Association between family history of cancers and risk of prostate cancer

Abstract 

Introduction

Family history of prostate cancer is an established risk factor for prostate cancer. However, the relationship between family history of cancers other than prostate cancer and prostate cancer risk is inconclusive. This study sought to examine the association between family history of cancers and prostate cancer.

Methods

A case–control study was conducted in which cases and controls were randomly selected from a large urology clinic in Central Virginia. Cases were 600 histologically confirmed prostate cancer patients who were diagnosed between January 2000 and December 2005, and controls were 686 patients who visited the clinic during the same period and were diagnosed with urological illnesses other than cancers and prostate-related problems. Data on family history of cancers, lifestyle and demographic factors were collected through mail survey utilizing the method suggested by Dillman. Unconditional logistic regression analysis was used to estimate the odds ratios (OR) and the corresponding 95% confidence intervals (CI) after adjustment for potential confounding factors including body mass index (BMI), alcohol intake, physical activity, smoking, diet, history of vasectomy and sexually transmitted disease (STD), age, race, marital history, education, and income. Multiple comparisons adjustments were made using the Bonferroni adjustment.

Results

Men with a family history of any cancer in first-degree relatives including parents (OR=2.42, 95% CI=1.53–3.84) and parents only (OR=1.90, 95% CI=1.23– 2.94) were at increased risk of developing prostate cancer. Significant increased risk was also observed with family history of prostate cancer in first-degree relatives (OR=2.68, 95% CI=1.53–4.69) and parents only (OR=3.26, 95% CI=1.71–6.24). Even after adjustments for multiple comparisons, the significance persisted both in first-degree relatives (OR=2.68, 95% CI=1.16–6.21) and parents alone (OR=3.26, 95% CI=1.24– 8.63).

Conclusion

This study demonstrated an increased prostate cancer risk for men with a family history of any cancer or prostate cancer in first-degree relatives and parents alone. Health care providers need to be aware of the potential risk of family history of cancers on prostate cancer.

Keywords: Prostate cancer, Risk factors, Family history, Case-control study, Logistic regression