Improvement in overall and cancer-specific survival in contemporary, metastatic prostate cancer chemotherapy exposed patients

Treatment patterns and oncological outcomes of older adults with metastatic prostate cancer in real-world setting

BACKGROUND

The landscape of systemic therapies for metastatic hormone-sensitive (mHSPC) and castration resistant prostate cancer (mCRPC) extensively improved within the last decades resulting in a significantly prolonged overall survival. However, subgroup analyses of phase III trials suggest potentially different overall survival outcomes for older adults.

METHODS

We relied on our institutional metastatic prostate cancer database to identify mHSPC and subsequently mCRPC patients. Older adults were stratified according to age groups 70-74 versus ≥75-79 versus ≥80 years at metastatic occurrence. Subsequently, uni- and multivariable time to mCRPC and overall survival analyses were performed.

RESULTS

Of 494 older adults, 217 (44%) were 70-74 versus 180 (36%) 75-79 versus 97 (20%) ≥80 years old. Rates of local prostate cancer treatment differed significantly between all three groups (p < 0.01). Regarding mHSPC treatment, androgen receptor signaling inhibitors (ARSI) were administered in 30-39% of patients and docetaxel with 9% in age group 70-74 years and 6% and 3% in age groups 75-79 years and ≥80 years. Regarding mCRPC treatment, significant differences between treatment proportions were observed (p < 0.01). Most common treatment was ARSI for all three groups. Conversely, chemotherapy was more frequently administered in patients aged 70-74 (16%), relative to 4% and 3% in 75-79 year and ≥80 year aged patients. In univariable and multivariable time to mCRPC analyses, overall survival in mHSPC and OS in mCRPC analyses, no significant differences between all three age groups were observed (all p ≥ 0.3).

CONCLUSIONS

Treatment patterns differ significantly between older adults with metastatic prostate cancer. However, these differences may not result in differences of overall life expectancy.

Feasibility of Next-generation Sequencing of Liquid Biopsy (Circulating Tumor DNA) Samples and Tumor Tissue from Patients with Metastatic Prostate Cancer in a Real-world Clinical Setting in Germany

BACKGROUND AND OBJECTIVE

With European Medicines Agency approval of PARP inhibitors in metastatic castration-resistant prostate cancer and ongoing trials in metastatic hormone-sensitive prostate cancer, detection of genetic alterations in BRCA1/2 and other homologous recombination repair genes has gained an important role. Our aim was to investigate the feasibility and comparability of comprehensive next-generation sequencing (NGS) of liquid biopsy (LB; circulating tumor DNA) and tumor tissue (TT) samples in a real-world clinical setting.

METHODS

The study cohort consisted of 50 patients with metastatic prostate cancer (mPC) who had TT NGS performed for BRCA1/2 alterations and consent for additional LB NGS. The Oncomine Comprehensive Assay v3 (Thermo Fisher Scientific, Waltham, MA, USA) was used for TT NGS. The Guardant360 83-gene assay (Guardant Health, Palo Alto, CA, USA) was used for LB NGS, including all types of somatic alterations, microsatellite instability, and blood tumor mutational burden. We calculated BRCA1/2 alteration rates and the negative percentage agreement (NPA) and positive percentage agreement (PPA) between TT and LB results.

KEY FINDINGS AND LIMITATIONS

TT NGS was successful in 44/50 patients (88%), with pathogenic BRCA1/2 alterations detected in four (9%). LB NGS was successful in all 50 patients (100%), with BRCA1/2 alterations detected in ten (20%). In a subgroup analysis for the 44 patients with successful TT NGS, NPA was 85% and PPA was 50%. The median time between TT sample collection and blood sampling for NGS was 132 wk (IQR 94-186). The limited sample size and differences in the time of NGS assessment are limitations.

CONCLUSIONS AND CLINICAL IMPLICATIONS

LB NGS resulted in a higher detection rate for BRCA1/2 alterations in comparison to conventional TT NGS (20% vs 9%). Ideally, BRCA1/2 testing should be based on both approaches to identify all patients with mPC eligible for PARP inhibitor therapy.

PATIENT SUMMARY

Our study shows that genetic tests for both tumor tissue and blood samples results in higher rates of detection of BRCA1/2 gene alterations in patients with metastatic prostate cancer.

Descriptive analysis of prostate cancer pathology data from diagnosis and surgery in men from the 45 and Up Study

