Identifying the Best Candidates for Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography as the Primary Staging Approach Among Men with High-risk Prostate Cancer and Negative Conventional Imaging.

Prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) is an emerging imaging modality with greater sensitivity and specificity over conventional imaging for prostate cancer (PCa) staging. Using data from two prospective trials (NCT03368547 and NCT04050215), we explored predictors of overall upstaging (nodal and metastatic) by PSMA PET/CT among patients with cN0M0 National Comprehensive Cancer Network high-risk PCa on conventional imaging (n = 213). Overall, 21.1%, 8.9%, and 23.9% of patients experienced nodal, metastatic, and overall upstaging, respectively, without histologic confirmation. On multivariable analysis, Gleason grade group (GG) and percent positive core (PPC) on systematic biopsy significantly predict overall upstaging (odds ratio [OR] 2.15, 95% confidence interval [CI] 1.33-3.45; p = 0.002; and OR 1.03, 95% CI 1.01-1.04; p < 0.001). Overall upstaging was significantly more frequent among men with GG 5 disease (33.0% vs. 17.6%; p = 0.0097) and PPC ≥50% (33.0% vs 15.0%; p = 0.0020). We constructed a nomogram that predicts overall upstaging using initial prostate-specific antigen, PPC, GG, and cT stage, with coefficients estimated from a standard logistic regression model (using maximum likelihood estimation). It is internally validated with a tenfold cross-validated area under the receiver operating characteristic curve estimated at 0.74 (95% CI 0.67-0.82). In our cohort, 90% of patients who had a nomogram-estimated risk below the cutoff of 22% for overall upstaging could have been spared PSMA PET/CT as our model correctly predicted no upstaging. In other words, the predictive model only missed 10% of patients who would otherwise have benefitted from PSMA PET/CT. PATIENT SUMMARY: We analyzed predictors of overall upstaging (lymph node or/and metastasis) by prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) from conventional imaging in men with high-risk prostate cancer undergoing initial staging deemed free of disease in the lymph nodes and distant metastasis by conventional imaging techniques. We found that the pathologic grade and disease burden in a prostate biopsy are associated with upstaging. We also developed a tool that predicts the probability of upstaging according to an individual patient's characteristics. Our study may help in defining patient groups who are most likely to benefit from the addition of a PSMA PET/CT scan.

Prostate cancer incidence across stage, NCCN risk groups, and age before and after USPSTF Grade D recommendations against prostate-specific antigen screening in 2012.

BACKGROUND: We sought to determine the extent to which US Preventive Services Task Force (USPSTF) 2012 Grade D recommendations against prostate-specific antigen screening may have impacted recent prostate cancer disease incidence patterns in the United States across stage, National Comprehensive Cancer Network (NCCN) risk groups, and age groups. METHODS: SEER*Stat version 8.3.4 was used to calculate annual prostate cancer incidence rates from 2010 to 2015 for men aged ≥50 years according to American Joint Committee on Cancer stage at diagnosis (localized vs metastatic), NCCN risk group (low vs unfavorable [intermediate or high-risk]), and age group (50-74 years vs ≥75 years). Age-adjusted incidences per 100,000 persons with corresponding year-by-year incidence ratios (IRs) were calculated using the 2000 US Census population. RESULTS: From 2010 to 2015, the incidence (per 100,000 persons) of localized prostate cancer decreased from 195.4 to 131.9 (Ptrend  < .001) and from 189.0 to 123.4 (Ptrend  < .001) among men aged 50-74 and ≥75 years, respectively. The largest relative year-by-year decline occurred between 2011 and 2012 in NCCN low-risk disease (IR, 0.77 [0.75-0.79, P < .0001] and IR 0.68 [0.62-0.74, P < .0001] for men aged 50-74 and ≥75 years, respectively). From 2010-2015, the incidence of metastatic disease increased from 6.2 to 7.1 (Ptrend  < .001) and from 16.8 to 22.6 (Ptrend  < .001) among men aged 50-74 and ≥75 years, respectively. CONCLUSIONS: This report illustrates recent prostate cancer "reverse migration" away from indolent disease and toward more aggressive disease beginning in 2012. The incidence of localized disease declined across age groups from 2012 to 2015, with the greatest relative declines occurring in low-risk disease. Additionally, the incidence of distant metastatic disease increased gradually throughout the study period.

Genomic Validation of 3-Tiered Clinical Subclassification of High-Risk Prostate Cancer.

