Real-world outcomes of sipuleucel-T treatment in PROCEED, a prospective registry of men with metastatic castration-resistant prostate cancer.

BACKGROUND: The large registry, PROVENGE Registry for the Observation, Collection, and Evaluation of Experience Data (PROCEED)(NCT01306890), evaluated sipuleucel-T immunotherapy for asymptomatic/minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). METHODS: PROCEED enrolled patients with mCRPC receiving 3 biweekly sipuleucel-T infusions. Assessments included overall survival (OS), serious adverse events (SAEs), cerebrovascular events (CVEs), and anticancer interventions (ACIs). Follow-up was for ≥3 years or until death or study withdrawal. RESULTS: In 2011-2017, 1976 patients were followed for 46.6 months (median). The median age was 72 years, and the baseline median prostate-specific antigen level was 15.0 ng/mL; 86.7% were white, and 11.6% were African American. Among the patients, 1902 had 1 or more sipuleucel-T infusions. The median OS was 30.7 months (95% confidence interval [CI], 28.6-32.2 months). Known prognostic factors were independently associated with OS in a multivariable analysis. Among the 1255 patients who died, 964 (76.8%) died of prostate cancer (PC) progression. The median time from the first infusion to PC death was 42.7 months (95% CI, 39.4-46.2 months). The incidence of sipuleucel-T-related SAEs was 3.9%. The incidence of CVEs was 2.8%, and the rate per 100 person-years was 1.2 (95% CI, 0.9-1.6). The CVE incidence among 11,972 patients with mCRPC from the Surveillance, Epidemiology, and End Results-Medicare database was 2.8%; the rate per 100 person-years was 1.5 (95% CI, 1.4-1.7). One or more ACIs (abiraterone, enzalutamide, docetaxel, cabazitaxel, or radium 223) were received by 77.1% of the patients after sipuleucel-T; 32.5% and 17.4% of the patients experienced 1- and 2-year treatment-free intervals, respectively. CONCLUSIONS: PROCEED provides contemporary survival data for sipuleucel-T-treated men in a real-world setting of new life-prolonging agents, which will be useful in discussing treatment options with patients and in powering future trials with sipuleucel-T. The safety and tolerability of sipuleucel-T in PROCEED were consistent with previous findings.

Primary androgen deprivation (AD) followed by active surveillance (AS) for newly diagnosed prostate cancer (PC): A retrospective study.

BACKGROUND: Active surveillance (AS) is only recommended for Low-Risk prostate cancer (PC) with <34% biopsies positive. Studies describing the long-term outcome of men treated with androgen deprivation (AD) followed by AS are sparse. MATERIALS AND METHODS: One hundred two men were treated with 12 months of AD in a medical oncology clinic specializing in PC between 1998 and 2007 and were followed for a median of 7.25 years. The biopsy complete response rate after AD and the incidence of disease progression while on subsequent AS was assessed. Baseline age, D'Amico risk category, PSA velocity, percentage core biopsies, and prostate volume were evaluated as potential predictors of disease progression. RESULTS: D'Amico risk category for the 102 men: Low: n = 22, Intermediate: n = 30, and High: n = 50. Medians: Age 67.3, PSA 7.8, Gleason 3 + 4, >50% core biopsies positive, stage T1c. Seventy men had a clear biopsy and 31 of these had disease progression leading to additional treatment after a median of 52 months. D'Amico risk category of the 57 men with a positive biopsy after AD or disease progression on AS was: Low: n = 4 (18%), Intermediate: n = 16 (53%), and High: n = 37 (74%). No PC deaths occurred. Three men had clinical progression. In stepwise logistic regression analysis only higher D'Amico risk category and lower prostate volume predicted disease progression. CONCLUSIONS: Despite a high prevalence of ≥50% core biopsies positive at baseline, AD induces durable remissions in most men with Low-Risk and about half with Intermediate-Risk PC.

Performance characteristics and relationship of PSA value/kinetics on carbon-11 acetate PET/CT imaging in biochemical relapse of prostate cancer.

