Thursday, 19 October 2017

Biochemical failure in prostate cancer

«The definition of biochemical recurrence following radiation therapy is complicated by the incomplete ablation of all functioning prostatic epithelium, which creates difficulty in establishing a meaningful absolute nadir and the phenomenon of “PSA bounce”» [4]. Biochemical failure after external beam radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer by 2005 RTOG-ASTRO Phoenix Consensus Conference is: 1) prostate-specific antigen (PSA) rise by 2 ng/mL or more above the nadir PSA; and 2) a recurrence evaluation should be considered when PSA has been confirmed to be increasing after radiation even if the rise above nadir is not yet 2 ng/mL, especially in candidates for salvage local therapy who are young and healthy [1]. «This definition accepts some limitation on sensitivity in the interest of increased specificity for detecting failures associated with clinical outcomes other than cure» [4].
Following radical prostatectomy, a cutoff of 0.2 ng/mL has been associated with a high likelihood of subsequent PSA progression [2]. More recently, 0.4 ng/mL and rising has been proposed as a definition associated more closely with the development of distant metastases [3].
Bibliographic references:
[1] Roach M 3rd, Hanks G, Thames H Jr, et al. Defining biochemical failure following radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer: recommendations of the RTOG-ASTRO Phoenix Consensus Conference. Int J Radiat Oncol Biol Phys. 2006 Jul 15;65(4):965-74. Available at: https://doi.org/10.1016/j.ijrobp.2006.04.029.
[2] Freedland SJ, Sutter ME, Dorey F, Aronson WJ. Defining the ideal cutpoint for determining PSA recurrence after radical prostatectomy. Prostate-specific antigen. Urology. 2003 Feb;61(2):365-9. Available at: http://dx.doi.org/10.1016/S0090-4295(02)02268-9.
[3] Amling CL, Bergstralh EJ, Blute ML, et al. Defining prostate specific antigen progression after radical prostatectomy: what is the most appropriate cut point? J Urol. 2001 Apr;165(4):1146-51. Available at: http://dx.doi.org/10.1016/S0022-5347(05)66452-X.
[4] Nielsen ME, Partin AW. The Impact of Definitions of Failure on the Interpretation of Biochemical Recurrence Following Treatment of Clinically Localized Prostate Cancer. Rev Urol. 2007 Spring;9(2):57-62.