Real-world uptake, safety profile and outcomes of docetaxel in newly diagnosed metastatic prostate cancer

Does Research from Clinical Trials in Metastatic Hormone-sensitive Prostate Cancer Treatment Translate into Access to Treatments for Patients in the "Real World"? A Systematic Review

CONTEXT

Since 2015 there have been major advances in the management of primary metastatic hormone-sensitive prostate cancer (mHSPC) following the publication of key clinical trials that demonstrated significant clinical benefits with docetaxel chemotherapy or novel hormone therapy (NHT) in addition to androgen deprivation therapy (ADT). Despite these advances, there is evidence to show that these treatments are not being utilised for mHSPC in clinical practice.

OBJECTIVE

To determine the utilisation of docetaxel and NHT in mHSPC in routine practice and the determinants of variation in their use.

EVIDENCE ACQUISITION

MEDLINE and Embase were searched systematically for studies on utilisation of treatments for primary mHSPC that were based on regional or national data sets and published after January 2005. Study results were summarised using a narrative synthesis.

EVIDENCE SYNTHESIS

Thirteen papers were included in the analysis, six full-text articles and seven abstracts, on studies that included a total of 166 876 patients. The utilisation rate of treatment intensification with either docetaxel or NHT (enzalutamide, apalutamide, or abiraterone) in addition to ADT ranged from 9.3% to 38.1% across the studies. Younger, White patients with fewer comorbidities and living in more urban settings were more likely to be prescribed treatment intensification. Patients treated in private academic institutions by oncologists were more likely to receive docetaxel or NHT. Socioeconomic status did not impact receipt of systemic therapy. NHT utilisation rates appear to have increased over time.

CONCLUSIONS

These results highlight the need to change the approach to the treatment of primary mHSPC in the real world by harnessing the practice-changing results from recent trials in this setting to optimise upfront systemic therapy for this patient population.

PATIENT SUMMARY

We reviewed the use of treatments for primary metastatic hormone-sensitive prostate cancer that showed a benefit in key clinical trials. We found that these treatments are underused, particularly among certain patient groups.

Far from the truth: Real-world treatment patterns among newly diagnosed metastatic prostate cancer in the era of treatment intensification

OBJECTIVES

Real-world uptake of treatment intensification (TI) with novel hormonal agents (NHA) or chemotherapy as treatment of metastatic prostate cancer remains low outside of trial settings. We aim to report the prescription patterns and treatment outcomes of de novo metastatic hormone-sensitive prostate cancer (mHSPC) in a tertiary institution.

METHODS

This is a retrospective cohort study using real-world data from a prospectively maintained prostate cancer registry. We selected patients newly diagnosed with mHSPC from January 2016 to December 2020. Clinicopathological parameters were recorded to determine their impact on prescription patterns.

RESULTS

In total, 585 patients with metastatic prostate cancer were identified. Prescription of NHA increased from 10.5% (2016) to 50.4% (2020), but that of chemotherapy declined. Factors associated with TI were (1) baseline health status: Charlson Comorbidity Index 0-2, ECOG 0-1, age ≤ 65, (2) disease burden: PSA (>400, CHAARTED high volume disease, p = 0.004), development of systemic complications and (3) physician factor: primary physician being uro-oncologist and medical oncologist versus general urologist. Patients with TI had a longer mean time to castration-resistant prostate cancer (45.0 vs. 32.5 months, HR 0.567, 95% CI: 0.441-0.730, p < 0.001) and overall survival (55.3 vs. 46.8 months, HR 0.612, 95% CI, 0.447-0.837, p = 0.001).

CONCLUSION

This study demonstrated the trend of treatment prescription of mHSPC and factors contributing to the use of TI. TI improved mean time to CRPC and OS.

Role of multidisciplinary team meetings in implementation of chemohormonal therapy in metastatic prostate cancer in daily practice

BACKGROUND

The recommended treatment for a subset of patients with metastatic prostate cancer (mPC) changed from androgen deprivation therapy (ADT) to combinations with chemotherapy such as docetaxel. Implementation of new evidence from trials is however complex and challenging. We investigated the effect of multidisciplinary team meetings (MDTs) on adopting the newest emerging combination therapy in patients with mPC and assessed the overall survival of chemohormonal therapy in a real-world setting.

