Prostate-specific antigen doubling time as a progression criterion in an active surveillance programme for patients with localized prostate cancer

Vaccination against RhoC induces long-lasting immune responses in patients with prostate cancer: results from a phase I/II clinical trial

Background

Peptide-based vaccination is a rational option for immunotherapy of prostate cancer. In this first-in-man phase I/II study, we assessed the safety, tolerability and immunological impact of a synthetic long peptide vaccine targeting Ras homolog gene family member C (RhoC) in patients with prostate cancer. RhoC is a small GTPase overexpressed in advanced solid cancers, metastases and cancer stem cells.

Methods

Twenty-two patients who had previously undergone radical prostatectomy received subcutaneous injections of 0.1 mg of a single RhoC-derived 20mer peptide emulsified in Montanide ISA-51 every 2 weeks for the first six times, then five times every 4 weeks for a total treatment time of 30 weeks. The drug safety and vaccine-specific immune responses were assessed during treatment and thereafter within a 13-month follow-up period. Serum level of prostate-specific antigen was measured up to 26 months postvaccination.

Results

Most patients (18 of 21 evaluable) developed a strong CD4 T cell response against the vaccine, which lasted at least 10 months following the last vaccination. Three promiscuouslypresented HLA-class II epitopes were identified. Vaccine-specific CD4 T cells were polyfunctional and effector memory T cells that stably expressed PD-1 (CD279) and OX-40 (CD134), but not LAG-3 (CD223). One CD8 T cell response was detected in addition. The vaccine was well tolerated and no treatment-related adverse events of grade ≥3 were observed.

Conclusion

Targeting of RhoC induced a potent and long-lasting T cell immunity in the majority of the patients. The study demonstrates an excellent safety and tolerability profile. Vaccination against RhoC could potentially delay or prevent tumor recurrence and metastasis formation.

Trial registration number

NCT03199872.

The role of MRI in active surveillance for prostate cancer

Approximately one in seven American men will be diagnosed with prostate cancer during his lifetime, and at least 50% of newly diagnosed patients will present with low-risk disease. In the last decade, the decision-making paradigm for management has shifted due to high rates of disease detection and overtreatment, attributed to prostate-specific antigen screening, with more men deferring definitive treatment for active surveillance. The advent of multiparametric magnetic resonance imaging (MP-MRI) and MRI/ transrectal ultrasound-guided fusion-guided prostate biopsy has refined the process of diagnosis, identifying patients with clinically-significant cancer and larger disease burden who would most likely benefit from intervention. In parallel, the utilization of MP-MRI in the surveillance of low-grade, low-volume disease is on the rise, reflecting support in a growing body of literature. The aim of this review is to appraise and summarize the data evaluating the role of magnetic resonance imaging in active surveillance for prostate cancer.

Effect of a 2-year home-based endurance training intervention on physiological function and PSA doubling time in prostate cancer patients

AIM

Physical activity after prostate cancer diagnosis has been shown to reduce the risk of disease progression. Here, we aimed to evaluate the effect of a 2-year home-based endurance training intervention on body composition, biomarkers levels, and prostate-specific antigen (PSA) doubling time as a surrogate end-point for progressing disease.

METHODS

Out-clinic patients with either biochemical recurrence following radical prostatectomy or patients managed on active surveillance were randomized to either 24 months (3 times/week) of home-based endurance training or usual care. Aerobic fitness, body composition, insulin sensitivity, and biomarkers were measured at 0, 6, and 24 months of intervention. PSA doubling time (PSADT) was calculated based on monthly PSA measurements.

RESULTS

Twenty-five patients were enrolled, and 19 patients completed the study. PSADT increased in the training group from 28 to 76 months (p < 0.05) during the first 6 months and was correlated with changes in VO2max (p < 0.01, r (2) = 0.41). The training group lost 3.6 ± 1.0 kg (p < 0.05) exclusively as fat mass, yet the changes in body composition were not associated with the increased PSADT. The training group showed significant improvements in plasma triglycerides, adiponectin, IGF-1, IGFBP-1, and fasting glucose levels, but no changes in insulin sensitivity (measured as Matsuda index), testosterone, cholesterols, fasting insulin, plasma TNF-alpha, IL-6, or leptin levels. The control group showed no changes in any of the evaluated parameters across the 2-year intervention.

CONCLUSION

In this small randomized controlled trial, we found that improvements in fitness levels correlated with increasing PSADT, suggesting a link between training and disease progression.

