907P - Confirmation of the prognostic value of modeled PSA clearance after radical prostatectomy: results of the validation PSAMODEL study

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Biomarkers
Prostate Cancer
Presenter Denis Maillet
Authors D. Maillet1, A. Ruffion2, G. Freyer3, M. Tod4, M. Wilbaux4, P. Perrin2, E. Henin4, B. You5
  • 1Oncologie, Lyon-Sud Hospital, Lyon/FR
  • 2Urology, Lyon-Sud Hospital, 69310 - Lyon/FR
  • 3Medical Oncology, Centre Hospitalier Lyon Sud, 69495 - Pierre Bénite/FR
  • 4Emr3738, University Lyon 01, 69000 - Lyon/FR
  • 5Medical Oncology, Lyon-Sud Hospital, Lyon/FR

Abstract

Background

Early predictors of relapse after radical prostatectomy are needed. We previously showed that mathematical modeling of PSA kinetics during the first 50 days after surgery provides a parameter, PSA clearance (CLPSA), which may be an independent early predictor of relapse [1](You et al; Prostate 2009;69:1325). Prospective validation of these outcomes was warranted.

Methods

PSAMODEL was a prospective validation study including prostate cancer patients treated with radical prostatectomy. Modeled individual CLPSA was estimated with 4 values of PSA centrally measured during the first 50 post-operative days, using the bi-compartment model previously reported [1] with NONMEM program. The prognostic value of modeled CLPSA regarding 3-year biochemical relapse-free survival (3 y-bRFS) was assessed using survival univariate and multivariate analyses.

Results

Total 119 patients were included in PSAMODEL study. Among them, 13 patients (11%) experienced a relapse after median 6.5 months. Despite high inter-individual variability, individual PSA decline profiles were well fitted by the model. CLPSA, categorized by the 0.048 cut-off previously reported [1], was a significant prognostic factor of 3 y-bRFS using log-rank test (3 y-bRFS: 97% vs 66%, p = 0.009). Moreover it had independent significant prognostic value when adjusted on D'Amico score items using multivariate Cox model (p < 0.05).

Conclusion

We confirm modeled CLPSA estimated with 4 PSA values in the first 50 days after radical prostactectomy is a prognostic factor of relapse, independently on d'Amico score. The role of post-operative modeled CLPSA in adjuvant treatment decision will be assessed. [1] You et al; Prostate 2009;69:1325

Disclosure

All authors have declared no conflicts of interest.