Latrophilin-3 as a downstream effector of the androgen receptor induces urothelial tumorigenesis.

Emerging evidence indicates that androgen receptor (AR) signaling plays a critical role in the pathogenesis of male-dominant urothelial cancer. Meanwhile, latrophilins (LPHNs), a group of the G-protein-coupled receptor to which a spider venom latrotoxin is known to bind, remain largely uncharacterized in neoplastic diseases. The present study aimed to determine the functional role of LPHN3 (encoded by the ADGRL3 gene), in association with AR signaling, in urothelial tumorigenesis. In human normal urothelial SVHUC cells, AR overexpression and androgen treatment considerably increased the expression levels of ADGRL3/LPHN3, while chromatin immunoprecipitation assay revealed the binding of AR to the promoter region of ADGRL3. In SVHUC or SVHUC-AR cells with exposure to a chemical carcinogen 3-methylcholanthrene, LPHN3 activation via ligand (e.g., α-latrotoxin, FLRT3) treatment during the process of the neoplastic/malignant transformation or LPHN3 knockdown via shRNA virus infection induced or reduced, respectively, the oncogenic activity. In N-butyl-N-(4-hydroxybutyl)nitrosamine-treated female mice, α-latrotoxin or FLRT3 injection accelerated the development of bladder tumors. Immunohistochemistry in surgical specimens further showed the significantly elevated expression of LPHN3 in non-muscle-invasive bladder tumors, compared with adjacent normal urothelial tissues, which was associated with a marginally (p = 0.051) higher risk of disease recurrence after transurethral resection. In addition, positivity of LPHN3 and AR in these tumors was strongly correlated. These findings indicate that LPHN3 functions as a downstream effector of AR and promotes urothelial tumorigenesis.

Differential impact of proton pump inhibitor on survival outcomes of patients with advanced urothelial carcinoma treated with chemotherapy versus pembrolizumab.

OBJECTIVES: We clarified the effect of concomitant proton pump inhibitor use on oncological outcomes in patients with advanced urothelial carcinoma treated either with chemotherapy or immune checkpoint inhibitor. METHODS: We retrospectively reviewed patients with advanced urothelial carcinoma who received paclitaxel-gemcitabine therapy or pembrolizumab after platinum-based chemotherapy. The patients were divided into four groups based on the treatment regimen and the concomitant use of proton pump inhibitor. We compared survival outcomes between the groups and determined which factors predicted overall survival. RESULTS: Among the 60 and 75 patients treated with paclitaxel-gemcitabine and pembrolizumab, 15 and 29 used a concomitant proton pump inhibitor. Progression-free and overall survival was significantly shorter in patients who were administered pembrolizumab with concomitant proton pump inhibitor compared to those without. The use of a concomitant proton pump inhibitor had no effect on survival outcomes in patients who received paclitaxel-gemcitabine therapy. Furthermore, progression-free and overall survival were significantly shorter in patients treated with paclitaxel-gemcitabine therapy compared to those treated with pembrolizumab among patients without concomitant proton pump inhibitor. In contrast, there was no difference in survival outcomes between the two regimens among patients with concomitant proton pump inhibitor. Concomitant proton pump inhibitor use was associated with poor overall survival only in patients treated with pembrolizumab. CONCLUSION: The use of a concomitant proton pump inhibitor use had no impact on oncological outcomes in patients with advanced urothelial carcinoma treated with paclitaxel-gemcitabine therapy, different from those treated with pembrolizumab.

Androgen Receptor Signaling Induces Cisplatin Resistance via Down-Regulating GULP1 Expression in Bladder Cancer.

The underlying molecular mechanisms of resistance to cisplatin-based systemic chemotherapy in bladder cancer patients remain to be elucidated, while the link between androgen receptor (AR) activity and chemosensitivity in urothelial cancer has been implicated. Our DNA microarray analysis in control vs. AR knockdown bladder cancer lines identified GULP1 as a potential target of AR signaling. We herein determined the relationship between AR activity and GULP1 expression in bladder cancer cells and then assessed the functional role of GULP1 in cisplatin sensitivity. Androgen treatment in AR-positive cells or AR overexpression in AR-negative cells considerably reduced the levels of GULP1 expression. Chromatin immunoprecipitation further showed direct interaction of AR with the promoter region of GULP1. Meanwhile, GULP1 knockdown sublines were significantly more resistant to cisplatin treatment compared with respective controls. GULP1 knockdown also resulted in a significant decrease in apoptosis, as well as a significant increase in G2/M phases, when treated with cisplatin. In addition, GULP1 was immunoreactive in 74% of muscle-invasive bladder cancers from patients who had subsequently undergone neoadjuvant chemotherapy, including 53% of responders showing moderate (2+)/strong (3+) expression vs. 23% of non-responders showing 2+/3+ expression (P = 0.044). These findings indicate that GULP1 represents a key downstream effector of AR signaling in enhancing sensitivity to cisplatin treatment.