PURPOSE: Recent data and National Comprehensive Cancer Network (NCCN) guidelines suggest that high-risk prostate cancer (cT3-4, Gleason score ≥8, or prostate-specific antigen [PSA] >20 ng/mL) is a heterogenous group in terms of long-term patient outcomes. We sought to determine whether subclassification of high-risk prostate cancer based on clinical factors correlates with genomic markers of risk. METHODS AND MATERIALS: We identified 3220 patients with NCCN unfavorable intermediate-risk (n = 2000) or high-risk (n = 1220) prostate cancer from a prospective multi-institutional registry cohort. We defined the following subclassification of high-risk prostate cancer based on previously published data: favorable high risk (cT1c, Gleason 6, and PSA >20 ng/mL or cT1c, Gleason 4 + 4 = 8, PSA <10 ng/mL); very high risk (cT3b-T4 or primary Gleason pattern 5); and standard high risk (all others with cT3a, Gleason score ≥8, or PSA >20 ng/mL). We used a set of 33 previously developed genomic classifiers, including Decipher, to determine whether high-risk genomic features correlate with clinical subclasses of high-risk prostate cancer. RESULTS: Among those with favorable high-risk, standard high-risk, and very high-risk prostate cancer, 50.4%, 64.2%, and 81.6% had a high-risk Decipher score, respectively (P < .001). Among 32 other genomic signatures, 29 had a similar trend of increasing risk scores across the 3 subclasses of high-risk disease (P < .05 after correction for multiple hypothesis testing). Patients in the 3 subclasses of high-risk disease had a median of 4, 6, and 13 high-risk signatures, respectively. In comparison, among those with unfavorable intermediate-risk prostate cancer, 38.2% had a high-risk Decipher score, and the median number of high-risk signatures was 3. CONCLUSIONS: Although NCCN guidelines currently use a 2-tiered system for high-risk prostate cancer, genomic markers of risk correlate with the clinically validated subclassification of high-risk prostate cancer into favorable high-risk, standard high-risk, and very high-risk disease, further confirming the prognostic utility of this 3-tiered stratification.

Use and early mortality outcomes of active surveillance in patients with intermediate-risk prostate cancer.

BACKGROUND: Certain patients with intermediate-risk prostate cancer (PCa) may be appropriate candidates for active surveillance (AS). In the current study, the authors sought to characterize AS use and early mortality outcomes for patients with intermediate-risk PCa in the United States. METHODS: The novel Surveillance, Epidemiology, and End Results Active Surveillance/Watchful Waiting database identified 52,940 men diagnosed with National Comprehensive Cancer Network intermediate-risk PCa (cT2b-c, Gleason score of 7, or a prostate-specific antigen level of 10-20 ng/mL) and actively managed (AS, radiotherapy, or radical prostatectomy) from 2010 through 2015. The Cuzick test assessed AS time trends, and logistic multivariable regression characterized features associated with AS. Fine-Gray and Cox modeling determined PCa-specific mortality (PCSM) and overall survival, respectively. RESULTS: The rate of AS increased from 3.7% in 2010 to 7.3% in 2015, and from 7.2% to 11.7% among men aged ≥70 years. Among men with favorable and unfavorable intermediate-risk disease, the use of AS increased from 7.2% to 14.9% and from 2.2% to 3.8%, respectively (all P value for trend, <.001). The mean age of those patients managed with AS decreased from 69.9 years to 67.9 years (P = .0004). Factors found to be associated with AS included favorable risk disease; black race; higher socioeconomic status; older age; and diagnosis in the West, Northwest, or Midwest regions of the United States. The 5-year PCSM rate was comparable to AS versus treatment among patients with low-risk and favorable intermediate-risk disease, but was worse with AS among those with unfavorable intermediate-risk disease (PCSM, 1.3% vs 0.5%; adjusted hazard ratio, 2.48 [95% CI, 1.11-5.50; P = .026]) and intermediate-risk disease overall (PCSM, 1.1% vs 0.4%; adjusted hazard ratio, 2.34 [95% CI, 1.25-4.37; P = .008]). CONCLUSIONS: The use of AS for patients with intermediate-risk PCa is increasing across the United States, particularly for older men and those with favorable intermediate-risk disease. Early estimates of cancer-specific and overall mortality rates are low with AS, although significantly higher compared with treatment.

A comparative analysis of overall survival between high-dose-rate and low-dose-rate brachytherapy boosts for unfavorable-risk prostate cancer.

