Taguchi Optimization of Wetting, Thermal and Mechanical Properties of Sn-1.0wt.%Ag-0.5wt.%Cu Alloys Modified with Bi and Sb.

This study was conducted on SAC105 (Sn-1wt.%Ag-0.5wt.%Cu) lead-free solder modified with Bi and Sb. The wetting, melting point, and mechanical properties were analysed with the addition of 1~5 wt.%Bi and 1~5 wt.%Sb for SAC105 base alloy. The wetting characteristics were assessed by wetting time (zero cross time, ZCT) obtained from wetting balance tests. The mechanical properties were analysed by tensile tests. Considering two factors (Bi, Sb), a three-level (0, 1, 2 wt.%) design of experiment (DOE) method array was applied for Taguchi optimization. The results indicated that the solder wetting increased as Bi content increased, while it decreased with Sb. The ZCT decreased with increasing Bi content up to 4 wt.%, while it increased proportionally to Sb content. The melting point, measured using a differential scanning calorimeter (DSC), showed that the melting point tended to decrease according to Bi increase, while it increases depending on the Sb content. Increase in Bi and Sb levels resulted in enhanced tensile strength in the mechanical properties tests, with Bi having a more noticeable impact. The Taguchi optimized conditions for the Bi and Sb studies were found to be 2 wt.%Bi and 2 wt.%Sb. This led to an optimal set of 0.9 s of wetting time, a 222.55 °C melting point, a 55 MPa tensile strength, and a 50% elongation.

Engineering Tissue-Specific, Multiscale Microvasculature with a Capillary Network for Prevascularized Tissue.

Although there are various pre-existing technologies for engineering vasculatures, multiscale modeling of the architecture of human vasculature at a capillary scale remains a challenge. In this study, a novel technology is developed for the production of a functional, multiscale microvasculature comprising of endothelialized channels and tissue-specific capillary networks. Perfusable, endothelialized channels are bioprinted, after which angiogenic sprouts are grown into user-designed capillary networks. The induction of branched and liver-lobule-like capillary networks confirm that the technology can produce various types of tissue-specific multiscale microvasculatures. Further, the channels and capillaries are deemed to be functional when evaluated in vitro. An ex vivo assay demonstrates that the microvasculature can induce neovessel ingrowth, integrate with host vessels, and facilitate blood flow. Remarkably, blood flows through the implanted capillary network without any change in its morphology. Finally, the technology is applied to produce a vascularized liver tissue; it significantly improves its hepatic function. It is believed that this new technology will create new possibilities in the development of highly vascularized and functional tissues/organs on a clinically relevant scale.

Optimal PSA Threshold for Androgen-Deprivation Therapy in Patients with Prostate Cancer following Radical Prostatectomy and Adjuvant Radiation Therapy.

PURPOSE: The benefits of early administration of androgen-deprivation therapy (ADT) in patients with prostate-specific antigen (PSA)-only recurrent prostate cancer (PCa) following radical prostatectomy (RP) are controversial. We investigated the impact of early versus delayed ADT on survival outcomes in patients with non-metastatic, localized or locally advanced PCa who received radiation therapy (RT) following RP and later developed distant metastasis. MATERIALS AND METHODS: A retrospective analysis was performed on 69 patients with non-metastatic, localized or locally advanced PCa who received RT following RP and later developed distant metastasis between January 2006 and December 2012. Patients were stratified according to the level of PSA at which ADT was administered (<2 ng/mL vs. ≥2 ng/mL). Study endpoints were progression to castration-resistant prostate cancer (CRPC)-free survival and cancer-specific survival (CSS). RESULTS: Patients were stratified according to the criteria of 2 ng/mL of PSA at which ADT was administered, based on the Youden sensitivity analysis. Delayed ADT at PSA ≥2 ng/mL was an independent prognosticator of cancer-specific mortality (p=0.047), and a marginally significant prognosticator of progression to CRPC (p=0.051). During the median follow-up of 81.0 (interquartile range 54.2-115.7) months, patients who received early ADT at PSA <2 ng/mL had significantly higher CSS rates compared to patients who received delayed ADT at PSA ≥2 ng/mL (p=0.002). Progression to CRPC-free survival was comparable between the two groups (p=0.331). CONCLUSION: Early ADT at the PSA level of less than 2 ng/mL confers CSS benefits in patients with localized or locally advanced PCa who were previously treated with RP.

