Muscle-invasive bladder cancer historically necessitated radical cystectomy, the surgical removal of the bladder, as the standard of care; however, this procedure is not without profound consequences, including lifelong dependence on urinary diversion devices and a substantial decline in quality of life due to complications. The pursuit of bladder-sparing protocols has therefore become a crucial focus of oncologic innovation, aiming to maintain organ function while effectively controlling tumor progression.

Circulating tumor DNA comprises short fragments of DNA shed into the bloodstream by apoptotic or necrotic cancer cells, providing a non-invasive window into tumor dynamics. The Fox Chase team rigorously evaluated ctDNA as a surrogate marker for treatment response and disease recurrence in patients undergoing bladder preservation through a combination of chemotherapy and immunotherapy. The incorporation of immunotherapeutic agents, particularly nivolumab, represents a cutting-edge advancement, targeting immune checkpoint pathways that tumors exploit to evade immune surveillance.

In the RETAIN-2 trial, over seventy patients with MIBC were administered induction chemotherapy concurrent with nivolumab, followed by maintenance immunotherapy. This strategic combination aims to elicit robust tumor regression while fostering durable systemic immunity. Patients who demonstrated a pathologic complete response were spared immediate cystectomy, instead entering a vigilant surveillance protocol. Impressively, approximately 80% of these patients remained free from metastatic disease after a two-year follow-up period, affirming the efficacy of this approach.

A meticulous analysis of serial blood samples revealed that the presence of ctDNA following treatment was strongly correlated with the eventual development of distant metastases, making ctDNA a powerful prognostic tool for systemic disease risk. Importantly, patients who were ctDNA-negative post-treatment exhibited favorable clinical outcomes regardless of whether bladder removal was performed, emphasizing ctDNA’s potential to inform personalized therapeutic decisions.

Contrary to its utility in predicting metastasis, ctDNA did not reliably signal local tumor recurrence within the bladder. While a considerable subset of patients developed intravesical recurrences during surveillance, the majority did not exhibit ctDNA elevation prior to detection, highlighting a significant limitation in ctDNA’s sensitivity for local disease monitoring. This finding underscores the necessity for adjunctive biomarkers or imaging modalities capable of early identification of bladder-localized recurrence to complement ctDNA profiling.

This nuanced understanding of ctDNA’s capabilities enables oncologists to refine patient selection for bladder preservation strategies more safely and effectively. Incorporating ctDNA analysis into clinical decision-making facilitates a response-adapted framework whereby patients with undetectable ctDNA can be considered for organ-sparing treatment without compromising oncologic control. Conversely, ctDNA positivity may prompt more aggressive interventions or closer monitoring to preclude metastatic progression.

The implications of these findings extend beyond immediate clinical utility, illuminating pathways for future research and trial design. The Fox Chase investigators are poised to embark on the RETAIN-3 clinical trial, aimed at prospectively validating ctDNA as a biomarker to tailor neoadjuvant and adjuvant treatment regimens with heightened precision. Such biomarker-driven approaches epitomize the evolution toward personalized oncology, reducing overtreatment and enhancing patient quality of life.

Further longitudinal follow-up from RETAIN-2 participants will elucidate the long-term durability of bladder preservation and metastasis-free survival afforded by this innovative combination therapy. It will also provide critical insights into the kinetics of ctDNA and its relationship to treatment resistance and disease relapse.

The integration of ctDNA testing into the clinical management of MIBC represents a compelling evolution in bladder cancer care, enabling a more nuanced balance between effective oncologic control and organ preservation. This biomarker-driven strategy directly addresses patient-centered concerns about the functional and psychological burdens of radical cystectomy.

Dr. Pooja Ghatalia, the study’s lead author and Associate Professor at Fox Chase, emphasized the transformative potential of these findings: “Our data suggest that ctDNA can be a pivotal factor in clinical decision-making, guiding who may safely continue with bladder preservation and who requires more aggressive treatment. Nevertheless, we must continue to identify complementary biomarkers to effectively detect bladder-local recurrence early.”

Presented at the 2026 American Society of Clinical Oncology Genitourinary Cancers Symposium in San Francisco, these findings underscore the integration of tumor biology insights with immunotherapy advances to tailor bladder cancer treatment. This pioneering work may soon change the therapeutic landscape for thousands of patients with MIBC worldwide.

