher than a man without prostate cancer in his family. Having first-degree relatives with prostate cancer carries a relative risk of 2.22, while having an affected second-degree relative creates a relative risk of 1.88. A father with prostate cancer imparts a relative risk of 2.12; a brother with prostate cancer causes a relative risk that is 2.87 times higher. Statistical comparison of pooled data demonstrated that a man’s relative risk is significantly higher if he has a brother with prostate cancer rather than an affected father (a difference in relative risk of 0.03).

Conclusions: This meta-analysis confirms that a man’s risk of prostate cancer is higher when his family contains men who have the disease.

A systematic review and meta-analysis of familial prostate cancer risk

British Journal of Urology 91(9): 789-94, June 2003
L E Johns and R S Houlston

Study purpose: This British study is an overview of the risk of prostate cancer within families. It looks at published studies on male relatives of men with prostate cancer and uses a meta-analysis to get precise estimates of risk for these men from studying their family history of prostate cancer. A meta-analysis is a statistical method combining study results in order to re-examine the overall evidence.

Study description: Internet medical databases were searched for relevant studies. Thirteen studies were found on the risk of prostate cancer in male relatives of men with prostate cancer. A meta-analysis was done pooling together the studies’ estimates of risk for relatives of men with prostate cancer (sons, fathers, brothers, cousins, nephews, grandsons). It then calculated the “relative risk” of prostate cancer for a man with a family history of prostate cancer compared to a man with no prostate cancer in his family.

Findings: First-degree relatives of men with prostate cancer (fathers, sons, brothers) had a pooled relative risk of prostate cancer that was 2.5 times higher then male members of families with no prostate cancer. Immediate relatives of men with prostate cancer diagnosed before age 60 had a 2.8 increase in relative risk. This seems to show that relative risk declines the older a man is at diagnosis. However, the risk for men with two relatives with prostate cancer increased 3.5-fold. The relative risk for sons of men with prostate cancer appears to be lower than for brothers. The reasons for this remain unknown.

Conclusions: The authors conclude that men with a family history of prostate cancer have a greater risk of developing the disease than men whose families contain no prostate cancer. The risks are greatest for relatives of men diagnosed with prostate cancer when young, and for men with more than one relative with prostate cancer.

Empiric risk of prostate carcinoma for relatives of patients with prostate carcinoma: A meta-analysis

Cancer 97(8):1894-1903, April 2003
Maurice P A Zeegers, Annemarie Jellema and Harry Ostrer

Study purpose: There is evidence that prostate cancer runs in families. However, this link has not been well studied using meta-analysis, a statistical method that combines different published studies to get new overall results. This meta-analysis from the Netherlands looks at studies of families with prostate cancer to develop what it calls a “recurrence risk ratio.” This calculates the raised risk of a man with prostate cancer in his family compared to a man with none. The meta-analysis shows degrees of risk that are linked to how closely a man is related to a male relative with prostate cancer, as well as degrees of risk linked to numbers of affected family members, and a man’s age at the time of a prostate cancer diagnosis.

Study description: Internet medical databases were searched for relevant studies. Thirteen studies were found on the risk of prostate cancer in male relatives of men with prostate cancer. A meta-analysis was done pooling together the studies’ estimates of risk for relatives of men with prostate cancer (sons, fathers, brothers, cousins, nephews, grandsons). It then calculated the “relative risk” of prostate cancer for a man with a family history of prostate cancer compared to a man with no prostate cancer in his family.

Findings: First-degree relatives of men with prostate cancer (fathers, sons, brothers) had a pooled relative risk of prostate cancer that was 2.5 times higher then male members of families with no prostate cancer. Immediate relatives of men with prostate cancer diagnosed before age 60 had a 2.8 increase in relative risk. This seems to show that relative risk declines the older a man is at diagnosis. However, the risk for men with two relatives with prostate cancer increased 3.5-fold. The relative risk for sons of men with prostate cancer appears to be lower than for brothers. The reasons for this remain unknown.

Conclusions: The studies reviewed show the importance of family history as a risk factor for prostate cancer.