Prognostic role of serum prostatic acid phosphatase for 103Pd-based radiation for prostatic carcinoma

Int J Radiat Oncol Biol Phys. 1999 Nov 1;45(4):853-6. doi: 10.1016/s0360-3016(99)00259-x.


Purpose: To establish the prognostic role of serum enzymatic prostatic acid phosphatase (PAP) in patients treated with palladium (103Pd) and supplemental external beam irradiation (EBRT) for clinically localized, high-risk prostate carcinoma.

Methods and materials: One hundred twenty-four consecutive patients with Stage T2a-T3 prostatic carcinoma were treated from 1992 through 1995. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (100 patients), Gleason score 7-10 (40 patients), pretreatment prostate specific antigen (PSA) >15 ng/ml (32 patients), or elevated serum PAP (25 patients). Patients received 41 Gy conformal EBRT to a limited pelvic field, followed 4 weeks later by a 103Pd boost (prescription dose 80 Gy). Biochemical failure was defined as a PSA greater than 1 ng/ml (normal <4 ng/ml).

Results: The overall, actuarial freedom from biochemical failure at 4 years after treatment was 79%. In Cox-proportional hazard multivariate analysis, the strongest predictor of failure was elevated pretreatment acid phosphatase (p = 0.02), followed by Gleason score (p = 0.1), and PSA (p = 0.14).

Conclusion: PAP was the strongest predictor of long-term biochemical failure. It may be a more accurate indicator of micrometastatic disease than PSA, and as such, we suggest that it be reconsidered for general use in radiation-treated patients.

MeSH terms

  • Acid Phosphatase / blood*
  • Aged
  • Aged, 80 and over
  • Brachytherapy
  • Humans
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Neoplasm Proteins / blood*
  • Neoplasm Staging
  • Palladium / therapeutic use*
  • Prognosis
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / radiotherapy*
  • Radioisotopes / therapeutic use*
  • Treatment Failure


  • Neoplasm Proteins
  • Radioisotopes
  • Palladium
  • Acid Phosphatase
  • Prostate-Specific Antigen