Bone-targeted therapy in castration-resistant prostate cancer: where do we stand?

A systematic review of cytoreductive prostatectomy outcomes and complications in oligometastatic disease

Objective

To analyze outcomes and complications of cytoreductive prostatectomy (CRP) for oligometastatic prostate cancer (PCa) in order to elucidate its role in this space.

Methods

We performed a systematic literature search using three databases (Medline, Scopus, and Web of Science). The primary endpoints were oncologic outcomes. The secondary endpoints were complication rates and functional results.

Results

In all studies, overall survival was better or at least comparable variable in the groups with CRP compared to no local treatment. The greatest benefit from CRP in 5-year overall survival in one study was 67.4% for CRP versus 22.5% for no local treatment. Cancer-specific survival (CSS) showed the same trend. Several authors found significant benefits from CSS in the CRP group: from 79% vs. 46% to 100% vs. 61%. CRP was a predictor of better CSS (hazard ratio 0.264, p=0.004). Positive surgical margin rates differed widely from 28.6% to 100.0%. Urinary continence in CRP versus RP for localized PCa was significantly lower (57.4% vs. 90.8%, p<0.0001). Severe incontinence occurred seldom (2.5%-18.6%). Total complication rates after CRP differed widely, from 7.0% to 43.6%. Rates of grades 1 and 2 events prevailed. Patients on ADT alone also showed a considerable number of complications varying from 5.9% to 57.7%.

Conclusion

CRP improves medium-term cancer control in patients with oligometastatic PCa. The morbidity and complication rates of this surgery are comparable with other approaches, but postoperative incontinence rate is higher compared with RP for localized disease.

Prognostic factors in metastatic castration resistant prostate cancer patients treated with radium-223: a retrospective study

BACKGROUND

Our study aims to identify baseline prognostic factors in metastatic castration resistant prostate cancer (mCRPC) patients treated with radium-223.

METHODS

Data about demographics, ECOG performance status, lymph node (LN) involvement, local treatment for prostate cancer, previous systemic treatments, cells blood count, PSA, ALP, albumin, LDH, bone protecting agents use (BPA), analgesic use and survival were collected. Univariable and multivariable analyses were performed.

RESULTS

Seventy-five men received radium-223 between September 2013 and December 2019. Median age was 73 years. Thirty-four (45.3%) had ECOG PS 0, 41 (54.7%) PS 1-2. In univariable analysis, LN involvement (HR 1.68, 95% CI 1.01-2.80, P=0.047), absence of local treatment on primary tumor (HR 1.93, 95% CI 1.13-3.29, P=0.016), baseline strong opioidsuse (HR 1.82, 95% CI 1.08-3.06, P=0.024), high platelets to lymphocyte ratio (PLR) (HR 1.91, 95% CI 1.06-3.45, P=0.03), high baseline ALP (HR 1.81, 95% CI 1.10-2.99, P=0.019) and high baseline LDH (HR 3.86,95% CI 2.01-7.41, P<0.001) were significantly associated with worst OS. At multivariable analysis, LN involvement, strong opioids use, baseline ALP, LDH and PLR levels were significantly associated with outcome.

CONCLUSIONS

In mCRPC patients treated with Radium-223, baseline ALP, LDH, strong opioid use, PLR, LN involvement and treatment on primary site are associated with different OS.

Do disease status and race affect the efficacy of zoledronic acid in patients with prostate cancer? A systematic review and meta-analysis of randomized control trials

BACKGROUND

Zoledronic acid (ZA) does not improve the overall survival (OS) of metastatic castration-resistant prostate cancer (mCRPC); however, little is known about the efficacy of ZA in to hormone-sensitive prostate cancer (HSPC), metastatic hormone-sensitive prostate cancer (mHSPC), and non- metastatic castration-resistant prostate cancer (nmCRPC). Therefore, we assessed the efficacy of ZA in patients with prostate cancer (PCa) and different disease statuses.

METHODS

Fifteen eligible randomized-control trials (RCTs) with ZA intervention, including 8280 participants with HSPC, mHSPC, nmCRPC, and mCRPC, were analyzed. The primary and secondary outcome were overall survival(OS), and skeletal-related events (SREs), and bone mineral density (BMD).

