Using Circulating Tumor DNA in Colorectal Cancer: Current and Evolving Practices

Prospective Evaluation of Circulating Tumor DNA Using Next-generation Sequencing as a Biomarker During Neoadjuvant Chemotherapy in Localized Pancreatic Cancer

OBJECTIVE

In this prospective study, we aim to characterize the prognostic value of circulating tumor DNA (ctDNA) by next-generation sequencing (NGS) in patients undergoing neoadjuvant chemotherapy (NAC) for pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

ctDNA is a promising blood-based biomarker that is prognostic in several malignancies. Detection of ctDNA by NGS may provide insights regarding the mutational profiles in PDAC to help guide clinical decisions for patients in a potentially curative setting. However, the utility of ctDNA as a biomarker in localized PDAC remains unclear.

METHODS

Patients with localized PDAC were enrolled in a prospective study at Northwestern Medicine between October 2020 and October 2022. Blood samples were collected to perform targeted tumor-agnostic NGS utilizing the Tempus x|F 105 gene panel at 3 timepoints: pretherapy (at diagnosis), post-NAC, and after local therapy, including surgery. The relationship between ctDNA detection and CA19-9 and the prognostic significance of ctDNA detection were analyzed.

RESULTS

Fifty-six patients were included in the analysis. ctDNA was detectable in 48% at diagnosis, 33% post-NAC, and 41% after local therapy. After completion of NAC, patients with detectable ctDNA had higher CA19-9 levels versus those without (78.4 vs 30.0; P =0.02). The presence of baseline ctDNA was associated with a CA19-9 response; those without ctDNA had a significant CA19-9 response following NAC (109.0 vs 31.5 U/mL; P =0.01), while those with ctDNA present at diagnosis did not (198.1 vs 113.8 U/mL; P =0.77). In patients treated with NAC, the presence of KRAS ctDNA at diagnosis was associated with and independently predicted worse progression-free survival.

CONCLUSIONS

This report demonstrates the prognostic value of ctDNA analysis with NGS in localized PDAC. NGS ctDNA is a biomarker of treatment response to NAC. KRAS ctDNA at diagnosis independently predicts worse survival in patients treated with NAC.

Nanomaterials in the diagnosis and treatment of gastrointestinal tumors: New clinical choices and treatment strategies

Nanomaterials have emerged as a promising modality in the diagnosis and treatment of gastrointestinal (GI) tumors, offering significant advancements over conventional methods. In diagnostic applications, nanomaterials facilitate enhanced imaging techniques, including magnetic resonance imaging (MRI), computed tomography (CT), and fluorescence imaging, which provide improved resolution and more accurate detection of early-stage cancers. Nanoparticles (NPs), such as liposomes, dendrimers, and quantum dots, are increasingly employed for the targeted imaging of specific biomarkers associated with GI malignancies, thereby enhancing diagnostic sensitivity and specificity. Liposomes are primarily used for drug delivery due to their ability to encapsulate hydrophobic drugs, dendrimers are useful for both drug delivery and gene therapy due to their highly branched structure, and quantum dots are primarily used in imaging and diagnostics because of their fluorescent properties. We also discuss their respective advantages and limitations. In therapeutic contexts, nanomaterials play a pivotal role in the development of targeted drug delivery systems. These systems address the limitations of traditional chemotherapy by improving drug bioavailability, reducing systemic toxicity, and promoting selective accumulation at tumor sites via both passive and active targeting mechanisms. Nanomedicines, including NPs and nanocarriers, enable the precise delivery of chemotherapeutic agents, nucleic acid -based therapies, and immunomodulators directly to cancer cells, thereby optimizing therapeutic efficacy. Furthermore, nanotechnology offers the potential to modulate the tumor microenvironment (TME), a critical factor in overcoming challenges related to tumor resistance and metastasis. Despite these promising advancements, several challenges persist, including concerns regarding long-term toxicity, stability, and regulatory approval. Nonetheless, the integration of nanomaterials into clinical practice holds substantial potential for revolutionizing the management of GI cancers, paving the way for more precise, personalized, and effective therapeutic strategies.

KRAS mutations in colorectal cancer: impacts on tumor microenvironment and therapeutic implications

INTRODUCTION

Despite decreasing trends in incidence, colorectal cancer (CRC) is still a major contributor to malignancy-related morbidities and mortalities. Groundbreaking advances in immunotherapies and targeted therapies benefit a subset of CRC patients, with sub-optimal outcomes. Hence, there is an unmet need to design and manufacture novel therapies, especially for advanced/metastatic disease. KRAS, the most highly mutated proto-oncogene across human malignancies, particularly in pancreatic adenocarcinoma, non-small cell lung cancer, and CRC, is an on-off switch and governs several fundamental cell signaling cascades. KRAS mutations not only propel the progression and metastasis of CRC but also critically modulate responses to targeted therapies.

AREAS COVERED

We discuss the impacts of KRAS mutations on the CRC's tumor microenvironment and describe novel strategies for targeting KRAS and its associated signaling cascades and mechanisms of drug resistance.

EXPERT OPINION

Drug development against KRAS mutations has been challenging, mainly due to structural properties (offering no appropriate binding site for small molecules), critical functions of the wild-type KRAS in non-cancerous cells, and the complex network of its downstream effector pathways (allowing malignant cells to develop resistance). Pre-clinical and early clinical data offer promises for combining KRAS inhibitors with immunotherapies and targeted therapies.

Efficacy assessment in phase I clinical trials: endpoints and challenges

The scope of phase I clinical trials in oncology goes beyond the conventional safety evaluation-only objectives of these trials in other specialties. Rather, most first-in-human oncology clinical trials have therapeutic intent, and efficacy signals observed in phase I trials can drive a go/no-go decision of advancing a new molecule to phase II testing. The complexity of efficacy assessment in the context of a small, heterogeneous patient population and a complex study design requires a more liberal perspective compared with later trial phases when looking into efficacy endpoints. Classically, in later-phase clinical trials, these endpoints would include the objective response rate, progression-free survival, and overall survival. However, new, evolving endpoints may be worth investigating when looking into the antitumor activity signals in phase I trials. Integration of all these endpoints into trial designs can improve the assessment of therapeutic efficacy during early drug development and guide decisions related to the further advancement of novel molecules into later phases. In this review, we discuss the advantages and pitfalls of different classic efficacy endpoints when evaluated as part of phase I trials in oncology and describe how challenges in assessing the antitumor activity of new drugs can be overcome through the incorporation of novel endpoints that have thus far proven successful in clinical trials.

Risk of Recurrence in Screen-Detected vs Non-Screen-Detected Colorectal Cancer Patients

BACKGROUND AND AIMS

Patients with screen-detected colorectal cancer (CRC) have a better stage-specific overall survival than non-screen-detected CRC. Currently, it is unknown if recurrence rates differ between screen-detected and non-screen-detected CRCs, and whether this could explain the observed difference in overall survival. Therefore, we aimed to assess the disease-free survival (DFS) rates in screen-detected and non-screen-detected CRCs and if recurrence affects overall survival.

METHODS

Dutch CRC (stage I-III) patients, diagnosed by screening or not in the first 6 months of 2015, were included from the Netherlands Cancer Registry. DFS and survival data were retrieved and analyzed by Kaplan-Meier method. The association between mode of detection and recurrence and overall survival was evaluated with a Cox regression model.

RESULTS

A total of 3725 CRC patients were included, 2073 (55.7%) non-screen detected and 1652 (44.3%) screen detected. Three-year DFS was significantly higher in screen-detected CRC compared with non-screen-detected CRC (87.8% vs 77.2%; P < .001). Stage-specific DFS rates for screen-detected vs non-screen-detected CRC were 94.7% vs 92.3% for stage I (P = .45), 84.3% vs 81.4% for stage II (P = .17), and 77.9% vs 66.7% for stage III (P < .001), respectively. Detection by screening was independently associated with a lower risk of recurrence (hazard ratio, 0.67; 95% confidence interval, 0.55-0.81; P < .001) when adjusted for age, sex, tumor location, stage and treatment. Recurrence independently predicted overall survival (hazard ratio, 15.90; 95% confidence interval, 13.28-19.04; P < .001).

CONCLUSION

DFS was significantly better in screen-detected compared with non-screen-detected CRCs independent of age, sex, tumor location, stage and treatment, and was associated with an overall survival benefit.

Circulating tumor DNA using a plasma-only assay predicts survival in patients with oligometastatic colorectal cancer after definitive therapy

Background

Patients with colorectal cancer (CRC) and oligometastases are usually treated with surgery and radiation. The addition of adjuvant chemotherapy is controversial. The detection of circulating tumor DNA (ctDNA) may provide further insight in prognosis as well as help in decision of adjuvant therapies. We aim to show that detection of ctDNA after definitive therapy in oligometastatic CRC is associated with worse outcomes.

Methods

A single centre prospective study included patients with oligometastatic CRC treated with surgery or radiation with definitive intent. Plasma samples were collected before procedure and 4 weeks after, prior to adjuvant chemotherapy. Plasma samples were analyzed using a tumor-naive assay focusing on genomic and methylation alterations (Guardant Reveal). Disease-free survival (DFS) and overall survival (OS) were estimated using Kaplan Meier method.

Results

A total of 25 patients were included: 19 were evaluated at baseline and post-treatment. ctDNA detection at baseline was not associated with any clinicopathological characteristics, neither OS nor DFS. In contrast, patients with ctDNA detection post-treatment had worse OS [hazard ratio (HR): 11.28; 95% confidence interval (CI): 1.31-97.05] and a trend to shorter DFS (HR: 2.97; 95% CI: 0.97-9.06). Patients who were persistently negative or cleared ctDNA had similar outcomes.

Conclusions

ctDNA detection after surgery/radiation in oligometastatic CRC predicts worse OS and DFS. ctDNA could help to guide the decision regarding need of adjuvant chemotherapy in this population.