An elevated serum prostate-specific antigen (PSA) level alone cannot distinguish between local-regional recurrences and distant metastases after treatment with curative intent. With available salvage treatments, it has become important to localize the site of recurrence. 11C-Acetate PET/CT was performed in patients with rising PSA, with statistical analysis of detection rates, sites/location of detection, PSA kinetics and comparison with other tracers (FDG and Choline). Correlation to biopsy, subsequent imaging and PSA response to focal treatment was also performed. 88% (637) of 721 11C-Acetate PET/CT scans performed were positive. There was a statistically significant difference in PSA values between the positive and negative scans (P < 0.001 for mean difference) with the percentage of positive scans and PSA having a positive correlation. A PSA of 1.09 ng/mL was found to be an optimal cutoff. PSAdT was significantly correlated with a positive scan only when the PSA was < 1.0 ng/mL. For this subgroup, a PSAdT of < 3.8 months appeared significant (P < 0.05) as an optimal cutoff point. 11C-Acetate PET/CT demonstrates a high detection rate for the site of recurrence/metastasis in biochemical relapsed prostate cancer (88% overall detection rate, PPV 90.8%). This analysis suggests an optimal PSA threshold of > 1.09 ng/mL or a PSAdT of < 3.8 months when the PSA is below 1.0 ng/mL as independent predictors of positive findings.

Short-term enzalutamide treatment for the potential remission of active surveillance or intermediate-risk prostate cancer: a case study, review, and the need for a clinical trial.

Active surveillance (AS) is a widely recognized and utilized option by which prostate cancer patients with less aggressive tumors on diagnosis defer immediate traditional conventional therapy (surgery, radiation) and undergo close monitoring by a physician for any clinical or pathologic changes. The juxtaposition of low- to intermediate-risk elderly patients between effective and conventional treatment with associated risks and monitoring without the opportunity for relief of anxiety and other psychological problems can be significant. Minimal and safe treatment over 6 months with the hope of eliminating the existing disease is of significant interest to prostate cancer patients. Unfortunately, dietary supplements have failed to improve and have sometimes even contributed to disease progression. In addition, the use of multiple medications is not always appropriate or safe. In this case study, we administered low doses of enzalutamide (80 mg/day-120 mg/day) in an AS patient during a 6 month period. Results showed a significant reduction in tumor size, as evidenced by magnetic resonance imaging and color Doppler, as well as a an undetectable level of prostate specific antigen during, and immediately following treatment. The use of an oral second-generation androgen-receptor signaling inhibitor was shown to be of benefit to patients unwilling to pursue AS and conventional treatment. Administration of enzalutamide did not reduce testosterone levels, but helped maintain good quality of life, was more cost effective at low doses, and was previously shown to be heart healthy and efficacious during early stages of castration-resistant prostate cancer. Although we do not advocate enzalutamide as a treatment approach in these situations, we believe that a clinical trial to evaluate short-term low-dose treatment using enzalutamide is warranted.

Cell cycle progression score and treatment decisions in prostate cancer: results from an ongoing registry.

OBJECTIVE: The cell cycle progression (CCP) test (Prolaris) is a novel prognostic assay that provides accurate risk of prostate cancer-specific disease progression and disease specific mortality when combined with standard clinicopathologic parameters. This prospective study evaluated the impact of the CCP report on physician treatment recommendations for prostate cancer. METHODS: Physicians ordering the CCP test in clinical practice completed surveys regarding treatment recommendations before and after they received and discussed the test results with patients. Clinicians also rated the influence of the test result on treatment decisions. Treatment selections were confirmed via third-party audit of patient charts following final survey responses. RESULTS: Overall, 65% of cases showed a change between intended treatment pre- and post-CCP test reporting. Pre-CCP testing, 164 of 305 cases received a recommendation for interventional treatment. Post-CCP test, interventional therapy was recommended for 103 of these cases, a reduction of 37.2%. Conversely, 141 of 305 cases were recommended pre-CCP testing for non-interventional treatment; 108 of these remained with non-interventional treatment while 33 shifted to interventional options, a 23.4% increase. There was a 49.5% reduction in surgical interventions and a 29.6% reduction in radiation treatment. A third-party audit identified 80.2% concordance between the post-CCP testing treatment recommendation and actual treatment. Re-assignment to intervention or non-intervention generally correlated with the result of the CCP report. Study limitations included physician selection of patients for testing, no evaluation of patient input in therapeutic choice, and other potential treatment decision factors not queried by the survey. CONCLUSION: Based on responses of ordering physicians, the CCP report adds meaningful new information to risk assessment for localized prostate cancer patients. Test results led to changes in treatment with reductions and increases in interventional treatment that were directionally aligned with prostate cancer risk specified by the test.

