TORONTO, CANADA. Dr. Laurence Klotz of the University of Toronto believes that localized prostate cancer is overtreated and that many men with "good risk" prostate cancer can avoid radical intervention (radiation or prostate removal) and still live long enough to die of causes other than prostate cancer. Dr. Klotz recently reported on an ongoing study involving 299 men over the age of 70 years with prostate cancer. At the start of the study in 1995 the men had a PSA (prostate specific antigen) value below 15 ng/mL, a Gleason score of 7 or less, and their cancer rated as stage 2b or less. The men were all placed under active surveillance, which included frequent PSA measurements and a repeat biopsy at 12-18 months after initial diagnosis.
Dr. Klotz believes that the time it takes for the PSA level to double is a good indicator of the aggressiveness of the cancer. If the PSA level doubles in less than 2 years or progression is noted on repeat biopsy or digital rectal examination, then the patient should be offered radical intervention. The PSA doubling time should be based on 3 separate measurements during a minimum of 6 months and the final value should be greater than 8 ng/mL before radical intervention is considered.
The median PSA doubling time (DT) among the 299 patients was 7 years and 42% of the men had
a DT of
greater than 10 years. Only 21% had a DT less than 3 years. Only 2 patients died from prostate
the first 5 years and after 8 years of follow-up the prostate cancer specific mortality in the group
was only 1%.
About 60% of the patients remained on active surveillance after 55 months, with the remaining
opting for radical
therapy either because of diagnosed progression or by personal preference. Dr. Klotz concludes
surveillance with selective delayed intervention in patients whose PSA DT is less than 3 years may
be a practical
compromise between across-the-board radical therapy for all patients with localized prostate cancer
watchful waiting with palliative therapy only.