Information available from the New South Wales Cancer Registry (NSWCR) about the aggressiveness of prostate cancer is limited to the summary stage variable 'degree of spread', which contains a high proportion of cases defined as 'unknown'. In this study we demonstrate the feasibility of obtaining and analysing prostate cancer pathology data from stored pathology records. Pathology data were extracted from stored pathology records of incident prostate cancer cases in men participating in the 45 and Up Study, a large Australian prospective cohort study, who were diagnosed between January 2006 and December 2013. Baseline questionnaires from the 45 and Up Study were linked to the NSWCR. Demographic and pathology items were tabulated and associations described. We evaluated the completeness of pathological characteristics by degree of spread of cancer at diagnosis. Among the 123,921 men enrolled in the 45 and Up Study, 5,091 had incident prostate cancer and 5,085 were linked to a pathology record. The most complete variables included grade group of diagnostic (85.8%) and surgical (99.8%) specimens, margin status (98.1%), extraprostatic extension (95.1%) and seminal vesicle invasion (96.8%). Most diagnostic specimens were grade group 1 (26.6%) or 2 (23.5%). Of the 5,085 cases, 30.8% were classified by the NSWCR with unknown degree of spread; a pathology record could be extracted for 99.4% of these. The unknown degree of spread cases had similar levels of completeness and distribution of diagnostic and surgical pathology features to those with a localised degree of spread. This study demonstrated the feasibility of obtaining and analysing data derived from pathology reports from centralised state-based cancer registry notifications. Supplementing degree of spread information with pathology data from diagnosis and surgery will improve both the quality of research and policy aimed at improving the lives of men with prostate cancer.

The diagnosis and treatment of castrate-sensitive oligometastatic prostate cancer: A review

BACKGROUND

Oligometastatic prostate cancer (OMPCa) is emerging as a transitional disease state between localized and polymetastatic disease. This review will assess the current knowledge of castrate-sensitive OMPCa.

METHODS

A review of the current literature was performed to summarize the definition and classification of OMPCa, assess the diagnostic methods and imaging modalities utilized, and to review the treatment options and outcomes. We further identify gaps in knowledge and areas for future research.

RESULTS

Currently there is no unified definition of OMPCa. National guidelines mostly recommend systemic therapies without distinguishing oligometastatic and polymetastatic disease. Next generation imaging is more sensitive than conventional imaging and has led to early detection of metastases at initial diagnosis or recurrence. While mostly retrospective in nature, recent studies suggest that treatment (surgical or radiation) of the primary tumor and/or metastatic sites might delay initiation of androgen deprivation therapy while increasing survival in selected patients.

CONCLUSIONS

Prospective data are required to better assess the incremental improvement in survival and quality of life achieved with various treatment strategies in patients with OMPCa.

Comparison of peri- and intraoperative outcomes of open vs robotic-assisted partial nephrectomy for renal cell carcinoma: a propensity-matched analysis

BACKGROUND

Partial nephrectomy (PN) is the gold standard surgical treatment for resectable renal cell carcinoma (RCC) tumors. However, the decision whether a robotic (RAPN) or open PN (OPN) approach is chosen is often based on the surgeon's individual experience and preference. To overcome the inherent selection bias when comparing peri- and postoperative outcomes of RAPN vs. OPN, a strict statistical methodology is needed.

MATERIALS AND METHODS

We relied on an institutional tertiary-care database to identify RCC patients treated with RAPN and OPN between January 2003 and January 2021. Study endpoints were estimated blood loss (EBL), length of stay (LOS), rate of intraoperative and postoperative complications, and trifecta. In the first step of analyses, descriptive statistics and multivariable regression models (MVA) were applied. In the second step of analyses, to validate initial findings, MVA were applied after 2:1 propensity-score matching (PSM).

RESULTS

Of 615 RCC patients, 481 (78%) underwent OPN vs 134 (22%) RAPN. RAPN patients were younger and presented with a smaller tumor diameter and lower RENAL-Score sum, respectively. Median EBL was comparable, whereas LOS was shorter in RAPN vs. OPN. Both intraoperative (27 vs 6%) and Clavien-Dindo > 2 complications (11 vs 3%) were higher in OPN (both < 0.05), whereas achievement of trifecta was higher in RAPN (65 vs 54%; p = 0.028). In MVA, RAPN was a significant predictor for shorter LOS, lower rates of intraoperative and postoperative complications as well as higher trifecta rates. After 2:1 PSM with subsequent MVA, RAPN remained a statistical and clinical predictor for lower rates of intraoperative and postoperative complications and higher rates of trifecta achievement but not LOS.

CONCLUSIONS

Differences in baseline and outcome characteristics exist between RAPN vs. OPN, probably due to selection bias. However, after applying two sets of statistical analyses, RAPN seems to be associated with more favorable outcomes regarding complications and trifecta rates.

Effect of chemotherapy in metastatic prostate cancer according to race/ethnicity groups

BACKGROUND

No North-American study tested the survival benefit of chemotherapy in de novo metastatic prostate cancer according to race/ethnicity. We addressed this void.

METHODS

We identified de novo metastatic prostate cancer patients within the Surveillance, Epidemiology, and End Results database (2014-2015). Separate and specific Kaplan-Meier plots and Cox regression models tested for overall survival differences between chemotherapy-exposed versus chemotherapy-naïve patients in four race/ethnicity groups: Caucasian versus African-American versus Hispanic/Latino vs Asian. Race/ethnicity specific propensity score matching was applied. Here, additional landmark analysis was performed.