Primary intermittent androgen deprivation as initial therapy for men with newly diagnosed prostate cancer.

BACKGROUND: The purpose of this study was to describe the long-term incidence of cancer progression and mortality in men with localized prostate cancer treated with primary androgen deprivation (AD). METHODS: A retrospective chart review, from a medical oncology practice specializing in prostate cancer, was conducted of 73 men eligible for surgery or radiation treated with induction AD. Entry criteria consisted of a minimum of 9 months of induction AD, treatment initiation before 1999, clinical stage < T3, and outcome defined as the incidence of delayed local therapy, cancer progression, cancer mortality, and mortality from other causes. RESULTS: Median follow-up was 12 years. Fifteen men were at low risk, 38 were at intermediate risk, and 20 were at high risk. Three men (4%) experienced metastatic disease and died of prostate cancer after 3.5, 7.7, and 11 years, respectively. Two men were in the intermediate-risk category and 1 was high risk. Nineteen men (26%) died of non-prostate cancer causes. None had metastatic disease at the time of death. Of the remaining 51 survivors, none has experienced bone metastasis. Twenty-one men (29%) required no further therapy after the first induction course of AD. Twenty-four men (33%) maintained a prostate-specific antigen (PSA) level < 5.0 ng/mL with 2 to 5 cycles of intermittent AD. Twenty-eight men (38%) underwent delayed local therapy after a median of 5.5 years. Median follow-up after local therapy was 6.2 years. Three of these men experienced subsequent rising PSA levels but none has progressed to bone metastasis. Sixteen of 20 men (80%) in the high-risk category but only 12 of 53 men (23%) in the low- and intermediate-risk categories had delayed local therapy. CONCLUSIONS: Primary intermittent AD is feasible for men with localized prostate cancer. Men who are younger and men with high-risk disease undergo delayed local therapy more frequently.

Intermittent use of testosterone inactivating pharmaceuticals using finasteride prolongs the time off period.

PURPOSE: Men with prostate cancer treated intermittently with TIP benefit from improved quality of life when TOP with recovered testosterone is prolonged. We examined factors influencing the duration of TOP. MATERIALS AND METHODS: We retrospectively reviewed the charts of 101 men treated with intermittent TIP in a 9-year period. Men with positive bone scan, men in whom a PSA nadir of less than 0.1 ng/ml on TIP failed to be achieved and maintained and men in whom testosterone failed to recover to greater than 150 ng/dl during the first 12 months of TOP were excluded. Potential factors predicting prolonged TOP or accelerated time to AIPC were studied with Cox regression analysis. RESULTS: Patient characteristics were clinical stage T1c-T2a in 51 and T2b-T3b in 11, PSA relapse in 29, and T3c, D0 or D1 in 10. Median PSA was 7.6 ng/ml, Gleason score was 3 + 4 = 7 and TIP duration was 15.8 months. The 60 group 1 patients received finasteride and the 41 in group 2 received no finasteride. Median TOP in groups 1 and 2 was 31 and 15 months, respectively, using Kaplan-Meier analysis. Cox regression analysis indicated that longer TIP, finasteride and increased age predicted longer TOP. A slow PSA decrease while on TIP, higher baseline PSA and increased Gleason score predicted shorter TOP. Cox regression analysis indicated that only higher clinical stage but not finasteride predicted the earlier onset of AIPC. CONCLUSIONS: Finasteride doubles the duration of TOP. AIPC was not increased by finasteride after almost 9 years of observation.