FOXO1 inactivation induces cisplatin resistance in bladder cancer.

We found that FOXO1-shRNA sublines or FOXO1-positive cells co-treated with a FOXO1 inhibitor were significantly more resistant to cisplatin treatment at pharmacological concentrations, compared with respective control sublines or those with mock treatment. Western blot demonstrated considerable increases in the expression levels of a phosphorylated inactive form of FOXO1 (p-FOXO1) in cisplatin-resistant sublines established by long-term culture with low/increasing doses of cisplatin, compared with respective controls. Immunohistochemistry in surgical specimens from patients with muscle-invasive bladder cancer undergoing cisplatin-based neoadjuvant therapy further showed a strong trend to associate between p-FOXO1 positivity and unfavorable response to chemotherapy.

Mineralocorticoid receptor signaling inhibits bladder cancer progression.

The biological or clinical significance of mineralocorticoid receptor (MR) in urothelial cancer remains largely unknown. The present study aimed to determine the functional role of MR in bladder cancer progression. In two of the human bladder cancer lines expressing MR, treatment with a natural MR ligand, aldosterone, significantly reduced cell proliferation and migration, which was restored by three MR antagonists clinically used, spironolactone (except colony formation of androgen receptor-positive cells cultured in the presence of androgens), eplerenone, and esaxerenone. Similarly, MR knockdown via shRNA virus infection resulted in significant increases in cell viability/migration, as well as colony formation, compared with control sublines. In addition, MR knockdown augmented the expression of ß-catenin, c-fos, and N-cadherin, and lowered that of E-cadherin and p53, indicating the induction of the cadherin switching. Immunohistochemistry in surgical specimens detected MR signals in 58 (92.1%; 36.5% weakly-positive/1+, 44.4% moderately-positive/2+, and 11.1% strongly-positive/3+) of 63 muscle-invasive bladder cancers, which was significantly lower than in adjacent non-neoplastic urothelial tissues (100%; 15.7% 1+, 37.3% 2+, and 47.1% 3+). Moreover, patients with MR-high (3+) tumor had a significantly lower risk of cancer-specific mortality (P=0.039). Multivariable analysis further showed that strong MR expression was an independent predictor of cancer-specific survival in patients with muscle-invasive bladder cancer (hazard ratio 0.117, P=0.039). These findings suggest that MR signaling functions as a tumor suppressor in urothelial carcinoma and prevents tumor growth. Accordingly, there is a possibility that the concurrent use of anti-mineralocorticoids, particularly eplerenone and esaxerenone, in patients with bladder cancer rather contributes to the promotion of disease progression.

Melatonin Inhibits Chemical Carcinogen-mediated Malignant Transformation of Urothelial Cells: In Vitro Evidence.

BACKGROUND/AIM: The efficacy of melatonin and its biological significance in human bladder cancer remain poorly understood. This study aimed to investigate the functional role of melatonin in urothelial carcinogenesis. MATERIALS AND METHODS: In human normal urothelial SVHUC cells with exposure to the chemical carcinogen 3-methylcholanthrene, we assessed the effects of melatonin on the neoplastic/malignant transformation. RESULTS: In the in vitro system with carcinogen challenge, melatonin significantly prevented the neoplastic transformation of SV-HUC-1 cells. In addition, melatonin treatment resulted in increased expression of SIRT1, Rb1, and E-cadherin, and decreased expression of N-cadherin and FGFR3 in SV-HUC-1 cells. Furthermore, publicly available datasets from GSE3167 revealed that the expression of melatonin receptor 1 and melatonin receptor 2 was significantly down-regulated in bladder urothelial carcinoma tissues, compared with adjacent normal urothelial tissues. CONCLUSION: These findings indicate that melatonin serves as a suppressor for urothelial tumorigenesis. To the best of our knowledge, this is the first preclinical study demonstrating the impact of melatonin on the development of urothelial cancer.