METHODS

All mPC patients diagnosed between October 2015 and April 2016 in the Netherlands were identified from the population-based Netherlands Cancer Registry (n = 962). Logistic regression analyses were performed to examine the role of patient- and tumor characteristics, with special emphasis on MDTs, on receiving chemohormonal therapy versus ADT monotherapy. Kaplan-Meier survival curves were used to assess overall survival (OS).

RESULTS

As many patients received ADT monotherapy as chemohormonal therapy (both n = 452). Being discussed in a MDT as patient, younger age, less comorbidities, a better performance status and high-volume disease were significantly associated with receiving chemohormonal therapy compared to ADT monotherapy. After adjustment for these factors, the presence of a MDT was independently associated with the administration of chemohormonal therapy (OR 2.77, 95% CI 1.68-4.59). The 2-year OS was 82.1% (95% CI: 78.5-85.6%) for patients receiving chemohormonal therapy and 59.9% (95% CI: 55.4-64.4%) for patients receiving ADT monotherapy.

CONCLUSION

Being discussed in a MDT is independently associated with the administration of chemohormonal therapy in this group of patients with mPC. This supports the hypothesis that implementation of innovative treatment options is facilitated by an organizational structure with MDTs.

Real-world utilization and outcomes of docetaxel among older men with metastatic prostate cancer: a retrospective population-based cohort study in Canada

BACKGROUND

The adoption of docetaxel for systemic treatment of metastatic prostate cancer (PCa), in both castration-sensitive (mCSPC) and castration-resistant (mCRPC) settings, is poorly understood. This study examined the real-world utilization of docetaxel in these patients and their outcomes.

METHODS

A retrospective population-based study used administrative data from Ontario, Canada, to identify men aged ≥66 years who were diagnosed with de novo mCSPC or mCRPC between 2014 and 2019 and received docetaxel. The study assessed treatment tolerability and toxicity, and survival in both cohorts. Descriptive and comparative statistical analysis were conducted.

RESULTS

The study identified 11.2% (399/3556) and 13.2% (203/1534) patients diagnosed with de novo mCSPC and with mCRPC who received docetaxel respectively. The median age in both cohorts was 72 years (IQR: 68-76). Overall, 43.9% (n = 175) patients with de novo mCSPC and 52.1% (n = 85) with mCRPC completed ≥6 cycles of docetaxel. Over two-fifth also needed dose adjustments in both cohorts. Hospitalization or emergency department visit for febrile neutropenia were noted in 15.8% (n = 63) of de novo mCSPC patients and similarly in 19% (n = 31) of mCRPC cohort. The median survival of PCa patients who completed ≥6 cycles of docetaxel was significantly longer relative to those who completed <4 cycles: 32.7 vs. 23.5 months (p < 0.001) for mCSPC and 20.5 vs. 10.7 (p = 0.012) for mCRPC respectively.

CONCLUSIONS

In this population-based study of elderly patients with metastatic PCa, treatment with docetaxel was associated with poor tolerability and higher toxicity compared with clinical trials. Receipt of limited cycles and reduced overall dose of docetaxel were associated with inferior overall survival.

Combination treatment in metastatic prostate cancer: is the bar too high or have we fallen short?

Androgen deprivation therapy (ADT) alone has been the cornerstone of treatment for patients with newly diagnosed metastatic prostate cancer for the past century. Based on results from landmark trials in the past decade, combination approaches of ADT with chemotherapy or novel hormonal agents have established a new standard of care for these patients. This paradigm shift in treatment has been reflected in the updates to guideline recommendations of major professional associations. However, real-world data from around the world have highlighted the dismal adoption of combination therapy, despite evidence-based recommendations. The disparity between evidence and practice is concerning, especially with emerging evidence of survival benefit with further treatment intensification using triplet combinations (ADT, docetaxel and novel hormonal agents). Thus, a pressing need to raise awareness and call the uro-oncology community to action exists to deliver evidence-based care for these patients.

