BACKGROUND: Epidemiologic studies suggest that metformin has antitumor effects. Laboratory studies indicate metformin impacts cancer stem-like cells (CSCs). As part of a phase II trial, we evaluated the impact of metformin on CSC number and on carcinoma-associated mesenchymal stem cells (CA-MSCs) and clinical outcomes in nondiabetic patients with advanced-stage epithelial ovarian cancer (EOC). METHODS: Thirty-eight patients with stage IIC ( n = 1)/III ( n = 25)/IV ( n = 12) EOC were treated with either (a) neoadjuvant metformin, debulking surgery, and adjuvant chemotherapy plus metformin or (b) neoadjuvant chemotherapy and metformin, interval debulking surgery, and adjuvant chemotherapy plus metformin. Metformin-treated tumors, compared with historical controls, were evaluated for CSC number and chemotherapy response. Primary endpoints were (a) a 2-fold or greater reduction in aldehyde dehydrogenase–positive (ALDH ⁺ ) CD133 ⁺ CSCs and (b) a relapse-free survival at 18 months of more than 50%. RESULTS: Metformin was well tolerated. Median progression-free survival was 18.0 months (95% CI 14.0–21.6) with relapse-free survival at 18 months of 59.3% (95% CI 38.6–70.5). Median overall survival was 57.9 months (95% CI 28.0–not estimable). Tumors treated with metformin had a 2.4-fold decrease in ALDH ⁺ CD133 ⁺ CSCs and increased sensitivity to cisplatin ex vivo. Furthermore, metformin altered the methylation signature in CA-MSCs, which prevented CA-MSC–driven chemoresistance in vitro. CONCLUSION: Translational studies confirm an impact of metformin on EOC CSCs and suggest epigenetic change in the tumor stroma may drive the platinum sensitivity ex vivo. Consistent with this, metformin therapy was associated with better-than-expected overall survival, supporting the use of metformin in phase III studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT01579812.

Metastatic castrate resistant prostate cancer (mCPRC) remains an aggressive form of prostate cancer that no longer responds to traditional hormonal treatment alone. Despite the advent of novel anti-androgen medications, many patients continue to progress, and as a result, there is a growing need for additional treatment options. Lutetium-177 (¹⁷⁷Lu) - PSMA-617 has become one of the new frontline treatment options for refractory metastatic castrate resistant prostate cancer after the failure of novel anti-androgen therapy and chemotherapy. Lu-177 has been used in real-world prospective trials and is now becoming utilized in newer phase III clinical trials. Here, we present a comprehensive overview of the current literature, covering retrospective studies, prospective studies, and clinical trials that established Lutetium-177-PSMA-617 (¹⁷⁷Lu-PSMA-617) for the treatment of mCRPC. ¹⁷⁷Lu - PSMA-617 has been approved for treatment of mCRPC based on positive phase III studies. While this treatment is tolerable and effective, biomarkers are necessary to determine which patients will benefit. In the future, radioligand treatments will likely be utilized in earlier lines of therapy and potentially in combination with other prostate cancer treatments.

In JAVELIN Bladder 100, avelumab first-line maintenance (1LM) improved overall survival (OS) and progression-free survival (PFS) in patients with locally advanced/metastatic urothelial carcinoma (la/mUC) without progression following 1L platinum-based chemotherapy (PBC) versus best supportive care. PATRIOT-II describes real-world outcomes with avelumab 1LM. This observational, retrospective study of avelumab 1LM in US community/academic centers used medical record data collected from avelumab initiation for ≥12 months to assess survival, safety, and healthcare resource utilization; analyses are descriptive. The study included 160 patients from 37 centers (median age, 70 years; 77% male). Avelumab 1LM was initiated at a median of 4 weeks (IQR 3-6) after PBC completion. Median follow-up from avelumab 1LM was 16 months (IQR 11-21). At study end, 19.4% of patients continued avelumab; 73.7% had discontinued due to progression, adverse events (AEs), or performance status deterioration. Median PFS and OS from avelumab initiation were 5.4 months (95% CI, 3.8-6.9) and 24.4 months (95% CI, 20.4-28.4), respectively. Grade ≥3 treatment-related AEs (TRAEs) occurred in 15 patients (9.4%); 35 (21.9%) had any-grade immune-related AEs, and 23 (14.3%) received high-dose systemic corticosteroids for AEs. Forty-four patients (27.5%) were hospitalized during the avelumab treatment period, of whom 13 (8.1%) were hospitalized due to TRAEs. Limitations of this study include a small sample size, potential selection bias, and missing/unknown data. These results align with the JAVELIN Bladder 100 clinical trial and other real-world studies, supporting avelumab 1LM use in patients with la/mUC without progression following 1L PBC.

