Time In Prostate Cancer Research Articles

Prevalence of germline BRCA1/2 pathogenic variants in Japanese patients treated with castration-resistant prostate cancer and efficacy of CRPC treatment in real-world clinical practice.

The companion diagnosis for olaparib, a poly (ADP-ribose) polymerase inhibitor for prostate cancer, aims to detect BRCA1/2 gene variants. In clinical practice, the frequency of germline BRCA1/2 variants in patients receiving castration-resistant prostate cancer treatment is unknown. We aimed to evaluate the prevalence of germline BRCA1/2 variants and their relationship to prognosis and treatment efficacy in castration-resistant prostate cancer. Between June 2021 and 2023, 92 patients receiving castration-resistant prostate cancer treatment were examined for germline BRCA1/2 variants using BRACAnalysis CDx®. Furthermore, the associations between BRCA1/2 pathogenic variants and clinical outcomes were assessed. Of the 92 patients referred for genetic testing, 6 (6.5%) carried germline pathogenic variants in BRCA1/2. The BRCA2 variant was the most frequent (n=5), followed by BRCA1 variant (n=1). Among the five variants in BRCA2, the p.Asp427Thrfs*3 variant was identified for the first time in prostate cancer. Overall survival from castration-resistant prostate cancer for patients with BRCA1/2 variants was significantly shorter than for patients without BRCA1/2 variants (P=0.043). Progression-free survival of androgen receptor signaling inhibitors for patients with BRCA1/2 variants was significantly shorter than for those without (P=0.003). Progression-free survival of taxane chemotherapy was significantly shorter in patients with BRCA1/2 variants than in those without (P=0.0149). In clinical practice, 6.5% of patients treated with castration-resistant prostate cancer carried germline BRCA1/2 pathogenic variants. Japanese castration-resistant prostate cancer patients with germline BRCA1/2 mutants have a poor prognosis and may be less responsive to treatment with androgen receptor signaling inhibitors and taxane-based chemotherapy for castration-resistant prostate cancer.

Completion time in prostate cancer treated with proton beam therapy: Do interruptions matter?

e17553 Background: The association between completion time of proton therapy(PT) in prostate cancer and biochemical control is unknown. Methods: We queried the multi-institutional, prospectively collected, proton collaborative group registry for prostate cases treated definitively with PT. Kaplan meier methodology was used for biochemical failure free (bFF) rates and multivariable regression analyses (MVA) were used to identify correlates of treatment interruptions (TI) and bF. Results: After exclusion, 2794 men with 693 low, 869 favorable intermediate, 627 unfavorable intermediate, and 605 high risk prostate cancers had available data. The median age was 68 years(40-92), 90% were white and 8% were black. Androgen deprivation therapy (ADT) was given to 676 patients, 312 treatments were hypofractionated, and median EQD2 dose = 75(74-86) GyE1.5. Kaplan-meier median follow-up was 79 months. In total 900 patients (32%) had at least one TI. Shorter treatments (HR = 0.95 per day, P < 0.01) and high risk (HR = 0.72, P < 0.04) cases were less likely to have Tis on MVA. There was no difference in 5-year bFF rate with (92.7) and without (93.1%) TIs. In a subset of only high risk patients treated with ADT (n = 385), the 5-year bFF was 83% without TIs and 75% with TIs (HR = 2.10, P = 0.06). This discrepancy was significant with multivariable binomial regression (HR = 2.36, P = 0.03), and the bF difference was greatest when > 5 treatment days were missed per receiver operating characteristic curve. Conclusions: Largely, there was no correlation between TIs and bF in prostate cancer treated with PT, however completion time may play a more significant role in high risk disease.