The Omission of Upfront Treatment Intensification Does Not Adversely Affect Oncological Outcomes in a Subset of Castration-Highly Sensitive Metastatic Prostate Cancer.

BACKGROUND/AIM: In patients with metastatic castration-sensitive prostate cancer (mCSPC), upfront treatment intensification with the addition of new hormonal agents and/or docetaxel to androgen deprivation therapy (ADT) is recommended. However, this modality is potentially excessive in a subset of these patients. This study aimed to identify patients who may be eligible to omit upfront treatment intensification. PATIENTS AND METHODS: Patients with mCSPC who underwent ADT were enrolled. The association between undetectable prostate-specific antigen (PSA) (<0.2 ng/ml) after ADT initiation and overall or castration-resistance-free survival was evaluated. RESULTS: Ninety-seven out of the 242 enrolled patients had low-risk and/or low-volume cancer and were further analyzed. Of these, 45 (46.4%) patients achieved undetectable PSA. The median follow-up period after ADT initiation was 70 months. The median overall survival among patients with undetectable PSA was quite long, reaching 226 months and significantly longer than that among patients with detectable PSA [71 months, hazard ratio (HR)=0.27, 95% confidence interval (CI)=0.15-0.49, p<0.001]. Time to development of castration-resistance was also long and significantly longer in the undetectable PSA group than that in the detectable PSA group (median: 124 vs. 17 months, HR=0.20, 95% CI=0.12-0.34, p<0.001). CONCLUSION: Patients with low-risk and/or low-volume mCSPC showed long-term survival when undetectable PSA was achieved during conventional ADT. In these patients, skipping upfront treatment intensification does not seem to negatively impact survival.

Optimal Number of Cycles of First-line Platinum-based Chemotherapy for Metastatic Urothelial Carcinoma.

BACKGROUND/AIM: In recent years, switch maintenance after platinum-based chemotherapy has been a standard of care. However, the appropriate number of systemic chemotherapy cycles against advanced-stage urothelial carcinoma (UC) remains unclear. This study assessed the survival outcomes of first-line platinum-based chemotherapy according to treatment cycles in patients with metastatic disease. PATIENTS AND METHODS: We retrospectively evaluated patients with metastatic bladder and upper urinary tract cancer who received platinum-based combination therapy. Overall survival (OS) was evaluated using the Kaplan-Meier method and the log-rank test. RESULTS: Of 179 patients, 47 (26.3%) were women, and 73 (40.8%) had upper urinary tract cancer. Furthermore, 47 (26.3%) who were not eligible for cisplatin received carboplatin. The median number of treatment cycles was 3 (range=1-14 cycles). The rates of progressive disease within two cycles, from two to four cycles, and from four to six cycles were 18.4%, 19.2%, and 30.6%, respectively. The median OS of patients with 2, 3, 4, 5-6, and ≥7 treatment cycles were 8.6, 14.3, 21.3, 24.4, and 26.1 months, respectively. The OS did not significantly differ between patients receiving four treatment cycles and those receiving ≥5 treatment cycles. In patients with disease control (complete or partial response or stable disease) receiving ≥4 treatment cycles, there was no significant difference in terms of OS between patients receiving four cycles and those receiving six cycles. CONCLUSION: Four cycles of first-line platinum-based chemotherapy can be effective in patients with metastatic UC.

Inhibition of aldo-keto reductase 1C3 overcomes gemcitabine/cisplatin resistance in bladder cancer.

Systemic chemotherapy with gemcitabine and cisplatin (GC) has been used for the treatment of bladder cancer in which androgen receptor (AR) signaling is suggested to play a critical role. However, its efficacy is often limited, and the prognosis of patients who develop resistance is extremely poor. Aldo-keto reductase 1C3 (AKR1C3), which is responsible for the production of a potent androgen, 5α-dihydrotestosterone (DHT), by the reduction of 5α-androstane-3α,17ß-dione (5α-Adione), has been attracting attention as a therapeutic target for prostate cancer that shows androgen-dependent growth. By contrast, the role of AKR1C3 in bladder cancer remains unclear. In this study, we examined the effect of an AKR1C3 inhibitor on androgen-dependent proliferation and GC sensitivity in bladder cancer cells. 5α-Adione treatment induced the expression of AR and its downstream factor ETS-domain transcription factor (ELK1) in both T24 cells and newly established GC-resistant T24GC cells, while it did not alter AKR1C3 expression. AKR1C3 inhibitor 2j significantly suppressed 5α-Adione-induced AR and ELK1 upregulation, as did an AR antagonist apalutamide. Moreover, the combination of GC and 2j in T24GC significantly induced apoptotic cell death, suggesting that 2j could enhance GC sensitivity. Immunohistochemical staining in surgical specimens further revealed that strong expression of AKR1C3 was associated with significantly higher risks of tumor progression and cancer-specific mortality in patients with muscle-invasive bladder cancer. These results suggest that AKR1C3 inhibitors as adjunctive agents enhance the efficacy of GC therapy for bladder cancer.