Expectant management for men with early stage prostate cancer

Since the dissemination of prostate-specific antigen screening, most men with prostate cancer are now diagnosed with localized, low-risk prostate cancer that is unlikely to be lethal. Nevertheless, nearly all of these men undergo primary treatment with surgery or radiation, placing them at risk for longstanding side effects, including erectile dysfunction and impaired urinary function. Active surveillance and other observational strategies (ie, expectant management) have produced excellent long-term disease-specific survival and minimal morbidity for men with prostate cancer. Despite this, expectant management remains underused for men with localized prostate cancer. In this review, various approaches to the expectant management of men with prostate cancer are summarized, including watchful waiting and active surveillance strategies. Contemporary cancer-specific and health care quality-of-life outcomes are described for each of these approaches. Finally, contemporary patterns of use, potential disparities in care, and ongoing research and controversies surrounding expectant management of men with localized prostate cancer are discussed.

Active surveillance for localized prostate cancer: an analysis of patient contacts and utilization of healthcare resources

OBJECTIVE

Evidence supports active surveillance (AS) as a means to reduce overtreatment of low-risk prostate cancer (PCa). The consequences of close and long-standing follow-up with regard to outpatient visits, tests and repeated biopsies are widely unknown. This study investigated the trajectory and costs of AS in patients with localized PCa.

MATERIALS AND METHODS

In total, 317 PCa patients were followed in a prospective, single-arm AS cohort. The primary outcomes were number of patient contacts, prostate-specific antigen (PSA) tests, biopsies, hospital admissions due to biopsy complications and patients eventually undergoing curative treatment. The secondary outcome was cost.

RESULTS

The 5 year cumulative incidence of discontinued AS in a competing-risk model was 40%. During the first 5 years of AS patients underwent a median of two biopsy sets, and patients were seen in an outpatient clinic including PSA testing three to four times annually. In total, 38 of the 406 biopsy sessions led to hospital admission and 87 of the 317 patients required treatment for bladder outlet obstruction (BOO). With a median of 3.7 years' follow-up, the total cost of AS was euro (€) 1,240,286. Assuming all patients had otherwise undergone primary radical prostatectomy, the cost difference favoured AS with a net benefit of €662,661 (35% reduction).

CONCLUSIONS

AS entails a close clinical follow-up with a considerable risk of rebiopsy complication, treatment of BOO and subsequent delayed definitive therapy. This risk should be weighed against a potential economic benefit and reduction in the risk of overtreatment compared to immediate radical treatment.

ERG protein expression in diagnostic specimens is associated with increased risk of progression during active surveillance for prostate cancer

BACKGROUND

Compelling biomarkers identifying prostate cancer patients with a high risk of progression during active surveillance (AS) are needed.

OBJECTIVE

To examine the association between ERG expression at diagnosis and the risk of progression during AS.

DESIGN, SETTING, AND PARTICIPANTS

This study included 265 patients followed on AS with prostate-specific antigen (PSA) measurements, clinical examinations, and 10-12 core rebiopsies from 2002 to 2012 in a prospectively maintained database. ERG immunohistochemical staining was performed on diagnostic paraffin-embedded formalin-fixed sections with a ready-to-use kit (anti-ERG, EPR3864). Men were characterised as ERG positive if a minimum of one tumour focus demonstrated ERG expression.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall AS progression was defined as clinical progression: increased clinical tumour category ≥cT2b by digital rectal examination and ultrasound, and/or histopathologic progression: upgrade of Gleason score, more than three positive cores or bilateral positive cores, and/or PSA progression: PSA doubling time <3 yr. Risk of progression was analysed using multiple cause-specific Cox regression and stratified cumulative incidences (Aalen-Johansen method). Curatively intended treatment, watchful waiting, and death without progression were treated as competing events.

RESULTS AND LIMITATIONS

A total of 121 of 142 ERG-negative and 96 of 123 ERG-positive patients had complete diagnostic information. In competing risk models, the ERG-positive group showed significantly higher incidences of overall AS progression (p<0.0001) and of the subgroups PSA progression (p<0.0001) and histopathologic progression (p<0.0001). The 2-yr cumulative incidence of overall AS progression was 21.7% (95% confidence interval [CI], 14.3-29.1) in the ERG-negative group compared with 58.6% (95% CI, 48.7-68.5) in the ERG-positive group. ERG positivity was a significant predictor of overall AS progression in multiple Cox regression (hazard ratio: 2.45; 95% CI, 1.62-3.72; p<0.0001). The main limitation of this study is its observational nature.

CONCLUSIONS

In our study, ERG positivity at diagnosis can be used to estimate the risk of progression during AS. If confirmed, ERG status can be used to individualise AS programmes.

PATIENT SUMMARY

The tissue biomarker ERG identifies active surveillance patients with an increased risk of disease progression.