Emergence of triplet therapy for metastatic castration-sensitive prostate cancer: An updated systematic review and network meta-analysis

INTRODUCTION

There have been a growing number of treatment options available for men with metastatic castration-sensitive prostate cancer. Not only have newer agents entered the clinical landscape, there is a trend toward treatment intensification by combining multiple agents simultaneously. We aim to assess the best contemporary treatment option for men with mCSPC.

MATERIALS AND METHODS

We perform an updated systematic review and network meta-analysis of randomized control trials that evaluated systemic therapies in men with castration-sensitive prostate cancer. We searched multiple databases up to April 2022. We included all randomized trials assessing the effect of systemic agents. We performed subgroup analyses based on disease volume and timing of presentation. Statistical analysis was performed with Bayesian methods.

RESULTS

We found 10 eligible trials with 10,065 patients who were included in this analysis. Triplet therapy with darolutamide or abiraterone with docetaxel and ADT improved overall survival. In the sensitivity analysis, the respective hazard ratios for triplet therapy was HR 0.70 (95%CI 0.61-0.80) compared to docetaxel+ADT and 0.77 (95%CI 0.65-0.91) compared to androgen receptor pathway inhibitors+ADT combinations. It was estimated that there was 96% chance that one of the triplet therapy combinations were the best treatment option from an OS perspective. Triplet therapy also improved progression-free survival. These benefits were pronounced in men with high-volume disease burden and those with de novo metastatic disease.

CONCLUSION

The finding suggest that triplet therapy is likely the most efficacious available option in men with metastatic, castration-sensitive prostate cancer, especially in those with high-volume disease burden.

Docetaxel chemotherapy plus androgen-deprivation therapy in high-volume disease metastatic hormone-sensitive prostate cancer in Chinese patients: an efficacy and safety analysis

OBJECTIVE

To investigate the efficacy and safety of docetaxel chemotherapy combined with androgen-deprivation therapy for patients with high-volume disease metastatic hormone-sensitive prostate cancer.

METHODS

153 cases of high-volume disease metastatic hormone-sensitive prostate cancer in Minhang Hospital between January 2018 and December 2019 were analyzed retrospectively, including the number of patients, age, initial PSA level, Gleason score, TNM stage and ECOG score. 90 patients in the endocrine therapy group received continuous ADT, and 63 patients in the combined chemotherapy group received docetaxel plus ADT. The progression-free survival time (time from initiation of prostate cancer treatment to progression to CRPC), PSA response rate, and adverse reactions were compared between the two groups.

RESULTS

All 153 cases were closely followed up for a period of 12.3-35.3 months, with a median follow-up time of 23.5 months. The median time to reach the lowest point of PSA in the two groups was 6.3 months and 7.9 months (P = 0.018) in the combination chemotherapy group and the ADT group alone, with 27 (42.9%) and 12 (13.3%) cases in the two groups Within 12 months of treatment, PSA decreased to below 0.2 ng/ml (P = 0.02), and progression-free survival was 16.9 months (6.5-28.5 months) and 11.2 months (4.3-22.7 months) in the two groups. (P < 0.001). There were 18 cases (28.6%) and 54 cases (60%) in the two groups with disease progression (P < 0.001). There were 6 cases (9.5%) and 15 cases (16.7%) in the combination chemotherapy group and the ADT group died of prostate cancer and related complications, respectively. All 63 cases in the combined chemotherapy group completed 6 cycles of chemotherapy. 39 (61.9%) cases experienced varying degrees of neutropenia, of which 12 (19%) experienced grade 3-4 neutropenia, with 6 cases (9.5%) developed febrile neutropenia. 30 cases (47.6%) had toxic reactions in the digestive system, and 3 case (4.3%) had grade 3 liver dysfunction. 27 cases (42.8%) had skin and mucosal toxicity. 9 cases (14.3%) had mild fluid retention. No blood and digestive toxicity were observed in the ADT group. 33 cases (52.4%) and 48 (53.3%) of the two groups had symptoms of afternoon hot flashes and fatigue, (P = 0.961).

CONCLUSION

Docetaxel chemotherapy combined with endocrine therapy could be one of effective treatments for delaying castration resistance of HVD-mHSPC, which could prolong PFS effectively and obtain a higher PSA response rate, high safety under close monitoring, and controllable adverse reactions.