Establishment of patient-derived three-dimensional organoid culture in renal cell carcinoma.

Purpose: Renal cell carcinoma is a heterogeneous kidney cancer, and over 403,000 cases were reported worldwide in 2018. Current methods for studying renal cell carcinoma are limited to two-dimensional (2D) culture of primary cell lines and patient-derived xenograft models. Numerous studies have suggested that 2D culture poorly represents the diversity, heterogeneity, and drug-resistance of primary tumors. The time and cost associated with patient-derived xenograft models poses a realistic barrier to their clinical utility. As a biomimetic model, patient-derived three-dimensional (3D) organoid culture can overcome these disadvantages and bridge the gap between in vitro cell culture and in vivo patient-derived xenograft models. Here, we establish a patient-derived 3D organoid culture system for clear cell renal cell carcinoma and demonstrate the biomimetic characteristics of our model with respect to both primary kidney cancer and conventional 2D culture. Materials and Methods: Normal renal tissues and tumor tissues were collected from patients with clear cell renal cell carcinoma. The dissociated cells were cultured as conventional 2D culture and 3D organoid culture. The biomimetic characteristic of the two cultures were compared. Results: Compared with 2D culture, the 3D organoid cultures retained the characteristic lipid-rich, clear cell morphology of clear cell renal cell carcinoma. Carbonic anhydrase 9 and vimentin were validated as biomarkers of renal cell carcinoma. Expression of the two validated biomarkers was more enhanced in 3D organoid culture. Conclusions: Patient-derived 3D organoid culture retains the characteristics of renal cell carcinoma with respect to morphology and biomarker expression.

Long short-term memory artificial neural network model for prediction of prostate cancer survival outcomes according to initial treatment strategy: development of an online decision-making support system.

PURPOSE: The delivery of precision medicine is a primary objective for both clinical and translational investigators. Patients with newly diagnosed prostate cancer (PCa) face the challenge of deciding among multiple initial treatment modalities. The purpose of this study is to utilize artificial neural network (ANN) modeling to predict survival outcomes according to initial treatment modality and to develop an online decision-making support system. METHODS: Data were collected retrospectively from 7267 patients diagnosed with PCa between January 1988 and December 2017. The analyses included 19 pretreatment clinicopathological covariates. Multilayer perceptron (MLP), MLP for N-year survival prediction (MLP-N), and long short-term memory (LSTM) ANN models were used to analyze progression to castration-resistant PCa (CRPC)-free survival, cancer-specific survival (CSS), and overall survival (OS), according to initial treatment modality. The performances of the ANN and the Cox-proportional hazards regression models were compared using Harrell's C-index. RESULTS: The ANN models provided higher predictive power for 5- and 10-year progression to CRPC-free survival, CSS, and OS compared to the Cox-proportional hazards regression model. The LSTM model achieved the highest predictive power, followed by the MLP-N, and MLP models. We developed an online decision-making support system based on the LSTM model to provide individualized survival outcomes at 5 and 10 years, according to the initial treatment strategy. CONCLUSION: The LSTM ANN model may provide individualized survival outcomes of PCa according to initial treatment strategy. Our online decision-making support system can be utilized by patients and health-care providers to determine the optimal initial treatment modality and to guide survival predictions.

Postoperative biochemical recurrence of pathologically localized high-grade prostate cancer in adjuvant treatment-naïve patients.

PURPOSE: To evaluate biochemical recurrence (BCR) risk in men with localized prostate cancer (PC) of pathological Gleason score (pGS) 8-10. Although such patients have low BCR-free survival (BCRFS) following radical prostatectomy (RP), they are not recommended for adjuvant radiation therapy (ART) as per current guidelines. METHODS: Among an adjuvant treatment-naïve cohort between 1995 and 2015, 1272 men were identified and categorized into group 1 [pGS7 (3 + 4) and pT3; n = 654], group 2 [pGS7 (4 + 3) and pT3; n = 408], and group 3 (pGS 8-10 and pT2; n = 210). The BCR risk of group 3 was compared with that of groups 1 and 2 who are the candidates for ART. RESULTS: At a median follow-up of 60 months (interquartile range: 39-86), 432 men experienced BCR. BCRFS was lower in group 3 than in groups 1 and 2 (p < 0.001 and p = 0.021, respectively). In multivariate analysis, this association persisted and surgical margin (SM) was found to be a significant BCR predictor. Although statistically not significant, BCRFS was lower in group 3 with positive SM (PSM) than in group 2 with PSM (p = 0.101). BCRFS was significantly worse in group 3 with negative SM (NSM) than in group 1 with PSM (p = 0.038), while it was better in group 2 with PSM (p = 0.297). CONCLUSION: Localized high-grade PC with PSM showed lower BCRFS and that with NSM showed better BCRFS without statistical significance than locally advanced GS 7 PC with PSM that are eligible for ART.