RESULTS

Of 4232 de novo metastatic prostate cancer patients, 2690 (63.3%) were Caucasian versus 783 (18.5%) African-American versus 504 (11.8%) Hispanic/Latino versus 257 (6.1%) Asian. Chemotherapy rates were: 21.3% versus 20.8% versus 21.0% versus 20.2% for Caucasians versus African-Americans versus Hispanic/Latinos versus Asians, respectively. At 30 months of follow-up, overall survival rates between chemotherapy-exposed versus chemotherapy-naïve patients were 61.5 versus 53.2% (multivariable hazard ratio [mHR]: 0.76, 95 confidence interval [CI]: 0.63-0.92, p = 0.004) in Caucasians, 55.2 versus 51.6% (mHR: 0.76, 95 CI: 0.54-1.07, p = 0.11) in African-Americans, 62.8 versus 57.0% (mHR: 1.11, 95 CI: 0.73-1.71, p = 0.61) in Hispanic/Latinos and 77.7 versus 65.0% (mHR: 0.31, 95 CI: 0.11-0.89, p = 0.03) in Asians. Virtually the same findings were recorded after propensity score matching within each race/ethnicity group.

CONCLUSIONS

Caucasian and Asian de novo metastatic prostate cancer patients exhibit the greatest overall survival benefit from chemotherapy exposure. Conversely, no overall survival benefit from chemotherapy exposure could be identified in either African-Americans or Hispanic/Latinos. Further studies are clearly needed to address these race/ethnicity specific disparities.

Non-organ confined stage and upgrading rates in exclusive PSA high-risk prostate cancer patients

BACKGROUND

The pathological stage of prostate cancer with high-risk prostate-specific antigen (PSA) levels, but otherwise favorable and/or intermediate risk characteristics (clinical T-stage, Gleason Grade group at biopsy [B-GGG]) is unknown. We hypothesized that a considerable proportion of such patients will exhibit clinically meaningful GGG upgrading or non-organ confined (NOC) stage at radical prostatectomy (RP).

MATERIALS AND METHODS

Within the Surveillance, Epidemiology, and End Results database (2010-2015) we identified RP-patients with cT1c-stage and B-GGG1, B-GGG2, or B-GGG3 and PSA 20-50 ng/ml. Rates of GGG4 or GGG5 and/or rates of NOC stage (≥ pT3 and/or pN1) were analyzed. Subsequently, separate univariable and multivariable logistic regression models tested for predictors of NOC stage and upgrading at RP.

RESULTS

Of 486 assessable patients, 134 (28%) exhibited B-GGG1, 209 (43%) B-GGG2, and 143 (29%) B-GGG3, respectively. The overall upgrading and NOC rates were 11% and 51% for a combined rate of upgrading and/or NOC stage of 53%. In multivariable logistic regression models predicting upgrading, only B-GGG3 was an independent predictor (odds ratio [OR]: 5.29; 95% confidence interval [CI]: 2.21-14.19; p < 0.001). Conversely, 33%-66% (OR: 2.36; 95% CI: 1.42-3.95; p = 0.001) and >66% of positive biopsy cores (OR: 4.85; 95% CI: 2.84-8.42; p < 0.001), as well as B-GGG2 and B-GGG3 were independent predictors for NOC stage (all p ≤ 0.001).

CONCLUSIONS

In cT1c-stage patients with high-risk PSA baseline, but low- to intermediate risk B-GGG, the rate of upgrading to GGG4 or GGG5 is low (11%). However, NOC stage is found in the majority (51%) and can be independently predicted with percentage of positive cores at biopsy and B-GGG.

Effect of Chemotherapy on Overall Survival in Contemporary Metastatic Prostate Cancer Patients

Introduction

Randomized clinical trials demonstrated improved overall survival in chemotherapy exposed metastatic prostate cancer patients. However, real-world data validating this effect with large scale epidemiological data sets are scarce and might not agree with trials. We tested this hypothesis.

Materials and Methods

We identified de novo metastatic prostate cancer patients within the Surveillance, Epidemiology, and End Results (SEER) database (2014-2015). Kaplan-Meier plots and Cox regression models tested for overall survival differences between chemotherapy-exposed patients vs chemotherapy-naïve patients. All analyses were repeated in propensity-score matched cohorts. Additionally, landmark analyses were applied to account for potential immortal time bias.

Results

Overall, 4295 de novo metastatic prostate cancer patients were identified. Of those, 905 (21.1%) patients received chemotherapy vs 3390 (78.9%) did not. Median overall survival was not reached at 30 months follow-up. Chemotherapy-exposed patients exhibited significantly better overall survival (61.6 vs 54.3%, multivariable HR:0.82, CI: 0.72-0.96, p=0.01) at 30 months compared to their chemotherapy-naïve counterparts. These findings were confirmed in propensity score matched analyses (multivariable HR: 0.77, CI:0.66-0.90, p<0.001). Results remained unchanged after landmark analyses were applied in propensity score matched population.

Conclusions

In this contemporary real-world population-based cohort, chemotherapy for metastatic prostate cancer patients was associated with better overall survival. However, the magnitude of overall survival benefit was not comparable to phase 3 trials.