Evaluation of T1 relaxation time in prostate cancer and benign prostate tissue using a Modified Look-Locker inversion recovery sequence

Purpose of this study was to evaluate the diagnostic performance of T1 relaxation time (T1) for differentiating prostate cancer (PCa) from benign tissue as well as high- from low-grade PCa. Twenty-three patients with suspicion for PCa were included in this prospective study. 3 T MRI including a Modified Look-Locker inversion recovery sequence was acquired. Subsequent targeted and systematic prostate biopsy served as a reference standard. T1 and apparent diffusion coefficient (ADC) value in PCa and reference regions without malignancy as well as high- and low-grade PCa were compared using the Mann-Whitney U test. The performance of T1, ADC value, and a combination of both to differentiate PCa and reference regions was assessed by receiver operating characteristic (ROC) analysis. T1 and ADC value were lower in PCa compared to reference regions in the peripheral and transition zone (p < 0.001). ROC analysis revealed high AUCs for T1 (0.92; 95%-CI, 0.87–0.98) and ADC value (0.97; 95%-CI, 0.94 to 1.0) when differentiating PCa and reference regions. A combination of T1 and ADC value yielded an even higher AUC. The difference was statistically significant comparing it to the AUC for ADC value alone (p = 0.02). No significant differences were found between high- and low-grade PCa for T1 (p = 0.31) and ADC value (p = 0.8). T1 relaxation time differs significantly between PCa and benign prostate tissue with lower T1 in PCa. It could represent an imaging biomarker for PCa.

Contemporary analysis of the effect of marital status on survival of prostate cancer patients across all stages: A population-based study

BackgroundMarital status rates may have changed over time in prostate cancer (PC) patients and may have affected cancer-specific mortality (CSM) and other-cause mortality (OCM). MethodsWithin the Surveillance, Epidemiology, and End Results database (2004–2015), we identified PC patients who were either married (n = 326,664) or unmarried (n = 106,533). Temporal trends, cumulative incidence plots, as well as multivariable competing risks regression analyses focused on (1) the overall population, (2) D'Amico low-risk N0M0 PC, (3) D'Amico intermediate-risk N0M0 PC, (4) D'Amico high-risk N0M0 PC, (5) N1M0 PC, and (6) M1 PC patients. ResultsOf all, 24.6 % were unmarried and increased trend over time (23.0%–26.9%, P < 0.001). Unmarried men experienced higher CSM rates (9.8% vs. 6.3% in married men, P < 0.001) and OCM rates (24.3% vs. 17.1% in married men, P < 0.001) in the overall population, as well as in all subgroup analyses. Unmarried status represented an independent predictor of higher CSM (hazard ratio: 1.19, P < 0.001) and OCM (hazard ratio: 1.41, P < 0.001) in the overall cohort, as well as in all subgroup analyses except for the N1M0 subgroup, where marital status did not reach independent predictor status for CSM. ConclusionsUnmarried PC patients are at higher risk of CSM and OCM. This relationship applies to all stage subgroups, except for the N1M0 subgroup. Consequently, unmarried individuals should ideally benefit of improved counseling, closer follow-up, as well as of other measures aimed at reducing the CSM and OCM disadvantages.

1173 - Contemporary analysis of the effect of marital status on survival of prostate cancer patients across all stages: A population-based study

Abstract Background Marital status rates may have changed over time in prostate cancer (PC) patients and may have affected cancer-specific mortality (CSM) and other-cause mortality (OCM). Methods Within the Surveillance, Epidemiology, and End Results database (2004–2015), we identified PC patients who were either married (n = 326,664) or unmarried (n = 106,533). Temporal trends, cumulative incidence plots, as well as multivariable competing risks regression analyses focused on (1) the overall population, (2) D'Amico low-risk N0M0 PC, (3) D'Amico intermediate-risk N0M0 PC, (4) D'Amico high-risk N0M0 PC, (5) N1M0 PC, and (6) M1 PC patients. Results Of all, 24.6 % were unmarried and increased trend over time (23.0%–26.9%, P Conclusions Unmarried PC patients are at higher risk of CSM and OCM. This relationship applies to all stage subgroups, except for the N1M0 subgroup. Consequently, unmarried individuals should ideally benefit of improved counseling, closer follow-up, as well as of other measures aimed at reducing the CSM and OCM disadvantages.

Bayesian nonparametric statistics: A new toolkit for discovery in cancer research.

