Impact of clinical trial participation on survival in patients with castration-resistant prostate cancer: a multi-center analysis

Factors associated with clinical trial participation for patients with renal cell carcinoma

OBJECTIVE

Recruitment of a diverse and representative study population is critical to the external validity of oncology clinical trials. The primary objective of this study was to characterize the factors associated with clinical trial participation for patients with renal cell carcinoma and the secondary objective was to examine differences in survival outcomes.

MATERIALS AND METHODS

We used a matched case-control design by querying the National Cancer Database for patients with renal cell carcinoma who were coded as having enrolled in a clinical trial. Trial patients were matched in a 1:5 ratio to the control cohort based on clinical stage and then sociodemographic variables were compared between the 2 groups. Multivariable conditional logistic regression models evaluated factors associated with clinical trial participation. The trial patient cohort was then matched again in a 1:10 ratio based on age, clinical stage, and comorbidities. Log-rank test was used to compare overall survival (OS) between these groups.

RESULTS

From 2004 to 2014, 681 patients enrolled in clinical trials were identified. Clinical trial patients were significantly younger and had a lower Charlson-Deyo comorbidity score. On multivariate analysis, male patients and white patients were more likely to participate compared to their Black counterparts. Having Medicaid or Medicare negatively associated with trial participation. Median OS was greater among clinical trial participants.

CONCLUSION

Patient sociodemographic factors remain significantly associated with clinical trial participation and trial participants experienced superior OS to their matched counterparts.

Trial Participation is Not Associated with Better Biochemical Recurrence-free Survival in a Large Cohort of External Beam Radiotherapy-Treated Intermediate- and High-Risk Prostate Cancer Patients

AIMS

There is a widespread belief that outcomes of cancer patients treated within clinical trials might not be representative of the outcomes obtained within standard clinical settings. We sought to investigate the effect of trial participation on biochemical recurrence (BCR) in localised, D'Amico intermediate- and high-risk prostate cancer patients treated with external beam radiotherapy (EBRT).

MATERIALS AND METHODS

We relied on a study population treated with EBRT between January 2001 and January 2021 at a single tertiary care centre, stratified according to trial enrolment. Separate Kaplan-Meier and multivariable Cox regression models tested BCR-free survival at 60 months within intermediate- and high-risk EBRT patients, after adjustment for covariables. Additionally, the analyses were refitted after inverse probability treatment weighting was performed separately for both risk subgroups.

RESULTS

Of 932 eligible patients, 635 (68%) and 297 (32%) had intermediate- and high-risk prostate cancer, respectively. Overall, 53% of patients were trial participants. BCR rates were 11 versus 5% (P = 0.27) and 12 versus 14% (P = 0.08) in trial participants versus non-participants for intermediate- and high-risk subgroups, respectively. Differences in patient and clinical characteristics were recorded. Trial participation status failed to reach predictor status in multivariable Cox regression models for BCR in both intermediate-risk (hazard ratio 1.34; 95% confidence interval 0.71-2.49; P = 0.4) and high-risk patients (hazard ratio 1.03; 95% confidence interval 0.45-2.34; P = 0.9). Virtually the same results were recorded in inverse probability treatment weighting cohorts.

CONCLUSIONS

Relying on a large cohort of EBRT-treated intermediate- and high-risk patients, no BCR differences were recorded between trial participants and non-participants after accounting for confounders.

Inequities in Alliance Acute Leukemia Clinical Trial and Biobank Participation: Defining Targets for Intervention

PURPOSE

Representativeness in acute leukemia clinical research is essential for achieving health equity. The National Cancer Institute's mandate for Comprehensive Cancer Centers (CCCs) to define and assume responsibility for cancer control and treatment across a geographic catchment area provides an enforceable mechanism to target and potentially remediate participatory inequities.

METHODS

We examined enrollee characteristics across 15 Cancer and Leukemia Group B/Alliance cooperative group adult acute leukemia clinical trials (N = 3,734) from 1998 to 2013, including participation in optional companion biobanks. We determined enrollment odds by race-ethnicity for all participants adjusted for national incidence, and for those enrolled at CCCs adjusted for catchment area incidence. We modeled biobank participation by sociodemographics using logistic regression.