PURPOSE: External beam radiation therapy (EBRT) with low-dose-rate (LDR) brachytherapy boost has been associated with improved biochemical progression-free survival and overall survival (OS) compared with dose-escalated EBRT (DE-EBRT) alone for unfavorable-risk prostate cancer. However, it is not known whether high-dose-rate (HDR) boost provides a similar benefit. We compare HDR boost against LDR boost and DE-EBRT with respect to OS. METHODS: Using the National Cancer Database, we identified 122,896 patients who were diagnosed with National Comprehensive Cancer Network intermediate- or high-risk prostate cancer between 2004 and 2014 and treated with DE-EBRT (75.6-86.4 Gy), LDR boost, or HDR boost. We compared the OS among the three groups using multivariable Cox proportional hazards regression. Inverse probability treatment weighting was used to adjust for covariate imbalance. RESULTS: On multivariable Cox proportional hazards regression, HDR boost was associated with a similar OS to LDR boost (adjusted hazard ratio [AHR] 1.03 [0.96, 1.11]; p = 0.38) but significantly better OS than DE-EBRT (AHR 1.36 [1.29, 1.44]; p < 0.001). Inverse probability treatment weighting analysis yielded similar results. There was no significant difference between LDR and HDR boosts for National Comprehensive Cancer Network intermediate-risk (AHR 1.05 [0.96, 1.15]; p = 0.32) and high-risk (AHR 1.00 [0.89, 1.12]; p = 0.98) subgroups (p-interaction = 0.55). CONCLUSIONS: Our results suggest that HDR brachytherapy boost yields similar OS benefits compared with LDR brachytherapy boost for unfavorable-risk prostate cancer. HDR boost may be a suitable alternative to LDR boost.

Lack of Benefit From the Addition of External Beam Radiation Therapy to Brachytherapy for Intermediate- and High-risk Prostate Cancer.

PURPOSE: A recent randomized controlled trial demonstrated that the addition of external beam radiation therapy (EBRT) to brachytherapy did not improve progression-free survival in select patients with intermediate-risk prostate cancer. We evaluated whether the addition of EBRT to brachytherapy improves prostate cancer-specific mortality (PCSM) for intermediate- and high-risk disease using a large national database. METHODS AND MATERIALS: We identified 5836 patients in the Surveillance, Epidemiology, and End Results-Medicare linked database with a diagnosis of National Comprehensive Cancer Network intermediate-risk (Gleason score 7, prostate-specific antigen 10-20 ng/mL, or stage cT2b-T2c) or high-risk (Gleason score 8-10 or prostate-specific antigen >20 ng/mL and stage ≤cT3a) prostate cancer who had undergone brachytherapy, with or without EBRT and androgen deprivation therapy (ADT). Patients were diagnosed from 2004 through 2009. Intermediate-risk patients with Gleason score ≤3+4 and 1 intermediate-risk factor were considered favorable and all others unfavorable. We used multivariable Fine-Gray competing risks regression to study PCSM while adjusting for sociodemographic and clinical factors and ADT use. RESULTS: Overall, 50.3% of intermediate- and high-risk patients who received brachytherapy and EBRT did not have significantly improved PCSM compared with that of the patients who received brachytherapy alone (adjusted hazard ratio [AHR] 1.46, 95% confidence interval [CI] 0.69-3.11; P=.322; 5-year PCSM 2.4% vs 1.0%). This lack of benefit was seen among favorable intermediate-risk (AHR 2.66, 95% CI 0.93-7.62, P=.069; 5-year PCSM 1.3% vs 0.6%), unfavorable intermediate-risk (AHR 0.68, 95% CI 0.16-2.96, P=.612; 5-year PCSM 1.0% vs 1.2%), and high-risk (AHR 1.82, 95% CI 0.67-4.98, P=.242; 5-year PCSM 5.3% vs 2.1%) subgroups. CONCLUSIONS: These results suggest that certain patients with intermediate- or high-risk prostate cancer treated with brachytherapy might not benefit from the addition of EBRT. A randomized controlled trial of brachytherapy plus ADT with or without EBRT for unfavorable intermediate- and favorable high-risk organ-confined prostate cancer should be undertaken.

Association Between Travel Distance and Choice of Treatment for Prostate Cancer: Does Geography Reduce Patient Choice?

OBJECTIVE: To determine whether the distance between a prostate cancer patient's home and treatment facility was related to the choice of treatment received among those opting for surgery or radiation. METHODS AND MATERIALS: We identified 222,804 patients diagnosed with National Comprehensive Cancer Network low-, intermediate-, or high-risk N0M0 prostate cancer and treated with local therapy (surgery or radiation alone, with or without hormone therapy) using the National Cancer Database. We used multivariable logistic regression to determine whether the choice of radiation therapy vs radical prostatectomy varied by distance among patients living in rural and urban areas. Analyses were adjusted for geographic location within the United States, age, race, Charlson/Deyo comorbidity score, year of diagnosis, income quartile, education quartile, Gleason score, prostate-specific antigen level, and T stage. RESULTS: Patients living in urban or rural areas were less likely to receive radiation compared with surgery if they lived farther from the treatment facility. Among urban patients living ≤5 miles from the treatment facility, 53.3% received radiation, compared with 47.0%, 43.6%, and 33.8% of those living 5 to 10, 10 to 15, or >15 miles away, respectively (P<.001 in all cases). Similarly, rural patients were less likely to receive radiation the farther they lived from the treatment facility (≤25 miles: 62.3%; 25-50 miles: 55.5%; 50-75 miles: 38.4%; >75 miles: 23.8%; P<.05 in all cases). These trends were also present when each risk group was analyzed separately. CONCLUSION: Patients with prostate cancer in both urban and rural settings were less likely to receive radiation therapy rather than surgery the farther away they lived from a treatment center. These findings raise the possibility that the geographic availability of radiation treatment centers may be an important determinant of whether patients are able to choose radiation rather than surgery for localized prostate cancer.

