While increased screening for prostate cancer reduced the number of prostate cancer-related deaths in Europe, it has also led to the overdiagnosis and overtreatment of low-risk prostate cancer.1 2 The Prostate Cancer Research International Active Surveillance (PRIAS) project investigated active surveillance as an alternative option to treatment for men with low-risk prostate cancer.3-5 This involved regular tests, where patients were monitored for any changes in their cancer and switched onto active treatment only when necessary. In the 10-year study conducted on active surveillance, prostate cancer mortality was <1%, making it a safe option comparable to treatment.5


For men with low-risk prostate cancer, side effects from treatment (e.g. erectile dysfunction and incontinence) can be more severe than the cancer symptoms themselves – especially if the cancer is not growing. While prostate-specific antigen (PSA) screening initiatives for prostate cancer reduced the number of prostate cancer-related deaths in Europe by up to 31%, they also increased the overdiagnosis and overtreatment of low-risk prostate cancer.1 2


Active surveillance aims to prevent overtreatment by closely monitoring men with low-risk prostate cancer without them having to undergo cancer treatment. Patients have regular tests to detect any changes in their cancer. These tests may include PSA tests, prostate biopsies and digital rectal examinations (DREs). Patients are switched onto active treatment when the tests indicate that treatment is needed.5

The Prostate Cancer Research International Active Surveillance (PRIAS) project is the biggest study on active surveillance in low-risk prostate cancer. Clinicians were asked to follow a simple protocol of PSA tests, DREs and prostate biopsies, and were given guidelines for switching patients onto active treatment based on test results.5

Clinicians could view the PRIAS protocol online and were also given a printed copy to keep at their desks for discussions with their patients. Patients were able to record and track their test results in a mobile app called Follow myPSA.6


What has it achieved?

The 10-year PRIAS study included 5,302 men with low-risk prostate cancer across 18 countries. Of these men, 944 (18%) were switched onto active treatment during the study.5

Prostate cancer mortality was <1% over the 10-year period. In the 5 years and 10 years after diagnosis, respectively, only 2% and 6% of men on active surveillance had a recurrence, metastasis or cancer-related death.5

In addition, treatment costs were saved, as 48% of men were still on active surveillance at the 5-year follow-up and 27% were still on active surveillance at the 10-year follow-up.5

Other studies looked at the effect of active surveillance on patients’ quality of life. Men under active surveillance reported:

  • similar or lower levels of anxiety and depression than men in active treatment for prostate cancer (radical prostatectomy or radiotherapy)7
  • similar or better quality of life than men in active treatment for prostate cancer.8 9


Next steps

A key strength of the PRIAS study is the simplicity of its clinical protocol. Additional research is currently exploring whether magnetic resonance imaging can improve the protocol further – either by increasing its accuracy or decreasing the number of prostate biopsies needed.10 


Further information


  1. Welch HG, Black WC. 2010. Overdiagnosis in cancer. J Natl Cancer Inst 102(9): 605-13
  2. Roobol MJ, Kerkhof M, Schroder FH, et al. 2009. Prostate cancer mortality reduction by prostate-specific antigen-based screening adjusted for nonattendance and contamination in the European Randomised Study of Screening for Prostate Cancer (ERSPC). Eur Urol 56(4): 584-91
  3. Bul M, Zhu X, Rannikko A, et al. 2012. Radical prostatectomy for low-risk prostate cancer following initial active surveillance: results from a prospective observational study. Eur Urol 62(2): 195-200
  4. Bul M, Zhu X, Valdagni R, et al. 2013. Active surveillance for low-risk prostate cancer worldwide: the PRIAS study. Eur Urol 63(4): 597-603
  5. Bokhorst LP, Valdagni R, Rannikko A, et al. 2016. A decade of active surveillance in the PRIAS Study: an update and evaluation of the criteria used to recommend a switch to active treatment. Eur Urol 70(6): 954-60
  6. enderbos LDF, Roobol MJ. 2017. m-PRIAS: an e-health technology for men on active surveillance for prostate cancer. Qual Life Res 26(1): 99
  7. van den Bergh RC, Essink-Bot ML, Roobol MJ, et al. 2009. Anxiety and distress during active surveillance for early prostate cancer. Cancer 115(17): 3868-78
  8. Ansmann L, Winter N, Ernstmann N, et al. 2018. Health-related quality of life in active surveillance and radical prostatectomy for low-risk prostate cancer: a prospective observational study (HAROW - Hormonal therapy, Active Surveillance, Radiation, Operation, Watchful Waiting). BJU Int 122(3): 401-10
  9. Bellardita L, Valdagni R, van den Bergh R, et al. 2015. How does active surveillance for prostate cancer affect quality of life? A systematic review. Eur Urol 67(4): 637-45
  10. PRIAS Project. 2013. Prostate cancer research international: active surveillance (PRIAS) MRI study. The Netherlands: PRIAS Project