Efficacy of Platinum-based Chemotherapy in Patients With Metastatic Urothelial Carcinoma With Variant Histology.

BACKGROUND/AIM: Variant urothelial carcinoma (VUC, defined herein as urothelial carcinoma with any histological variant) is frequently observed at an advanced stage. However, the efficacy of systemic chemotherapy against VUC in metastatic disease has rarely been reported. This study assessed the therapeutic response and survival outcomes of platinum-based chemotherapy as first-line treatment in patients with metastatic VUC. PATIENTS AND METHODS: We retrospectively analyzed consecutive patients with metastatic bladder and upper urinary tract cancer who received gemcitabine plus cisplatin (or carboplatin) at the University of Occupational and Environmental Health Hospital between November 2008 and November 2022. Progression-free survival and overall survival were evaluated using the Kaplan-Meier method and Cox proportional hazard models. RESULTS: Out of 131 patients recorded, 86 (65.6%) had pure urothelial carcinoma (PUC) and 45 (34.4%) had VUC. The most common variant element was squamous differentiation (44.4%). Compared to those with PUC, patients with VUC showed a comparable objective response rate (33.3% vs. 41.9%, p=0.451) and disease control rate (64.5% vs. 75.6%, p=0.221). They also had poorer progression-free survival (median=4.9 months vs. 7.9 months, p=0.014) and overall survival (median=10.9 months vs. 18.2 months, p=0.037) than those with PUC. On multivariate analysis, VUC was an independent predictor of progression (hazard ratio=1.79; 95% confidence interval=1.19-2.69; p=0.005) and mortality (hazard ratio=1.64; 95% confidence interval=1.08-2.48; p=0.020). CONCLUSION: Although the response of metastatic VUC to platinum-based chemotherapy was not inferior to that of PUC, VUC had progressed faster than PUC. VUC was significantly associated with a poor prognosis after platinum-based chemotherapy as first-line treatment.

Prognostic Impact of Histologic Subtype and Divergent Differentiation in Patients with Metastatic Urothelial Carcinoma Treated with Enfortumab Vedotin: A Multicenter Retrospective Study.

Subtype of urothelial carcinoma (SUC), defined here as urothelial carcinoma with any histologic subtype or divergent differentiation, is a clinically aggressive disease. However, the efficacy of enfortumab vedotin (EV) against SUC remains unclear. Hence, this study aimed to assess the oncological outcomes of patients with SUC treated with EV for metastatic disease. We retrospectively evaluated consecutive patients with advanced lower and upper urinary tract cancer who received EV after platinum-based chemotherapy and immune checkpoint blockade therapy at six institutions. The objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were compared between patients with pure urothelial carcinoma (PUC) and those with SUC. We identified 44 and 18 patients with PUC and SUC, respectively. Squamous differentiation was the most common subtype element, followed by glandular differentiation and sarcomatoid subtype. Although patients with SUC had a comparable ORR to those with PUC, the duration of response for SUC was short. Patients with SUC had poorer PFS than those with PUC; however, no significant difference was observed in OS. Multivariate analysis revealed that SUC was significantly associated with shorter PFS. Although the response of metastatic SUC to EV was similar to that of PUC, SUC showed faster progression than PUC.

Prostate-specific Antigen Kinetics During Androgen-deprivation Therapy Predict Response to Enzalutamide in Metastatic Castration-resistant Prostate Cancer.