Beneath the surface of colorectal cancer: Unmasking the evolving nature of (Neo)RAS

Metastatic colorectal cancer (mCRC) remains a major clinical challenge, despite therapeutic advancements. Mutations in KRAS and NRAS (RAS) oncogenes drive resistance to anti-EGFR drugs, necessitating RAS mutational analysis prior to treatment. While tissue biopsy remains the gold standard for molecular profiling, it has limitations such as invasiveness, intra-tumoral heterogeneity, and delayed results. Liquid biopsy (LB), on the other hand, offers a non-invasive alternative by analyzing circulating tumor DNA (ctDNA) and it provides a dynamic view of molecular changes over time. Indeed, ctDNA analysis has expanded the understanding of the mCRC's molecular landscape, revealing that RAS mutated (MT) subclones undergo both a positive and a negative selection during treatment. This negative selection has been described as the "NeoRAS WT phenomenon." The temporary disappearance of RAS mutations opens "RAS WT windows," thus making potential candidates for anti-EGFR therapies even patients initially diagnosed as RAS MT. This review examines numerous studies investigating the clinical significance of the "NeoRas WT phenomenon" as a distinct pathological entity. It also highlights the key limitations arising from the variability in study designs, detecting methods and ctDNA shedding rates. The results of ongoing prospective trials are necessary to determine whether NeoRAS WT stands as a reliable marker for guiding anti-EGFR treatment strategies in RAS-mutated patients.

Liquid Biopsy in Peritoneal Carcinomatosis from Colorectal Cancer: Current Evidence and Future Perspectives

Peritoneal carcinomatosis (PC) represents a challenge in the management of metastatic colorectal cancer (mCRC) because of the difficulties in diagnosis, tumor burden assessment, and in selecting the optimal treatments. A critical limitation is the lack of robust prognostic and predictive biomarkers, largely relying on serum markers (e.g., carcinoembryonic antigen) or the peritoneal carcinomatosis index (PCI) for disease extent. Circulating tumor DNA (ctDNA)-genomic fragments shed by tumor cells into the bloodstream-is now recommended by international guidelines for mCRC management. Its potential extends to PC, where it may enhance diagnostic, therapeutic, and follow-up strategies. However, PC from CRC (PC-CRC) is associated with lower ctDNA levels and detection rates compared to other metastatic sites, posing a challenge for its clinical utility. To address these limitations, peritoneal fluid analysis has emerged as a promising alternative, with peritoneal tumor DNA (ptDNA) detected at higher concentrations in this anatomical space. Integrating ctDNA and ptDNA may offer a deeper understanding of PC-CRC biology and provide more precise tools for managing this complex disease. This approach has the potential to revolutionize the treatment paradigm for PC-CRC, bringing precision medicine even to this subgroup of patients traditionally associated with poor outcomes. This review aims to evaluate the diagnostic, prognostic, and therapeutic implications of ctDNA and ptDNA in PC-CRC, highlighting current limitations and future directions.

Clinical utility and future perspectives of liquid biopsy in colorectal cancer

Patelli et al. critically evaluate the clinical utility of liquid biopsy-based circulating tumor DNA (ctDNA) analyses in colorectal cancer management. By addressing its applications across metastatic, locoregional, and early disease settings, the authors highlight both the transformative potential and current limitations of ctDNA in guiding personalized treatment decisions.

Integrating comprehensive genomic profiling in the management of oncology patients: applications and challenges in Taiwan

Comprehensive genomic profiling (CGP) refers to the detailed genomic analysis of cancers for oncology patients. With the rapid development of next-generation sequencing (NGS) technologies, CGP has been widely applied to clinical practice and managing oncology patients. CGP can be performed on the tumor DNA and RNA, as well as non-tumor tissues (e.g., blood, pleural effusion, and ascites). In this article, we review the current evidence supporting the use of CGP in the management of oncology patients, both in real-world practice and the bridging to clinical trials. We also discuss the role of the molecular tumor board on the application of CGP in oncology patients. We provide an overview of the current scheme of CGP reimbursement in Taiwan and the precision oncology branch of the National Biobank Consortium of Taiwan. Finally, we discuss about the potential barriers and challenges of applying CGP in managing oncology patients and the future perspectives of CGP in precision oncology.

The global progress and quality assessment of research on the association between circulating tumor DNA and clinical prognosis: a systematic review

Objective

Circulating tumor DNA (ctDNA) has shown potential as a prognostic biomarker in patients with solid tumors. This study aimed to systematically summarize the global application of ctDNA in the prognostic management of solid tumor patients and to evaluate the quality of the current studies.

Methods

PubMed, Web of Science, Embase, Cochrane Library, Scopus, and clinical trials.gov databases were searched to collect cohort studies on ctDNA in the prognosis of solid tumor patients from January 2016 to May 2022. The language was limited to English. Information including general information, participants and cancer characteristics, ctDNA and outcome information were extracted. The quality of the studies was assessed using the Newcastle-Ottawa Scale checklist.

Results

A total of 214 studies were included in the final analysis, encompassing 21,076 patients. The number of studies has increased annually from 2016 to 2022. The most common types of solid tumors studied were colorectal cancer (27.10 %), lung cancer (20.09 %), pancreatic cancer (16.82 %), and breast cancer (14.02 %). The top three journals by number of publications had an impact factor in 2023 greater than 10. Of the studies, the median sample size was 69 (interquartile range: 41-111), 69.81 % had a sample size <100, 68.92 % had a median/mean age ≥60 years, and 74.05 % were from developed countries. Multi-center studies accounted for 40.36 %. Additionally, 29.82 % of the studies had a bias risk score ≤6. Only 16.67 % of studies on liver cancer had a bias risk score >6. The primary criteria not met by the studies included "Adequacy of follow-up of cohorts" (33.33 %), "Assessment of outcome" (32.16 %) and "Representativeness of the exposed cohort" (27.49 %).

Conclusions

The prognostic value of ctDNA in patients with solid tumors is gaining increasing attention, leading to a steady rise in the number of studies. However, many studies still suffer from small sample sizes and a lack of representativeness. Furthermore, details regarding ctDNA detection methods and results reporting are often insufficiently described. There is an urgent need to improve the quality of such research.

Extrachromosomal circular DNA as a novel biomarker for the progression of colorectal cancer

BACKGROUND

Extrachromosomal circular DNA (eccDNA) has potential in tumor diagnosis, particularly for improving diagnostic accuracy and early cancer detection; however, many challenges remain in its application to clinical practice.

METHODS

We conducted a Circle-Seq analysis on clinical samples at different stages of colorectal cancer progression to examine the dynamic changes of eccDNA during the progression of colorectal cancer. We used breakpoint-specific PCR to verify candidate eccDNAs identified by Circle-Seq. The results were further validated using the AOM/DSS-induced colorectal cancer model.

RESULTS

There was an increase in the abundance of eccDNA with the progression of colorectal cancer. The genes associated with these eccDNA molecules were primarily related to signaling pathways involved in tumor development and metastasis. Our analysis also revealed that eccDNA abundance positively correlates with gene expression, and eccDNA derived from specific genes has potential value for the early diagnosis of tumors.

CONCLUSIONS

This study revealed a connection between eccDNA and colorectal cancer progression and highlights the clinical potential of eccDNA for the early diagnosis of colorectal cancer.

Single-Tube, Switched Temperature Amplicon Barcoding for Multiplex Detection of Rare Mutations in Circulating Tumor DNA

Detection and analysis of circulating tumor DNA (ctDNA) as a biomarker for cancer is a promising approach. Applications for ctDNA analysis include screening, diagnosis, treatment selection, treatment monitoring, minimal residual disease detection, and recurrence monitoring. Detection of ctDNA is challenging and requires highly sensitive methods. Approaches such as digital PCR are appropriate when only a small number of targets is being interrogated, whereas next-generation sequencing (NGS) is typically used when more targets are being analyzed. There are several NGS methods available, some of which are published and can be implemented in laboratories with the required expertise while other, commercial approaches are proprietary and are only available as a service. Of the published methods, most use some kind of unique molecular identifiers (or barcodes) to facilitate NGS error correction and detection of rare mutations at mutant allele frequencies of <0.1%. However, incorporation of barcodes and amplification of the resulting libraries are not trivial and typically require multiple steps and considerable hands-on time by an experienced molecular biologist. Herein, a novel approach for switched temperature amplicon barcoding was used, in which barcoding and library amplification were performed in the same tube using a two-stage PCR protocol with no additional manipulation. Total hands-on time was 10 to 15 minutes for reaction setup; the library was then cleaned and was ready for sequencing.

Evolution of Neo-RAS-WT in Circulating Tumor DNA from First-Line to Subsequent Therapies in Metastatic Colorectal Cancer

Background/Objectives: In metastatic colorectal cancer (mCRC), liquid biopsy has enabled the identification of "neo-RAS-Wild-Type (WT)", a transient phase characterized by the disappearance of RAS mutations, with significant clinical implications for re-sensitization to EGFR blockade. This study aimed to prospectively track the kinetics of neo-RAS-WT in circulating tumor DNA (ctDNA) among RAS-mutant mCRC patients receiving first-line and subsequent systemic therapies. Methods: A total of 380 serial blood samples from 35 patients were analyzed. Each patient provided a median of 10 ctDNA samples at three-month intervals during first-line and subsequent therapies. The patients were categorized into three groups: neo-RAS-WT, non-shedding, and persistent mutant. Results: During first-line treatment, 68% of patients transitioned to RAS-WT. Of these, 17% were neo-RAS-WT, while the majority were classified as non-shedding. In the second-line setting, the percentage of neo-RAS-WT increased to 34%, which dropped to 8.5% during the third-line setting. The duration of the neo-RAS-WT window was significantly longer in neo-RAS-WT patients compared to non-shedding patients (p = 0.037). Patients who achieved RAS-WT status had improved progression-free survival (PFS) compared to those with persistent mutant, with significant differences observed across all treatment lines: first-line (p = 0.004), second-line (p < 0.0001), and third-line (p = 0.001). Multivariate analysis revealed that the duration of the RAS-WT window correlated with extended first-line PFS (HR: 0.78; 95% CI: 0.69-0.89; p < 0.0001), second-line PFS (HR: 0.66; 95% CI: 0.52-0.84; p = 0.001), and overall survival (OS) (HR: 0.82; 95% CI: 0.72-0.95; p = 0.006). Conclusions: While the neo-RAS-WT window is transient in non-shedding, it is durable in neo-RAS-WT patients, persisting until disease progression. These findings highlight the potential utility of ctDNA testing in refining treatment strategies for RAS-mutant mCR.

