Clinical implications of a prostate-specific antigen bounce after radiation therapy for prostate cancer, "Beyond the Abstract," by Richard Wilder, MD, MS, MBA

BERKELEY, CA (UroToday.com) - Many studies have suggested that age ≤ 60-70 years predicts for a PSA bounce.[1, 2, 3, 4, 5] Young age is the most consistent predictor of a PSA bounce. In the study by Naghavi et al., patients aged 70 years or younger experienced a trend towards a PSA bounce (p=0.12 on multivariate analysis).

Mehta et al.[6] have suggested that a low Gleason score predicts for a PSA bounce. Similarly, in the study by Naghavi et al., a Gleason score 6 predicted for a PSA bounce on multivariate analysis (p < 0.0001 on multivariate analysis).

In the study by Naghavi et al., 226/691 (33%) of patients had at least one PSA bounce post-irradiation. Because a PSA bounce occurs in a sizeable number of prostate cancer patients treated with radiotherapy, clinicians should make their patients aware of this phenomenon. Critz et al.[7] observed a PSA bounce as high as 15.8 ng/mL. Similarly, in the report by Naghavi et al., the maximum PSA bounce was as high as 17.0 ng/mL. Median time from completion of radiotherapy to first PSA bounce ranges from 9 to 35 months.[5] Median time to first PSA bounce was 17 months in the report by Naghavi et al.(95% CI: 15-18 months). In contrast, median time to biochemical failure was 41 months (95% CI: 28-53 months). As a result, time from the end of radiotherapy to PSA elevation can help one to distinguish a PSA bounce from a biochemical failure.[6, 8, 9]

Groups have advised against prostate biopsies within 24-30 months of the completion of radiotherapy since an elevated PSA may simply represent a PSA bounce, whereas an elevated PSA after this time is more consistent with recurrent prostate cancer.[8, 9] Caution should be used when interpreting a rising PSA after neoadjuvant and adjuvant androgen deprivation therapy (ADT). Gradual recovery of testosterone levels after the completion of ADT may cause the PSA to rise and is not necessarily indicative of a biochemical recurrence.[10] Also, distinguishing treatment effect in normal prostatic tissue from recurrent cancer in prostate needle biopsy specimens can be challenging post-irradiation.[9] Resolution of treatment effect may require up to 30 months post-irradiation.[9] Consequently, prostate biopsies are not recommended until more than 24-30 months have passed since the completion of radiotherapy.[9] If the PSA rapidly rises within 24-30 months of the completion of radiotherapy, then imaging such as magnetic resonance imaging of the abdomen and pelvis with contrast is indicated to rule out the presence of regional and/or distant metastases.[9]

References:

  1. Akyol F, Ozyigit G, Selek U, et al. (2005). PSA bouncing after short term androgen deprivation and 3D-conformal radiotherapy for localized prostate adenocarcinoma and the relationship with the kinetics of testosterone. Eur Urol 48:40-45.
  2. Ciezki JP, Reddy CA, Garcia J, et al. (2006). PSA kinetics after prostate brachytherapy: PSA bounce phenomenon and its implications for PSA doubling time. Int J Radiat Oncol Biol Phys 64:512-517.
  3. Horwitz EM, Levy LB, Thames HD, et al. (2006). Biochemical and clinical significance of the posttreatment prostate-specific antigen bounce for prostate cancer patients treated with external beam radiation therapy alone: a multiinstitutional pooled analysis. Cancer 107:1496-1502.
  4. Merrick GS, Butler WM, Wallner KE, et al. (2002). Prostate-specific antigen spikes after permanent prostate brachytherapy. Int J Radiat Oncol Biol Phys 54:450-456.
  5. Sheinbein C, Teh BS, Mai WY, et al. (2010). Prostate-specific antigen bounce after intensity-modulated radiotherapy for prostate cancer. Urology 76:728-733.
  6. Mehta NH, Kamrava M, Wang PC, et al. (2013). Prostate-specific antigen bounce after high-dose-rate monotherapy for prostate cancer. Int J Radiat Oncol Biol Phys 86:729-733.
  7. Critz FA, Williams WH, Benton JB, et al. (2000). Prostate specific antigen bounce after radioactive seed implantation followed by external beam radiation for prostate cancer. J Urol 163:1085-1089.
  8. Caloglu M, Ciezki JP, Reddy CA, et al. (2011). PSA bounce and biochemical failure after brachytherapy for prostate cancer: a study of 820 patients with a minimum of 3 years of follow-up. Int J Radiat Oncol Biol Phys 80:735-741.
  9. Gaztanaga M, Crook J (2013). Interpreting a rising prostate-specific antigen after brachytherapy for prostate cancer. Int J Urol 20:142-147.
  10. Stone NN (2013). Editorial Comment from Dr Stone to interpreting a rising prostate-specific antigen after brachytherapy for prostate cancer. Int J Urol 20:148.

Written by:
Richard Wilder, MD, MS, MBA as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.

Department of Radiation Oncology
Moffitt Cancer Center
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Tampa, FL USA

Clinical implications of a prostate-specific antigen bounce after radiation therapy for prostate cancer - Abstract

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