However, the PIVOT trial showed no survival benefit at all between observation and surgery.
Both overall survival and cancer specific survival (CSS) were similar. Additionally, ProtecT also showed no difference between surgery, radiotherapy and active monitoring in these outcomes. All 3 trials did show that there is a clear advantage for local treatment with regards to progression.
Dr. Mottet continued to give several important key messages that these 3 trials provide:
1) Randomization is feasible, provided there is a will.
2) Death rate from localized prostate cancer is low even with an attitude resembling watchful waiting. However with longer follow-up, there is more progression/relapse, and more side effects if patients are treated.
3) Surgery is far from being undoubtedly superior to radiotherapy. So far it has been shown in randomized prospective trials that it is equal to surgery, although there are differences in the side effect profile. However, it is most important to note that surgery has been shown to be equal to radiotherapy with the addition of 6 months of hormonal androgen deprivation therapy, as was given in the ProtecT trial, even to patients with low risk disease.
Dr. Mottet elaborated on the information we still lack. Firstly, there is no data on these patients beyond 13 years of follow-up, which is clearly not long enough. Comorbidities are the key driver for overall survival and longer follow-up is needed. Unfortunately, there is no validated practical tool available to define life expectancy and the existing tools based on comorbidities like the Charlson comorbidity score, are not clinically practical on a day to day basis. There is also no data on different types of radiotherapy effectiveness, including brachytherapy, hypo-fractionation and the combination of EBRT and brachytherapy.
Current focal treatment studies are performed only on low risk disease patients, and more accurately, very low risk disease patients, which makes us wonder whether these patients need any kind of treatment at all. Therefore, Dr. Mottet recommends active surveillance (AS) for low risk patients and for specific patients with intermediate risk disease, as has been recommended by the ASCO guidelines, adopted from the Canadian guidelines. In a 10 and 15 year follow-up of AS patients there is 98% and 94.3% CSS rate, respectively.
In conclusion, in low risk disease patients there is no survival impact after a follow-up of 12 years for local treatment. There might be a survival impact for local disease for patients with intermediate risk, after 12 years of follow-up. Therefore, active treatment should not be offered to patients with a life expectancy of less than 10 years. Additionally, at a median of 12 years follow-up, for many screen detected patients systematic treatment is far too aggressive for low risk disease patients, and questionable for some intermediate risk disease patients. Better selection tools are required for both groups.
Speaker: Nicolas Mottet, France
Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, @GoldbergHanan, at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal