Investigation of eligibility for adjuvant therapy from real-world data of patients with urothelial carcinoma undergoing radical cystectomy and radical nephroureterectomy.

OBJECTIVE: Adjuvant nivolumab prolonged disease-free survival compared with placebo in patients at high risk of recurrence following radical cystectomy or radical nephroureterectomy in the CheckMate 274 trial. However, the ideal eligibility criteria for adjuvant therapy in real-world clinical practice remain controversial. METHODS: We retrospectively analyzed clinical data of 409 patients who underwent radical cystectomy (n = 252) or radical nephroureterectomy (n = 157) and validated the risk of recurrence based on the classification used in the CheckMate 274 trial. We also investigated the impact of perioperative chemotherapy, lymph node dissection and pathological factors on prognosis. RESULTS: The median follow-up time was 37.5 and 32.1 months in bladder cancer and upper tract urothelial carcinoma, respectively. Among the high-risk patients based on CheckMate 274 trial, disease-free survival was considerably shorter for bladder cancer and upper tract urothelial carcinoma patients than for low-risk patients (hazard ratios: 4.132 and 7.101, respectively). The prevalence of adjuvant chemotherapy in high-risk patients was low (24 and 38% for bladder cancer and upper tract urothelial carcinoma, respectively). The extent of lymph node dissection in bladder cancer and presence of lymph node dissection in upper tract urothelial carcinoma did not affect prognosis. Cox proportional multivariate analysis revealed CheckMate 274-high-risk as a poor prognostic factor in bladder cancer and upper tract urothelial carcinoma. CONCLUSIONS: This study validated the risk classification for recurrence following radical cystectomy and radical nephroureterectomy using the CheckMate 274 criteria in real-world practice. Further research would help assess the degree of benefit obtained from adjuvant nivolumab.

Trend in overall survival from the start of first-line chemotherapy in patients with metastatic urothelial carcinoma.

New approaches involving immune checkpoint inhibitors and antibody-drug conjugates prolong overall survival in patients with metastatic urothelial carcinoma. However, the access to such systemic therapy in clinical practice is suboptimal, and whether these agents improve overall survival in patients with metastatic urothelial carcinoma over time remains unclear. Hence, we investigated the overall survival trend from the initiation of first-line therapy with these agents to identify changes due to the medication and time of treatment initiation. We retrospectively evaluated 195 patients from a single center. They were treated with chemotherapy, pembrolizumab, or avelumab or enfortumab vedotin. The treatment was categorized into chemotherapy, pembrolizumab or avelumab/enfortumab vedotin period. The new agents prolonged overall survival from the start of first-line therapy. Furthermore, sequential treatment with these agents in real-world clinical practice has been reported to prolong overall survival. These study results will have major implications when a new first-line therapy is approved in the future.

Irradiation plus myeloid-derived suppressor cell-targeted therapy for overcoming treatment resistance in immunologically cold urothelial carcinoma.

BACKGROUND: Radiotherapy (RT) has recently been highlighted as a partner of immune checkpoint inhibitors. The advantages of RT include activation of lymphocytes while it potentially recruits immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs). This study aimed to investigate the mechanism of overcoming treatment resistance in immunologically cold tumours by combining RT and MDSC-targeted therapy. METHODS: The abscopal effects of irradiation were evaluated using MB49 and cisplatin-resistant MB49R mouse bladder cancer cells, with a focus on the frequency of immune cells and programmed cell death-ligand 1 (PD-L1) expression in a xenograft model. RESULTS: MB49R was immunologically cold compared to parental MB49 as indicated by the fewer CD8+ T cells and lower PD-L1 expression. Polymorphonuclear MDSCs increased in both MB49 and MB49R abscopal tumours, whereas the infiltration of CD8+ T cells increased only in MB49 but not in MB49R tumours. Interestingly, PD-L1 expression was not elevated in abscopal tumours. Finally, blocking MDSC in combination with RT remarkably reduced the growth of both MB49 and MB49R abscopal tumours regardless of the changes in the frequency of infiltrating CD8+ T cells. CONCLUSIONS: The combination of RT and MDSC-targeted therapy could overcome treatment resistance in immunologically cold tumours.

