Clinical utility of circulating tumor DNA for colorectal cancer

Mutational profiling using liquid biopsy to guide targeted therapy in patients with metastatic cancer

Liquid biopsy gained significant interest in the area of cancer management. This study aims to evaluate the effectiveness of molecular testing using ctDNA (circulating tumor DNA) to; detect genetic alterations, screen for abnormalities, identify mutations associated with treatment sensitivity or resistance and guide therapy decision for several types of cancer in patients with metastasis. A total of 85 samples were collected from 74 patients recruited at our center, as part of their routine clinical follow-up. 17 different cancer types were analyzed. Genetic testing was conducted in patients with metastasis after failure of standard treatments. Sequencing was conducted in plasma-ctDNA samples; and when it was possible on the tumor tissue as well. Our analysis revealed that 88% (65 patients) of patients were eligible for treatment guidance using liquid biopsy. Among them, 64% (47 patients) received an FDA-approved drug, and treatment decisions were based on molecular testing using ctDNA. Somatic gene mutations were detected in 89% (66 patients) of the patients tested; 81% (60 patients) of patients had at least two mutations, 8% (6 patients) had only one mutation and 11% (8 patients) had no detected mutations. Interestingly, among the genes tested, BRCA2, EGFR, MSH6, and NF1 were the most frequently mutated in our patients. Our study highlights the potential benefits of personalized medicine through a non-invasive genetic testing across patients with metastasis regardless of the cancer types. Moreover, our study identified the frequent occurrence of specific gene mutations across various types of cancer, which paves the way for considering targeted therapies that could be applicable to multiple cancer types, rather than being restricted to just a few.

cfDNA hydroxymethylcytosine profiling for detection metastasis and recurrence of Esophageal Squamous Cell Carcinoma

BACKGROUND

A blood-based approach to monitor metastasis and recurrence of esophageal squamous cell carcinoma (ESCC) remains undeveloped. This study aimed to establish a dependable model utilizing cfDNA 5-hydroxymethylcytosines (5hmC) signatures to detect these conditions in ESCC.

METHODS

The 5hmC-Seal technique was employed to generate comprehensive 5hmC profiles from the plasma cell-free DNA (cfDNA) of 122 ESCC patients, classified into 72 with metastasis, 50 without metastasis, 30 with recurrence, and 92 without recurrence. Initial steps involved identifying distinct hydroxymethylation signatures linked to metastasis and recurrence. Machine learning algorithms were then utilized to construct predictive models.

RESULTS

The study confirmed that 5hmC-based markers are predictive of metastasis and recurrence among ESCC patients. The analysis of 14 5hmC biomarkers revealed a sensitivity of 88.90% and a specificity of 84.00% (AUC = 0.922) in differentiating patients with ESCC metastasis from those without in the validation cohort. Similarly, 11 5hmC biomarkers showed a sensitivity of 93.30% and a specificity of 89.10% (AUC = 0.936) in identifying recurrent versus non-recurrent ESCC cases. Additionally, a wp-score for metastasis and recurrence, derived from the 5hmC marker, prognosticated patient outcomes.

CONCLUSIONS

The findings indicate that 5hmC markers from cfDNA serve as effective epigenetic indicators for the non-invasive detection of ESCC metastasis and recurrence.

Liver-First Resection in Patients With Synchronous Colorectal Liver Metastases Is Associated With Inferior Recurrence-Free Survival: Reconsidering the Importance of the Primary Cancer

BACKGROUND

Synchronous colorectal liver metastases may be managed with primary-first, simultaneous, or liver-first resection. Relative oncologic outcomes based on treatment sequencing are understudied.

OBJECTIVE

This study aimed to assess oncologic survival outcomes in patients with synchronous colorectal liver metastases managed with each of the 3 treatment strategies, with respect to early or delayed removal of the primary tumor.

DESIGN

Retrospective analysis of the prospectively maintained database, with 1:1 propensity score matching of relevant clinicopathologic variables comparing liver-first to primary-first/simultaneous approaches.

SETTINGS

Single-institution, tertiary cancer center.

PATIENTS

Patients undergoing curative-intent hepatectomy for synchronous colorectal liver metastases from 2003 to 2019.

MAIN OUTCOME MEASURES

Overall and recurrence-free survival.

