Circulating tumor cells (CTCs) represent a powerful, minimally invasive window into tumor biology and disease evolution. Technological progress over the past decade has markedly improved the ability to isolate, preserve, and interrogate viable CTCs, transforming them from simple prognostic markers to functional tools for precision oncology. Advances in microfluidic platforms, immunomagnetic enrichment, aptamer-based capture, and nanostructured interfaces have expanded the efficiency and fidelity of CTC recovery, enabling comprehensive molecular profiling and ex vivo analysis. These innovations have paved the way for the development of CTC-derived preclinical models, including xenografts, organoids, and chorioallantoic membrane assays, which recapitulate patient-specific tumor heterogeneity and support individualized drug-sensitivity testing. In this review, we summarize current technologies for CTC isolation, outline recent achievements in functional and pharmacological characterization, and discuss the translational impact of CTC-derived models. We further identify persistent challenges and emerging opportunities, highlighting how integration of multi-omics platforms, artificial intelligence, and standardized workflows may accelerate the clinical implementation of CTC-guided personalized therapy.

Background: Circulating tumor DNA (ctDNA) analysis has emerged as a promising tool for real-time disease monitoring in muscle-invasive bladder cancer (MIBC). This narrative review summarizes current clinical evidence regarding ctDNA across disease stages. Methods: We examine recent translational and clinical findings, incorporating key prospective data from practice-changing trials, as well as insights into minimal residual disease (MRD) detection, treatment escalation and de-escalation strategies, and systemic barriers to adoption. Results: Postoperative ctDNA positivity consistently identifies patients with molecular residual disease (MRD) who face a substantially higher risk of recurrence and mortality, frequently preceding radiographic relapse by several months. Prospective evidence now validates ctDNA as a predictive biomarker to guide adjuvant immunotherapy escalation, while sustained ctDNA negativity correlates with high long-term disease-free survival. Beyond plasma ctDNA, emerging multi-compartment liquid biopsies—integrating urinary tumor DNA (utDNA)—demonstrate enhanced sensitivity, particularly in bladder-sparing and local surveillance settings. Furthermore, integrating genomic ctDNA profiling with novel post-transcriptional layers like epitranscriptomics offers a functional framework to capture tumor adaptation under therapeutic pressure. However, clinical translation remains constrained by a lack of assay harmonization, variable analytical sensitivity, and the need for standardized intervention thresholds. Conclusions: Longitudinal liquid biopsies are rapidly shifting MIBC management from static, stage-based paradigms toward dynamic, molecularly informed precision oncology. While ctDNA-guided strategies show robust clinical utility, prospective interventional validation and technical standardization are required before widespread routine integration.

Background: Renal cell carcinoma (RCC) is the most common kidney cancer in adults. The advent of immune checkpoint inhibitors (ICIs), particularly in combination with tyrosine kinase inhibitors (TKIs), has significantly improved outcomes in advanced disease. Case presentation: A 67-year-old woman with stage IV clear cell RCC and intermediate-risk features presented with pulmonary, nodal, and peritoneal metastases. She received first-line pembrolizumab plus axitinib, achieving durable disease control and partial response with good tolerability. After 32 months she achieved sustained disease stability and underwent robot-assisted left nephrectomy. Histology revealed complete pathological response. Postoperatively, pembrolizumab was continued with a pseudo-adjuvant intent, and as of March 2026, the patient remains in radiological near-complete response with a progression-free survival of approximately 41 months from treatment initiation. Discussion and conclusions: This case illustrates that ICI–TKI combinations can induce profound and durable responses even in intermediate-risk metastatic RCC. Consolidative surgery after systemic control, though still under debate, may be beneficial for carefully selected patients. Overall, this report underscores the potential of immunotherapy–TKI combinations to achieve long-term remission and the importance of a multidisciplinary, personalized treatment approach in advanced RCC.

Introduction: Immunotherapy has reshaped the adjuvant landscape, with several immune checkpoint inhibitors (ICIs) approved in different tumor types. This meta-analysis evaluates the benefit of adjuvant ICIs across solid tumors. Methods: A systematic literature search of PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and the proceedings of the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) was performed from January 2015 to June 2026 in accordance with PRISMA to identify phase II and III randomized controlled trials (RCTs) testing ICIs versus non-ICI controls in the adjuvant setting. Trials with a single arm, local treatments, or combinations of ICIs with non-ICI systemic treatments (including chemotherapy, radiotherapy, targeted therapies, or vaccines) were excluded. Eligible comparisons included ICI-based adjuvant strategies versus randomized comparator arms defined by the original trial design. Trials comparing an ICI strategy with an alternative active immunotherapy regimen were considered eligible when the experimental intervention represented the ICI strategy under evaluation and the comparator reflected the established standard of care. Dual-checkpoint blockade regimens consisting exclusively of immune checkpoint inhibitors were considered eligible and analyzed separately. Hazard ratios (HRs) for recurrence-related outcomes (DFS/RFS/PFS) and overall survival (OS) were pooled using random-effects models. A sensitivity analysis restricted to phase III trials was performed to evaluate the robustness of the primary findings. Subgroup analyses were conducted by tumor type and ICI mechanism of action. Results: Twenty-one randomized controlled trials (RCTs), including 17,446 randomized patients across eight different solid tumors, were analyzed. These trials contributed 23 treatment comparisons due to multiple experimental comparisons from IMMUNED and CheckMate 914. Adjuvant ICIs significantly improved DFS/RFS/PFS (HR 0.74, 95% CI 0.68–0.82, p<0.0001) and OS (HR 0.84, 95% CI 0.78–0.90, p<0.0001) compared with non-ICI controls. The DFS/RFS benefit was observed across several tumor types, including melanoma, urothelial carcinoma, renal cell carcinoma, and NSCLC (HRs 0.65, 0.78, 0.84, and 0.87, respectively). Regarding ICI class, significant DFS/RFS improvements were observed with CTLA-4, anti–PD-1, and anti–PD-L1 inhibitors (HRs 0.77, 0.69, and 0.89, respectively). Exploratory meta-regression identified a significant overall association between ICI class and treatment effect (QM p = 0.0183; R² = 45.2%); however, no individual checkpoint class showed a statistically significant difference compared with the reference category. These findings should therefore be interpreted cautiously and considered hypothesis-generating. Tumor-specific OS benefits were statistically significant in melanoma and urothelial carcinoma (HRs 0.76 and 0.85, respectively), whereas OS effects in other tumor types remain uncertain due to limited data availability and variable follow-up maturity. Discussion: Overall, these findings support the efficacy of adjuvant ICIs across multiple solid tumors, with consistent improvements in DFS/RFS and a significant pooled OS benefit. Exploratory meta-regression suggested that tumor type may contribute to between-study heterogeneity; however, results should be interpreted cautiously given the limited number of studies, trial-level differences, and potential ecological bias. Systematic review registration: https://www.crd.york.ac.uk/prospero/ , identifier CRD420251249507.