Effects of exercise on inflammation, circulating tumor cells, and circulating tumor DNA in colorectal cancer

BACKGROUND

The biological mechanisms by which postdiagnosis physical activity improves disease-free survival in colorectal cancer survivors remain incompletely understood. This trial tested the hypothesis that 12 wk of moderate-intensity aerobic exercise, when compared with a control group, would change inflammation, CTCs, and ctDNA in a manner consistent with an improved cancer prognosis.

METHODS

This trial randomized Stages I-III colorectal cancer survivors to 12 wk of home-based moderate-intensity aerobic exercise or a waitlist control group. The co-primary endpoints were high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6), secondary endpoints were soluble tumor necrosis factor-α receptor 2 (sTNFαR2) and circulating tumor cells (CTCs), and the exploratory endpoint was tumor fraction quantified from circulating tumor DNA.

RESULTS

Sixty subjects were randomized (age = 60.6 ± 10.8 years, mean ± SD; 39 (65%) females; 46 (77%) colonic primary tumor), and 59 (98%) subjects completed the study. Over 12 wk, exercise adherence was 92% (95% confidence interval (95%CI): 86‒99). Exercise improved submaximal fitness capacity (0.36 metabolic equivalents; 95%CI: 0.05‒0.67; p = 0.025) and objectively measured moderate-to-vigorous-intensity physical activity (34.8%, 95%CI: 11.3‒63.1; p = 0.002) compared to control. Exercise did not change hs-CRP (20.9%, 95%CI: -17.1 to 76.2; p = 0.32), IL-6 (11.4%, 95%CI: -7.5 to 34.0; p = 0.25), or sTNFαR2 (-3.6%, 95%CI: -13.7 to 7.7; p = 0.52) compared to control. In the subgroup of subjects with elevated baseline hs-CRP (n = 35, 58.3%), aerobic exercise reduced hs-CRP (-35.5%, 95%CI: -55.3 to -3.8; p = 0.031). Exercise did not change CTCs (0.59 cells/mL, 95%CI: -0.33 to 1.51; p = 0.21) or tumor fraction (0.0005, 95%CI: -0.0024 to 0.0034; p = 0.73). In exploratory analyses, higher aerobic exercise adherence correlated with a reduction in CTCs (ρ = -0.37, 95%CI: -0.66 to -0.08; p = 0.013).

CONCLUSION

Colorectal cancer survivors achieved high adherence to a home-based moderate-intensity aerobic exercise prescription that improved fitness capacity and physical activity but did not reduce inflammation or change tumor endpoints from a liquid biopsy.

Incorporating Circulating Tumor DNA Testing Into Clinical Trials: A Position Paper by the National Cancer Institute GI Oncology Circulating Tumor DNA Working Group

PURPOSE

Circulating tumor DNA (ctDNA) is an emerging tool in the evaluation of GI cancers. Challenges remain in defining its utility and role as a primary end point in therapeutic trials. The National Cancer Institute (NCI) ctDNA GI working group was created to evaluate current data and provide guidance on the inclusion of ctDNA in GI cancer trials.

METHODS

The NCI GI steering committee assigned four task force members to serve as co-chairs for the working group. Co-chairs identified experts within each GI disease group to form a panel that convened to review data and provide recommendations. The group focused on ctDNA's role as a potential surrogate for assessing prognosis and guiding treatment decisions that may enhance GI cancer trials. A manuscript was drafted, circulated, revised, and voted on by the panel. The final draft was reviewed by the Cancer Therapy Evaluation Program.

RESULTS

Further data are required to support ctDNA as a primary end point for late-phase therapeutic trials, particularly in studies that could change the standard-of-care. However, the group supports ctDNA as a primary efficacy end point for phase II studies and as a noninvasive evaluation strategy for new drug development. Incorporation of ctDNA as a biomarker in trial design must consider the specific context of disease biology of the GI cancer subtypes. ctDNA should be incorporated as an exploratory end point across a variety of disease settings and indications. Several practical considerations were identified to optimize the incorporation of ctDNA in future trial design.

CONCLUSION

Prospective trials are required to clarify the role of ctDNA as a valid surrogate end point for progression-free or overall survival in GI cancers.

The Method of Minimal Residual Disease Detection With Circulating Tumor DNA and Its Clinical Applications in Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) remains a significant health concern in the world. The existing standard of care guidelines for CRC surveillance fall short of effectively and timely detecting recurrence or metastasis.

RECENT FINDINGS

In recent years, circulating tumor DNA (ctDNA) has emerged as a promising material for minimal residual disease (MRD) detection. In this article, we provide an exhaustive review of the methods utilized for MRD detection via ctDNA, present evidence supporting the potential of ctDNA MRD as a valuable biomarker in clinical applications, and engage in a discussion regarding ongoing ctDNA MRD-based clinical trials in CRC. Finally, we offer insights into future prospects of ctDNA-based MRD methodological advancements and clinical research.

CONCLUSION

It is foreseeable that more sensitive, flexible, and economical MRD detection methods will emerge with the deeper research on cell-free DNA (cfDNA) genomics, fragmentomics, methylomes, and nucleosome imprinting. At the same time, MRD-guided intervention studies will evolve for revolutionizing the treatment paradigm of CRC.

Preoperative liquid biopsy for optimal patient selection in metastatic colorectal cancer

OBJECTIVE

In this pilot study, we sought to determine if preoperative circulating tumor DNA could be a useful predictor to avoid futile metastasectomy, predict early postoperative recurrence, and determine optimal chemotherapy duration during the management of patients with resectable metastatic colorectal cancer.

METHODS

Patients from 2021 to 2023 were enrolled prospectively and evaluated with circulating tumor DNA preoperatively and postoperatively for detection of recurrence. Clinicopathologic and treatment factors as well as disease-free survival were compared between those with undetectable versus detectable preoperative circulating tumor DNA.

RESULTS

Twenty-eight patients were evaluated, with a median follow-up time of 24 months. The median preoperative circulating tumor DNA level was 0.16 MTM/mL [0.00, 2.30]. Of the 10 patients (40%) with a preoperative circulating tumor DNA level of zero, 5 patients (50%) recurred between 4 and 18 months postoperatively. Among the 18 patients whose disease recurred, 10 patients (56%) had circulating tumor DNA detected postoperatively. Median change between preoperative and postoperative circulating tumor DNA levels was 0.00 [-0.02, 0.05] in those who did not recur and 0.00 [-7.04, 0.00] in those who recurred. When disease-free survival was evaluated by detectable versus undetectable preoperative circulating tumor DNA levels, there was no difference in disease-free survival estimates (P value = .11). On univariate Cox proportional hazards analysis, the preoperative circulating tumor DNA level, change between preoperative and postoperative circulating tumor DNA levels, and postoperative circulating tumor DNA levels did not influence disease-free survival. However, those with detectable postoperative circulating tumor DNA were 3.96 (95% confidence interval 1.30-12.06) times as likely to recur compared to those with undetectable postoperative circulating tumor DNA.

CONCLUSION

New technologies including use of circulating tumor DNA may help better predict which patients with colorectal liver metastases will undergo futile surgery. Our preliminary findings suggest that postoperative, and not preoperative, circulating tumor DNA is predictive of recurrence following metastasectomy. Use of circulating tumor DNA in guiding operative management should be done in conjunction with high-quality imaging and other serologic markers to determine which patients with colorectal liver metastases are likely to receive durable benefit from operative intervention.

Current and future perspectives in the management and treatment of colorectal cancer

In this editorial, we reviewed the article by Fadlallah et al that was recently published in the World Journal of Clinical Oncology. The article provided a comprehensive and in-depth view of the management and treatment of colorectal cancer (CRC), one of the leading causes of cancer-related morbidity and mortality worldwide. The article analyzed the therapeutic modalities and their sequencing, focusing on total neoadjuvant therapy for locally advanced rectal cancer. It highlighted the role of immunotherapy in tumors with high microsatellite instability or deficient mismatch repair, addressing recent advances that have improved prognosis and therapeutic response in localized and metastatic CRC. Innovations in surgical techniques, advanced radiotherapy, and systemic agents targeting specific mutational profiles are also discussed, reflecting on how they revolutionized clinical management. Circulating tumor DNA has emerged as a promising tool for detecting minimal residual disease, prognosis, and therapeutic monitoring, solidifying its role in precision oncology. This review emphasized the importance of technological and therapeutic advancements in improving clinical outcomes and personalizing CRC treatment.

Circulating Tumor DNA Dynamics and Clinical Outcome in Metastatic Colorectal Cancer Patients Undergoing Front-Line Chemotherapy

PURPOSE

We tested whether circulating tumor DNA (ctDNA) changes may be used to assess early response and clinical outcomes in patients with metastatic colorectal cancer (mCRC) undergoing first-line systemic anticancer therapy (SACT).

