Clinical utility of plasma ctDNA sequencing in metastatic urothelial cancer

The Application of Circulating Tumour DNA (ctDNA) in the Diagnosis, Prognosis, and Treatment Monitoring of Gynaecological and Breast Cancers (Review)

Gynaecological cancers, including endometrial, ovarian, and cervical cancers as well as breast cancer, despite numerous studies, still constitute a challenge for modern oncology. For this reason, research aimed at the application of modern diagnostic methods that are useful in early detection, prognosis, and treatment monitoring deserves special attention, Great hopes are currently being placed on the use of liquid biopsy (LB), which examines various tumour components, including cell-free RNA (cfRNA), circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), exosomes, and tumour-educated platelets (TEPs). LB has shown promise as a minimally invasive means of early diagnosis of cancers, detection of recurrence, prediction of therapy response, treatment monitoring, and drug selection. The integration of this test into clinical practice in modern oncology is challenging, but offers many benefits, including reducing the risks associated with invasive procedures, improving diagnostic and therapeutic efficacy, and improving the quality of life of oncology patients. The aim of this review is to present recent reports on the use of ctDNA in diagnosing, predicting the outcome of, and monitoring the treatment of gynaecological and breast cancers.

Circulating tumour DNA and circulating tumour cells in bladder cancer - from discovery to clinical implementation

Liquid biopsies, indicating the sampling of body fluids rather than solid-tissue biopsies, have the potential to revolutionize cancer care through personalized, noninvasive disease detection and monitoring. Circulating tumour DNA (ctDNA) and circulating tumour cells (CTCs) are promising blood-based biomarkers in bladder cancer. Results from several studies have shown the clinical potential of ctDNA and CTCs in bladder cancer for prognostication, treatment-response monitoring, and early detection of minimal residual disease and disease recurrence. Following successful clinical trial evaluation, assessment of ctDNA and CTCs holds the potential to transform the therapeutic pathway for patients with bladder cancer - potentially in combination with the analysis of urinary tumour DNA - through tailored treatment guidance and optimized disease surveillance.

Current and Future Role of Circulating DNA in the Diagnosis and Management of Urothelial Carcinoma

The growing sophistication of tumor molecular profiling has helped to slowly transition oncologic care toward a more personalized approach in different tumor types, including in bladder cancer. The National Comprehensive Cancer Network recommends that all patients with stage IVA and stage IVB urothelial carcinoma have molecular analysis that integrates at least FGFR3 testing to help facilitate the selection of future therapeutic options. Sequencing of tumor-derived tissue is the mainstay to obtain this genomic testing, but as in other cancers, there has been extensive research into the integration of liquid biopsies in longitudinal management. Liquid biopsies broadly refer to the isolation of both cellular and noncellular tumor components including proteins and nucleic acids such as mRNA and circulating free DNA within a liquid sample. Although protein-based testing and testing of circulating tumor cells are options, the bulk of promising research in bladder cancer is investigating the role of plasma-based circulating tumor DNA (ctDNA). Currently, a universal consensus on optimal preanalytic and analytic approaches has not been fully defined, and the exact role that liquid biopsies should have in screening, diagnosis, prognostication, treatment selection, and monitoring is not yet known. Still, it can be expected that ctDNA testing will be a part of appropriate management of muscle-invasive bladder cancer and metastatic bladder cancer in the near future. In this review, the goal is to provide a practical overview of the current and future role of ctDNA in bladder cancer including ongoing trials.

Unlocking the future of cancer diagnosis - promises and challenges of ctDNA-based liquid biopsies in non-small cell lung cancer

