Trends in the management of low-risk prostate cancer across parts of Canada


A newly published paper on the patterns of care for the treatment of low-risk prostate cancer in Canada from 2010 to 2013 is interesting but does need to be read with a good deal of caution.

The full text of this paper by Tran et al. is available on line, and offers us a great deal of insight into the variations in patterns of care for low-risk prostate cancer in seven of the 13 Canadian provinces. Alas, British Columbia, Ottawa, and Quebec provinces didn’t participate in the study “because of resource constraints or limitations of the available data.” This means that data from three of the four provinces with by far the highest populations and the highest annual incidence of prostate cancer in Canada aren’t included. The other three provinces that were not included were the Yukon Territory, the Northwest Territories, and Nunavent. The annual incidence of prostate cancer in these three large but relatively sparsely populated areas is perhaps a little less worrying. (For details see note below.)

The other important problem with the paper is that the authors were unable to accurately define the form of management of men who received no surgical or radiation treatment within 1 year after their diagnosis. The authors classified these men as having “No record of treatment.” They then used this is a proxy for active surveillance, but that was not really the best idea because no record of treatment could actually mean any one of several other options:

  • The patient simply refused any form of treatment.
  • The patient was just monitored on watchful waiting because no immediate treatment was either appropriate or necessary (for reasons such as his age, comorbidities, etc.); this is a non-curative form of care which may require the later use of androgen deprivation therapy when prostate cancer progresses.
  • The patient was actually monitored on active surveillance with the intent to implement curative treatment should this become necessary.
  • The patient was given some other form of treatment (e.g., HIFU or cryotherapy) that was not effectively captured by the available data sets.

It is clear from the full text of the paper that the authors understand this limitation on their study data. What is less clear is whether they really appreciate the importance of the distinctions between active surveillance and watchful waiting which make these very different management options that are both entirely appropriate … but under very different circumstances.

Because the authors used “No record of treatment” as a proxy for active surveillance, they go on to report the following trends for the management of low-risk prostate cancer in the seven provinces included in the study for the period from 2010 to 2013:

  • Use of radical prostatectomy ranged from 12.0 percent in New Brunswick to 35.9 percent in Nova Scotia.
  • Use of first-line external-beam radiation therapy or brachytherapy ranged from 4.1 percent in Newfoundland and Labrador to 17.6 percent in Alberta.
  • Treatment trends over time suggest an increase in the use of active surveillance.
    • The proportion of men with no record of surgical or radiation treatment within 1 year of diagnosis ranged from 53.3 percent in Nova Scotia to 80.8 percent in New Brunswick.
    • The proportion of men with no record of surgical or radiation treatment in all seven provinces combined rose from 46.1 percent in 2010 to 69.9 percent in 2013.

Again, The “New” Prostate Cancer InfoLink find the data trends in this paper to be interesting, but we are less than convinced that there has been a real increase in the use of prospective, structured active surveillance (as described by Klotz and others) as opposed to something much more like simple watchful waiting. And herein lies the problem. Just monitoring a patient’s PSA level is not active surveillance. Active surveillance also requires a repeat biopsy within 12 months to confirm the original biopsy data and then regular tests to assure that the cancer has not progressed — ideally using both MRIs and biopsies as appropriate (as well as regular PSA testing).

Note: The population of Canada in 2015 was about 35.8 million. The combined population of Ontario, Quebec, and British Columbia in 2015 was about 26.7 million (74.6 percent of the total). The combined population of the Yukon Territory, the Northwest Territories, and Nunavent in 2015 was just 118.4 thousand (0.3 percent of the total). The combined population of the remaining seven other Canadian provinces included in this study in 2015 was about 9.0 million (25.1 percent of the total), and one of those seven provinces (Alberta) has a population of about 4.2 million. The data in this study are therefore based on trends across only a quarter of the Canadian population.

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