Many commonly used statistical methods for data analysis or clinical trial design rely on incorrect assumptions or assume an over-simplified framework that ignores important information. Such statistical practices may lead to incorrect conclusions about treatment effects or clinical trial designs that are impractical or that do not accurately reflect the investigator's goals. Bayesian nonparametric (BNP) models and methods are a very flexible new class of statistical tools that can overcome such limitations. This is because BNP models can accurately approximate any distribution or function and can accommodate a broad range of statistical problems, including density estimation, regression, survival analysis, graphical modeling, neural networks, classification, clustering, population models, forecasting and prediction, spatiotemporal models, and causal inference. This paper describes 3 illustrative applications of BNP methods, including a randomized clinical trial to compare treatments for intraoperative air leaks after pulmonary resection, estimating survival time with different multi-stage chemotherapy regimes for acute leukemia, and evaluating joint effects of targeted treatment and an intermediate biological outcome on progression-free survival time in prostate cancer.

Targeting multiple pro-apoptotic signaling pathways with curcumin in prostate cancer cells.

Curcumin, an extract from the turmeric rhizome (Curcuma longa), is known to exhibit anti-inflammatory, antioxidant, chemopreventive and antitumoral activities against aggressive and recurrent cancers. Accumulative data indicate that curcumin may induce cancer cell death. However, the detailed mechanism underlying its pro-apoptotic and anti-cancer effects remains to be elucidated. In the present study, we examined the signaling pathways triggered by curcumin, specifically, the exact molecular mechanisms of curcumin-induced apoptosis in highly metastatic human prostate cancer cells. The effect of curcumin was evaluated using for the first time in prostate cancer, a gel-free shotgun quantitative proteomic analysis coupled with Tandem Mass Tag isobaric labeling-based-signaling networks. Results were confirmed at the gene expression level by qRT-PCR and at the protein expression level by western blot and flow cytometry. Our findings revealed that curcumin induced an Endoplasmic Reticulum stress-mediated apoptosis in PC3. The mechanisms by which curcumin promoted cell death in these cells were associated with cell cycle arrest, increased reactive oxygen species, autophagy and the Unfolded Protein Response. Furthermore, the upregulation of ER stress was measured using key indicators of ER stress: Glucose-Regulated Protein 78, Inositol-Requiring Enzyme 1 alpha, Protein Disulfide isomerase and Calreticulin. Chronic ER stress induction was concomitant with the upregulation of pro-apoptotic markers (caspases 3,9,12) and Poly (ADP-ribose) polymerase. The downregulated proteins include anti-apoptotic and anti-tumor markers, supporting their curcumin-induced pro-apoptotic role in prostate cancer cells. Taken together, these data suggest that curcumin may serve as a promising anticancer agent by inducing a chronic ER stress mediated cell death and activation of cell cycle arrest, UPR, autophagy and oxidative stress responses.

The chemomodulatory effects of glufosfamide on docetaxel cytotoxicity in prostate cancer cells.

Background. Glufosfamide (GLU) is a glucose conjugate of ifosfamide in which isophosphoramide mustard is glycosidically linked to the β-D-glucose molecule. Based on GLU structure, it is considered a targeted chemotherapy with fewer side effects. The main objective of the current study is to assess the cytotoxic potential of GLU for the first time in prostate cancer (PC) cells representing different stages of the tumor. Furthermore, this study examined the potential synergistic activity of GLU in combination with docetaxel (DOC).Methods. Two different cell lines were used, LNCaP and PC-3. Concentration-response curves were assessed. The tested groups per cell line were, control, GLU, DOC and combination. Treatment duration was 72 h. Cytotoxicity was assessed using sulforhodamine B (SRB) assay and half maximal inhibitory concentration (IC50) was calculated. Synergy analyses were performed using Calcusyn®software. Subsequent mechanistic studies included β-glucosidase activity assay, glucose uptake and apoptosis studies, namely annexin V-FITC assay and the protein expression of mitochondrial pathway signals including Bcl-2, Bax, Caspase 9 and 3 were assessed. Data are presented as mean ± SD; comparisons were carried out using one way analysis of variance (ANOVA) followed by Tukey-Kramer’s test for post hoc analysis.Results. GLU induced cytotoxicity in both cell lines in a concentration-dependent manner. The IC50 in PC-3 cells was significantly lower by 19% when compared to that of LNCaP cells. The IC50 of combining both drugs showed comparable effect to DOC in PC-3 but was tremendously lowered by 49% compared to the same group in LNCaP cell line. β-glucosidase activity was higher in LNCaP by about 67% compared to that determined in PC-3 cells while the glucose uptake in PC-3 cells was almost 2 folds that found in LNCaP cells. These results were directly correlated to the efficacy of GLU in each cell line. Treatment of PC cells with GLU as single agent or in combination with DOC induced significantly higher apoptosis as evidenced by Annexin V-staining. Apoptosis was significantly increased in combination group by 4.9 folds and by 2.1 Folds when compared to control in LNCaP cells and PC-3 cells; respectively. Similarly, the expression of Bcl-2 was significantly decreased while Bax, caspase 9 and 3 were significantly increased in the combined treatment groups compared to the control.Conclusion. GLU has a synergistic effect in combination with DOC as it increases the cell kill which can be attributed at least partially to apoptosis in both the tested cell lines and it is suggested as a new combination regimen to be considered in the treatment of the prostate cancer. Further experiments and clinical investigations are needed for assessment of that regimen.