A retrospective study on optimal number of cycles of the first-line platinum-based chemotherapy for metastatic urothelial carcinoma.

BACKGROUND: Recently, switch maintenance with avelumab has been approved for the treatment of advanced or metastatic urothelial carcinoma (UC), with no progression after four to six cycles of first-line platinum-based chemotherapy. However, the optimal number of cycles of platinum-based chemotherapy has not been determined. OBJECTIVE: To analyze the clinical characteristics of patients with advanced UC who were treated with platinum-based chemotherapy and investigate the association between the number of cycles of the treatment and the patients' overall survival. METHODS: A total of 124 patients with advanced UC who were treated with first-line platinum-based chemotherapy at Osaka City University Hospital between April 2009 and January 2020 were retrospectively reviewed. RESULTS: Of the 124 patients, clinical information regarding overall survival was available for 115 patients. The median age was 72 years (range, 43-95 years). Only 59 patients (51.3 %) were treated with gemcitabine and cisplatin, and 52 patients (45.2 %) were treated with gemcitabine and carboplatin. The median number of cycles was three (1-8), and the percentage of patients who discontinued chemotherapy due to progressive disease was 80.3%, 64.0%, and 86.4% in those receiving one to three, four, and five or more cycles, respectively. Moreover, no difference in overall survival was observed between patients who received four cycles and those who received five or more cycles at both univariate and multivariate levels. CONCLUSIONS: The present study shows that five or more cycles of first-line platinum-based chemotherapy did not prolong overall survival compared with four cycles, suggesting that four cycles of chemotherapy might be sufficient, considering the new treatment strategy involving switch maintenance with avelumab.

Myeloid-derived suppressor cells are essential partners for immune checkpoint inhibitors in the treatment of cisplatin-resistant bladder cancer.

Myeloid-derived suppressor cells (MDSCs) are one of the key players that contribute to immune evasion. The purpose of the present study was to investigate whether MDSCs could be a novel target for the treatment of cisplatin-resistant bladder cancer. We established cisplatin-resistant bladder cancer cell lines (MB49R, MBT-2R, and T24R) and evaluated chemokine expression and MDSC expansion. We also assessed the antitumor effect by depleting MDSCs with or without a α-PD-L1 antibody using MB49R xenograft models. The chemokine expression of CXCL1, CXCL2, and CCL2 increased in cisplatin-resistant cells compared to those in their parent strains. Monocytic MDSCs (Mo-MDSCs) were observed more frequently compared to polymorphonuclear MDSCs (PMN-MDSCs) in MB49R tumors. The immunosuppressive genes arginase 1 and iNOS were comparably expressed in each MDSC subtype. In vivo, combination therapy targeting both PMN- and Mo-MDSCs using α-Gr1 and α-Ly6C antibodies significantly reduced tumor volume with increased infiltration of CD8 T cells in the tumor. Finally, co-targeting pan-MDSCs and PD-L1 remarkably reduced the tumor growth. These findings suggest that targeting MDSCs might enhance the therapeutic effect of immune checkpoint inhibitors in cisplatin-resistant bladder cancers.

Steroid sulfatase promotes invasion through epithelial-mesenchymal transition and predicts the progression of bladder cancer.