RESULTS

Non-Hispanic (NH)-White patients were more likely to be enrolled than NH-Black, NH-Asian, or Hispanic patients (odds ratio [OR], 0.75, 0.48, and 0.44, respectively; all P < .001), but less likely than NH-Native American patients (OR, 1.91; P < .001), adjusted for national incidence. Enrollment odds were lower for NH-Black, NH-Asian, and Hispanic patients at CCCs adjusted for catchment area incidence (OR, 0.57, 0.26, and 0.32, respectively; P < .001); differences were driven by overenrollment of NH-White patients from outside self-defined catchment areas (18.1% v 12.3%; χ2 P = .01) and by CCCs with less absolute enrollee diversity (rank sum P = .03). Among all enrollees, NH-White race-ethnicity and lower neighborhood deprivation correlated with biobank participation (OR, 1.81 and 1.45, respectively; P = .01 and .03). For CCC enrollees, the correlation of race-ethnicity with biobank participation was attenuated by a measure accounting for their site's degree of enrollment disparity but not neighborhood deprivation.

CONCLUSION

Acute leukemia clinical research disparities are substantial and driven by structural trial enrollment barriers at CCCs. Real-time CCC access and enrollment monitoring is needed to better align research participation with local populations.

Racial and ethnic enrollment disparities and demographic reporting requirements in acute leukemia clinical trials

Public demographic reporting for acute leukemia trials is inadequate, and NH-White subjects are more likely to be enrolled.

Larger racial-ethnic enrollment disparities were documented after federal reporting requirements, which may be from more data transparency.

Data regarding racial and ethnic enrollment diversity for acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL) clinical trials in the United States are limited, and little is known about the effect of federal reporting requirements instituted in the late 2000s. We examined demographic data reporting and enrollment diversity for ALL and AML trials in the United States from 2002 to 2017, as well as changes in reporting and diversity after reporting requirements were instituted. Of 223 AML trials and 97 ALL trials with results on ClinicalTrials.gov, 68 (30.5%) and 51 (52.6%) reported enrollment by both race and ethnicity. Among trials that reported race and ethnicity (AML, n = 6554; ALL, n = 4149), non-Hispanic (NH)-Black, NH-Native American, NH-Asian, and Hispanic patients had significantly lower enrollment compared with NH-White patients after adjusting for race-ethnic disease incidence (AML odds ratio, 0.68, 0.31, 0.75, and 0.83, respectively; ALL odds ratio, 0.74, 0.27, 0.67, and 0.64; all, P ≤ .01). The proportion of trials reporting race increased significantly after implementation of the reporting requirements (44.2% to 60.2%; P = .02), but race-ethnicity reporting did not (34.8% to 38.6%; P = .57). Reporting proportions according to number of patients enrolled increased significantly after the reporting requirements were instituted (race, 51.7% to 72.7%; race-ethnicity, 39.5% to 45.4%; both, P < .001), and relative enrollment of NH-Black and Hispanic patients decreased (AML odds ratio, 0.79 and 0.77; ALL odds ratio, 0.35 and 0.25; both P ≤ .01). These data suggest that demographic enrollment reporting for acute leukemia trials is suboptimal, changes in diversity after the reporting requirements may be due to additional enrollment disparities that were previously unreported, and enrollment diversification strategies specific to acute leukemia care delivery are needed.

Outcomes among pediatric patients with cancer who are treated on trial versus off trial: A matched cohort study

BACKGROUND

Approximately 50% of children with cancer in the United States who are aged <15 years receive primary treatment on a therapeutic clinical trial. To the authors' knowledge, it remains unknown whether trial enrollment has a clinical benefit compared with the best alternative standard therapy and/or off trial (ie, clinical trial effect). The authors conducted a retrospective matched cohort study to compare the morbidity and mortality of pediatric patients with cancer who are treated on a phase 3 clinical trial compared with those receiving standard therapy and/or off trial.