RESULTS

The participants included 8280 men (7856 non-Asian and 424 Asian). Seven trials yielded a pooled hazard ratio (HR) of 0.95 (0.88, 1.03; P = 0.19) for OS. Subgroup analysis revealed no significant improvement in OS in the HSPC, castration-resistant prostate cancer (CRPC), M0 and M1(bone metastasis) groups, with pooled HR (95%CI) of 0.96 (0.88,1.05), 0.78 (0.46,1.33), 0.95 (0.81,1.13), 0.85 (0.69,1.04) respectively. The Asian group exhibited improved in OS with an HR of 0.67 (0.48, 0.95; P = 0.02), whereas the non-Asian group showed no improvement in OS with an HR of 0.97 (0.90, 1.06; P = 0.52). Five trials yielded pooled odds ratio (OR) of 0.65 (0.45, 0.95; P = 0.02) for SREs. In the subgroup, SREs were significantly decreased in the M1 and Asian groups with ORs of 0.65 (0.45, 0.95; P = 0.02) and 0.42 (0.24, 0.71; P = 0.001), respectively. Six trials yielded a pooled mean difference (MD) of 8.08 (5.79, 10.37; P < 0.001) for BMD. In the HSPC we observed a stable improvement in increased BMD percentage with an MD (95%CI) of 6.65 (5.67, 7.62) (P = 0.001).

CONCLUSIONS

ZA intervention does not significantly improve OS in patients with prostate cancer (HSPC, CRPC, M0, M1) but probably improves OS in the Asian populations. M1 and Asian groups had exhibit a significant reduction in SREs regardless of the HSPC or CRPC status after ZA administration. Moreover, ZA treatment increases BMD percentage.

Enzalutamide in patients with castration-resistant prostate cancer: retrospective, multicenter, real life study

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) is the final stage of pCa history and represents a clinically relevant phenotype with an elevated burden of mortality. The aim of the present study was to evaluate the efficacy and safety of enzalutamide in a "real-life" setting in mCRPC patients.

METHODS

Data about all mCRPC patients treated with enzalutamide from September 2017 to September 2018 were collected. Demographics, comorbidities, clinical parameters, outcomes, toxicity, overall survival and progression free survival were analyzed.

RESULTS

Overall, 158 patients were enrolled. Mean age was 75.8 (±8.7) years with a baseline median PSA of 16.5 (IQR 7.4-47.8) ng/mL. The median follow-up lasted 7.7 (IQR 4-14.1) months. Of all the 10.1% of patients reported grade 3-4 adverse events. 43.7% of patients experienced a progression. Overall, the 6 and 12 months PFS rates were 69.5% (95% CI: 61.7-78.3%) and the 45.6% (95% CI: 36.5-57.1%); a median baseline PSA>16 ng/mL (HR:2.0, 95% CI: 1.2-3.3, P<0.005), the use of opioid (HR: 3.1, 95% CI: 1.9-5.0, P<0.001), a previous treatment (abiraterone, docetaxel or abiraterone + docetaxel) were significantly associated with higher rates of cancer progression. Conversely, a brief pain questionnaire of 0-1 (HR: 0.4, 95% CI: 0.2-0.7, P<0.001), a 12 weeks 50% PSA reduction (HR: 0.4, 95% CI: 0.2-0.8, P<0.006) and a longer time to mCRPC (HR: 0.4, 95% CI: 0.3-0.7, P<0.002) were related to lower cancer progression rates.

CONCLUSIONS

Our data shows an effective and safe profile of enzalutamide in a "real world" perspective in patients with mcRPC.

Impact of Extraskeletal Metastases on Skeletal-Related Events in Metastatic Castration-Resistant Prostate Cancer with Bone Metastases

The therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC) has substantially evolved over the last decade. Nonetheless, a better understanding of bone-targeted agents (BTAs) action in mCRPC remains an unmet need. Theuse of BTAs aims to reduce the incidence of skeletal-related events (SREs) in patients with mCRPC. Less frequent BTA schedules are currently being studied to minimize adverse events. In this study, the impact of metastatic compartment (bone and extraskeletal metastases (BESM) vs. bone-only metastases (BOM)) on bone biomarker kinetics, time to first on-study SRE, and symptomatic skeletal events (SSEs) is evaluated. This is a retrospective analysis of the prospective, randomized, multicenter clinical trial of denosumab vs. zoledronic acid in patients with mCRPC and bone metastases. A total of 1901 patients were included, 1559 (82.0%) with BOM and 342 with BESM (18.0%). Bone metastases burden was balanced between groups. Baseline levels and normalization rates of corrected urinary N-terminal telopeptide and bone alkaline phosphatase did not differ between groups. However, BESM patients had a higher risk of SREs (adjusted HR 1.21; 95% CI 1.01–1.46; p = 0.043) and SSEs (adjusted HR 1.30; 95% CI 1.06–1.61; p = 0.014). This difference was more pronounced in the first 12 months of BTA treatment.In mCRPC, strategies of BTA schedule de-escalation may take into account presence of extraskeletal metastases.