Androgen signal has been recently suggested to be associated with the progression of bladder cancer. Steroid sulfatase (STS) is a steroid sulfate activation enzyme, considered to be one of the key enzymes in the androgen signaling pathway. However, the role of STS in bladder cancer has not been elucidated. The purpose of the present study was to determine the clinical and functional significance of STS in bladder cancer. Immunohistochemical analysis of surgical specimens obtained by radical cystectomy (n=114) demonstrated that overexpression of STS was associated with the invasion of bladder cancer, as evidenced by the incidence of STS-positive cancers (11.5 and 37.1% in non-muscle invasive and muscle invasive bladder cancers, respectively; P=0.003). STS-positive cancer demonstrated shorter recurrence-free survival and cancer-specific survival (P=0.0027 and 0.0030, respectively). Furthermore, knockdown of STS significantly reduced cell migration and invasion capacities of bladder cancer cells (P<0.001 and P=0.005, respectively), accompanied by the upregulation of E-cadherin and downregulation of vimentin. In summary, the present study demonstrated that STS promotes the invasion capability of bladder cancer via regulation of the epithelial-mesenchymal transition, and may be a useful marker for predicting the progression of bladder cancers.

Androgen Receptor Splice Variant 7 Drives the Growth of Castration Resistant Prostate Cancer without Being Involved in the Efficacy of Taxane Chemotherapy.

Expression of androgen receptor (AR) splice variant 7 (AR-V7) has been identified as the mechanism associated with the development of castration-resistant prostate cancer (CRPC). However, a potential link between AR-V7 expression and resistance to taxanes, such as docetaxel or cabazitaxel, has not been unequivocally demonstrated. To address this, we used LNCaP95-DR cells, which express AR-V7 and exhibit resistance to enzalutamide and docetaxel. Interestingly, LNCaP95-DR cells showed cross-resistance to cabazitaxel. Furthermore, these cells had increased levels of P-glycoprotein (P-gp) and their sensitivity to both docetaxel and cabazitaxel was restored through treatment with tariquidar, a P-gp antagonist. Results generated demonstrated that P-gp mediated cross-resistance between docetaxel and cabazitaxel. Although the LNCaP95-DR cells had increased expression of AR-V7 and its target genes (UBE2C, CDC20), the knockdown of AR-V7 did not restore sensitivity to docetaxel or cabazitaxel. However, despite resistance to docetaxel and carbazitaxel, EPI-002, an antagonist of the AR amino-terminal domain (NTD), had an inhibitory effect on the proliferation of LNCaP95-DR cells, which was similar to that achieved with the parental LNCaP95 cells. On the other hand, enzalutamide had no effect on the proliferation of either cell line. In conclusion, our results suggested that EPI-002 may be an option for the treatment of AR-V7-driven CRPC, which is resistant to taxanes.

Comparison of efficacy and toxicity of second-line combination chemotherapy regimens in patients with advanced urothelial carcinoma.

BACKGROUND: The aim of this study was to evaluate the efficacy and toxicities of second-line chemotherapy regimens with docetaxel and gemcitabine (GD), or paclitaxel and gemcitabine (GP) for advanced or metastatic urothelial carcinoma (UC) that did not respond to first-line platinum-based chemotherapy. METHODS: From 2002 to 2017, 78 patients with metastatic UCs that progressed after platinum-based chemotherapy were treated with either GD (n = 41) or GP (n = 37). We compared these two different regimens by analyzing their efficacy and toxicities in a retrospective manner. RESULTS: Of the 78 patients enrolled in this study, it was possible to determine treatment efficacy in 70; the proportion of patients with objective response and disease control were 8.6 (9/70) and 54.3% (38/70), respectively. The median progression-free survival and overall survival in the total population (GP and GD) were 3.5 (95% CI 0.6-53.3) and 9.6 months (95% CI 1.2-53.3), respectively. There was no significant difference between the two regimens (GD or GP) regarding survival outcomes. Treatment-related adverse events were mostly manageable, but one patient died as a result of febrile neutropenia. The presence of liver metastasis and anemia (Hb < 10.0 g/dl) was prognostic factors for worse survival. CONCLUSIONS: Combination chemotherapy with either GP or GD was a favorable and well-tolerated second-line treatment regimen for patients with advanced or metastatic UC following the failure of a platinum-based regimen. Further study using a large prospective cohort is needed to identify patients who will benefit from second-line combination therapy.