BACKGROUND/AIM: No practical predictive biomarkers exist to date for the response to androgen receptor-axis targeted (ARAT) therapies in metastatic castration-resistant prostate cancer (mCRPC). This study investigated whether prostate-specific antigen (PSA) kinetics in primary androgen-deprivation therapy for advanced hormone-sensitive prostate cancer may be associated with the response to ARAT agents in mCRPC. PATIENTS AND METHODS: This study assessed 102 patients with mCRPC treated with enzalutamide or abiraterone to evaluate the associations between clinical outcomes and PSA kinetics, including the ratio of initial to nadir PSA (I/N PSA) level in primary combined androgen blockade. The PSA response was defined as a ≥50% decrease at 3 months from baseline in patients with mCRPC. RESULTS: In patients treated with enzalutamide, the optimal cut-off I/N PSA value for PSA response was 531 ng/ml (sensitivity=66.7%, specificity=88.2%, area under the curve=0.73, using a receiver operating characteristic curve). The PSA response was 83.3% and 25.0% in the high and low I/N PSA groups, respectively. The median overall survival and radiographic progression-free survival from enzalutamide initiation were longer for the high compared to the low I/N PSA group. Multivariate analysis revealed I/N PSA (hazard ratio=0.275, p=0.026) as an independent risk factor for overall survival in the patients treated with enzalutamide. In contrast, I/N PSA showed no predictive ability for PSA response in patients treated with abiraterone. CONCLUSION: In patients with mCRPC, I/N PSA can be a practical predictive biomarker for response to the ARAT agent enzalutamide.

Initial-to-nadir Prostate-specific Antigen Ratio Predicts Response to First-line Enzalutamide in Metastatic Castration-resistant Prostate Cancer.

BACKGROUND/AIM: No practical biomarkers predict the response to enzalutamide in chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC). The present study aimed to evaluate the prognostic value of the initial-to-nadir prostate-specific antigen (PSA) ratio (I/N PSA) in primary hormone therapy for metastatic hormone-naïve prostate cancer associated with the response to first-line enzalutamide in mCRPC. PATIENTS AND METHODS: Twenty-eight patients with mCRPC received first-line enzalutamide to determine the associations between I/N PSA in combined androgen blockade and clinical outcomes. The PSA response was defined as ≥90% decline from baseline in patients with mCRPC. RESULTS: The optimal cutoff I/N PSA value for PSA response was 1,219 (sensitivity=71.4%, specificity=92.9%, area under the receiver operating characteristic curve=0.85). The PSA response was 90.9% in the high I/N PSA group and 23.5% in the low I/N PSA group. The median overall survival, prostate cancer-specific survival, and radiographic progression-free survival after initiation of enzalutamide were statistically greater for the high I/N PSA group than the low group. Multivariable analysis showed that I/N PSA was an independent predictor of overall survival (hazard ratio=0.23; p=0.026). CONCLUSION: In chemotherapy-naïve patients with mCRPC, I/N PSA was a predictive and prognostic biomarker for first-line enzalutamide. The I/N PSA can enable optimization of individual treatment in real-world clinical practice.

Protective role of mineralocorticoid receptor signaling in urothelial tumorigenesis.

The expression status of mineralocorticoid receptor (MR) and its biological significance in human urothelial carcinoma remain unknown. The present study aimed to determine the functional role of MR in the development of urothelial cancer. In human normal urothelial SVHUC cells with exposure to a chemical carcinogen 3-methylcholanthrene (MCA), we assessed the effects of a natural MR ligand, aldosterone, and 3 MR antagonists, including spironolactone, eplerenone, and esaxerenone, as well as knockdown of MR via shRNA virus infection, on their neoplastic/malignant transformation. The in vitro system with carcinogen challenge showed that aldosterone and anti-mineralocorticoids significantly prevented and promoted, respectively, the neoplastic transformation of SVHUC cells. Similarly, MR knockdown in SVHUC cells considerably induced MCA-mediated neoplastic transformation, compared with a control subline. In addition, MR knockdown or antagonist treatment resulted in increases in the expression of ß-catenin, c-Fos, and N-cadherin, and a decrease in that of E-cadherin. Meanwhile, spironolactone, which is known to possess anti-androgenic activity, rather suppressed the neoplastic transformation of a SVHUC subline stably expressing wild-type androgen receptor, indicating its dominant effect via the androgen receptor pathway. Immunohistochemistry in surgical specimens detected MR signals in 77 (98.7%; 23.1% weak/1+, 42.3% moderate/2+, and 33.3% strong/3+) of 78 non-invasive bladder tumors, which was significantly (P<0.001) lower than in adjacent non-neoplastic urothelial tissues (100%; 20.5% 2+ and 79.5% 3+). Moreover, the risks for disease recurrence after transurethral surgery were marginally lower in female patients with MR-high (2+/3+) tumor (P=0.068) and significantly lower in all patients with MR-high/glucocorticoid receptor-high tumor (P=0.025), compared with respective controls. These findings suggest that MR signaling functions as a suppressor for urothelial tumorigenesis.