The advent of liquid biopsies has brought significant changes to the diagnosis and monitoring of non-small cell lung cancer (NSCLC), presenting both promise and challenges. Molecularly targeted drugs, capable of enhancing survival rates, are now available to around a quarter of NSCLC patients. However, to ensure their effectiveness, precision diagnosis is essential. Circulating tumor DNA (ctDNA) analysis as the most advanced liquid biopsy modality to date offers a non-invasive method for tracking genomic changes in NSCLC. The potential of ctDNA is particularly rooted in its ability to furnish comprehensive (epi-)genetic insights into the tumor, thereby aiding personalized treatment strategies. One of the key advantages of ctDNA-based liquid biopsies in NSCLC is their ability to capture tumor heterogeneity. This capability ensures a more precise depiction of the tumor's (epi-)genomic landscape compared to conventional tissue biopsies. Consequently, it facilitates the identification of (epi-)genetic alterations, enabling informed treatment decisions, disease progression monitoring, and early detection of resistance-causing mutations for timely therapeutic interventions. Here we review the current state-of-the-art in ctDNA-based liquid biopsy technologies for NSCLC, exploring their potential to revolutionize clinical practice. Key advancements in ctDNA detection methods, including PCR-based assays, next-generation sequencing (NGS), and digital PCR (dPCR), are discussed, along with their respective strengths and limitations. Additionally, the clinical utility of ctDNA analysis in guiding treatment decisions, monitoring treatment response, detecting minimal residual disease, and identifying emerging resistance mechanisms is examined. Liquid biopsy analysis bears the potential of transforming NSCLC management by enabling non-invasive monitoring of Minimal Residual Disease and providing early indicators for response to targeted treatments including immunotherapy. Furthermore, considerations regarding sample collection, processing, and data interpretation are highlighted as crucial factors influencing the reliability and reproducibility of ctDNA-based assays. Addressing these challenges will be essential for the widespread adoption of ctDNA-based liquid biopsies in routine clinical practice, ultimately paving the way toward personalized medicine and improved outcomes for patients with NSCLC.

Pembrolizumab for advanced urothelial carcinoma: exploratory ctDNA biomarker analyses of the KEYNOTE-361 phase 3 trial

Circulating tumor DNA (ctDNA) is emerging as a potential biomarker in early-stage urothelial cancer, but its utility in metastatic disease remains unknown. In the phase 3 KEYNOTE-361 study, pembrolizumab with and without chemotherapy was compared with chemotherapy alone in patients with metastatic urothelial cancer. The study did not meet prespecified efficacy thresholds for statistical significance. To identify potential biomarkers of response, we retrospectively evaluated the association of pre- and posttreatment ctDNA with clinical outcomes in a subset of patients who received pembrolizumab (n = 130) or chemotherapy (n = 130) in KEYNOTE-361. Baseline ctDNA was associated with best overall response (BOR; P = 0.009), progression-free survival (P < 0.001) and overall survival (OS; P < 0.001) for pembrolizumab but not for chemotherapy (all; P > 0.05). Chemotherapy induced larger ctDNA decreases from baseline to treatment cycle 2 than pembrolizumab; however, change with pembrolizumab (n = 87) was more associated with BOR (P = 4.39 × 10-5) and OS (P = 7.07 × 10-5) than chemotherapy (n = 102; BOR: P = 1.01 × 10-4; OS: P = 0.018). Tumor tissue-informed versions of ctDNA change metrics were most associated with clinical outcomes but did not show a statistically significant independent value for explaining OS beyond radiographic change by RECIST v.1.1 when jointly modeled (pembrolizumab P = 0.364; chemotherapy P = 0.823). These results suggest distinct patterns in early ctDNA changes with immunotherapy and chemotherapy and differences in their association with long-term outcomes, which provide preliminary insights into the utility of liquid biopsies for treatment monitoring in metastatic urothelial cancer. Clinical trial registration: NCT02853305 .

Circulating tumor DNA (ctDNA) application in investigation of cancer: Bench to bedside

Now, genomics forms the core of the precision medicine concept. Comprehensive investigations of tumor genomes have made it possible to characterize tumors at the molecular level and, specifically, to identify the fundamental processes that cause condition. A variety of kinds of tumors have seen better outcomes for patients as a result of the development of novel medicines to tackle these genetic-driving processes. Since therapy may exert selective pressure on cancers, non-invasive methods such as liquid biopsies can provide the opportunity for rich reservoirs of crucial and real-time genetic data. Liquid biopsies depend on the identification of circulating cells from tumors, circulating tumor DNA (ctDNA), RNA, proteins, lipids, and metabolites found in patient biofluids, as well as cell-free DNA (cfDNA), which exists in those with cancer. Although it is theoretically possible to examine biological fluids other than plasma, such as pleural fluid, urine, saliva, stool, cerebrospinal fluid, and ascites, we will limit our discussion to blood and solely cfDNA here for the sake of conciseness. Yet, the pace of wider clinical acceptance has been gradual, partly due to the increased difficulty of choosing the best analysis for the given clinical issue, interpreting the findings, and delaying proof of value from clinical trials. Our goal in this review is to discuss the current clinical value of ctDNA in cancers and how clinical oncology systems might incorporate procedures for ctDNA testing.

