Worldwide, prostate cancer is the second most frequent cancer diagnosis made in men and the fifth leading cause of death. In Canada, 24,600 men will be diagnosed with prostate cancer in 2022, representing 20 percent of all new cancer cases in men, and 4,600 Canadian men will die from it. On average, 67 Canadian men are diagnosed with prostate cancer every day, and 13 die from it. About 99 percent of cases occur in men aged 50 and over.

Currently, there is no evidence on how to prevent prostate cancer; however, it is possible to reduce the risk of developing it. The risk factors are well known. In addition to nonmodifiable risk factors such as age, ethnicity, genetic factors, and family history, prostate cancer has been positively associated with factors men can control, such as increased consumption of saturated animal fat and red meat, limited intake of fruits and vegetables, insufficient vitamin levels, obesity, and inactivity. Other linked factors include inflammation, hyperglycemia, infections, and environmental exposure to chemicals or ionizing radiation. Clearly, there is a role for clinicians to play in making patients aware of the risk factors and counselling them on healthy lifestyle options.  

Staging

Prostate cancer is divided into four stages that describe how far the cancer has spread:

  • cancer that is present but not detectable by digital rectal exam (DRE) or imaging
  • tumour that is palpable in DRE but is confined to the prostate
  • cancer that has penetrated the prostate capsule
  • cancer that has metastasized to other organs

Fortunately, 74 percent of prostate cancers in Canadian men are detected in the early stages, and the probability of surviving at least five years after diagnosis is about 93 percent.

There are a number of tests that are used singly or in combination to determine what stage prostate cancer has progressed to, including DRE, PSA blood test, ultrasound, biopsy, bone scan, MRI, and PET scan.

Screening for Prostate Cancer

The mortality rate in North America and most other western countries has been declining in recent years. Although there is no clear indication of why this is happening, there is speculation that it may reflect a combination of early detection and improved treatment. A mainstay of early detection has been the PSA blood test; however, studies have produced conflicting evidence about its value. A randomized control trial in the US failed to demonstrate benefits of PSA testing in decreasing prostate cancer deaths, while other research conducted in Europe showed benefits of PSA testing.

In 2014 the Canadian Task Force on Preventive Health Care published guidelines that recommended against PSA screening for prostate cancer, stating that available evidence does not conclusively show that PSA screening will reduce prostate cancer mortality, but that it clearly shows an increased risk of harm. Among the harms cited are:

  • excessive numbers of false positive results
  • short-term complications such as infections and additional surgeries
  • long-term erectile dysfunction
  • urinary incontinence

Since the release of the 2014 Task Force guidelines, there have been new studies and updates. Updates of two systematic reviews and a de novo review will be conducted to synthesize the evidence on the benefits and harms of screening for prostate cancer with a DRE and/or PSA test. Findings from the planned systematic reviews will inform the Task Force on the update of the recommendations for primary care clinicians on screening for prostate cancer in adults.

Keep Your Knowledge Current

As the landscape changes with regard to prostate cancer, it is critical for clinicians to keep up with the latest developments. Explore the most timely and clinically-relevant educational resources focused in the area of prostate cancer at OncologyEducation, including the following session:

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