Comparison of docetaxel pharmacokinetics between castration-resistant and hormone-sensitive metastatic prostate cancer patients

Purpose

Recently, docetaxel treatment of metastatic prostate cancer patients shifted towards the hormone-sensitive stage of the disease. There are contradictive reports on differences in toxicity of docetaxel in metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic castration-resistant prostate cancer (mCRPC) patients. Possible differences in toxicity might be attributed to different pharmacokinetics (PK) in the two patient populations.

Methods

Patients with mCRPC or mHSPC and a standard indication for docetaxel treatment were included in the study. All patients had suppressed serum testosterone levels (≤ 0.5 ng/mL or 1.73 nmol/L). Venous blood samples were obtained at the first docetaxel treatment, until 48 h after infusion. Plasma concentrations of docetaxel, unbound docetaxel and docetaxel metabolites were measured using validated liquid chromatography coupled tandem mass spectrometry (LC–MS/MS) assays and compared between the two groups. Moreover, serum levels of docetaxel transporting α1-acid glycoprotein were measured and docetaxel toxicity recorded.

Results

A total of ten mCRPC and nine mHSPC patients were included in the study. The two cohorts differed in the number of prior treatments and opiate use, which were higher for mCRPC patients. The docetaxel PK was not different between mCRPC and mHSPC patients, with areas under the plasma concentration versus time curve (AUC_0-48) 1710 [coefficient of variation (CV) 28.4%] and 1486 (CV 25.2%) ng/mL*h (p = 0.27), respectively. Also, the PK profile of unbound docetaxel, M1/M3, M2 and M4 metabolites were similar in both groups. Docetaxel doses were reduced in 50% of the mCRPC patients and 11% of the mHSPC patients.

Conclusion

The PK profile of docetaxel was similar in mCPRC and mHSPC patients. Therefore, possible differences in toxicity between mCRPC and mHSPC patients cannot be explained by differences in docetaxel PK in our study population. These results suggest that treatment adaptations are not recommended in the new population of patients with mHSPC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04433-3.

Feasibility and efficacy of early docetaxel plus androgen deprivation therapy for metastatic hormone-sensitive prostate cancer in a rural health care setting

AIM/BACKGROUND

The aim of this study was to evaluate the feasibility and efficacy, in terms of overall survival, of intensified upfront systemic therapy in patients with metastatic hormone-sensitive prostate cancer who lived in rural Nordland County, Norway.

PATIENTS AND METHODS

Overall 117 patients were included in this retrospective study. Three cohorts were created: early docetaxel and androgen deprivation therapy (ADT; the CHAARTED regimen; n = 37), ADT only during the same time period (2014-2020; n = 33), and ADT only in the years 2009-2014 (n = 47).

RESULTS

Four patients (11%) did not complete 6 cycles of docetaxel, one of these due to early progression of cancer. During follow-up, 8 patients (22%) progressed to castration-resistant disease (mCRPC), compared to 24 (73%) with ADT only and 35 (75%) in the historical cohort, p = 0.000001. Such progression occurred within 12 months in 3 patients (8%) treated with docetaxel and 9 patients (27%) treated with ADT only during the same time period, p = 0.05. Median survival was 56 months (95% CI: 40-72 months), compared to 30 months in both other cohorts. 3-year survival rates were 79%, 38% and 37%, respectively (p = 0.016). In multivariate analysis, the CHAARTED regimen was associated with significantly improved survival.

CONCLUSION

In this rural health care setting, early docetaxel was feasible and effective in reducing progression to mCRPC and prolonging survival. Median survival was very close to the 58 months reported in the CHAARTED trial.

Management of newly diagnosed metastatic hormone-sensitive prostate cancer: A survey of UK Uro-oncologists

AIM

To explore the practice and views of uro-oncologists in the United Kingdom regarding their use of chemotherapy and androgen receptor-targeted agents (ARTAs) in patients with newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC).

METHODS

An expert-devised paper or online questionnaire was completed by members of the British Uro-oncology Group.