EXPERIMENTAL DESIGN

Eight hundred sixty-two plasma samples were collected 4-weekly from baseline (BL) until disease progression in patients with mCRC receiving first-line SACT. ctDNA was tested using tissue-agnostic next-generation sequencing panels. ctDNA normalization was defined as ≥99% clearance after 1 month of therapy (Mo1) in the three variants with the highest allele frequency in BL ctDNA.

RESULTS

Eighty-three paired samples from 75 patients were available for analysis. Twelve pairs (14.4%) showed no variants in either BL or Mo1. In the remaining 71 comparisons (65 patients), 37 (52.1%) showed ctDNA normalization at Mo1. Patients who cleared ctDNA had significantly longer overall (45.6 months) and progression-free survival (13.9 months) compared with nonnormalized patients [overall survival = 22.6 months (log-rank P = 0.01) and progression-free survival = 10.7 months (log-rank P = 0.036), respectively]. In addition, a higher response rate was observed in patients with ctDNA clearance (72.9%) compared with nonnormalized cases (38.2%). Longitudinal sequencing of at least four time points in patients with a progression-free survival of >10 months showed emerging variants in 47.8% of cases; in all these patients, the trajectory of these new "outlier" variants seemed in stark contrast with the clinical-radiological course of disease and the trend in other mutations.

CONCLUSIONS

ctDNA clearance represents an early indicator of benefit from SACT in patients with mCRC; serial tracking of multiple variants is warranted to improve specificity and avoid misleading information due to the emergence of mutations of unknown clinical significance.

Circulating tumour DNA in predicting and monitoring survival of patients with locally advanced rectal cancer undergoing multimodal treatment: long-term results from a prospective multicenter study

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) is the standard for locally advanced rectal cancer (LARC). However, distant metastasis remains the primary cause of treatment failure. Early identification of high-risk individuals for personalized treatment may offer a solution. Circulating tumour DNA (ctDNA) could assist in this process.

METHODS

From September 2017 to June 2019, the study prospectively recruited 113 patients with LARC (cT3-4N0M0 or cTanyN + M0) who underwent nCRT followed by radical surgery across 8 tertiary centers. ctDNA was analysed using large-panel targeted sequencing at baseline, during nCRT, pre-surgery, post-surgery, post-adjuvant chemotherapy (ACT), and during annual follow-ups for 3 years.

FINDINGS

We analysed 103 tissue and 669 plasma samples from 103 patients. With a median 53-month follow-up, significantly worse progression-free survival (PFS) and overall survival (OS) were observed if median variant allele frequency (mVAF) of baseline ctDNA per patient was ≥0.5% (PFS, HR 4.39, p < 0.001; OS, HR 5.61, p = 0.004) or ctDNA was still detectable two weeks into nCRT (PFS, HR 7.63, p < 0.001; OS, HR 5.08, p < 0.001). Furthermore, when compared to the low-risk (C1) group (characterized by "ctDNA undetected during nCRT with baseline mVAF <0.5%" or "ctDNA undetected during nCRT with TMB (tumour mutational burden) ≥20/Mb"), the high-risk (C2) group (characterized by "ctDNA detected during nCRT" or "baseline mVAF ≥0.5% with TMB <20/Mb") showed significantly worse long-term outcomes (3 y-PFS, 55.9% vs. 94.2%; 3 y-OS, 79.4% vs. 100%). The ctDNA clearance during nCRT, baseline mVAF, and TMB may be effective prognostic indicators.

INTERPRETATION

Our findings reaffirm the clinical monitoring value of ctDNA and demonstrate the strong prognostic value of baseline ctDNA and its early clearance status in patients with LARC undergoing nCRT. This highlights the potential of dynamic ctDNA monitoring as actionable stratified indicators to guide personalized neoadjuvant treatment strategies.

FUNDING

This work was supported by the Major Grants Program of Beijing Science and Technology Commission (No. D171100002617003) and the National High Level Hospital Clinical Research Funding (2022-PUMCH-C-005).

Prognostic Value of Preoperative Albumin-to-Alkaline Phosphatase Ratio for Survival in Colorectal Cancer Patients Undergoing Surgery

Background and Objectives: This study aimed to evaluate the prognostic significance of the pre-treatment albumin-to-alkaline phosphatase ratio (AAPR) in early-stage colorectal cancer patients and to compare it with the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) within the same patient cohort. Materials and Methods: This retrospective study included 540 patients who were followed up after a diagnosis of early-stage colorectal cancer and whose albumin (ALB), alkaline phosphatase (ALP), neutrophil, platelet, and lymphocyte values were measured before treatment. Results: In the receiver operating characteristic (ROC) curve analysis for overall survival (OS), the AAPR index Area Under Curve (AUC):0.560, (p = 0.018), NLR index (p = 0.079), and PLR index (p = 0.692) were evaluated. In the ROC analysis for OS, a cut-off value of the AAPR index of ≤0.423 was found. In the AAPR-low group, the relapse and death rates were higher than in the AAPR-high group (p = 0.004 and p = 0.001, respectively). As the AAPR index decreased, the NLR and PLR indexes increased (p = 0.027 and p = 0.003, respectively). Median disease-free survival (DFS) was worse in the AAPR-low group (128 versus 156) months (p = 0.015). The AAPR index significantly affected OS with hazard ratio (HR):0.42 (95%CI, 0.18-0.97) (p = 0.044). At 5 years, 68% of the patients in the AAPR-low group and 79% of the patients in the AAPR-high group were alive (p = 0.005). In a multivariate analysis, low AAPR, patient age at diagnosis, TNM stage, and recurrence status were independent factors affecting OS (p = 0.022, p < 0.001, p = 0.002, and p < 0.001, respectively). Conclusions: In early-stage colorectal cancer patients, the OS was worse in the AAPR-low group than in the AAPR-high group. The AAPR index demonstrated significant prognostic value for OS compared to the NLR and PLR in the same patient cohort.

Circulating tumor DNA (ctDNA) trajectories predict survival in trifluridine/tipiracil-treated metastatic colorectal cancer patients

Late-line treatment in metastatic colorectal cancer (mCRC) can improve prognosis. However, not every patient has a benefit and may experience severe side effects. Thus, predictive/prognostic biomarkers are urgently needed. We investigated the prognostic role of circulating tumor DNA (ctDNA) in mCRC patients before and during treatment with trifluridine/tipiracil (FTD/TPI). This noninterventional translational biomarker phase II study enrolled 30 mCRC patients (60% male, 40% female). Using a 77-gene panel, ctDNA was detectable in 90% of patients. Tumor levels were assessed based on aneuploidy (ichorCNA) as well as the highest variant allele frequency, and correlated with overall survival (OS). Uni- and multivariate survival analyses were performed with clinical variables. Longitudinal changes in tumor levels over time were analyzed with linear mixed and joint models. The median OS was 8.1 months, with a recorded disease control rate of 30%. High ctDNA levels (≥ 5%) were associated with inferior survival after undergoing FTD/TPI therapy. Elevated tumor level trajectories over time were associated with higher risks of death. Therefore, ctDNA can help identify patients who are unlikely to benefit significantly from this treatment in late-stage disease, thus preventing unnecessary treatments and their associated side effects, ultimately enhancing quality of life.

Circulating Tumor DNA Testing for Minimal Residual Disease and Its Application in Colorectal Cancer

Colorectal cancer (CRC) represents a heterogeneous group of diseases that imposes a considerable global and national health burden. Although most CRC patients are diagnosed at an early stage and undergo potentially curative treatment, a significant proportion experience recurrence. Currently, adjuvant chemotherapy decisions are primarily based on clinicopathological characteristics, which have well-recognized limitations in accurately identifying patients harboring minimal residual disease (MRD), often resulting in unnecessary chemotherapy exposure. Circulating tumor DNA (ctDNA) has emerged as a promising surrogate marker for MRD, offering a more precise approach to identifying patients at risk of recurrence after curative-intent surgery and refining adjuvant chemotherapy decisions. Growing evidence from multiple studies has demonstrated that ctDNA outperforms traditional clinicopathological factors as a marker for MRD. This review synthesizes key studies supporting the role of ctDNA in MRD detection for CRC patients and evaluates clinical trials investigating the application of ctDNA in guiding adjuvant therapy decisions. This emerging strategy holds the potential to transform the adjuvant treatment paradigm in colorectal cancer by optimizing therapeutic precision and minimizing unnecessary treatment.

Assessment of cfDNA release dynamics during colorectal cancer surgery

Approximately two-thirds of patients with colorectal cancer (CRC) undergo resection with curative intent; however, 30% to 50% of these patients experience recurrence. The concentration of cell-free DNA (cfDNA) before and after surgery may be related to the prognosis of patients with CRC, but there is limited information regarding cfDNA levels at the time of surgery. Here, we analyzed surgical cfDNA release using plasma samples from 30 colorectal cancer patients at three key points during surgery: preoperative (immediately before surgery), intraoperative (during surgery), and postoperative (at the end of surgery). Automated electrophoresis was used to analyze cfDNA concentrations and fragment sizes, which were then correlated with clinical variables. Our findings indicate a significant increase in cfDNA release during and after surgery (2.8- and 2.2-fold higher respectively, p < 0.01). Characteristic fragments of cfDNA (<400 bp) predominated at all surgical stages; however, the release of genomic material (>400 bp) was also observed. We found that cfDNA concentration increases during and after surgery in patients over 60 years old (2.9-fold higher intraoperatively than preoperatively and 2.3 folds higher postoperatively than preoperatively, p < 0.01); in patients with comorbidities (3.0-fold higher intraoperatively and 2.3-fold higher postoperatively, p < 0.01); and in patients with CEA levels >5 ng/mL (3.1-fold higher intraoperatively and 1.3-fold higher postoperatively, p < 0.01). Interestingly, cfDNA release during surgery is significantly higher in patients with adverse clinical characteristics. Patients bearing locally advanced tumors or metastasis had a 3.1-fold increase in cfDNA release intraoperatively and 2.4-fold increase postoperatively, p < 0.01. cfDNA concentration also increases intraoperatively in patients with a high score of tumor buds (2.6 folds higher, p < 0.02), patients with perineural invasion (3.4-fold higher, p < 0.02) and in patients with lymphovascular invasion (3.1-fold higher, p < 0.05). Furthermore, we observed that cfDNA concentration may rise in correlation with the duration of the surgery, highlighting its potential as a marker of surgical quality. Taken together, our results suggest that in addition to physiological age, comorbidities and unfavorable clinical traits, intense surgical manipulation from the tumor's extent, may result in greater tissue damage and elevated cfDNA release.

