BACKGROUND: The management of intermediate-risk prostate cancer (PCa) is controversial, in part due to the heterogeneous nature of patients falling within this classification.
OBJECTIVE: We propose a new risk stratification system for intermediate-risk PCa to aid in prognosis and therapeutic decision making.
DESIGN, SETTING, AND PARTICIPANTS: Between 1992 and 2007, 1024 patients with National Comprehensive Cancer Network intermediate-risk PCa and complete biopsy information were treated with definitive external-beam radiation therapy (EBRT) utilizing doses ≥81Gy. Unfavorable intermediate-risk (UIR) PCa was defined as any intermediate-risk patient with a primary Gleason pattern of 4, percentage of positive biopsy cores (PPBC) ≥50%, or multiple intermediate-risk factors (IRFs; cT2b-c, prostate-specific antigen [PSA] 10-20, or Gleason score 7).
INTERVENTION: All patients received EBRT with ≥81Gy with or without neoadjuvant and concurrent androgen-deprivation therapy (ADT).
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Univariate and multivariate analyses were performed using a Cox proportional hazards model for PSA recurrence-free survival (PSA-RFS) and distant metastasis (DM). PCa-specific mortality (PCSM) was analyzed using a competing-risk method.
RESULTS AND LIMITATIONS: Median follow-up was 71 mo. Primary Gleason pattern 4 (hazard ratio [HR]: 3.26; p< 0.0001), PPBC ≥50% (HR: 2.72; p=0.0007), and multiple IRFs (HR: 2.20; p=0.008) all were significant predictors of increased DM in multivariate analyses. Primary Gleason pattern 4 (HR: 5.23; p< 0.0001) and PPBC ≥50% (HR: 4.08; p=0.002) but not multiple IRFs (HR: 1.74; p=0.21) independently predicted for increased PCSM. Patients with UIR disease had inferior PSA-RFS (HR: 2.37; p< 0.0001), DM (HR: 4.34; p=0.0003), and PCSM (HR: 7.39; p=0.007) compared with those with favorable intermediate-risk disease, despite being more likely to receive neoadjuvant ADT. Short follow-up and retrospective study design are the primary limitations.
CONCLUSIONS: Intermediate-risk PCa is a heterogeneous collection of diseases that can be separated into favorable and unfavorable subsets. These groups likely will benefit from divergent therapeutic paradigms.
Written by:
Zumsteg ZS, Spratt DE, Pei I, Zhang Z, Yamada Y, Kollmeier M, Zelefsky MJ. Are you the author?
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Reference: Eur Urol. 2013 Mar 23. pii: S0302-2838(13)00257-1.
doi: 10.1016/j.eururo.2013.03.033
PubMed Abstract
PMID: 23541457
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