Grade and stage misclassification in intermediate unfavorable-risk prostate cancer radiotherapy candidates

Prostate. 2022 Jun;82(10):1040-1050. doi: 10.1002/pros.24349. Epub 2022 Apr 1.

Abstract

Background: We tested for upgrading (Gleason grade group [GGG] ≥ 4) and/or upstaging to non-organ-confined stage ([NOC] ≥ pT3/pN1) in intermediate unfavorable-risk (IU) prostate cancer (PCa) patients treated with radical prostatectomy, since both change the considerations for dose and/or type of radiotherapy (RT) and duration of androgen deprivation therapy (ADT).

Methods: We relied on Surveillance, Epidemiology, and End Results (2010-2015). Proportions of (a) upgrading, (b) upstaging, or (c) upgrading and/or upstaging were tabulated and tested in multivariable logistic regression models.

Results: We identified 7269 IU PCa patients. Upgrading was recorded in 479 (6.6%) and upstaging in 2398 (33.0%), for a total of 2616 (36.0%) upgraded and/or upstaged patients, who no longer fulfilled the IU grade and stage definition. Prostate-specific antigen, clinical stage, biopsy GGG, and percentage of positive cores, neither individually nor in multivariable logistic regression models, discriminated between upgraded and/or upstaged patients versus others.

Conclusions: IU PCa patients showed very high (36%) upgrading and/or upstaging proportion. Interestingly, the overwhelming majority of those were upstaged to NOC. Conversely, very few were upgraded to GGG ≥ 4. In consequence, more than one-third of IU PCa patients treated with RT may be exposed to suboptimal dose and/or type of RT and to insufficient duration of ADT, since their true grade and stage corresponded to high-risk PCa definition, instead of IU PCa. Data about magnetic resonance imaging were not available but may potentially help with better stage discrimination.

Keywords: MRI; PSA; pathology; prostate biopsy; prostatectomy; risk stratification.

MeSH terms

  • Androgen Antagonists / therapeutic use
  • Humans
  • Male
  • Neoplasm Grading
  • Neoplasm Staging
  • Prostate-Specific Antigen
  • Prostatectomy / methods
  • Prostatic Neoplasms* / pathology

Substances

  • Androgen Antagonists
  • Prostate-Specific Antigen