Impact of Cerebrovascular Disease on Survival Benefits from Local Treatment in Patients with De Novo Metastatic Hormone-Sensitive Prostate Cancer.

PURPOSE: Local treatment has become a treatment option for patients with de novo metastatic hormone-sensitive prostate cancer (mHSPC). Subgroup analyses based on a history of cerebrovascular disease (CVD) were performed to evaluate the impact thereof on overall survival (OS) after local treatment. MATERIALS AND METHODS: A retrospective analysis was performed for 879 patients with de novo mHSPC between August 2003 and November 2016. Patients were stratified according to prior CVD history and the type of initial treatment: androgen-deprivation therapy (ADT) alone versus local treatment consisting of radical prostatectomy (RP) or radiation therapy (RT) with ADT, with or without metastasis-directed therapy. The primary outcome was OS assessed by Kaplan-Meier analysis and Cox-regression models. RESULTS: Of 879 patients, 660 (75.1%) men underwent ADT alone, and 219 (24.9%) men underwent RP or RT with ADT, with or without metastasis-directed therapy. The median follow-up was 38 months. Multivariable analysis showed CVD history to be associated with a higher risk of overall mortality (p=0.001). In the overall cohort and in patients without a history of CVD, patients who underwent local treatment exhibited higher OS than men who received ADT alone (all p<0.001). However, the survival benefit conferred by local treatment was not seen in patients with a history of CVD (p=0.324). OS was comparable between patients who received RP and RT (p=0.521). CONCLUSION: Local treatment with or without metastasis-directed therapy may provide OS advantages for mHSPC patients without a history of CVD. Further prospective studies are needed to address these important concerns.

Outcomes of pathologically localized high-grade prostate cancer treated with radical prostatectomy.

Adjuvant radiation therapy (ART) is recommended without consideration of radical prostatectomy Gleason score (RP GS) for cases with adverse features. We compared the outcomes of pathologically localized high-grade (GS 8-10) prostate cancer (PC) with those of pT3 GS 7 PC.A total of 1585 men who underwent RP between 1995 and 2015 comprised the cohort, which was divided into group 1 (RP GS 7(3 + 4) and pT3; n = 760), group 2 (RP GS 7(4 + 3) and pT3; n = 565), and group 3 (RP GS 8-10 and pT2; n = 260). Biochemical recurrence (BCR), all-cause mortality (ACM), and PC-specific mortality (PCSM) risk were compared among groups using Cox regression and competing risk analysis.At a median follow-up of 58 months (interquartile range: 37-85), 721 men experienced BCR and 84 died (22 due to PC). BCR-free survival rates were lower in group 3 than in group 1 (P < .001); nevertheless, no difference was observed between groups 2 and 3 (P = .638). Furthermore, no difference in ACM was noted among groups. PCSM rates were higher in group 3 than in groups 1 and 2 (P = .001 and P = .005, respectively). This association persisted in multivariate models after adjustment for clinicopathological variables.Patients with RP GS 8-10 and pT2 PC had higher BCR and PCSM rates than those with RP GS 7 and pT3 PC. Localized high-grade PC should be considered in decision-making for ART.

Effect of Prior Local Treatment and Prostate-Specific Antigen Kinetics during Androgen-Deprivation Therapy on the Survival of Castration-Resistant Prostate Cancer.

