Prostate cancer: introduction
In Scotland, prostate cancer is the most commonly diagnosed cancer in men, after non-melanoma skin cancer. In 2014, 3,202 men were diagnosed with prostate cancer in Scotland. Survival from prostate cancer is moderately favourable with a 5-year relative survival of 87.7% in patients diagnosed between 2007 and 2011. Prostate cancer is the second most common cause of death from cancer in men, after lung cancer, accounting for 11.2% of male deaths from cancer.
The causes of prostate cancer are largely unestablished, but the main risk factors seem to be increasing age, family history, African descent, and various aspects of diet.
The age-standardised incidence rate of prostate cancer has increased for many years, with especially steep increases occurring during the 1990s. There has been a slight decrease in recent years. While part of the increasing incidence of prostate cancer may reflect a genuine increase in risk, much of it seems likely to reflect increased detection of latent disease through increasing use of the prostate-specific antigen (PSA) test (Brewster et al, 2000). Variations in use of PSA testing make it difficult to interpret geographical variations in incidence and survival.
It is expected that the incidence of prostate cancer will continue to increase up to the period 2016-20, partly due to ageing of the population (Scottish Executive, 2004).
Screening for prostate cancer using the prostate-specific antigen (PSA) test remains controversial. In a Cochrane review, based on a meta-analysis of five randomised trials, the authors concluded that screening does not reduce prostate cancer-specific and overall mortality; that harms associated with PSA-based screening and subsequent diagnostic evaluations are frequent, and moderate in severity; and that over-diagnosis and over-treatment are common and are associated with treatment-related harms (Ilic et al, 2013).