PURPOSE: Circulating tumor DNA (ctDNA) detection in blood has emerged as a prognostic and predictive biomarker demonstrating improved assessment of treatment response in patients receiving immune checkpoint inhibitors (ICIs). Here, we performed a pilot study to support the role of ctDNA for longitudinal treatment response monitoring in patients with advanced genitourinary (GU) malignancies receiving ICIs. MATERIALS AND METHODS: Patients with histologically confirmed advanced GU malignancies were prospectively enrolled. All eligible patients received ICI treatment for at least 12 weeks, followed by serial collection of blood samples every 6-8 weeks and conventional scans approximately every 12 weeks until disease progression. ctDNA analysis was performed using Signatera, a tumor-informed multiplex-polymerase chain reaction next-generation sequencing assay. Overall, the objective response rate (ORR) was reported and its association with ctDNA status was evaluated. Concordance rate between ctDNA dynamics and conventional imaging was also assessed. RESULTS: ctDNA analysis was performed on 98 banked plasma samples from 20 patients (15 renal, four urothelial, and one prostate). The median follow-up from the time of initiation of ICI to progressive disease (PD) or data cutoff was 67.7 weeks (range, 19.6-169.6). The ORR was 70% (14/20). Eight patients ultimately developed PD. The overall concordance between ctDNA dynamics and radiographic response was observed in 83% (15/18) of patients. Among the three patients with discordant results, two developed CNS metastases and one progressed with extracranial systemic disease while ctDNA remained undetectable. CONCLUSION: In this pilot study, longitudinal ctDNA analysis for monitoring response to ICI in patients with advanced GU tumors was feasible. Larger prospective studies are warranted to validate the utility of ctDNA as an ICI response monitoring tool in patients with advanced GU malignancies.

PURPOSE: The purpose of this study was to elucidate the relationship between the tumor microenvironment (TME) and cellular diversity in bladder cancer (BLCA) progression, leveraging single-cell RNA sequencing (scRNA-seq) data to identify potential prognostic biomarkers and construct a prognostic model for BLCA. METHODS: We analyzed scRNA-seq data of normal and tumor bladder cells from the Gene Expression Omnibus (GEO) database to uncover crucial markers within the bladder TME. The study compared gene expression in normal versus tumor bladder cells, identifying differentially expressed genes. These genes were subsequently assessed for their prognostic significance using patient follow-up data from The Cancer Genome Atlas. Prognostic models were constructed using Least Absolute Shrinkage and Selection Operator and multivariate Cox regression analyses, focusing on eight genes of interest. The predictive performance of the model was also tested against additional GEO data sets (GSE31684, GSE13507, and GSE32894). RESULTS: The prognostic model demonstrated reliable prediction of patient outcomes. Validation through gene set enrichment analysis and immune cell infiltration assessment supported the model's efficacy. The results from both the univariate and multivariate analyses suggest that the risk score is an independent prognostic factor with a hazard ratio of 2.97 (95% CI, 2.28 to 3.9, P < .001). In the validation cohort, the AUC at 1, 2, and 3 years is 0.74, 0.74, and 0.72, respectively. CONCLUSION: Our findings proposed biomarkers with prognostic potential, laying the groundwork for future in vitro validation and therapeutic exploration. This contributes to a deeper understanding of the genes associated with bladder TME and may improve prognostic precision in BLCA management.