Prostate-specific antigen (PSA) kinetics predicts survival in castration-resistant prostate cancer (CRPC); however, the influence of prior treatment on this relationship is unclear. Patients with CRPC were stratified according to time to PSA nadir and time to CRPC progression to investigate their prognostic significance on prostate cancer-specific survival (PCSS) and whether PSA kinetics may serve as prognosticators regardless of prior local treatment. This multicenter retrospective study included 295 patients diagnosed with CRPC between September 2009 and November 2017. PSA kinetics during androgen-deprivation therapy (ADT) including %PSA decline, PSA nadir level, time to PSA nadir, and time to CRPC progression was investigated. Subgroup analysis was performed according to the prior history of local curative treatment. Patients who did not receive prior local treatment with ≥6 months to PSA nadir and <12 months to CRPC, showed lower PCSS rates than those with <6 months to PSA nadir (23.3% vs. 45.3%; p = 0.031) and ≥12 months to CRPC (20.0% vs. 47.8%; p = 0.001). In patients who had received local treatment, PSA kinetic parameters did not influence PCSS. Our results indicate that time to PSA nadir and time to CRPC progression are prognosticators of PCSS in patients with CRPC who did not previously receive curative local treatment.

Pathological Characteristics of Prostate Cancer in Men Aged < 50 Years Treated with Radical Prostatectomy: a Multi-Centre Study in Korea.

BACKGROUND: Recently, younger prostate cancer (PCa) patients have been reported to harbour more favourable disease characteristics after radical prostatectomy (RP) than older men. We analysed young men (<50 years) with PCa among the Korean population, paying attention to pathological characteristics on RP specimen and biochemical recurrence (BCR). METHODS: The multi-centre, Severance Urological Oncology Group registry was utilized to identify 622 patients with clinically localized or locally advanced PCa, who were treated with RP between 2001 and 2017. Patients were dichotomized into two groups according to age (< 50-year-old [n = 75] and ≥ 50-year-old [n = 547]), and clinicopathological characteristics were analysed. Propensity score matching was used when assessing BCR between the two groups. RESULTS: Although biopsy Gleason score (GS) was lower in younger patients (P = 0.033), distribution of pathologic GS was similar between the two groups (13.3% vs. 13.9% for GS ≥ 8, P = 0.191). There was no significant difference in pathologic T stage between the < 50- and ≥ 50-year-old groups (69.3% vs. 68.0% in T2 and 30.7% vs. 32.0% in ≥ T3, P = 0.203). The positive surgical margin rates were similar between the two groups (20.0% vs. 27.6%, P = 0.178). BCR-free survival rates were also similar (P = 0.644) between the two groups, after propensity matching. CONCLUSION: Contrary to prior reports, younger PCa patients did not have more favourable pathologic features on RP specimen and showed similar BCR rates compared to older men. These findings should be considered when making treatment decisions for young Korean patients with PCa.

The Association of A Number of Predictive Factors for The Recurrence of Papillary Urothelial Neoplasm of Low Malignant Potential: Prognostic Analysis From Multiple Academic Centers.

PURPOSE: To identify clinically useful predictors for the recurrence of papillary urothelial neoplasm of low malignant potential (PUNLMP), we reviewed the clinical information of patients who were diagnosed and treated in multiple tertiary-care academic facilities. MATERIALS AND METHODS: Between February 2007 and April 2015, 95 patients diagnosed with PUNLMP after transurethral resection of bladder (TURB) were included in this study. Age, gender, body mass index, smoking history, the presence or absence of previous history of urothelial neoplasm, the presence or absence of gross hematuria, cytological results at the time of diagnosis, tumor diameter, and multiplicity of tumor were estimated as variablesfor analysis. Cox regression tests were used for identifying predictive factors for recurrence of PUNLMP. RESULTS: Sixty-nine cases of PUNLMP were de novo primary bladder PUNLMPs without known urothelial lesions in the urinary tract, and 26 PUNLMPs were identified on surveillance biopsies of patients with a previous history of urothelial neoplasm. During the follow-up period, recurrences developed in 13 patients (13.7%). Recurrence rates were 4.2% and 9.5% at 12 and 24 months, respectively. On univariate and multivariate Cox regression analyses, previous history of urothelial neoplasm [95% confidence interval (CI): 0.057-0.604, hazard ratio (HR) = 0.185, P = .005] and multiplicity of tumors [95% CI = 0.064-0.584, HR = 0.193, P = .004] were identified as independent predictors for recurrence-free survival of patients with PUNLMP. CONCLUSION: Tumor multiplicity and previous history of urothelial neoplasm are independent prognostic factors forprediction of recurrence of PUNLMP. More careful and closer follow-up should be recommended for PULNMPpatients with tumor multiplicity or a previous history of urothelial neoplasm.

Optimal sequencing strategy using docetaxel and androgen receptor axis-targeted agents in patients with castration-resistant prostate cancer: utilization of neutrophil-to-lymphocyte ratio.