As bladder cancer research progresses, the convergence of molecular diagnostics such as ctDNA with evolving systemic therapies heralds a new era of precision medicine, optimizing survival outcomes while preserving patient autonomy and quality of life.

Subject of Research: Muscle-invasive bladder cancer and circulating tumor DNA as a biomarker for bladder-preserving treatment strategies.

Article Title: Induction enfortumab vedotin plus pembrolizumab followed by maintenance pembrolizumab in first-line metastatic urothelial carcinoma (IMPROEV).

News Publication Date: 27-Feb-2026

Web References: http://dx.doi.org/10.1200/JCO.2026.44.7_suppl.TPS893

Image Credits: Fox Chase Cancer Center

Keywords: Muscle-invasive bladder cancer, circulating tumor DNA, ctDNA, bladder preservation, neoadjuvant chemoimmunotherapy, nivolumab, metastatic risk, bladder-sparing treatment, RETAIN-2 clinical trial, immunotherapy, biomarkers, tumor recurrence

DNA methylation, the attachment of methyl groups to the DNA molecule, plays an essential role in regulating gene expression. This biochemical modification influences cellular function, turning genes on and off without altering the underlying DNA sequence. Aberrant methylation patterns are intimately linked to cancer development, often silencing tumor suppressor genes or activating oncogenes. Accurate profiling of these methylation marks is therefore vital for early cancer detection, therapy selection, and monitoring treatment response, especially using minimally invasive liquid biopsies.

Historically, bisulfite sequencing has served as the gold standard for methylation detection. This technique converts unmethylated cytosines into uracils, which are read differently during sequencing, while leaving methylated cytosines unaltered. However, traditional bisulfite treatment is harsh; the chemical reactions involved severely fragment DNA, particularly problematic when working with the extremely limited and fragile DNA present in blood samples or formalin-fixed tissues. This damage results in biased, incomplete data and compromised reproducibility.

To mitigate this, enzyme-based alternatives like enzymatic methyl-seq (EM-seq) have emerged. These methods utilize enzymes to detect methylation marks under milder conditions, thereby preserving DNA integrity. Nonetheless, these enzyme-based protocols remain complex, often require labor-intensive workflows, and suffer from pronounced false positive rates, especially when sample DNA input is low—common in clinical liquid biopsy settings. This inconsistency undermines their reliability for clinical applications.

UMBS-seq breaks this stalemate by fundamentally reengineering the bisulfite chemistry itself instead of abandoning it. Led by Professor Chuan He, the research team refined the chemical formulation and meticulously optimized reaction parameters to achieve near-complete cytosine conversion while maintaining ultra-mild reaction conditions. This approach retains the high confidence of bisulfite sequencing but minimizes DNA degradation dramatically.

Extensive head-to-head comparisons demonstrated that UMBS-seq surpasses both conventional bisulfite and enzymatic sequencing technologies across multiple critical metrics. The method yields higher library complexity and integrity, ensuring more uniform genomic coverage. Importantly, it provides exceptional conversion efficiency, translating into highly accurate methylation calls that are crucial for detecting subtle epigenetic changes linked to early cancer states.

One of UMBS-seq’s standout advantages is its streamlined protocol. Unlike enzymatic methods, which are time-consuming and technically demanding, the UMBS-seq workflow simplifies experimental procedures, reducing turnaround times without sacrificing data quality. This makes it attractive not just for research laboratories but also for clinical testing environments where speed and reliability are paramount.

Applying UMBS-seq to human cell-free DNA—fragments circulating in blood—revealed its superior capacity to preserve DNA integrity and generate comprehensive coverage of cancer-associated methylation sites. This capability is transformative for liquid biopsy approaches aiming at non-invasive cancer diagnostics, where the amount of available DNA is minuscule and extremely susceptible to damage.

The researchers envision that UMBS-seq will soon become the new benchmark for DNA methylation analysis, broadly adopted in both investigative and diagnostic domains. By enabling more sensitive, reproducible, and cost-effective epigenetic profiling, this technique could accelerate the deployment of methylation biomarkers in clinical oncology, paving the way for earlier detection and more personalized treatment regimens.

Capitalizing on this innovative science, Ellis Bio Inc., a biotechnology company spun out from The University of Chicago, has secured exclusive licensing rights to UMBS-seq. The company is developing the SuperMethyl™ Max kit, built on this technology, to deliver ready-to-use tools tailored for cancer diagnostic test developers. An early-access program for the SuperMethyl Max kit is currently available, promising to bring this cutting-edge solution into the hands of researchers and clinicians globally.