METHODS

Subjects were aged birth to 19 years; were diagnosed between 2000 and 2010 with acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), rhabdomyosarcoma, or neuroblastoma; and had received initial treatment at the Children's Hospital of Philadelphia. On-trial and off-trial subjects were matched based on age, race, ethnicity, a diagnosis of Down syndrome (for patients with ALL or AML), prognostic risk level, date of diagnosis, and tumor type.

RESULTS

A total of 428 participants were matched in 214 pairs (152 pairs for ALL, 24 pairs for AML, 32 pairs for rhabdomyosarcoma, and 6 pairs for neuroblastoma). The 5-year survival rate did not differ between those treated on trial versus those treated with standard therapy and/or off trial (86.9% vs 82.2%; P = .093). On-trial patients had a 32% lower odds of having worse (higher) mortality-morbidity composite scores, although this did not reach statistical significance (odds ratio, 0.68; 95% confidence interval, 0.45-1.03 [P = .070]).

CONCLUSIONS

There was no statistically significant difference in outcomes noted between those patients treated on trial and those treated with standard therapy and/or off trial. However, in partial support of the clinical trial effect, the results of the current study indicate a trend toward more favorable outcomes in children treated on trial compared with those treated with standard therapy and/or off trial. These findings can support decision making regarding enrollment in pediatric phase 3 clinical trials.

Muscle Characteristics Obtained Using Computed Tomography as Prognosticators in Patients with Castration-Resistant Prostate Cancer

Limited studies have investigated the correlation between body composition and prostate cancer outcomes. We analyzed the effect of muscle mass and quality on castration-resistant prostate cancer (CRPC) outcomes. Skeletal muscle index (SMI) and skeletal muscle attenuation (SMA) were measured for 411 patients at the L3 vertebral level using computed tomography at CRPC diagnosis and were dived to low and high groups at the value of median. Analysis of the skeletal phenotypes and age (<70 and >70 years) was performed to evaluate the effect of SMI and SMA. The median survival rates for patients with low and high SMI were 19 and 24 months (p = 0.015), and those with low and high SMAs were 15 and 26 months (p < 0.001), respectively. In the subgroup analysis by age, SMA was a significant prognosticator in both groups, while SMI was a significant prognosticator only in patients aged >70 years. Patients with low SMA + low SMI had the worst prognosis. Muscle characteristics seems to be a prognosticator in survival of CRPC patients and may be considered in treatment planning.

The prophylactic use of fibrinogen concentrate in high-risk cardiac surgery

BACKGROUND

Perioperative blood loss is a major contributor to morbidity and mortality in cardiac surgery. Plasma fibrinogen levels play an essential role in hemostasis and deplete quickly during hemorrhage. The objective of this study was to determine whether prophylactic fibrinogen concentrate administration lowers overall blood product transfusion requirements in high-risk cardiac surgery in patients with low fibrinogen plasma levels.

METHODS

The study was performed in a prospective, randomized, and double-blinded design. The investigation included 62 patients undergoing elective, high-risk cardiac surgery. After weaning from cardiopulmonary bypass and reversal of heparin patients received either fibrinogen concentrate or placebo. The primary outcome variable was overall blood product usage 24 hours after intervention.

RESULTS

The fibrinogen group received numerically fewer total units of blood products than the placebo group, but the difference was not statistically or clinically significant (for groups n = 27; n = 29 and 19 vs 37 units, respectively, P = .908). The overall transfusion rate in both groups was significantly lower than the institutional average suggested (fibrinogen group 26%, placebo group 28%). The fibrinogen group showed significantly higher fibrinogen levels (2.38 vs 1.83 g/L (end of surgery), P < .001; 3.33 vs 2.68 g/L (12 hours after intervention), P = .003) and improved viscoelastic coagulation parameters (FIBTEM MCF, 27 vs 23 mm, P = .022).