PURPOSE: To investigate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) for the selection of the optimal sequencing strategy using docetaxel and androgen receptor axis-targeted (ARAT) agents in patients with M0 or M1 castration-resistant prostate cancer (CRPC). Currently, there is a need to identify biomarkers to guide optimal sequential treatment in CRPC. METHODS: This multicenter, retrospective analysis included 303 consecutive patients initially diagnosed with M0 or M1 CRPC between September 2009 and March 2017. Of these, 52 (17.2%) patients received pre-docetaxel ARAT agents and 189 (62.4%) patients received post-docetaxel ARAT agents. The prognostic ability of NLR at CRPC diagnosis regarding radiographic progression-free survival (rPFS) and cancer-specific survival (CSS) were investigated. For the analysis, the NLR level was dichotomized at 2.5, and evaluated according to sequencing strategy. RESULTS: Multivariate analysis revealed NLR ≥ 2.5 as an independent predictor of a lower risk for CSS. During the median follow-up of 18.5 months, patients with NLR ≥ 2.5 exhibited significantly lower 1-year rPFS (p = 0.011) and 2-year CSS rates (p = 0.005) compared to patients with NLR < 2.5. Among patients with NLR < 2.5, the post-docetaxel ARAT agent sequencing group exhibited higher 1-year rPFS (p = 0.031) and 2-year CSS (p = 0.026) rates compared to the pre-docetaxel ARAT agent sequencing group. Among patients with NLR ≥ 2.5, rPFS and CSS rates were comparable regardless of ARAT agent sequencing. CONCLUSION: NLR ≥ 2.5 at CRPC diagnosis is associated with a lower risk for CSS. Patients with NLR < 2.5 should primarily be offered docetaxel considering the survival benefit of docetaxel-to-ARAT agent sequencing.

Time to Disease Recurrence Is a Predictor of Metastasis and Mortality in Patients with High-risk Prostate Cancer Who Achieved Undetectable Prostate-specific Antigen Following Robot-assisted Radical Prostatectomy.

BACKGROUND: Robot-assisted radical prostatectomy (RARP) is a feasible treatment option for high-risk prostate cancer (PCa). While patients may achieve undetectable prostate-specific antigen (PSA) levels after RARP, the risk of disease progression is relatively high. We investigated metastasis-free survival, cancer-specific survival (CSS), and overall survival (OS) outcomes and prognosticators in such patients. METHODS: In a single-center cohort of 342 patients with high-risk PCa (clinical stage ≥ T3, biopsy Gleason score ≥ 8, and/or PSA levels ≥ 20 ng/mL) treated with RARP and pelvic lymph node dissection between August 2005 and June 2011, we identified 251 (73.4%) patients (median age, 66.5 years; interquartile range [IQR], 63.0-71.0 years) who achieved undetectable PSA levels (< 0.01 ng/mL) postoperatively. Survival outcomes were evaluated for the entire study sample and in groups stratified according to the time to biochemical recurrence dichotomized at 60 months. RESULTS: During the median follow-up of 75.9 months (IQR, 59.4-85.8 months), metastasis occurred in 38 (15.1%) patients, most often to the bones, followed by the lymph nodes, lungs, and liver. The 5-year metastasis-free, cancer-specific, and OS rates were 87.1%, 94.8%, and 94.3%, respectively. Multivariate Cox-regression analysis revealed time to recurrence as an independent predictor of metastasis (P < 0.001). Time to metastasis was an independent predictor of OS (P = 0.003). Metastasis-free and CSS rates were significantly lower among patients with recurrence within 60 months of RARP (log-rank P < 0.001). CONCLUSION: RARP confers acceptable oncological outcomes for high-risk PCa. Close monitoring beyond 5 years is warranted for early detection of disease progression and for timely adjuvant therapy.

Tubular organotypic culture model of human kidney.

Cell-culture methods that simplify the inherent complexities of the kidney have not sufficiently reproduced its true characteristics. Although reports indicate that organoid methodology surpasses traditional cell culture in terms of reproducing the nature of organs, the study of human kidney organoids have been confined to pluripotent stem cells. Furthermore, it has not yet progressed beyond the developmental state of embryonic kidney even after complicate additional differentiation processes. We here describe the kidney organotypic culture method that uses adult whole kidney tissues but mainly differentiates into tubular cells. This model was validated based on the retention of key kidney organotypic-specific features: 1) expression of Tamm-Horsfall protein; 2) dome-like organoid configurations, implying directed transport of solutes and water influx; and 3) organoid expression of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in response to nephrotoxic injury (i.e., gentamicin and cisplatin exposure). This 3D-structured organoid prototype of the human renal tubule may have applications in developing patient-specific treatments for kidney diseases.