Ruitu Lyu, the incoming Chief Technology Officer at Ellis Bio and co-author of the UMBS-seq study, emphasized the significance of this advance. “With UMBS-seq and the SuperMethyl Max kit, we can now read cancer’s epigenetic code without destroying the very few and precious molecules we need to study. It’s a practical, scalable solution that could accelerate the clinical use of methylation biomarkers for early detection and personalized therapy,” he stated.

As the landscape of cancer diagnostics shifts increasingly towards non-invasive tests based on liquid biopsies, technologies like UMBS-seq that preserve DNA integrity and improve analytical precision will be essential. This breakthrough method not only addresses long-standing technical challenges but also opens new avenues for understanding the epigenome’s role in cancer and other complex diseases.

The implications of UMBS-seq reach beyond oncology. Because methylation patterns also impact numerous biological processes and diseases, this technology could broaden epigenetic research horizons in neuroscience, immunology, aging, and more. With the promise of detailed, accurate methylation mapping from minimal DNA input, researchers will be empowered to dissect epigenetic regulation with unprecedented clarity.

In sum, UMBS-seq represents a significant scientific and technological leap that elegantly balances the biochemical rigor of traditional bisulfite sequencing with gentle reaction conditions to protect DNA. This advancement underscores the power of innovative chemistry combined with thoughtful experimental design to solve critical biomedical problems, setting a new standard for epigenetic analysis and clinical diagnostics in the 21st century.

Subject of Research: Human tissue samples
Article Title: Ultra-mild bisulfite outperforms existing methods for 5-methylcytosine detection with low input DNA
News Publication Date: 13-Nov-2025
Web References: 10.1038/s41467-025-66033-y
References: Nature Communications article authored by Professor Chuan He et al.
Image Credits: Not specified

Keywords

UMBS-seq, DNA methylation, bisulfite sequencing, epigenetics, cancer biomarkers, liquid biopsy, enzyme-based sequencing, DNA integrity, epigenome, cancer diagnostics, 5-methylcytosine, SuperMethyl Max kit

Pancreatic ductal adenocarcinoma remains one of the deadliest cancers, largely due to the paucity of early symptoms and the rapid progression once diagnosed. Traditional imaging techniques, which have long been the cornerstone for assessing tumor response to therapy, fall short in offering timely and precise evaluations, especially in contexts involving immunotherapies where radiological changes might lag behind or present ambiguous findings. ARTEMIS-DELFI addresses this clinical challenge by analyzing genome-wide DNA fragmentation patterns from cell-free DNA (cfDNA) circulating in plasma, thus bypassing reliance on tumor biopsies which may be challenging to obtain or may lack sufficient tumor cellularity.

The ARTEMIS-DELFI methodology leverages genome fragmentation profiles derived from millions of small cfDNA fragments alongside repeat landscape features of circulating genetic material, utilizing deep learning models trained to distinguish responders from non-responders. Unlike prior approaches requiring tumor-informed genomic data, ARTEMIS-DELFI operates independently of tumor tissue, dramatically expanding its applicability across diverse patient populations. By capturing subtle shifts in cfDNA fragmentation patterns induced by therapeutic pressures, it enables clinicians to detect treatment efficacy as early as four weeks after therapy initiation, a crucial time window for deciding whether to continue, modify, or halt a given regimen.

In parallel, researchers have developed WGMAF, a genome-wide mutation allele frequency assay which integrates tumor biopsy genomic data and plasma mutation frequency to evaluate response. While this tumor-informed approach has demonstrated significant predictive power, it faces practical limitations such as the difficulty in acquiring high-quality tumor samples and the confounding presence of non-tumor cells diluting mutation signals. ARTEMIS-DELFI supersedes such constraints by embracing a tumor-independent approach, offering enhanced logistical feasibility and broader clinical reach.

The robustness of ARTEMIS-DELFI was rigorously validated through two sizable clinical trials. Initial findings emerged from the phase 2 CheckPAC trial focused on immunotherapy treatment in pancreatic cancer patients, where ARTEMIS-DELFI successfully stratified patients based on response status. These results were subsequently corroborated in the PACTO trial, underscoring ARTEMIS-DELFI’s capacity to deliver accurate, rapid assessments of therapeutic outcome. This dual validation underscores the platform’s potential to become a standard tool for real-time therapeutic monitoring in pancreatic cancer management.