A Comprehensive Approach to Neoadjuvant Treatment of Locally Advanced Rectal Cancer

At the end of the past century, the introduction of Total Mesorectal Excision (TME), preceded by either short-course radiotherapy (SCRT) or chemoradiation (CRT), established the new standard of care for locally advanced rectal cancer (LARC). Recently, significant advancements were achieved for both dMMR/MSI and pMMR/MSS LARC patients. For the 2-3% of dMMR/MSI LARCs, ablative immunotherapy emerged as a curative approach, offering the possibility of avoiding chemotherapy (CT), radiotherapy, and surgery altogether. In pMMR/MSS LARCs, the intensification of preoperative treatments with Total Neoadjuvant Treatment (TNT) afforded three outcomes: (a) a reduction of distant metastases, positively impacting on survival endpoints, (b) a significant increase of complete clinical response (cCR) rate, paving the way for non-operative management (NOM), and (c) the selective omission of radiotherapy following induction CT. The choice of the most appropriate therapeutic strategy can only be made through the shared decision-making process between physician and patient based on risk stratification and patient preferences.

Liquid Biopsy and Challenge of Assay Heterogeneity for Minimal Residual Disease Assessment in Colon Cancer Treatment

This review provides a comprehensive overview of the evolving role of minimal residual disease (MRD) for patients with Colon Cancer (CC). Currently, the standard of care for patients with non-metastatic CC is adjuvant chemotherapy (ACT) for all patients with stage III and high-risk stage II CC following surgical intervention. Despite a 5-20% improvement in long-term survival outcomes, this approach also results in a significant proportion of patients receiving ACT without any therapeutic benefit and being unnecessarily exposed to the risks of secondary side effects. This underscores an unmet clinical need for more precise stratification to distinguish patients who necessitate ACT from those who can be treated with surgery alone. By employing liquid biopsy, it is possible to discern MRD enabling the categorization of patients as MRD-positive or MRD-negative, potentially revolutionizing the management of ACT. This review aimed to examine the heterogeneity of methodologies currently available for MRD detection, encompassing the state-of-the-art technologies, their respective advantages, limitations, and the technological challenges and multi-omic approaches that can be utilized to enhance assay performance. Furthermore, a discussion was held regarding the clinical trials that employ an MRD assay focusing on the heterogeneity of the assays used. These differences in methodology, target selection, and performance risk producing inconsistent results that may not solely reflect biological/clinical differences but may be the consequence of the preferential use of particular products in studies conducted in different countries. Standardization and harmonization of MRD assays will be crucial to ensure the liquid revolution delivers reliable and clinically actionable outcomes for patients.

Explainable Machine Learning Models for Colorectal Cancer Prediction Using Clinical Laboratory Data

IntroductionEarly diagnosis of colorectal cancer (CRC) poses a significant clinical challenge. This study aims to develop machine learning (ML) models for CRC risk prediction using clinical laboratory data.MethodsThis retrospective, single-center study analyzed laboratory examination data from healthy controls (HC), polyp patients (Polyp), and CRC patients between 2013 and 2023. Five ML algorithms, including adaptive boosting (AdaBoost), extreme gradient boosting (XGBoost), decision tree (DT), logistic regression (LR), and random forest (RF), were employed to classify subjects into HC vs Polyp vs CRC, HC vs CRC, and Polyp vs CRC, respectively.ResultsThis study included 31 539 subjects: 11 793 HCs, 10 125 polyp patients, and 9621 CRC patients. The XGBoost model achieved the highest AUCs of 0.966 for differentiating HC from CRC and 0.881 for Polyp from CRC, outperforming carcino-embryonic antigen (CEA) and fecal occult blood testing (FOBT) tests. This model could also identify CEA-negative or FOBT-negative CRC patients. Incorporating stool miR-92a detection into the model further improved diagnostic performance. Shapley additive explanations (SHAP) plots indicated that FOBT, CEA, lymphocyte percentage (LYMPH%), and hematocrit (HCT) were the most significant features contributing to CRC diagnosis. Additionally, a computational tool for predicting CRC risk based on the optimal model was developed, designed for researchers with programming experience.ConclusionFive ML models for CRC diagnosis, based on ten routine laboratory test items, were developed, achieving higher diagnostic accuracies than traditional CRC biomarkers. The diagnostic capabilities of these ML models can be further enhanced by including stool miR-92a levels.

Early detection of colorectal cancer using aberrant circulating cell-free mitochondrial DNA fragmentomics

BACKGROUND

Early detection of colorectal cancer (CRC) is crucial for improving the survival rates of patients.

OBJECTIVE

We aimed to develop a novel strategy for early CRC detection using the fragmentomic features of circulating cell-free mitochondrial DNA (ccf-mtDNA).

DESIGN

Here, a total of 1147 participants, including 478 healthy controls (HCs), 112 patients with advanced adenomas (AAs) and 557 patients with CRC, were enrolled from five hospitals and plasma samples were collected for capture-based ccf-mtDNA sequencing.

RESULTS

Our data analysis revealed significantly aberrant ccf-mtDNA fragmentomic features in patients with CRC and AA when compared with HCs. Then, a CRC detection (CD) model was constructed based on the fragmentomic features of ccf-mtDNA from 246 patients with CRC and 168 HC in the training cohort, showing area under the curve of 0.9863, sensitivity of 92.68% and specificity of 93.45%. Both internal and two external validation cohorts demonstrated the excellent capacity of CD model in distinguishing patients with early-stage CRC from HCs, greatly surpassing the performance of serum biomarkers. Furthermore, our CD model can also detect patients with AA with a sensitivity of 79.35% in AA cohort 1 and 85.00% in AA cohort 2.

CONCLUSION

In conclusion, based on aberrant ccf-mtDNA fragmentomic features, a novel and non-invasive approach was established for the detection of patients with early-stage CRC or AA, with high performance.

Circulating tumor DNA as a predictive biomarker for treatment response and survival in metastatic colorectal cancer

PURPOSE

To explore the potential of circulating tumor DNA (ctDNA) as a prognostic biomarker to predict treatment response and survival outcomes in patients with metastatic colorectal cancer (mCRC).

METHODS

A retrospective analysis was conducted on 134 patients with mCRC who were treated between January 2020 and December 2021. The patients were classified into ctDNA-negative and ctDNA-positive groups based on plasma ctDNA detection. Demographic, clinical, and laboratory parameters, treatment response, survival outcomes, and adverse events were recorded and analyzed.

RESULTS

No significant differences were observed in baseline characteristics between the two groups. Compared to the ctDNA-positive patients, ctDNA-negative patients exhibited superior outcomes, including a higher objective response rate (65.22% vs. 46.15%), disease control rate (81.16% vs. 63.08%), progression-free survival (8.24 ± 1.02 vs. 7.86 ± 0.91 months), overall survival (24.58 ± 3.58 vs. 23.27 ± 3.46 months), and 1-year survival rate (73.91% vs. 55.38%). The ctDNA-positive group had a significantly higher incidence of adverse events. Correlation analyses revealed significant associations between ctDNA status, tumor markers, treatment response, and survival outcomes.

CONCLUSIONS

ctDNA is a promising noninvasive biomarker for predicting treatment response, survival, and adverse events in mCRC, potentially guiding personalized therapeutic strategies.

Anti-EGFR Rechallenge in Metastatic Colorectal Cancer and the Role of ctDNA: A Systematic Review and Meta-analysis

BACKGROUND

Metastatic colorectal cancer (mCRC) remains a significant clinical challenge. While anti-EGFR inhibitors have improved survival rates, their long-term efficacy is limited by disease progression, which is often associated with the development of acquired resistance mutations. However, some patients may regain sensitivity to anti-EGFR agents after alternative therapies, suggesting a potential benefit for rechallenge strategies. Our study aims to conduct a systematic review and meta-analysis to comprehensively evaluate the efficacy and safety of EGFR rechallenge in patients with mCRC.

METHODS

A systematic search of the MEDLINE, EMBASE, and Cochrane databases was conducted between October 28 and December 24, 2023, to identify clinical trials investigating treatment regimens incorporating panitumumab or cetuximab as a rechallenge strategy. Pooled proportions or hazard ratios (HR) were calculated using a random effects model. Inter-study heterogeneity was assessed using the I2.

RESULTS

Among the 2105 articles identified through the search, 13 met the predetermined inclusion criteria. Of these, 12 were phase II studies, encompassing 92.3% of the patient population. Cetuximab was administered to 302 patients (75.1%), whereas panitumumab was utilized in 100 patients (24.9%).A pooled analysis of eight studies demonstrated an objective response rate of 20.50% (95% CI 7.94 to 33.07) and a disease control rate of 67.35% (95% CI 58.60 to 76.09). The median progression-free survival was estimated at 3.5 months (95% CI 2.68-6.69), with a median OS of 9.8 months (95% CI 6.71-12.89). Patients exhibiting RAS wild-type status in circulating tumor DNA (ctDNA) analysis derived enhanced benefits from anti-EGFR rechallenge (HR: 0.41; 95% CI 0.28-0.60, I2 = 60%). Common grade 3 or higher treatment-related adverse events included neutropenia (22.8%) and rash (14.9%).