Prognostic Factors of Penile Cancer and the Efficacy of Adjuvant Treatment after Penectomy: Results from a Multi-institution Study.

BACKGROUND: Penile cancer is a rare malignancy associated with high rates of mortality and morbidity. Currently, the efficacy of adjuvant treatment (AT), including radiotherapy and chemotherapy, for penile cancer remains unclear. Therefore, we investigated the prognostic factors for treatment outcomes and the efficacy of AT in consecutive patients who underwent penectomy for penile cancer at multiple Korean institutions between 1999 and 2013. METHODS: AT was defined as the administration of chemotherapy, radiotherapy, or both within 12 months after initial treatment. All patients were divided into two groups according to the AT status. RESULTS: Forty-three patients (median age 67.0 years) with a median follow-up after penectomy of 26.4 (interquartile range: 12.0-62.8) months were enrolled. Patients with AT had a significantly higher pathologic stage. However, no differences in age, histologic grade, or type of surgery were identified according to the presence of AT. The 3- and 5-year cancer-specific survival (CSS) rates were 79.0% and 33.0%, respectively. In a multivariate analysis, American Joint Committee on Cancer (AJCC) stage ≥ III disease was an independent predictor of CSS and recurrence-free survival (RFS). However, AT was not associated with CSS and RFS. The type of primary surgical treatment and inguinal lymph node dissection at diagnosis were also not significantly associated with overall survival, CSS, or RFS. CONCLUSION: AJCC stage ≥ III disease, which mainly reflects lymph node positivity, is a significant prognosticator in patients with penile cancer. By contrast, AT does not seem to affect CSS and RFS.

Age-adjusted Charlson Comorbidity Index as a prognostic factor for radical prostatectomy outcomes of very high-risk prostate cancer patients.

PURPOSE: Prostate cancer (PC) is a devastating and heterogeneous condition with diverse treatment options. When selecting treatments for patients with very high-risk PC, clinicians must consider patient comorbidities. We investigated the efficacy of the age-adjusted Charlson Comorbidity Index (ACCI) as a prognostic factor for patient outcomes after radical prostatectomy (RP). MATERIALS AND METHODS: We retrospectively investigated the medical records of PC patients at our institution who underwent RP from 1992 to 2010. Very high-risk PC was defined according to National Comprehensive Cancer Network guidelines. Patients with incomplete medical records or who had received neoadjuvant therapy were excluded. Preoperative comorbidity was evaluated by the ACCI, and the prognostic efficacy of the ACCI was analyzed using univariable and multivariable Cox regression, competing risk regression model and Kaplan-Meier curves. RESULTS: Our final analysis included 228 men with a median age of 66 years (interquartile range 62-71) and median prostate specific antigen of 10.7 ng/mL. There were 41 (18%) patients with an ACCI score >3 and 88 (38.6%) patients with a biopsy Gleason score >8. Preoperative evaluation revealed that 159 patients (69.7%) had a non-organ confined tumor (≥T3). Following RP, 8-year prostate cancer-specific survival (PCSS) and overall survival (OS) rates were 91.6% and 83.4%, respectively. Competing risk regression analysis revealed that ACCI was significantly associated with other-cause survival and OS (p<0.05). CONCLUSION: The ACCI is an effective prognostic factor for other-cause survival and OS in very high-risk PC patients. RP should be considered carefully for patients with an ACCI score >3.

Impact of Early Salvage Androgen Deprivation Therapy in Localized Prostate Cancer after Radical Prostatectomy: A Propensity Score Matched Analysis.