RESULTS

All respondents stated that they would offer patients with newly diagnosed mHSPC docetaxel and androgen deprivation therapy (ADT) if they were sufficiently fit to receive chemotherapy (this was the only option available at the time of the survey); 64% would strongly recommend docetaxel for those with high-volume metastatic disease and 31% for those with low-volume disease. Hypothetically, if both docetaxel and ARTAs were available in the United Kingdom for mHSPC, almost 65% of respondents would recommend an ARTA with ADT to these patients in at least one-half of all cases, with the strongest recommendations to patients with high-risk disease. Imaging for the response was conducted according to suspicion of disease progression, regardless of treatment, with the minority of clinicians recommending routine imaging. If a choice of therapy was available, docetaxel would be more likely to be offered to patients with liver or lung metastases, and ARTAs to patients with bone or lymph node only metastases. Almost all respondents would offer local radiotherapy to the primary tumour in patients with low-volume disease.

CONCLUSION

All the UK uro-oncologists surveyed stated that they would offer docetaxel in combination with ADT to all newly diagnosed patients with mHSPC if fit enough for chemotherapy. ARTAs would be offered to many patients if available, especially those with high-risk disease or those unfit to receive chemotherapy. Scanning was typically conducted following treatment only at the suspicion of disease progression.

Short-term outcomes of risk-adapted upfront docetaxel administration in patients with metastatic hormone-sensitive prostate cancer: a multicenter prospective study in Japan

We conducted a risk-adapted upfront docetaxel (DOC) in patients with metastatic hormone-sensitive prostate cancer (mHSPC). Here, we reported an interim analysis of the study. The study enrolled 68 patients with newly diagnosed mHSPC between 2016 and 2018. According to the presence of visceral metastasis, an EOD score ≥ 3, or prostate-specific antigen (PSA) level at 3 months of ≥ 1 ng/mL, patients were divided into low- and high-risk groups. Patients were treated with androgen deprivation therapy (ADT) with or without bicalutamide; those in the high-risk group received upfront treatment involving six cycles of DOC (70 mg/m²). Short-term treatment effect, adverse events, and quality of life (QOL) were evaluated. Fifty (73.5%) were classified in the high-risk group, and 46 (67%) received upfront ADT + DOC. In the ADT + DOC group, 43.5% (20/46) patients achieved a PSA level ≤ 0.2 ng/mL. PSA nadir and time to PSA nadir were 0.291 ng/mL and 288 days, respectively. In the ADT + DOC group, 76.1% (35/42) patients had adverse events (AEs) of grade ≥ 3. During a median follow-up of 18.5 months, 36.4% (8/22) patients in the ADT group and 43.5% (20/46) in the ADT + DOC group had CRPC. Two QOL scores including the physical status and appetite loss at 6 months significantly worsened in the ADT + DOC group but was resolved by 12 months. Upfront DOC achieved high PSA responses without long-term QOL deterioration. However, the short-term outcomes were limited. Longer follow-up is needed to determine the survival advantage.

Predictors of real-world utilisation of docetaxel combined with androgen deprivation therapy in metastatic hormone-sensitive prostate cancer

BACKGROUND

Docetaxel has emerged as a standard-of-care for metastatic hormone-sensitive prostate cancer (mHSPC). Uptake of docetaxel for mHSPC in Australia has not previously been reported.

AIMS

i) To investigate the real-world uptake of docetaxel in mHSPC; and ii) To identify predictors of utilisation of Docetaxel in mHSPC.

METHODS

Men diagnosed from June 2014 to December 2018 and enrolled in the Prostate Cancer Outcomes Registry-Victoria (PCOR-Vic) were included. Data collected includes demographics, diagnosis method and institution, staging investigations, and treatments within 12 months of diagnosis. Wilcoxon rank-sum, chi-square and trend tests were used to identify predictors of docetaxel utilisation. All predictors were entered as covariates simultaneously into a multivariable logistic regression model. Statistical significance was set at 0.05 (two-sided).

RESULTS

1014 men with mHSPC were analysed, 25% of whom received docetaxel with androgen deprivation therapy (ADT). Uptake of docetaxel increased from 20% in 2014 to 33% in 2018. Predictors of higher usage of docetaxel were younger age and treatment in a private hospital, with both remaining significant on multivariable analysis. Notably, the proportion of men under 70 receiving docetaxel increased from 54% in 2014-15 to 64% in 2016-18, while in men aged 70 and over the comparative figures were 15% and 22% respectively.