CONCLUSION

This randomized, controlled trial demonstrates that point-of-care guided and prophylactic treatment with fibrinogen concentrate does not reduce transfusion of blood products in a setting of unexpectedly low transfusion rate as tested in this cohort, but may improve coagulation parameters in the setting of high-risk cardiac surgery.

Age, Gleason Score, and PSA are important prognostic factors for survival in metastatic castration-resistant prostate cancer. Results of The Uroncor Group (Uro-Oncological Tumors) of the Spanish Society of Radiation Oncology (SEOR)

INTRODUCTION

The treatment of metastatic castration-resistant prostate cancer (mCRPC) has changed significantly in recent years. Inhibitors of androgen receptors have shown especially significant benefits in overall (OS) and progression-free survival (PFS), with a good toxicity profile. Treatment selection depends on the patient's individual clinical, radiological, and biological characteristics.

OBJECTIVE

To describe treatment outcomes (efficacy, toxicity) in a cohort of patients with mCRPC in Spain.

MATERIALS AND METHODS

Multicenter, retrospective study of patients with mCRPC included in a database of the Urological Tumour Working Group (URONCOR) of the Spanish Society of Radiation Oncology (SEOR). Metastatic CRPC was defined according to the prostate cancer working group 3 (PCWG3) criteria. The Kaplan-Meier technique was used to evaluate OS and the Common Terminology Criteria for Adverse Events (CTCAE, v.4.0) were used to assess toxicity. Univariate and multivariate Cox regression analyses were performed to identify the factors significantly associated with OS.

RESULTS

A total of 314 patients from 17 hospitals in Spain diagnosed with mCRPC between June 2010 and September 2017 were included in this study. Mean age at diagnosis was 68 years (range 45-89). At a median follow-up of 35 months, OS at 1, 3, and 5 years were 92%, 38%, and 28%, respectively. Grades 1-2 and grade 3 toxicity rates were, respectively, 68% and 19%. No grade 4 toxicities were observed. On the multivariate analysis, the following factors were significantly associated with OS: age (hazard ratio [HR] 0.42, p = 0.010), PSA value at diagnosis of mCRPC (HR 0.55, p = 0.008), and Gleason score (HR 0.61, p = 0.009).

CONCLUSIONS

Age, Gleason score, and PSA at diagnosis of mCRPC are independently associated with overall survival in patients with mCRPC. The efficacy and toxicity outcomes in this patient cohort treated in radiation oncology departments in Spain are consistent with previous reports.

Impact of clinical trial participation on survival in patients with castration-resistant prostate cancer: a multi-center analysis

BACKGROUND

Clinical trial (CT) participation may confer access to new, potentially active agents before their general availability. This study aimed to investigate the potential survival benefit of participation in investigational CTs of novel hormonal, chemotherapeutic, and radiopharmaceutical agents in patients with castration-resistant prostate cancer (CRPC).

METHODS

This multi-center, retrospective analysis included 299 consecutive patients with newly diagnosed, non-metastatic or metastatic CRPC between September 2009 and March 2017. Of these, 65 (21.7%) patients participated in CTs pertaining to systemic treatment targeting CRPC and 234 (78.3%) patients received pre-established, standard systemic treatment outside of a CT setting. The survival advantage of CT participation regarding cancer-specific survival (CSS) was investigated.

RESULTS

An Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2 at CRPC diagnosis was found in a lower proportion CT participants than in non-participants (4.6% vs. 14.9%; p = 0.033). During the median follow-up period of 16.0 months, CT participants exhibited significantly higher 2-year CSS survival rates (61.3% vs. 42.4%; p = 0.003) than did non-participants. Multivariate analysis identified prostate-specific antigen and alkaline phosphatase levels at CRPC onset, Gleason score ≥ 8, ECOG PS ≥2, less number of docetaxel cycles administered, and non-participation in CTs as independent predictors for a lower risk of CSS.

CONCLUSIONS

Patients diagnosed with CRPC who participated in CTs exhibited longer CSS durations than non-participants who received pre-established, standard systemic therapy outside of a CT setting. Our findings imply that CT participation is associated with CSS, and that CT participation should be offered to patients with CRPC whenever indicated.