Second-Line Systemic Therapy for Highly Aggressive Neuroendocrine Prostate Cancer.

Neuroendocrine prostate cancer (NEPC) is generally an aggressive form of prostate cancer that can arise de novo or develop as a castration-resistant mechanism. While first-line platinum-based chemotherapy is effective against NEPC, its limited response duration and subsequent treatments pose significant clinical challenges. Standard second-line treatments have not been established due to the limited data available. The aim of this review was to reveal the current status of second-line therapy for NEPC. A literature search was conducted using PubMed and Web of Science and a total of 13 articles were included in this review. Prospective and retrospective studies demonstrated that treatment outcome of second-line therapy using platinum with etoposide or docetaxel was unfavorable and progression-free survival was 3 months or shorter. Amrubicin and irinotecan were also frequently used as second-line therapy, however, efficacy of these agents was modest and response duration was less than 6 months. NEPC patients with homologous recombination repair gene alterations may benefit from treatment with poly (ADP-ribose) polymerase (PARP) inhibitors. Ongoing clinical studies investigate various agents, including immune checkpoint inhibitors, molecularly targeted agents, and PARP inhibitors. With the increasing recognition and active biopsy of NEPC lesions, the number of NEPC patients is anticipated to rise. Accumulating more knowledge and experience is crucial in developing novel treatment strategies to combat this disease.

Association Between Body Mass Index and Outcomes in Patients With Urothelial Carcinoma Treated With Pembrolizumab.

BACKGROUND/AIM: We aimed to clarify the association between body mass index (BMI) and clinical outcomes of pembrolizumab treatment for advanced urothelial cancer (UC). PATIENTS AND METHODS: We retrospectively reviewed the records of patients with advanced UC who received pembrolizumab after chemotherapy between March 2018 and December 2021. Patients were divided according to BMI into the non-overweight group (BMI <25 kg/m2) and the overweight group (BMI ≥25 kg/m2). We compared the two groups' tumour response, survival rates, and incidence of immune-related adverse events (irAEs) and investigated the factors predicting survival. RESULTS: Of 84 eligible patients, 63 (75%) and 21 (25%) were in the non-overweight and overweight groups, respectively. Although the objective response rate was higher in the overweight group (55%) than that in the non-overweight group (29%), the difference was not significant. Progression-free survival (PFS) was significantly longer in the overweight group (median 15.2 months) than that in the non-overweight group (median 4.8 months; p=0.01). Overall survival was also longer in the overweight group (median 36.1 months) compared to that in the non-overweight group (13.4 months), but the difference was not significant (p=0.11). Multivariable analysis showed that overweight was significantly associated with favourable PFS. Any and severe (grade 3) irAEs were observed in 15 (24%) and 5 (7.9%) patients in the non-overweight group, respectively, and in 8 (38%) and 2 (9.5%) patients in the overweight group, respectively, but the differences were not significant. CONCLUSION: BMI was associated with oncological outcomes in patients with advanced UC who received pembrolizumab but not with the development of irAEs.

Efficacy and Tolerability of Enfortumab Vedotin for Metastatic Urothelial Carcinoma: Early Experience in the Real World.

BACKGROUND/AIM: This study retrospectively investigated the impact of enfortumab vedotin (EV) monotherapy on the oncological outcome, safety profile, and health-related quality of life (HRQoL) in patients with metastatic urothelial carcinoma. PATIENTS AND METHODS: We assessed 26 consecutive patients who had received EV monotherapy after failure of platinum-based chemotherapy and immune checkpoint blockade therapy at our single institution from December 2021 to January 2023. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), incidence of adverse events (AEs), and EORTC QLQ-C30 as an HRQoL instrument were evaluated. RESULTS: The ORR and DCR were 57.7% and 80.8%, respectively. EV was effective regardless of the patient and tumor characteristics, including the efficacy of previous systemic therapy, performance status, number of Bellmunt risk factors, and presence of variant histology. With a median follow-up time of 7.5 months, the median durations of PFS and OS were 5.4 months and 10.3 months, respectively. Grade ≥3 AEs included neutropenia (15.4%), fatigue (7.7%), appetite loss (7.7%), rash (3.8%), febrile neutropenia (3.8%), hyperglycemia (3.8%), and interstitial pneumonia (3.8%). AEs resulting in withdrawal of EV, interruption of EV, and dose reduction occurred in two (7.7%), nine (34.6%), and 13 patients (50.0%), respectively. The EORTC QLQ-C30 scores from baseline to post-EV introduction remained stable. CONCLUSION: EV monotherapy demonstrated promising anti-tumor activity and tolerability in patients with metastatic urothelial carcinoma.