Factors associated with the omission of androgen deprivation therapy in radiation-managed high-risk prostate cancer.

PURPOSE: Androgen deprivation therapy (ADT) has been shown to improve survival for men with unfavorable-risk prostate cancer (PCa). We investigated the utilization and factors associated with the omission of ADT in radiation-managed high-risk PCa. METHODS AND MATERIALS: We used the National Cancer Database to identify men with National Comprehensive Cancer Network high-risk PCa treated with external beam radiation therapy (EBRT) with or without brachytherapy boost from 2004 to 2012. Multivariable logistic regression adjusting for clinical and sociodemographic factors was used to identify independent predictors for ADT use. RESULTS: A total of 57,968 radiation-treated high-risk PCa men were included in our analysis. There were 49,363 patients (85.2%) treated with EBRT alone and 8605 patients (14.8%) treated with EBRT plus brachytherapy boost. Overall, 77% of men received ADT. In multivariable regression analysis, the use of brachytherapy boost was associated with a significantly lower utilization of ADT (70% vs. 78%; adjusted odds ratio [AOR]: 0.65; 95% CI: 0.62-0.69; p-Value <0.0001), as was treatment at an academic vs. nonacademic center (AOR: 0.90; 95% CI: 0.86-0.95; p-Value <0.0001) and treatment in 2010-2012 compared to 2004-2006 (AOR: 0.85; 95% CI: 0.81-0.90; p-Value <0.0001). Conversely, greater ADT use was seen with higher Gleason scores, PSA, and T-category (all p-Values <0.001). CONCLUSIONS: Approximately one in four men with radiation-managed high-risk PCa do not receive ADT, which may reflect concerns about its toxicity profile despite known improvements in overall survival. Practice patterns suggest that some providers believe dose escalation through brachytherapy boost may obviate the need for ADT in some high-risk patients, but this hypothesis requires further testing.

Occult High-risk Disease in Clinically Low-risk Prostate Cancer with ≥50% Positive Biopsy Cores: Should National Guidelines Stop Calling Them Low Risk?

OBJECTIVE: To identify contemporary, clinically low-risk patients with ≥50% cores positive and compare the risk of upgrading at prostatectomy with other low- or intermediate-risk patients. MATERIALS AND METHODS: We studied 14,902 patients with prostate cancer in the Surveillance, Epidemiology, and End Results database in 2010-2011 treated with prostatectomy. Patients were categorized by National Comprehensive Cancer Network clinical risk groups, separating low-risk patients by percent positive biopsy cores (PBC). We measured incidence of pathologic high-risk disease, defined as pT3a-T4 or Gleason 8-10, and multivariable logistic regression was used to determine if patients with clinical low-risk disease and ≥50% PBC were similar to other low- or intermediate-risk patients. This analysis was repeated with favorable and unfavorable intermediate risk. RESULTS: At prostatectomy, 9.2% of clinically low-risk patients with <50% PBC, 18.6% of clinically low-risk patients with ≥50% PBC, and 27.6% of clinically intermediate-risk patients had occult, high-risk disease (P <.001). On multivariable logistic regression, low-risk patients with ≥50% PBC were more likely than low-risk patients with <50% PBC to have pathologic high-risk disease (adjusted odds ratio [AOR] 2.28, 95% confidence interval 1.90-2.73, P <.001), had similar risk to favorable intermediate patients overall (AOR 1.09, 0.91-1.31, P = .33), and had higher risk than favorable intermediate patients aged over 60 years (AOR 1.28, 1.00-1.64, P = .04). Low-risk patients with ≥50% PBC had a mean tumor size similar to unfavorable intermediate-risk patients (21.3 vs 21.0 mm, P = .82). CONCLUSION: Nearly 1 in 5 clinically low-risk prostate cancer patients with ≥50% PBC harbor occult pT3a-T4 or Gleason 8-10, suggesting that national guidelines should not classify low-risk patients with ≥50% cores positive as "low risk," and patients should be made aware of this excess risk if considering active surveillance.