Dr. Victor E. Velculescu, co-director of the cancer genetics and epigenetics program at Johns Hopkins, emphasizes the urgency for such innovations in pancreatic cancer care. Given the often fulminant progression of the disease and the emerging landscape of experimental therapies requiring rapid evaluation, ARTEMIS-DELFI provides a critical ‘fast-fail’ checkpoint. By enabling early discontinuation of ineffective treatments, it offers patients access to alternative therapeutic options without undue delay, potentially improving survival and quality of life.

Crucially, ARTEMIS-DELFI’s ability to analyze cfDNA fragmentation profiles without needing tumor biopsies presents an attractive paradigm shift. Tumor biopsies, aside from being invasive, are hampered by spatial heterogeneity within the tumor microenvironment, often yielding samples containing significant proportions of normal pancreatic tissue. This complexity complicates mutation-based monitoring assays, whereas fragmentation signatures reflect systemic tumor dynamics more comprehensively. Furthermore, the AI-driven interpretation of fragmentation landscapes mitigates user-dependent variability, enhancing diagnostic consistency.

The significance of this research extends beyond pancreatic cancer. Earlier in the year, the same investigative team successfully demonstrated the utility of a related cfDNA fragmentation assay, DELFI-TF, in assessing therapeutic response in colon cancer as documented in Nature Communications. These collective advances underscore a growing recognition of fragmentation-based liquid biopsies as transformative tools in precision oncology, enabling personalized, adaptive treatment plans driven by real-time molecular insights.

From a technical perspective, ARTEMIS-DELFI integrates an intricate analysis of cfDNA fragment size distribution, end motif profiles, and repeat element prevalence across the genome. This multi-dimensional data is fed into convolutional neural networks capable of learning complex, non-linear relationships indicative of tumor burden and dynamics. The use of plasma cfDNA reduces sampling biases and provides a temporal snapshot of tumor evolution, reflecting not only primary lesions but disseminated disease as well.

Financial backing for this endeavor stems from prominent organizations supporting cancer research innovation including the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation, Stand Up To Cancer, the Gray Foundation, and the National Institutes of Health, underscoring the high priority placed on translational tools that improve cancer patient outcomes. Beyond research support, several key team members hold equity stakes or patents related to ARTEMIS-DELFI technology through Delfi Diagnostics, exemplifying the interplay between academic research and industry partnerships in driving technological breakthroughs.

Looking ahead, prospective clinical trials will be essential to determine how ARTEMIS-DELFI-guided therapeutic decisions impact long-term survival and quality of life metrics. Moreover, integration of this AI-powered assay into broader oncology practice depends on further validation across different cancer types, treatment modalities, and patient demographics. If successful, ARTEMIS-DELFI could herald a new era where liquid biopsy-based real-time monitoring supplants traditional imaging, facilitating truly personalized and adaptive cancer therapy.

In conclusion, ARTEMIS-DELFI’s development marks a pivotal step forward in non-invasive cancer diagnostics, combining genomic science with artificial intelligence to deliver rapid, reliable insights into therapeutic efficacy. For pancreatic cancer patients, whose prognosis remains bleak with conventional approaches, this innovation promises to empower clinicians with dynamic, actionable intelligence—potentially transforming treatment paradigms and improving outcomes. As precision medicine continues to evolve, cfDNA fragmentation analysis stands poised to become a cornerstone technology in the fight against cancer.

Subject of Research: Pancreatic cancer treatment response monitoring using artificial intelligence-based analysis of circulating tumor DNA fragmentation patterns.

Article Title: ARTEMIS-DELFI: AI-Driven Liquid Biopsy for Rapid Assessment of Pancreatic Cancer Therapy Response

News Publication Date: May 21, 2024

Web References:

• Science Advances Publication
• Nature Communications Study on DELFI-TF

References:

• Velculescu et al., "Tumor-independent genome-wide cfDNA fragmentation profiling identifies therapeutic response in pancreatic cancer," Science Advances, 2024.

Image Credits: Carolyn Hruban

Keywords: Cancer cells, Oncology, Pancreatic cancer, Liquid biopsy, Artificial intelligence, Cell-free DNA, Therapeutic monitoring