Prognostic significance of circulating tumor DNA in urothelial carcinoma: a systematic review and meta-analysis

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as a noninvasive technique that provides valuable insights into molecular profiles and tumor disease management. This study aimed to evaluate the prognostic significance of circulating tumor DNA (ctDNA) in urothelial carcinoma (UC) through a systematic review and meta-analysis.

METHODS

A comprehensive search was conducted in MEDLINE, EMBASE, and the Cochrane Library from the inception to December 2023. Studies investigating the prognostic value of ctDNA in UC were included. Hazard ratios (HRs) of disease-free survival (DFS) and overall survival (OS) were extracted. Overall meta-analysis and subgroup exploration stratified by metastatic status, ctDNA sampling time, treatment type, and detection method was performed using the R software (version 4.2.2).

RESULTS

A total of 16 studies with 1725 patients were included. Fourteen studies assessed the association between baseline ctDNA status and patient outcomes. Patients with elevated ctDNA levels exhibited significantly worse DFS (HR=6.26; 95% CI: 3.71-10.58, P <0.001) and OS (HR=4.23; 95% CI: 2.72-6.57, P <0.001) regardless of metastatic status, ctDNA sampling time, treatment type, and detection methods. Six studies evaluated the prognostic value of ctDNA dynamics in UC. Patients who showed a decrease or clearance in ctDNA levels during treatment or observation demonstrated more favorable DFS (HR=0.26, 95% CI: 0.17-0.41, P <0.001) and OS (HR=0.21, 95% CI: 0.11-0.38, P <0.001) compared to those who did not. The association remained consistent across the subgroup analysis based on metastatic status and detection methods. In the immune checkpoint inhibitor-treated setting, both lower baseline ctDNA level and ctDNA decrease during the treatment were significantly associated with more favorable oncologic outcomes. Furthermore, specific gene mutations such as FGFR3 identified in ctDNA also demonstrated predictive value in UC patients.

CONCLUSION

This meta-analysis demonstrates a strong association of ctDNA status and its dynamic change with survival outcomes in UC, suggesting substantial clinical utility of ctDNA testing in prognosis prediction and decision making in this setting.

Unlocking the Potential: Biomarkers of Response to Antibody-Drug Conjugates

Antibody-drug conjugates (ADCs) have reshaped the cancer treatment landscape across a variety of different tumor types. ADCs' peculiar pharmacologic design combines the cytotoxic properties of chemotherapeutic agents with the selectivity of targeted therapies. At present, the approval of many ADCs used in clinical practice has not always been biomarker-driven. Indeed, predicting ADCs' activity and toxicity through the demonstration of specific biomarkers is still a great unmet need, and the identification of patients who can derive significant benefit from treatment with ADCs may often be uncertain. With the lack of robust predictive biomarkers to anticipate primary, intrinsic resistance to ADCs and no consolidated biomarkers to aid in the early identification of treatment resistance (ie, acquired resistance), the determination of precise biologic mechanisms of ADC activity and safety becomes priority in the quest for better patient-centric outcomes. Of great relevance, whether the target antigen expression is a determinant of ADCs' primary activity is still to be clarified, and available data remain quite controversial. Antigen expression assessment is typically performed on tissue biopsy, hence only providing information on a specific tumor site, therefore unable to capture heterogeneous patterns of tumor antigen expression. Quantifying the expression of the target antigen across all tumor sites would help better understand tumor heterogeneity, whereas molecularly characterizing tumor-intrinsic features over time might provide information on resistance mechanisms. In addition, toxicity can represent a critical concern, since most ADCs have a safety profile that resembles that of chemotherapies, with often unique adverse events requiring special management, possibly because of the differential in pharmacokinetics between the small-molecule agent versus payload of a similar class (eg, deruxtecan conjugate-related interstitial lung disease). As such, the identification of robust predictive biomarkers of safety and activity of ADCs has the potential to improve patient selection and enrich the population of patients most likely to derive a substantial clinical benefit, especially in those disease settings where different ADCs happen to be approved in competing clinical indications, with undefined biomarkers to make precise decision making and unclear data on how to sequence ADCs. At this point, the identification of clinically actionable biomarkers in the space of ADCs remains a top research priority.