Prostate Cancer

 

Epidemiology

Prostate cancer is the second most commonly diagnosed cancer in men, accounting for 15% of all cancers diagnosed. A systematic review of autopsy studies reported a prevalence of PCa at age < 30 years of 5% increasing by an odds ratio (OR) of 1.7 x per decade, to a prevalence of 50-70% by age > 79 year.

Risk factors

  • Family History: Men with one first-degree relative diagnosed with PCa still suffer an increased risk (relative risk [RR]: 1.8) of developing PCa, and this increases further in men with a father and brother (RR: 5.51) or two brothers (RR: 7.71) diagnosed with PCa

  • Genetic predisposition: Only a small subpopulation of men with PCa (<10%) has true hereditary disease. This is defined as three or more affected relatives or at least two relatives who have developed early-onset PCa (< 55 years). Hereditary PCa is associated with a 6 to 7-year earlier disease onset

  • Environmental factors: A variety of factors have been studied as being associated with the risk of developing PCa such as obesity, metabolic syndrome, and diet. However, the associations with PCa identified to date lack evidence for causality. As a consequence there is no data to suggest effective preventative strategies.

 

Prostate Cancer Screening

Screening refers to systematic examination of asymptomatic men (at risk)' and is designed to reduce in mortality and morbidity due to PCa. This has to be balanced with the risk over-diagnosis and over-treatment.

An an accepted consensus is to offer early PSA testing to well-informed men at elevated risk of having PCa:

  • men > 50 years of age;

  • men > 45 years of age and a family history of PCa;

  • men of African descent > 45 years of age;

  • men carrying BRCA2 mutations > 40 years of age.

 

Prostate Cancer Diagnosis

Prostate cancer is usually suspected on the basis of Digital Rectal Exam (DRE) and/or Prostate Serum Antigen (Blood test) elevation.

Definitive diagnosis depends on histopathological verification of adenocarcinoma in prostate biopsy cores.

There are no agreed standards defined for measuring PSA. It is a continuous parameter, with higher levels indicating greater likelihood of PCa. Many men may have PCa despite having low serum PSA.

Recent data suggests that using Magnetic resonance imaging (MRI) may improve the detection of significant high grade PCa and also detect significantly less low grade cancers.