CONCLUSIONS

Although docetaxel was not used in a majority of cases, there was a clear increase in docetaxel uptake especially in younger men following publication of the CHAARTED and STAMPEDE trials. Identifying barriers to real-world implementation of pivotal clinical trial data is critical to improving outcomes in mHSPC. This article is protected by copyright. All rights reserved.

Comparative Efficacy of Combined Radiotherapy, Systemic Therapy, and Androgen Deprivation Therapy for Metastatic Hormone-Sensitive Prostate Cancer: A Network Meta-Analysis and Systematic Review

Background: Recent randomized clinical trials have examined the efficacy of different combinations of systemic and local treatment approaches for metastatic hormone-sensitive prostate cancer (mHSPC). We compared the efficacy of these combined regimens in order to identify the optimal therapy for specific patient subgroups. Methods: The treatments were abiraterone (ABI), apalutamide (APA), docetaxel (DOC), enzalutamide (ENZ), and radiotherapy (RT) combined with androgen-deprivation therapy (ADT). Five electronic databases were searched up to May 7, 2020 for relevant trials. The risk of bias in the included trials was evaluated with the Cochrane tool. The hazard ratio (HR) with 95% confidence interval (CI) was determined for the included trials and indirect comparisons were performed using the R software. Results: In total, 10 randomized, controlled trials with 11,194 patients were included in the meta-analysis. ADT + RT was superior to ADT monotherapy in terms of overall survival (HR = 0.96, 95% CI: 0.85-1.1) and conferred a survival benefit in a subgroup of low-volume patients (HR = 0.68, 95% CI: 0.54-0.87). Combined systemic treatments were significantly superior to ADT monotherapy in comparisons of survival and prostate-specific antigen response, including in the high-volume subgroup; meanwhile, in the low-volume subgroup only ADT + ENZ (HR = 0.38, 95% CI 0.21-0.69) showed a significant clinical benefit. In the Gleason score <8 subgroup, all combined systemic treatments were superior to ADT monotherapy, but the results were only significant for ADT + APA (HR = 0.56, 95% CI: 0.33-0.95) and ADT + DOC (HR = 0.71, 95% CI: 0.54-0.92). In the Gleason score ≥8 subgroup, ADT monotherapy was inferior (albeit not significantly) to combined treatments. In a ranking of performed comparisons, ADT + ENZ was the optimal regimen, although this was non-significant. Combined therapies also demonstrated superiority in quality-of-life indicators such as time to skeletal events and pain progression. Conclusion: ADT + radiotherapy led to superior outcomes in mHSPC patients with low-volume disease. While all combined systemic regimens confer a survival advantage over ADT monotherapy, the optimal treatment approach for certain mHSPC patient subgroups remains to be determined.

Comparative assessment of docetaxel for safety and efficacy between hormone-sensitive and castration-resistant metastatic prostate cancer

OBJECTIVE

To compare toxicity and response of docetaxel chemotherapy between metastatic hormone-sensitive prostate cancer (mHSPC) and castration-resistant metastatic prostate cancer (mCRPC) patients of the same therapeutic era for assessing of upfront docetaxel against the benchmark of docetaxel in the castrate resistant stage in the setting outside of clinical trials.

METHODS

A prospectively collected database of real-world prostate cancer patients receiving docetaxel was divided in mHSPC and mCRPC cases and retrospectively analyzed. Principal objectives were toxicity measured by the common criteria of adverse events terminology and response characterized by Prostate specific antigen decline and radiographic progression-free disease at restaging. The prognostic value of suspected variables for grade 3 to 5 toxicity and response was investigated by logistic regression analysis.

RESULTS

Of 72 patients 34 (47%) were treated for mHSPC and 38 (53%) for mCRPC. Patients with mCRPC were older and had worse performance status (P< 0.01). In mHSPC total number of grade 3 to 5 adverse events (24, median 0, interquartile range 0-1) was significantly less than in mCRPC (46, median 1, interquartile range 1-2) (P = 0.01). Multivariable analysis revealed age as independent predictive variable for grade 3 to 5 toxicity (P = 0.03) but not disease stage, Prostate specific antigen predocetaxel, volume of disease, and Eastern Cooperative Oncology Group performance status (P > 0.05). Objective response was significantly higher in mHSPC compared to mCRPC patients (P < 0.01). Multivariable analysis confirmed mHSPC stage as independent prognostic factor for radiographic progression free disease at restaging (P < 0.01).

