Risk factors

Factors which determine the risk of developing prostatic carcinoma is not well documented. Three most important recognized risk factors for prostate cancer are

• increasing age
  • is the strongest risk factor and the average age at diagnosis is 70-74 years while the average age at mortality is 80-84 years (2)
  • it is rare before 50 years but after which the incidence increases approximately linearly with age (3)
  • according to autopsy studies the proportion of men with prostate cancer in the 2nd decade was 8%, 3rd decade 28%, 4th decade 39%, 5th decade 53%, 6th decade 66%, 7th decade 80%
  • it is also associated with high grade cancers (2)
    
    
• ethnical origin
  • men with black African or black Caribbean origin have a 3-fold higher risk of developing prostate cancer than white men
  • Asian and Oriental men have the lowest incidence (2)
    
    
• family history
  • in men with a family history of prostate cancer, the risk increases with increasing numbers of first-degree relatives diagnosed with the disease
    • 2.5-fold - if the father had prostate cancer
    • 3.4-fold if the brother had prostate cancer
    • 3.5-fold if there are two first-degree relatives with a history of prostate cancer
    • 4.3-fold if the relative was under 60 years of age at diagnosis (2)
  • around 9% patients are thought to have true hereditary prostatic carcinoma (4)

Other risk factors include:

• BRCA gene mutation - BRCA1/BRCA2 mutation carriers are at an increased risk of prostate cancer (5)
  
  
• diet - although effects of diet on prostate cancer is still inconclusive, the following has been observed
  • foods containing lycopenes, selenium - may have a protective effect
  • in protein or calcium from dairy products - may increase the risk (2)
    
    
• obesity - although obesity has been linked with prostate cancer in UK, it has not been proven as an important risk factor (2)
  
  
• smoking - increases the risk of fatal prostate cancer (1)

Reference:

• 1. National Cancer Institute 2011. Genetics of Prostate Cancer. Introduction
• 2. Prostate Cancer Risk Management Programme Information for primary care; PSA testing in asymptomatic men. Evidence document. NHS Cancer Screening Programmes, 2010
• 3. National Institute for Health and Clinical Excellence (NICE) 2008. Prostate cancer: diagnosis and treatment
• 4. Heidenreich A et al. EAU Guidelines on Prostate Cancer. Part I: Screening, Diagnosis, and Treatment of Clinically Localised Disease. Eur Urol. 2011;59(1):61-71.
• 5. Friedenson B. BRCA1 and BRCA2 pathways and the risk of cancers other than breast or ovarian. MedGenMed. 2005;7(2):60