Integration of copy number and transcriptomics provides risk stratification in prostate cancer: A discovery and validation cohort study

BackgroundUnderstanding the heterogeneous genotypes and phenotypes of prostate cancer is fundamental to improving the way we treat this disease. As yet, there are no validated descriptions of prostate cancer subgroups derived from integrated genomics linked with clinical outcome. MethodsIn a study of 482 tumour, benign and germline samples from 259 men with primary prostate cancer, we used integrative analysis of copy number alterations (CNA) and array transcriptomics to identify genomic loci that affect expression levels of mRNA in an expression quantitative trait loci (eQTL) approach, to stratify patients into subgroups that we then associated with future clinical behaviour, and compared with either CNA or transcriptomics alone. FindingsWe identified five separate patient subgroups with distinct genomic alterations and expression profiles based on 100 discriminating genes in our separate discovery and validation sets of 125 and 103 men. These subgroups were able to consistently predict biochemical relapse (p=0.0017 and p=0.016 respectively) and were further validated in a third cohort with long-term follow-up (p=0.027). We show the relative contributions of gene expression and copy number data on phenotype, and demonstrate the improved power gained from integrative analyses. We confirm alterations in six genes previously associated with prostate cancer (MAP3K7, MELK, RCBTB2, ELAC2, TPD52, ZBTB4), and also identify 94 genes not previously linked to prostate cancer progression that would not have been detected using either transcript or copy number data alone. We confirm a number of previously published molecular changes associated with high risk disease, including MYC amplification, and NKX3-1, RB1 and PTEN deletions, as well as over-expression of PCA3 and AMACR, and loss of MSMB in tumour tissue. A subset of the 100 genes outperforms established clinical predictors of poor prognosis (PSA, Gleason score), as well as previously published gene signatures (p=0.0001). We further show how our molecular profiles can be used for the early detection of aggressive cases in a clinical setting, and inform treatment decisions. InterpretationFor the first time in prostate cancer this study demonstrates the importance of integrated genomic analyses incorporating both benign and tumour tissue data in identifying molecular alterations leading to the generation of robust gene sets that are predictive of clinical outcome in independent patient cohorts.

Pomegranate Ellagitannin-Derived Metabolites Inhibit Prostate Cancer Growth and Localize to the Mouse Prostate Gland

