Elsevier

Radiotherapy and Oncology

Volume 101, Issue 3, December 2011, Pages 513-520
Radiotherapy and Oncology

Prostate cancer radiotherapy
The Cancer of the Prostate Risk Assessment (CAPRA) in patients treated with external beam radiation therapy: Evaluation and optimization in patients at higher risk of relapse

https://doi.org/10.1016/j.radonc.2011.05.080Get rights and content

Abstract

Background

The Cancer of the Prostate Risk Assessment (CAPRA) was developed to predict freedom from biochemical failure (FFBF) following radical prostatectomy (RP). Its utility following external beam radiation therapy (EBRT) has not been externally evaluated.

Methods

A retrospective study of 612 patients treated with dose-escalated EBRT at the University of Michigan Medical Center.

Results

Compared to the derivation cohort, EBRT treated patients had higher-risk disease (28% with CAPRA of 6–10 vs. 5%, respectively). A total of 114 patients (19%) had BF with 5-year BF ranging from 7% with CAPRA 0–3 to 35% with CAPRA 7–10. For RT patients the risk of BF at 5-year was similar to 4 surgical cohorts for CAPRA scores 0–2 but lower for all CAPRA scores ⩾ 3. The difference favoring RT increased with increasing CAPRA score reaching a 27–50% absolute improved at 5-years for CAPRA scores of 6–10. On multivariate analysis each CAPRA point increased the risk of BF (p < 0.0001) while Gleason pattern 5 in the biopsy also increased BF (p = 0.01) and long-term androgen deprivation therapy (ADT) significantly reduced the risk of BF (p = 0.015).

Conclusions

Compared to surgical series the risk of BF was lower with dose-escalated EBRT with the greatest difference at the highest CAPRA scores.

Section snippets

Patient selection

An institutional review board approved analysis was performed on 718 men with clinically localized prostate cancer treated with EBRT to at least 75 Gy with or without adjuvant ADT between 1998 and 2008. Patients were excluded if they did not fit the CAPRA criteria: T-stage > T3a (n = 33), PSA < 2.0 (n = 16), or no information about percent positive cores (n = 67); yielding 612 patients [9].

Risk stratification

Utilizing 2002 American Joint Committee on Cancer clinical T-stage, pretreatment PSA value, and biopsy GS, patients

Patient cohort

Median follow-up was 62 months with crude recurrence in 19% (114/612) a median of 42 months by the end of RT. In the CaPSURE derivation cohort a similar crude recurrence of 15% (210/1439) was reported at a median of 21 months [9]. In those without BF the follow-up was more than twice as long in the current study (median 57 months (IQR: 34–82)) than in the derivation cohort (median 21 months).

Overall 76% of patients were intermediate- or high-risk by NCCN-criteria. This included 65% with biopsy

Discussion

This is the first external validation of the CAPRA score following dose-escalated EBRT and demonstrates that CAPRA does have prognostic potential both for those treated with and without ADT with an overall c-index of 0.69. Nevertheless, for RT treated patients the CAPRA lacks discrimination within the intermediate-risk group (CAPRA score 2–5) mirroring the heterogeneity observed in patients stratified as NCCN intermediate-risk.

For most patients with prostate cancer there are few studies to

Conclusion

Although these findings need to be confirmed in additional EBRT based cohorts, they demonstrate that the CAPRA score is prognostic in men treated with EBRT ± ADT for prostate cancer in a cohort of men skewed toward higher CAPRA scores compared to the surgically treated populations. Further, in men treated as described here, with dose-escalated RT and frequent ADT use in men at higher risk, with CAPRA scoring to adjust clinical risk-features, this analysis would suggest that there may be a

Financial Disclosures

Funding: NCI 2P50 CA69568.

Conflicts of Interest

None declared.

References (43)

  • C.A. Lawton et al.

    An update of the phase III trial comparing whole pelvic to prostate only radiotherapy and neoadjuvant to adjuvant total androgen suppression: updated analysis of RTOG 94–13, with emphasis on unexpected hormone/radiation interactions

    Int J Radiat Oncol Biol Phys

    (2007)
  • D.F. Paulson et al.

    Radical surgery versus radiotherapy for adenocarcinoma of the prostate

    J Urol

    (1982)
  • M.V. Pilepich et al.

    Androgen suppression adjuvant to definitive radiotherapy in prostate carcinoma–long-term results of phase III RTOG 85–31

    Int J Radiat Oncol Biol Phys

    (2005)
  • M. Roach 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)
  • M.J. Scolieri et al.

    Neoadjuvant hormonal ablative therapy before radical prostatectomy: a review. Is it indicated?

    J Urol

    (2000)
  • Z. Symon et al.

    Dose escalation for localized prostate cancer: substantial benefit observed with 3D conformal therapy

    Int J Radiat Oncol Biol Phys

    (2003)
  • I.M. Thompson et al.

    Adjuvant radiotherapy for pathological T3N0M0 prostate cancer significantly reduces risk of metastases and improves survival: long-term followup of a randomized clinical trial

    J Urol

    (2009)
  • B.J. Trock et al.

    Tertiary Gleason patterns and biochemical recurrence after prostatectomy: proposal for a modified Gleason scoring system

    J Urol

    (2009)
  • A. Widmark et al.

    Endocrine treatment, with or without radiotherapy, in locally advanced prostate cancer (SPCG-7/SFUO-3): an open randomised phase III trial

    Lancet

    (2009)
  • K.H. Zhao et al.

    External validation of University of California, San Francisco, Cancer of the Prostate Risk Assessment score

    Urology

    (2008)
  • P.C. Albertsen et al.

    20-year outcomes following conservative management of clinically localized prostate cancer

    JAMA

    (2005)

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