CONCLUSIONS

The association of age with toxicity and of mHSPC stage with response resulted in significantly fewer grade 3 to 5 adverse events but higher response rates for upfront docetaxel in mHSPC compared with docetaxel in the later mCRPC stage.

Different therapeutic regimens in the treatment of metastatic prostate cancer by performing a Bayesian network meta-analysis

BACKGROUND

Although androgen deprivation therapy with or without chemotherapy are currently the mainstay of therapy for metastatic prostate cancer, accumulating data suggested the survival benefits from definitive local therapy such as radical prostatectomy or radiation therapy. Hence, this network meta-analysis was aimed to provide a hierarchy of different therapeutic regimens for mPCa.

METHODS

Relevant studies were retrieved comprehensively by searching the online databases of PubMed, EMBASE and Web of Science, published before July 1st, 2018. With the help of R-3.4.0 software and "gemtc-0.8.2" package, network meta-analysis was performed by random-effect model within a Bayesian framework. Hazard ratios and corresponding 95% credible intervals were calculated by Markov chain Monte Carlo methods. The surface under the cumulative ranking curve was also incorporated to rank the corresponding therapeutic regimens.

RESULTS

A total of 55,363 cases from 17 studies were ultimately involved in this study. Ten different therapeutic regimens and three clinical endpoints were finally assessed. As illustrated by our results, local therapy (such as radical prostatectomy or radiation therapy) could provide a relatively more favorable survival rate than systematic therapies (no local therapy, androgen deprivation therapy or androgen deprivation therapy + chemotherapy). Meanwhile, in the comparison of radiation therapy, brachytherapy and intensity modulated radiation therapy were among the best two therapies. Furthermore, radical prostatectomy had a relatively lower cancer specific mortality or all-cause mortality than brachytherapy or intensity modulated radiation therapy, in the comparison of local therapy, whereas brachytherapy showed a relatively longer overall survival than radical prostatectomy.

CONCLUSIONS

Our results indicated that local therapy was better than no local therapy. In a comprehensive comparison of three clinical endpoints (overall survival, cancer specific mortality or all-cause mortality), radical prostatectomy had a relatively lower cancer specific mortality or all-cause mortality than radiation therapy, whereas brachytherapy was superior to radical prostatectomy for overall survival.

The timing of docetaxel initiation in metastatic castrate-sensitive prostate cancer and the rate of chemotherapy-induced toxicity

Docetaxel pharmacokinetics are affected by androgen deprivation therapy (ADT), which is attributed to changes in liver metabolism induced by castration. In this retrospective analysis, we assessed whether initiating docetaxel treatment in close proximity to the start of ADT therapy for metastatic castrate-sensitive prostate cancer (mCSPC) is associated with more treatment-related toxicity. We identified all patients with mCSPC treated at The Ottawa Hospital that received docetaxel chemotherapy between June 2014 and September 2017. For each patient, we calculated the time to chemotherapy (TTC) interval between the start of ADT and the first cycle of docetaxel. We checked for an association between TTC and febrile neutropenia (FN), toxicity-induced dose reduction, toxicity-induced treatment delay, and toxicity-induced treatment discontinuation. Eighty-three patients were identified. The median TTC was 67 days (range 3-189). Twenty-three patients (27.7%) experienced FN. Docetaxel toxicity resulted in 8 patients (9.6%) having their treatment delayed, 30 patients (36.1%) having their dose reduced and 18 (21.6%) having their treatment discontinued before completing the scheduled 6 cycles. No correlation was found between the TTC and FN (P = 0.99), docetaxel dose reduction (P = 0.95), treatment delay (P = 0.06), and treatment discontinuation (P = 0.88). The timing of docetaxel treatment initiation in relation to ADT initiation in patients with mCSPC did not affect the rate of treatment-related toxicity. Therefore, there is no indication for upfront chemotherapy delay from start of ADT unless clinical factors warrant a delay in starting chemotherapy. A higher than expected FN rate was identified, and primary prophylaxis should be considered.