CONCLUSION

This meta-analysis underscores the efficacy and safety of anti-EGFR rechallenge as a promising therapeutic approach for a subset of patients afflicted with mCRC. The observed correlation between wild-type RAS status, as determined through ctDNA analysis, and improved OS signals the prospect of precision oncology in guiding treatment decisions.

Neoadjuvant immunotherapy for dMMR and pMMR colorectal cancers: therapeutic strategies and putative biomarkers of response

Approximately 15% of locally advanced colorectal cancers (CRC) have DNA mismatch repair deficiency (dMMR), resulting in high microsatellite instability and a high tumour mutational burden. These cancers are frequently sensitive to therapy with immune-checkpoint inhibitors (ICIs) in the metastatic setting. This sensitivity seems to be even more pronounced in locally advanced disease, and organ preservation has become a realistic aim in ongoing clinical trials involving patients with dMMR rectal cancer. By contrast, metastatic CRCs with proficient DNA mismatch repair (pMMR) are generally resistant to ICIs, although a proportion of locally advanced pMMR tumours seem to have a high degree of sensitivity to ICIs. In this Review, we describe the current and emerging clinical evidence supporting the use of neoadjuvant ICIs in patients with dMMR and pMMR CRC, and the potential advantages (based on a biological rationale) of such an approach. We discuss how neoadjuvant 'window-of-opportunity' trials are being leveraged to progress biomarker discovery and we provide an overview of potential predictive biomarkers of response to ICIs, exploring the challenges faced when evaluating such biomarkers in biopsy-derived samples. Lastly, we describe how these discoveries might be used to drive a rational approach to trialling novel immunotherapeutic strategies in patients with pMMR CRC, with the ultimate aim of disease eradication and the generation of long-term immunosurveillance.

Cancer Surveillance in Solid Organ Transplant Recipients With a Pretransplant History of Malignancy: Multidisciplinary Collaborative Expert Opinion

With improved medical treatments, the prognosis for many malignancies has improved, and more patients are presenting for transplant evaluation with a history of treated cancer. Solid organ transplant (SOT) recipients with a prior malignancy are at higher risk of posttransplant recurrence or de novo malignancy, and they may require a cancer surveillance program that is individualized to their specific needs. There is a dearth of literature on optimal surveillance strategies specific to SOT recipients. A working group of transplant physicians and cancer-specific specialists met to provide expert opinion recommendations on optimal cancer surveillance after transplantation for patients with a history of malignancy. Surveillance strategies provided are mainly based on general population recurrence risk data, immunosuppression effects, and limited transplant-specific data and should be considered expert opinion based on current knowledge. Prospective studies of cancer-specific surveillance models in SOT recipients should be supported to inform posttransplant management of this high-risk population.

Circulating Tumor DNA as a Prognostic Biomarker for Recurrence in Patients With Locoregional Esophagogastric Cancers With a Pathologic Complete Response

PURPOSE

After neoadjuvant therapy (NAT) and surgery, up to one third and one half of patients with esophagogastric adenocarcinoma with a pathologic complete response (pCR; tumor regression grade 0 [TRG-0]) and near-pCR (TRG-1) will recur, respectively. Our study aims to evaluate postoperative circulating tumor DNA (ctDNA) as a predictor of recurrence in patients with pCR or near-pCR after curative-intent neoadjuvant chemotherapy or neoadjuvant chemoradiation and surgery.

METHODS

We retrospectively identified patients from 11 institutions with stages I-IV esophagogastric cancers (EGCs) who completed NAT and had TRG-0/1 scores at the time of curative-intent surgery. Postoperative plasma samples were collected for ctDNA analysis within a 16-week molecular residual disease (MRD) window after definitive surgery, and during surveillance from January 7, 2020, to November 9, 2023, at the provider's discretion. ctDNA was assessed using a clinically validated, personalized, tumor-informed ctDNA assay (Signatera, Natera, Inc). The primary outcome was recurrence-free survival (RFS).

RESULTS

We obtained 309 blood samples from 42 patients with esophagogastric adenocarcinoma with a pCR after neoadjuvant treatment over a median follow-up time of 28.5 months (range, 0.2-81.7). Detectable ctDNA in the 16-week MRD window (N = 23) correlated with higher rates of recurrence (67%; 2/3) compared with undetectable ctDNA (15%; 3/20). Detectable ctDNA within the MRD window was associated with a significantly shorter RFS (hazard ratio [HR], 6.2; P = .049). Among 32 patients who had ctDNA analyzed in the surveillance setting, the recurrence rate was 100% (5/5) in the ctDNA-positive cohort compared with 7.4% (2/27) in ctDNA-negative patients and was associated with shorter RFS (HR, 37.6; P < .001).

CONCLUSION

Within the subgroup of patients with EGC and favorable pathologic responses (TRG 0-1) after NAT, the presence of postoperative ctDNA identified patients with elevated recurrence risk.

Survival analysis in pT1-3 and paracolic lymph-node invasion colorectal cancer: the prognostic role of positive paracolic lymph-node ratio for adjuvant chemotherapy

PURPOSE

Several studies have observed that some stage III colorectal cancer (CRC) patients cannot benefit from standard adjuvant chemotherapy. However, there is no unified screening standard to date.

METHODS

Consecutive patients with pathologically confirmed colon adenocarcinoma treated in 3 centers between January 2016 and December 2018 were included. Patients were divided into four groups according to different stages and positive paracolic lymph-node ratio (P-LNR) [Cohort 1: pT1-3N0M0, Cohort 2: pT1-3N + (P-LNR ≤ 0.15)M0, Cohort 3: pT4N0M0, Cohort 4: stage III patients except for pT1-3N + (P-LNR ≤ 0.15)M0], and further overall survival was compared by Kaplan-Meier method. The univariate and multivariate analyses were employed for cox proportional hazards model.

RESULTS

We retrospectively reviewed 5581 consecutive CRC patients with, and 2861 eligible patients were enrolled for further analysis. The optimal cut-off value of P-LNR in our study was 0.15. There was no significant difference in OS (91.36 vs. 93.74%) and DFS (87.65 vs. 90.96%) between stage III patients with pT1-3N + (P-LNR ≤ 0.15)M0 and those with pT1-3N0M0. Further analysis demonstrated that CRC patients with pT1-3N + (P-LNR ≤ 0.15)M0 were less likely to benefit from 8 cycles of CAPOX or FOLFOX chemotherapy and suffered fewer adverse events from declining chemotherapy. Comparing with 0-4 cycles versus 8 cycles, the overall survival rates were 91.35 versus 90.19% (P = 0.79), and with a DFS of 87.50 versus 88.24% (P = 0.49), the duration of adjuvant chemotherapy was not an independent risk factor for patients with pT1-3N + (P-LNR ≤ 0.15)M0 (HR: 0.70, 95% CI 0.90-1.30, P = 0.42).

CONCLUSION

The concept of P-LNR we proposed might have a high clinical application value and accurately enable clinicians to screen out specific CRC patients who decline or prefer limited chemotherapy.

TRIAL REGISTRY

The clinical trial registration number: ChiCTR2300076883.

NCI workshop on ctDNA in cancer treatment and clinical care

Detection of cell-free circulating tumor DNA (ctDNA) from solid tumors is a fast-evolving field with significant potential for improving patient treatment outcomes. The spectrum of applications for ctDNA assays is broad and includes very diverse intended uses that will require different strategies to demonstrate utility. On September 14-15, 2023, the National Cancer Institute held an in-person workshop in Rockville, MD titled "ctDNA in Cancer Treatment and Clinical Care." The goal of the workshop was to examine what is currently known and what needs to be determined for various ctDNA liquid biopsy use cases related to treatment and management of patients with solid tumors and to explore how the community can best assess the value of ctDNA assays and technology. Additionally, new approaches were presented that may show promise in the future. The information exchanged in this workshop will provide the community with a better understanding of this field and its potential to affect and benefit decision-making in the treatment of patients with solid tumors.

Molecular profiling of risk factors for relapse in Japanese patients with stage II colorectal cancer: a retrospective cohort study

BACKGROUND

The association between the molecular profiles and prognosis of Stage II colorectal cancer remains unclear. This study aimed to examine the risk factors for relapse of Stage II colorectal cancer using molecular profiling.

METHODS

We retrospectively enrolled patients with pStage II colorectal cancer who did not receive perioperative adjuvant therapy and whose surgically resected specimens were evaluated using gene expression and whole-exome analyses between January 2014 and December 2018. We evaluated the long-term outcomes and examined the risk factors for relapse-free survival.

RESULTS

We evaluated 322 patients with pStage II colorectal cancer, including 126 (39.1%) with right colon cancer. Eighty-seven patients (27.0%) had pT4 tumor, 175 (54.3%) had positive venous invasion, 120 (37.3%) had positive lymphatic invasion, and 68 (21.1%) had perineural invasion. The presence of mutations in key genes for colorectal cancer development based on whole-exome analyses was as follows: APC, 245 (76.1%); TP53, 208 (64.6%); and KRAS, 134 (41.6%). According to the consensus molecular subtype classification based on gene expression, 76 patients (23.6%) had consensus molecular subtype 4 and a significantly lower relapse-free survival than the other patients (5-year relapse-free survival: 83.8% vs. 92.9%, p = 0.017). Perineural invasion (hazard ratio: 5.316, p < 0.001) and consensus molecular subtype 4 (hazard ratio: 2.399, p = 0.020) were identified as independent risk factors for relapse-free survival.

CONCLUSIONS

Molecular profiling of Stage II colorectal cancer to assess the risk factors for relapse may contribute to the indication and drug selection for adjuvant chemotherapy.

