Prostate-specific Membrane Antigen Imaging in Clinical Guidelines: European Association of Urology, National Comprehensive Cancer Network, and Beyond.

Prostate-specific membrane antigen (PSMA) imaging is characterized by superior accuracy compared to conventional imaging for identification of nodal and distant metastases in prostate cancer. The majority of international clinical guidelines recommend PSMA positron emission tomography/computed tomography for patients experiencing biochemical recurrence, even at low prostate-specific antigen values, to identify candidates for salvage therapies. However, its use in for primary staging is still not recommended.

Development and Validation of a Clinical Prognostic Stage Group System for Nonmetastatic Prostate Cancer Using Disease-Specific Mortality Results From the International Staging Collaboration for Cancer of the Prostate.

Importance: In 2016, the American Joint Committee on Cancer (AJCC) established criteria to evaluate prediction models for staging. No localized prostate cancer models were endorsed by the Precision Medicine Core committee, and 8th edition staging was based on expert consensus. Objective: To develop and validate a pretreatment clinical prognostic stage group system for nonmetastatic prostate cancer. Design, Setting, and Participants: This multinational cohort study included 7 centers from the United States, Canada, and Europe, the Shared Equal Access Regional Cancer Hospital (SEARCH) Veterans Affairs Medical Centers collaborative (5 centers), and the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) registry (43 centers) (the STAR-CAP cohort). Patients with cT1-4N0-1M0 prostate adenocarcinoma treated from January 1, 1992, to December 31, 2013 (follow-up completed December 31, 2017). The STAR-CAP cohort was randomly divided into training and validation data sets; statisticians were blinded to the validation data until the model was locked. A Surveillance, Epidemiology, and End Results (SEER) cohort was used as a second validation set. Analysis was performed from January 1, 2018, to November 30, 2019. Exposures: Curative intent radical prostatectomy (RP) or radiotherapy with or without androgen deprivation therapy. Main Outcomes and Measures: Prostate cancer-specific mortality (PCSM). Based on a competing-risk regression model, a points-based Score staging system was developed. Model discrimination (C index), calibration, and overall performance were assessed in the validation cohorts. Results: Of 19 684 patients included in the analysis (median age, 64.0 [interquartile range (IQR), 59.0-70.0] years), 12 421 were treated with RP and 7263 with radiotherapy. Median follow-up was 71.8 (IQR, 34.3-124.3) months; 4078 (20.7%) were followed up for at least 10 years. Age, T category, N category, Gleason grade, pretreatment serum prostate-specific antigen level, and the percentage of positive core biopsy results among biopsies performed were included as variables. In the validation set, predicted 10-year PCSM for the 9 Score groups ranged from 0.3% to 40.0%. The 10-year C index (0.796; 95% CI, 0.760-0.828) exceeded that of the AJCC 8th edition (0.757; 95% CI, 0.719-0.792), which was improved across age, race, and treatment modality and within the SEER validation cohort. The Score system performed similarly to individualized random survival forest and interaction models and outperformed National Comprehensive Cancer Network (NCCN) and Cancer of the Prostate Risk Assessment (CAPRA) risk grouping 3- and 4-tier classification systems (10-year C index for NCCN 3-tier, 0.729; for NCCN 4-tier, 0.746; for Score, 0.794) as well as CAPRA (10-year C index for CAPRA, 0.760; for Score, 0.782). Conclusions and Relevance: Using a large, diverse international cohort treated with standard curative treatment options, a proposed AJCC-compliant clinical prognostic stage group system for prostate cancer has been developed. This system may allow consistency of reporting and interpretation of results and clinical trial design.

Assessment of the Rate of Adherence to International Guidelines for Androgen Deprivation Therapy with External-beam Radiation Therapy: A Population-based Study.

BACKGROUND: The National Comprehensive Cancer Network and the European Association of Urology guidelines recommend using radiation therapy (RT) with androgen deprivation therapy (ADT) to treat high-risk and locally advanced prostate cancer patients. OBJECTIVE: To evaluate the degree of adherence to these guidelines. DESIGN, SETTING, AND PARTICIPANTS: Between 2003 and 2009, in the Surveillance Epidemiology and End Results (SEER)-Medicare database, 14 180 patients were diagnosed with high-risk (T1-T2 with World Health Organization histologic grade 3) or locally advanced (T3-T4 with any histologic grade) prostatic adenocarcinoma. INTERVENTION: Administration of RT-ADT versus RT alone. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We assessed the rate of adherence to guidelines with respect to use of RT-ADT in the overall population and after stratification according to stage-grade groupings (T1-T2 G3 vs T3-T4 any grade), age (66-69, 70-74, 75-79, ≥80 yr), Charlson Comorbidity Index (CCI) (0, 1, ≥2), and preexisting baseline cardiovascular (CV) disease. We depicted the rate of RT-ADT administration graphically over the study period. Multivariable logistic regression analyses were performed to assess the predictors of RT-ADT use. RESULTS AND LIMITATIONS: RT-ADT rates and guideline adherence were 58-75%, with the highest rate (75%) in 2003 and the lowest (58%) in 2009. When stratified according to stage-grade groupings, age, CCI, and preexisting baseline CV disease, similar results were obtained. In multivariable analyses, year of diagnosis (p<0.001), patient age (p<0.001), stage-grade groupings (p<0.001), CCI (p=0.036), race (p<0.001), marital status (p<0.001), population density (p<0.001), and US regions (p<0.001) were independent predictors of RT-ADT use. The limitations of our study include age >65 yr and exclusive Medicare coverage. CONCLUSIONS: The rate of guideline adherence regarding the use of RT-ADT is suboptimal and decreases with time instead of increasing. PATIENT SUMMARY: This population-based study provides evidence of low adherence to international urologic guidelines regarding the combination of radiation therapy (RT) with androgen deprivation therapy (ADT) for high-risk and locally advanced prostate cancer (PCa) patients. Despite the increasing number of randomized controlled trials over time that showed a survival benefit for patients with high-risk and locally advanced PCa treated with RT-ADT compared with RT alone, the rate of adherence to guidelines decreased with time.