PURPOSE: Androgen deprivation therapy (ADT) is used as a salvage treatment for men with biochemical recurrence (BCR) of prostate cancer (PCa) following initial radical prostatectomy (RP). The optimal time at which to begin salvage ADT (sADT) remains controversial. In this retrospective study, we evaluated the efficacy of initiating sADT in patients before prostate-specific antigen (PSA) values met the clinical definition of BCR. MATERIALS AND METHODS: We identified 484 PCa patients who received sADT for BCR after RP. Median follow-up was 82 months. Propensity score matching was performed based on preoperative PSA level, pathologic T stage, and Gleason score. Patients were assigned to two groups of 169 patients each, based on PSA levels at the time of sADT: Group A (without meeting of the definition of BCR) and Group B (after BCR). Kaplan-Meier survival analyses and Cox regression analyses were performed. RESULTS: The median PSA level at sADT initiation was 0.12 ng/mL in group A and 0.42 ng/mL in group B. Kaplan-Meier analyses showed that group A had favorable disease progression-free survival (DPFS) and distant metastasis-free survival (DMFS), but did not have better cancer-specific survival (CSS) than group B. In subgroup analyses, group A showed better CSS rates in the non-organ confined PCa group. In Cox regression analyses, early sADT was associated significantly with DPFS and DMFS rates, however, did not correlate with CSS (p=0.107). CONCLUSION: Early sADT after RP improved DPFS and DMFS. Furthermore, early sADT patients demonstrated better CSS in non-organ confined PCa.

Predictors of adverse pathologic features after radical prostatectomy in low-risk prostate cancer.

BACKGROUND: Prostate-specific antigen (PSA) screening more frequently detects early stage prostate cancer (PC). However, adverse pathologic features (APFs) after radical prostatectomy (RP) in low-risk PC occur. Previous related studies had utilized outdated staging criteria or small sample cohorts. In this study, we analyzed predictors of APFs after RP in low-risk PC using classification under the current criteria. MATERIALS AND METHODS: We retrospectively reviewed medical records of 546 low-risk PC patients who had undergone RP. Low-risk PC was defined as PC with clinical T1-T2a, Gleason score ≤ 6, and PSA levels < 10 ng/mL. Clinical and pathological parameters were analyzed to predict APFs. APFs were defined as extracapsular extension (ECE), seminal vesicle invasion (SVI), or positive surgical margins (PSM). We analyzed our data using univariable and multivariable logistic regression analyses, as well as receiver operator characteristics to predict APFs. RESULTS: Among 546 patients, ECE, SVI, and PSM were present in 199 (36.4%), 8 (1.5%), and 179 cases (32.8%), respectively. PSM had a significant correlation with preoperative high PSA levels and number of positive cores obtained. ECE/SVI was also significantly correlated with PSA levels and number of positive cores. As a result, presence of APFs after RP was associated with high PSA levels and large number of positive cores. PSA > 4.5 ng/mL and number of positive cores > 2 in low-risk PC were significantly associated with APFs, and suggested as cut-off values for predicting APFs. CONCLUSIONS: PSA > 4.5 ng/mL and number of positive cores > 2 in low-risk PC were associated with presence of APFs and patients with such records should be considered carefully to provide active surveillance.

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.

Prostate-Specific Antigen Kinetics Following 5α-Reductase Inhibitor Treatment May Be a Useful Indicator for Repeat Prostate Biopsy.

PURPOSE: To evaluate parameters for determining repeat prostate biopsy in patients with 5α-reductase inhibitor (5ARI) treatment after initial negative biopsy. MATERIALS AND METHODS: From January 2007 to December 2015, patients who underwent a repeat prostate biopsy after an initial negative biopsy were enrolled from multiple institutions. Serial prostate-specific antigen (PSA) levels after the initial biopsy were analyzed for PSA kinetics. Clinicopathologic variables were evaluated according to the use of 5ARIs after the initial negative biopsy. RESULTS: Of 419 patients with initial negative biopsies (median age=67.0 years, median PSA=6.31 ng/mL), 101 patients (24.1%) were diagnosed with prostate cancer at the repeat biopsy. An increase in PSA level at 18 months, compared to that at 6 months, was a predictor of a positive repeat biopsy. However, the use of 5ARIs was not identified as a predictor. Of 126 patients receiving 5ARI treatment after the initial biopsy, 30 (23.8%) were diagnosed with prostate cancer at the repeat biopsy. Increase in PSA level at more than two time points after 6 months of 5ARI treatment (odds ratio=4.84, p=0.005) was associated with cancer detection at the repeat biopsy. There were no significant 5ARI group-related differences in the detection rates of prostate and high-grade cancers (Gleason score ≥7). CONCLUSION: The effects of 5ARIs on prostate cancer detection and chemoprevention remain uncertain. However, more than two increases in PSA level after 6 months of 5ARI treatment may indicate the presence of prostate cancer.