Prognostic Significance of 3-Month Prostate-specific Antigen Level Following Androgen-deprivation Therapy in Metastatic Hormone-sensitive Prostate Cancer.

BACKGROUND/AIM: We examined the prognostic use of the 3-month prostate-specific antigen (PSA3m) level after androgen-deprivation therapy in patients with de novo metastatic hormone-sensitive prostate cancer (mHSPC). PATIENTS AND METHODS: The present study included 145 patients with mHSPC who received primary androgen-deprivation therapy. RESULTS: The optimal cutoff PSA3m value for prediction of 5-year overall survival was 2.56 ng/ml (area under the receiver operating characteristics curve=0.67) using a time-dependent receiver operating characteristic (survival ROC) curve. In patients with CHAARTED low-volume and LATITUDE low-risk disease, the median overall survival was longer for patients with low PSA3m than that for those with high PSA3m. Multivariate analysis revealed PSA3m (hazard ratio=1.99; p=0.006) and age ≥80 years as independent risk factors for overall survival in patients with mHSPC. CONCLUSION: PSA3m can be a useful prognostic biomarker to avoid excessive upfront combination therapy, particularly in elderly patients with low-volume and low-risk mHSPC.

Impact of the Use of Proton Pump Inhibitors on Pembrolizumab Effectiveness for Advanced Urothelial Carcinoma.

BACKGROUND/AIM: This study aimed to clarify the impact of proton pump inhibitors (PPIs) on oncological outcomes in patients who received pembrolizumab for advanced urothelial carcinoma (UC). PATIENTS AND METHODS: Forty advanced UC patients treated with pembrolizumab were retrospectively reviewed and divided into two groups (PPI: 15 patients; without PPI: 25 patients). Tumor response and survival were compared between these groups. The factors associated with survival were also investigated. RESULTS: The objective response rate was significantly lower in the group with PPIs compared with the group without PPIs. Both progression-free survival (PFS) and overall survival (OS) were significantly shorter in the group with PPIs than in the group without PPIs. The use of PPIs was a significant predictor of poor PFS and OS in multivariate analysis. CONCLUSION: The use of PPIs was negatively associated with tumor response and survival in patients with advanced UC treated with pembrolizumab.

Immediate Prostate-specific Antigen Decline After Enzalutamide Following Abiraterone Predicts Survival in Castration-resistant Disease.

BACKGROUND/AIM: Although the sequential use of abiraterone and enzalutamide is not recommended because of possible cross-resistance, many patients with metastatic castration-resistant prostate cancer (mCRPC) are receiving sequential abiraterone and enzalutamide in the real world, and a subset of patients can benefit from sequential therapy with these drugs. This study aimed to identify patients who could benefit from the sequential use of enzalutamide after abiraterone use. PATIENTS AND METHODS: We included 70 patients with mCRPC who received enzalutamide sequentially following abiraterone treatment. Decline in the prostatespecific antigen (PSA) levels at 4 weeks after enzalutamide initiation and the association between decline in PSA levels and survival were analyzed. RESULTS: Sixteen men (22.9%) achieved a decline of >50% in PSA levels after 4 weeks of enzalutamide administration. Overall survival (OS) after enzalutamide among men with >50% decline at 4 weeks was significantly better than that among men with a PSA decline <50% (not reached vs. 34 months, p=0.008). OS after first-line abiraterone treatment for men with PSA decline >50% and <50% was not reached and 46 months, respectively (p=0.007). A PSA decline of >50% at 4 weeks of enzalutamide administration was an independent predictor of longer OS. CONCLUSION: A PSA decline of >50% at 4 weeks after the start of sequential enzalutamide treatment following abiraterone treatment predicted long-term survival in patients with mCRPC. Early PSA decline can identify patients who benefit from second-line enzalutamide after abiraterone treatment and can be useful as a decision-making tool regarding treatment.