The authors retrospectively reviewed the data for 1,010 consecutive patients who underwent radical prostatectomy between 1996 and 2008. Patients were excluded if they had neoadjuvant/adjuvant therapy and those without a nadir PSA level <0.2 ng/mL, resulting in 779 patients enrolled in the study. BCR was defined as elevation of PSA > 0.2 ng/mL. All patients underwent the first PSA measurement at 1 to 2 months after surgery. To detect BCR, PSA was generally measured at 3-month intervals for the first 2 years after surgery, at 6-months intervals for the next 3 years, and annually thereafter. The main outcomes were BCR rate and PSA doubling time (DT) following BCR at various times after radical prostatectomy. Patients were divided into 5 groups by setting multiple cut points at clinically convenient times of 1, 2, 3, and 5 years after surgery. The PSA-DT showed a log-normal distribution, and the minimum PSA-DT was set as the one-sided lower 95% confidence limit. The authors considered that the ideal PSA range for detection of BCR should be set at 0.2 to 0.4 ng/ml in order to start salvage treatment before PSA exceeds 0.5 ng/ml.
Over a mean follow-up of 8.8 years, BCR occurred in 179 patients. The BCR rate per year was 6% in the first year after surgery, 6% between 1-2 years, 3% between 2-3 years, 3% between 3-5 years, and 2% at > 5 years postoperatively. The minimum PSA-DT after BCR was 1.6, 2.4, 3.1, 6.1, and 6.4 months, respectively. These minimum PSA-DTs were taken to indicate the optimal follow-up interval during each period after surgery. As such, the take-home message from the findings is as follows: when a patient has a baseline PSA of 0.1 ng/mL, PSA should be measured at approximately –
- 3-month intervals for the first year
- 4-month intervals between 1-2 years
- 6-month intervals between 2-3 years
- Annually thereafter to definitely detect BCR before the PSA exceeds 0.4 ng/mL
Discussing with the authors, the strength of the study is that they have long-term follow-up with an appropriate number of events (BCR events) to formulate surveillance patterns for various clinical scenarios. Limitations of this study include that the study was conducted using PSA data for which the measurement interval in each patient was decided according to the physician and patient’s preferences, which may reduce the generalizability of the findings. Secondly, the authors could not make conclusions regarding the appropriate schedule for monitoring PSA in patients receiving neoadjuvant hormonal therapy, since the pattern of BCR is likely different. They concluded that for prostate cancer patients with BCR, the PSA-DT varies according to the time after radical prostatectomy. The minimum PSA-DT data may be useful for setting the optimal follow-up schedule to avoid overlooking BCR and missing the optimal time for delivering salvage therapy.Presented By: Kazuhiro Matsumoto, Keio University School of Medicine, Tokyo, Japan
Co-Authors: Seiya Hattori, Naoya Niwa, Takeo Kosaka, Ryuichi Mizuno, Toshikazu Takeda, Eiji Kikuchi, Hiroshi Asanuma, Mototsugu Oya, Tokyo, Japan
References:
1. Pound CR, Partin AW, Eisenberger MA, et al. Natural history of progression after PSA elevation following radical prostatectomy. JAMA. 1999;281:1591.
2. Mottet N, Bellmunt J, Briers E, et al. Guidelines on prostate cancer. European Association of Urology. 2016.
Written by: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre Twitter: @zklaassen_md at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA