The difference is not that monitoring causes disease, but you are not doing surgery or radiotherapy, and it is not doing that which results in higher risks, in

The difference is not that monitoring causes disease, but you are not doing surgery or radiotherapy, and it is not doing that which results in higher risks, in some patients. Unfortunately they mixed up Gleason 6 (low risk) and 7+ (intermediate and high risk) patients in the statistics. In the supplement they give information which allows you to see that the risk of dying is far higher (~10X higher) for the 7+ patients. But they do not provide this breakup for the risk of progression and metastases. So we cannot know what the risk is for low risk patients. And it is low risk patients who are usually recommended for active surveillance. People have a hard time believing this, but this kind of statistical fail is common, even normal in medical research. The average doctor, including medical researchers, has zero formal training in statistics. So they basically use cookbooks without really knowing what they are doing. So you get researchers saying that because they has a statistically insignificant result, they showed there is no effect. We had a study which had a slightly below significant result for fish oil reducing post natal depression in women with a 30% reduction(P=.11m where < .05 is arbitrarily counted as 'significant'). The lead researcher then gets on the media and tells the country <we showed fish oil is useless>. The Bayesian revolution in statistics has largely bypassed medicine even though it is well accepted in many other fields.