The Scandinavian study www.ncbi.nlm.nih.gov/pubmed/21542742
shows a steady rate of recurrence over 15 years, in both the surgical and watchful waiting group. The rate of recurrence doesn't increase or decrease over time. Because the slopes of the curves (the rate of recurrence) are different for the surgical and watchful waiting group, the benefit of treatment increases slowly the longer the followup. The number to treat to prevent one death with 15 years of followup is 1 in 15 for the whole study, but 1 in 7 for patients younger than 65 at the time of the treatment decision. There is no reduction in mortality in patients treated when they were 65 or older at the time of surgery. The majority of these men, about
80%, had their prostate cancer investigated and detected because of symptoms (like difficulty urinating) or a positive digital rectal examination. The benefits of surgery in reducing the risk of death was similar in low risk patients (PSA <10, Gleason 6 or lower at biopsy) to the whole group, but even the majority of these patients were not detected by PSA screening alone.
You'd guess that patients detected by screening alone, since they are, on average, earlier in their condition, would have less benefit from surgery at 15 years than these men--it would take longer to save lives.
Post Edited (Postop) : 5/20/2011 12:36:18 AM (GMT-6)