Colorectal cancer screening using a multi-locus blood-based assay targeting circulating tumor DNA methylation: a cross-sectional study in an average-risk population

BACKGROUND

Effective screening for colorectal cancer (CRC) enables earlier diagnosis and intervention to improve patient survival.

METHODS

In this study, we prospectively conducted a blood-based CRC screening program for community residents in Hanjiang District, Yangzhou City, and evaluated the screening efficacy of a blood-based multi-locus DNA methylation assay (ColonAiQ). The ColonAiQ-positive rate and colonoscopy participation rate of the population, detection rate of intestinal lesions, and positive predictive value (PPV) of CRC and advanced adenoma (AA) were calculated, and the associated factors were explored.

RESULTS

A total of 105,285 participants were enrolled from January 2021 to December 2022, all of whom completed the ColonAiQ assay, yielding a positive rate of 6.42% (6759/105,285). The colonoscopy compliance rate was 48.56% (3282/6759). Intestinal lesions were detected in 1773 individuals (54.02%), including 63 cases of CRCs (predominately early-stage), 1195 adenomas (441 cases of AAs), 327 polyps, and 188 other benign lesions. CRC patients exhibited higher ColonAiQ scores and more positive loci compared to healthy individuals. The PPVs were 1.92% for CRC and 13.44% for AA. Among participants, 66,121 (62.8%) completed questionnaires graded by the Asia-Pacific Colorectal Screening score, with 12,139 (18.36%) classified in the high-risk tier. High-risk participants had a higher ColonAiQ-positive rate (11.07%) and PPVs for CRC (3.46%) and AA (22.18%). Factors associated with increased detection rates for CRC and AA included male gender, older age, a history of alcohol consumption, and prior polyps.

CONCLUSIONS

Our study demonstrated that ColonAiQ assay effectively identifies high-risk population. These findings strongly suggest that the ColonAiQ assay represents a promising strategy for the early detection of CRC and AA in individuals at average risk.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov (NCT05336539).

Stool and blood biomarkers for colorectal cancer management: an update on screening and disease monitoring

BACKGROUND

Biomarkers have revolutionized the management of colorectal cancer (CRC), facilitating early detection, prevention, personalized treatment, and minimal residual disease (MRD) monitoring. This review explores current CRC screening strategies and emerging biomarker applications.

MAIN BODY

We summarize the landscape of non-invasive CRC screening and MRD detection strategies, discuss the limitations of the current approaches, and highlight the promising potential of novel biomarker solutions. The fecal immunochemical test remained the cornerstone of CRC screening, but its sensitivity has been improved by assays that combined its performance with other stool analytes. However, their sensitivity for advanced adenomas and the patient compliance both remain suboptimal. Blood-based tests promise to increase compliance but require further refinement to compete with stool-based biomarker tests. The ideal scenario involves leveraging blood tests to increase screening participation, and simultaneously promote stool- and endoscopy-based screening among those who are compliant. Once solely reliant on upfront surgery followed by stage and pathology-driven adjuvant chemotherapy, the treatment of stage II and III colon cancer has undergone a revolutionary transformation with the advent of MRD testing after surgery. A decade ago, the concept of using a post-surgical test instead of stage and pathology to determine the need for adjuvant chemotherapy was disruptive. Today, a blood test may be more informative of the need for chemotherapy than the stage at diagnosis.

CONCLUSION

Biomarker research is not just improving, but bringing a transformative change to CRC clinical management. Early detection is not just getting better, but improving thanks to a multi-modality approach, and personalized treatment plans are not just becoming a reality, but a promising future with MRD testing.

ctDNA-guided adjuvant immunotherapy in colorectal cancer

Circulating tumor DNA (ctDNA) represents a powerful measure of minimal residual disease (MRD) in colorectal cancer (CRC). Although immunotherapy has been widely established in metastatic CRC that is mismatch repair deficient or microsatellite instability-high (dMMR/MSI-H), its role in non-metastatic CRC is rapidly evolving. In resected, dMMR/MSI-H stage II CRC, adjuvant fluoropyrimidine has no benefit and is not recommended. There is growing evidence to suggest diminished benefit from neoadjuvant chemotherapy and chemoradiation in localized CRC that is dMMR/MSI-H. We present two cases of dMMR/MSI-H stage III CRC treated with definitive surgery wherein adjuvant oxaliplatin-based chemotherapy led to a failure to clear postoperative plasma ctDNA levels, prompting a change to immune checkpoint blockade with pembrolizumab and resultant ctDNA clearance. We illustrate that chemotherapy may achieve suboptimal disease control in localized colon cancer that is dMMR/MSI-H, while plasma ctDNA offers a window of opportunity to gauge the efficacy of oxaliplatin-based adjuvant chemotherapy to clear microscopic disease in resected, dMMR/MSI-H stage III colon cancer. These findings are important to contextualize given that relapse is inevitable with failure to clear MRD in the postoperative stage I-III CRC setting whereby chemotherapy remains the standard adjuvant therapy in resected, dMMR/MSI-H stage III colon cancer.

Dynamics of cell-free tumor DNA correlate with early MRI response during chemoradiotherapy in rectal cancer

BACKGROUND

In locally advanced rectal cancer, the prediction of tumor response during and after neoadjuvant treatment remains challenging. In terms of organ preservation, adaptive radiotherapy, and intensified (total) neoadjuvant therapies, biomarkers are desirable for patient stratification.

METHODS

In 16 patients, weekly blood samples (n = 86) to detect cell-free tumor DNA (ctDNA) during long-course neoadjuvant chemoradiotherapy were analyzed. Data were correlated with initial tumor volumes, MRI response in week 2 and 5 of radiotherapy as well as with pathologic tumor response after resection and outcome parameters.

RESULTS

Most patients showed decreasing ctDNA during the course of radiochemotherapy. However, we found heterogenous dynamics of ctDNA and could identify three groups: (1) decline (2) no clear decline and/or late shedding (3) persistence of ctDNA. In seven patients we could detect significant amounts of ctDNA in week 5 or week 6 of treatment. In our pilot cohort, we did not find significant correlations of ctDNA dynamics with pathologic response or outcome parameters. However, patients with distinct decline of ctDNA had larger tumor volumes prior to treatment, and MRI imaging in week 2 and 5 revealed bigger absolute decrease of tumor volumes. If significant levels of ctDNA were found in week 5 and / or 6, patients showed less absolute tumor volume decrease in week 2 and 5.

CONCLUSIONS

Weekly measurement of ctDNA during radiochemotherapy is feasible and might represent a promising biomarker. Bigger initial primary tumors showed different ctDNA shedding profiles compared with smaller primary tumors and correlations of ctDNA dynamics with early imaging response were found.

A study of the clinical significance of mSEPT9 in monitoring recurrence and prognosis in patients with surgically treated colorectal cancer

OBJECTIVE

To explore the medical significance of methylated septin9 (mSEPT9) in monitoring recurrence and prognostic assessment in individuals with surgically treated colorectal cancer (CRC).

METHODS

To investigate the role of Septin9 in colorectal cancer, we utilized the TIMER2.0 database to analyze its differential expression between tumor tissues and adjacent normal tissues. Colorectal cancer RNA-seq data from the TCGA database was downloaded and curated. The clinical relevance of mSEPT9 in colorectal cancer was explored by examining the correlation between Septin9 methylation levels and clinical characteristics using UALCAN and MethSurv software. Peripheral blood samples were obtained from 130 CRC subjects who underwent surgery for the detection of mSEPT9 and carcinoembryonic antigen (CEA) expression, along with collection of clinicopathological data such as age, gender, tumor site, TNM stage, and tumor differentiation. Patients were followed up for at least 3 years post-surgery until the death or final follow-up dates (31/12/2022). Additionally, peripheral blood samples were collected from 30 colorectal cancer surgery patients for mSEPT9 detection before and 7 days after surgery.

RESULTS

Through bioinformatic database analysis, we identified higher expression levels of SEPT9 mRNA in most tumor tissues compared to normal tissues. Similarly, both paired and unpaired CRC tissues exhibited elevated expression of Septin9 when compared to normal tissues. Following GO and KEGG analysis of Septin9 target genes, we discovered their significant associations with ncRNA metabolic processes, ribonucleoprotein complex biogenesis, spliceosomes, and viral carcinogenesis. Furthermore, the overexpression of mSeptin9 was observed in CRC tissues, and it demonstrated a correlation with colon cancer staging and histologic classification. In our clinical sample study, The positive rate of mSEPT9 in CRC patients 7 days after surgery was 43.44% lower than that of preoperative. The differences in TNM stage, tumor differentiation degree, and preoperative CEA expression level between the preoperative mSEPT9 positive and negative groups of CRC were statistically significant (P < 0.05). Recurrence free survival (RFS) and overall survival (OS) were shorter in the preoperative mSEPT9-positive group, meaning preoperative mSEPT9 status was a risk factor for CRC recurrence and prognosis (P < 0.05). The sensitivity, specificity, and AUC value of preoperative mSEPT9 and CEA levels for predicting postoperative recurrence in CRC patients were 88% vs. 72%, 56.19% vs. 55.24%, and 0.721 vs. 0.636 respectively, well the AUC value of the combined prediction of postoperative recurrence was 0.758.

CONCLUSION

The detection of mSEPT9 combined with CEA in preoperative plasma helps predict recurrence in colorectal cancer patients.

COL25A1 and METAP1D DNA methylation are promising liquid biopsy epigenetic biomarkers of colorectal cancer using digital PCR

BACKGROUND

Colorectal cancer is a public health issue and was the third leading cause of cancer-related death worldwide in 2022. Early diagnosis can improve prognosis, making screening a central part of colorectal cancer management. Blood-based screening, diagnosis and follow-up of colorectal cancer patients are possible with the study of cell-free circulating tumor DNA. This study aimed to identify novel DNA methylation biomarkers of colorectal cancer that can be used for the follow-up of patients with colorectal cancer.