Our group has shown in a phase II clinical trial that pomegranate juice (PJ) increases prostate specific antigen (PSA) doubling time in prostate cancer (CaP) patients with a rising PSA. Ellagitannins (ETs) are the most abundant polyphenols present in PJ and contribute greatly towards its reported biological properties. On consumption, ETs hydrolyze to release ellagic acid (EA), which is then converted by gut microflora to 3,8-dihydroxy-6H-dibenzo[b, d]pyran-6-one (urolithin A, UA) derivatives. Despite the accumulating knowledge of ET metabolism in animals and humans, there is no available data on the pharmacokinetics and tissue disposition of urolithins. Using a standardized ET-enriched pomegranate extract (PE), we sought to further define the metabolism and tissue distribution of ET metabolites. PE and UA (synthesized in our laboratory) were administered to C57BL/6 wild-type male mice, and metabolite levels in plasma and tissues were determined over 24 h. ET metabolites were concentrated at higher levels in mouse prostate, colon, and intestinal tissues as compared to other tissues after administration of PE or UA. We also evaluated the effects of PE on CaP growth in severe combined immunodeficient (SCID) mice injected subcutaneously with human CaP cells (LAPC-4). PE significantly inhibited LAPC-4 xenograft growth in SCID mice as compared to vehicle control. Finally, EA and several synthesized urolithins were shown to inhibit the growth of human CaP cells in vitro. The chemopreventive potential of pomegranate ETs and localization of their bioactive metabolites in mouse prostate tissue suggest that pomegranate may play a role in CaP treatment and chemoprevention. This warrants future human tissue bioavailability studies and further clinical studies in men with CaP.

DEDIFFERENTIATION OF PROSTATE CANCER GRADE WITH TIME IN MEN FOLLOWED EXPECTANTLY FOR STAGE T1C DISEASE

We assess whether the Gleason grade changes in men followed expectantly with clinical stage T1c prostate cancer. We studied 70 men with stage T1c prostate cancer who underwent watchful waiting with repeat needle biopsy sampling to assess for progression. After the initial cancer diagnosis all men had at least 1 other biopsy demonstrating cancer. Of 70 cases 9 (12.9%) showed a significant change in grade from Gleason scores 6 or less to 7 or greater. The average followup of those patients without a change in grade was 22 months and greater than those with a change in grade. There was no difference between the groups with and without changes in grade in regard to initial prostate specific antigen (PSA), percent-free PSA, or PSA density or velocity. Of 9 cases there were 5 (56%) and 8 (89%) with grade change that occurred at 12 and 15 months or less after initial biopsy, respectively. In contrast, only 1 of 24 (4%) patients in whom last re-biopsy was performed 24 months or greater after the initial cancer diagnosis had a change in grade. Of the 21 men who underwent radical prostatectomy 5 (24%) had worsening of grade on the radical prostatectomy specimen compared to biopsy, with a mean interval of 18 months between the initial cancer diagnosis and prostatectomy. This prevalence of grade change is less than in our population that underwent prostatectomy within 1 to 3 months after biopsy. Because most grade changes occurred relatively soon after biopsy, it implies that tumor grade did not evolve but rather the higher grade component was not initially sampled. During a 1 1/2 to 2-year period after biopsy there is no evidence that prostate cancer grade worsens significantly. Men with prostate cancer need not feel concerned about waiting several months before undergoing surgery after biopsy. Furthermore, men undergoing watchful waiting can be reassured that there is little evidence that prostate cancer grade worsens during the short term.

De‐differentiation with Time in Prostate Cancer and the Influence of Treatment on the Course of the Disease

There is little information on histological changes in prostate cancer during the course of the disease. We have studied 74 patients with carcinoma of the prostate who required 2 transurethral resections of the prostate (mean interval between resections 2.4 years). They constituted 18.4% of all patients with carcinoma of the prostate presenting to our clinic between January 1978 and April 1988. All tumours were staged by conventional methods and graded using the Gleason system. The Gleason sum score in those patients with tumour in both specimens increased in 49, remained constant in 12 and decreased in 7. Within this group were 34 patients who were treated expectantly. The mean Gleason sum scores in this group increased, with a concomitant increase in local tumour stage and development of metastases. Although this was not a randomised trial, there was no significant difference in survival between patients having "deferred" management and those treated immediately, either from time of diagnosis or from time of second resection. There was, however, a significant difference in the time to second resection, with the "deferred" group requiring repeat resection on average 1 year earlier. This study confirmed the concept of tumour de-differentiation with time and showed that this phenomenon occurs in both treated and untreated tumours. Although overall survival was not influenced by the type of initial therapy or its timing, local progression, as assessed by the need for further TURP, occurred earlier in those not receiving immediate therapy.