METHODS

A DNA methylation profile was established in the Gene Expression Omnibus (GEO) database (n = 507) using bioinformatics analysis and subsequently confirmed using The Cancer Genome Atlas (TCGA) database (n = 348). The in silico profile was then validated on local tissue and cell-free DNA samples using methylation-specific digital PCR in colorectal cancer patients (n = 35) and healthy donors (n = 35).

RESULTS

The DNA methylation of COL25A1 and METAP1D was predicted to be a colorectal cancer biomarker by bioinformatics analysis (ROC AUC = 1, 95% CI [0.999-1]). The two biomarkers were confirmed with tissue samples, and the combination of COL25A1 and METAP1D yielded 49% sensitivity and 100% specificity for cell-free DNA.

CONCLUSION

Bioinformatics analysis of public databases revealed COL25A1 and METAP1D DNA methylation as clinically applicable liquid biopsies DNA methylation biomarkers. The specificity implies an excellent positive predictive value for follow-up, and the high sensitivity and relative noninvasiveness of a blood-based test make these biomarkers compatible with colorectal cancer screening. However, the clinical impact of these biomarkers in colorectal cancer screening and follow-up needs to be established in further prospective studies.

The Role of Liquid Biopsy in Gastroenteropancreatic Neuroendocrine Neoplasms

Neuroendocrine neoplasms incidence has been increasing, arising the need for precise and early diagnostic tools. Liquid biopsy (LB) offers a less invasive alternative to tissue biopsy, providing real-time molecular information from circulating tumour components in body fluids. The aim of this review is to analyse the current evidence concerning LB in NENs and its role in clinical practice. We conducted a systematic review in July 2024 focusing on LB applications in NENs, including circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), micro RNA (miRNA), messenger RNA (mRNA) and extracellular vesicles. Sixty-five relevant articles were analysed. The LB showed potential in diagnosing and monitoring NENs. While CTCs face limitations due to low shedding, ctDNA provides valuable information on high-grade neoplasms. MiRNA and mRNA (e.g., the NETest) offer high sensitivity and specificity for diagnosis and prognosis, outperforming traditional markers like chromogranin A. The LB has significant potential for NEN diagnosis and monitoring but lacks widespread clinical integration due to limited prospective studies and guidelines, requiring further validation. Advances in sequencing technologies may enhance the clinical utility of LB in NENs. Future research should focus on refining LB methods, standardising protocols and exploring applications in high-grade NENs.

Genomic Landscape of Advanced Solid Tumors in Middle East and North Africa Using Circulating Tumor DNA in Routine Clinical Practice

INTRODUCTION

Next-generation sequencing (NGS) of tumor DNA can detect actionable drivers and help guide therapy for patients with advanced-stage cancers. While tissue-based genotyping is considered a standard of care, blood-based genotyping is emerging as a valid alternative. Tumor genomic profiles may vary by region, and data from the Middle East and North Africa (MENA) are not widely available. This study elucidates the genomic landscape of advanced solid cancers in patients from the MENA region by retrospectively analyzing results from NGS circulating tumor DNA (ctDNA) testing.

METHODS

In routine clinical practice, 926 plasma samples from 767 patients with advanced cancers from the MENA region were profiled using a comprehensive NGS assay (Guardant360®). We conducted a pan-cancer analysis and sub-analyses focusing on lung, breast, and colorectal cancers.

RESULTS

In the pan-cancer group, TP53 (58.5%), EGFR (20.4%), and KRAS (18.9%) were the most frequently mutated genes. EGFR (10.2%), FGFR1 (4.9%), and PIK3CA (4.9%) showed the most amplifications, while fusions were observed in 2.7% of patients, including ALK, FGFR2, and RET. For lung adenocarcinoma, EGFR (30.5%), KRAS (19.3%), and ERBB2 (4.6%) were the most frequently identified alterations among the genes recommended for evaluation by the National Comprehensive Cancer Network (NCCN). In patients with breast cancer, PIK3CA (35.3%), ESR1 (21.7%), and BRCA1/2 (13.3%) had the most prevalent alterations among NCCN-recommended genes. In colorectal cancer, KRAS (39.0%), NRAS (8.0%), and BRAF (V600E, 4.0%) were the most observed mutations among genes recommended by the NCCN. Comparing this cohort to publicly available Western and Eastern datasets also indicated similarities (including PIK3CA in breast cancer) and variances (including EGFR in lung adenocarcinoma) in key genes of interest in the analyzed cancer types.

CONCLUSION

Overall, our findings provide insight into the genomic landscape of individuals with advanced solid organ malignancies from the MENA region and support the role of ctDNA in guiding therapeutic decisions.

Identification of circulating tumor DNA as a biomarker for diagnosis and response to therapies in cancer patients

The sampling of circulating biomarkers provides an opportunity for non-invasive evaluation and monitoring of cancer activity. In modern day practice, this has typically been in the form of circulating tumor DNA (ctDNA) detected in plasma. The field of ctDNA has been a burgeoning technology, with prominent applications for blood-based cancer screening and in disease status assessment, especially after curative-intent surgery to evaluate for minimal residual disease (MRD). Clinical applications for the latter show an incredibly high sensitivity in certain cancer types with a need for additional studies to determine how much clinical decision-making should be adapted based on ctDNA results and which cancer types, stages, and treatments are best informed by ctDNA results. This chapter provides an overview of ctDNA detection as tool for cancer screening, detecting MRD, and/or molecularly characterizing a cancer, highlighting the rapidly amassing research as a prognostic biomarker and emerging data on ctDNA as a predictive biomarker.

Novel regimens and treatment strategies in neoadjuvant therapy for colorectal cancer: A systematic review

Objective

The objective of this systematic review was to describe novel regimens and treatment strategies in neoadjuvant therapy for colorectal cancer (CRC). The aim was to summarize the current advancements in neoadjuvant chemotherapy (NACT) for CRC, including the use of cytotoxic drugs, targeted treatments, and immunotherapy. The analysis aimed to provide insights into the potential benefits and drawbacks of these novel approaches and highlight the need for further research to optimize NACT use in CRC and improve patient outcomes.

Methods

From October 20, 2023, to December 10, 2023, a comprehensive literature search was conducted across multiple databases, including PubMed, Ovid, Web of Science, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Embase, and Scopus. Studies addressing the use of and treatment strategies for CRC and neoadjuvant therapies were included. Screening was conducted in two steps, initially by title and abstract and then by full-text articles. English-language articles were considered, while preprints, non-English publications, and articles published as grey literature were excluded from the study. A total of 85 studies were selected for further analysis after screening and filtering.

Results

After filtering out duplicates and items that were irrelevant to our research query from the initial database search's 510 results, 397 unique articles were found. Eighty-five studies were chosen for additional analysis after the articles underwent two rounds of screening.

Conclusion

The review concluded that neoadjuvant therapy for CRC has evolved beyond conventional approaches and holds promise for improving patient outcomes. Future prospects for advancing neoadjuvant approaches are promising, with ongoing clinical trials investigating the refinement of strategies, identification of predictive biomarkers, and optimization of patient selection. The adoption of novel regimens, precision medicine, and immunotherapy offers opportunities to redefine treatment paradigms and enhance patient care in CRC.

Neoadjuvant Chemotherapy in Colon Cancer: More Than Just an Optical Illusion

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Discovery and Validation of Methylation Signatures in Circulating Cell-Free DNA for the Detection of Colorectal Cancer

This study was conducted with the primary objective of assessing the performance of cfDNA methylation in the detection of colorectal cancer (CRC). Five tumor tissue, 20 peripheral blood leucocyte, and 169 cfDNA samples were collected for whole-genome bisulfite sequencing (WGBS) analysis. Bioinformatic analysis was conducted to identify differentially methylated regions (DMRs) and their functional characteristics. Quantitative methylation-specific PCR (qMSP) was used to validate the methylation levels of DMRs in the tissues and leucocytes. cfDNA samples from CRC patients and healthy controls were used to evaluate the performance of the DMR analysis. WGBS analysis revealed a decrease in DNA methylation levels in the CpG context in CRC tumor tissues compared with adjacent normal tissues. A total of 132 DMRs in cfDNA were identified as potential markers for diagnosing CRC. In a cohort of 95 CRC patients and 74 healthy controls, a combination of the three DMRs (DAB1, PPP2R5C, and FAM19A5) yielded an AUC of 0.763, achieving 64.21% sensitivity and 78.38% specificity in discriminating CRC patients from healthy controls. This study provides insights into DNA methylation patterns in CRC and identifies a set of DMRs in cfDNA with potential diagnostic value for CRC. These DMRs hold promise as biomarkers for CRC detection, offering promise for non-invasive CRC diagnosis. Further research is warranted to validate these findings in larger cohorts.

Exploring Predictive and Prognostic Biomarkers in Colorectal Cancer: A Comprehensive Review

Colorectal cancer (CRC) remains the second leading cause of cancer-related mortality worldwide. While immune checkpoint inhibitors have significantly improved patient outcomes, their effectiveness is mostly limited to tumors with microsatellite instability (MSI-H/dMMR) or an increased tumor mutational burden, which comprise 10% of cases. Advancing personalized medicine in CRC hinges on identifying predictive biomarkers to guide treatment decisions. This comprehensive review examines established tissue markers such as KRAS and HER2, highlighting their roles in resistance to anti-EGFR agents and discussing advances in targeted therapies for these markers. Additionally, this review summarizes encouraging data on promising therapeutic targets and highlights the clinical utility of liquid biopsies. By synthesizing current evidence and identifying knowledge gaps, this review provides clinicians and researchers with a contemporary understanding of the biomarker landscape in CRC. Finally, the review examines future directions and challenges in translating promising biomarkers into clinical practice, with the goal of enhancing personalized medicine approaches for colorectal cancer patients.