RESULTS

Of 151 patients, 23% (n = 35) had liver-first and 77% (n = 116; primary-first = 93 and simultaneous = 23) had primary-first/simultaneous approaches. The median follow-up was 45 months. Recurrence-free survival was worse for liver-first versus primary-first/simultaneous groups (median 12 versus 16 months, p = 0.02), driven by 3-year extrahepatic recurrence-free survival of 19%, 58%, and 50% for liver-first, primary-first, and simultaneous groups, respectively. Three-year overall survival was not significantly different at 86%, 79%, and 86%, respectively. Oncologic outcomes did not differ significantly between primary-first and simultaneous groups (all p > 0.4). Matching yielded 34 clinicopathologically similar patients per group (liver-first = 34, primary-first = 28, simultaneous = 6). The liver-first approach was associated with shorter recurrence-free survival (median 12 versus 23 months, p = 0.004), driven by extrahepatic recurrence-free survival (3 years: 20% versus 55%, p = 0.04). Overall survival was not significantly different at 3 years (79% versus 80%, p = 0.95) or 5 years (59% versus 59%, p > 0.99).

LIMITATIONS

This study has a retrospective design and a limited sample size.

CONCLUSIONS

A liver-first approach is associated with worse recurrence-free survival compared to primary-first or simultaneous resection, driven by extrahepatic recurrence. A prospective study of whether oncologic risk is associated with leaving the primary in situ is needed. Multidisciplinary treatment sequencing and enhanced postoperative surveillance for patients receiving liver-first resection are recommended. See Video Abstract .

LA RESECCIN DEL HGADO PRIMERO EN PACIENTES CON METSTASIS HEPTICAS COLORRECTALES SINCRNICAS SE ASOCIA CON UNA SUPERVIVENCIA INFERIOR SIN RECURRENCIA RECONSIDERACIN DE LA IMPORTANCIA DEL CNCER PRIMARIO

ANTECEDENTES:Las metástasis hepáticas colorrectales sincrónicas se pueden tratar con resección primaria, simultánea o hepática. Los resultados oncológicos relativos basados en la secuenciación del tratamiento están poco estudiados.OBJETIVO:Este estudio tuvo como objetivo evaluar los resultados de supervivencia oncológica en pacientes con metástasis hepáticas colorrectales sincrónicas tratadas con cada una de las tres estrategias de tratamiento, con respecto a la extirpación temprana o tardía del tumor primario.DISEÑO:Análisis retrospectivo de una base de datos mantenida prospectivamente, con coincidencia de propensión 1:1 de variables clínico-patológicas relevantes que comparan enfoques de hígado primero con enfoques primarios primero/simultáneos.AJUSTES:Centro oncológico terciario de una sola institución.PACIENTES:Pacientes sometidos a hepatectomía con intención curativa por metástasis hepáticas colorrectales sincrónicas entre 2003 y 2019.MEDIDAS PRINCIPALES DE RESULTADOS:Supervivencia general y libre de recurrencia.RESULTADOS:De 151 pacientes, el 23% (n=35) tuvo un abordaje hepático primero y el 77% (n=116; primario primero=93 y simultáneo=23) tuvo un abordaje primario primero/simultáneo. La mediana de seguimiento fue de 45 meses. La supervivencia libre de recurrencia fue peor para los grupos de hígado primero versus primario primero/simultáneo (mediana 12 versus 16 meses, p = 0,02), impulsada por la supervivencia libre de recurrencia extrahepática a tres años del 19%, 58% y 50% para grupos de hígado primero, primario primero y simultáneo, respectivamente. La supervivencia general a tres años no fue significativamente diferente: 86%, 79% y 86%, respectivamente. Los resultados oncológicos no difirieron significativamente entre los grupos primario-primero y simultáneo (todos p > 0,4). El emparejamiento produjo 34 pacientes clínico-patológicamente similares por grupo (hígado primero = 34, primario primero = 28/simultáneo = 6). El enfoque de hígado primero se asoció con una supervivencia libre de recurrencia más corta (mediana de 12 frente a 23 meses, p = 0,004), impulsada por la supervivencia libre de recurrencia extrahepática (3 años: 20 % frente a 55 %, p = 0,04). La supervivencia general no fue significativamente diferente a los 3 años (79% versus 80%, p = 0,95) o a los 5 años (59% versus 59%, p > 0,99).LIMITACIONES:Este estudio tiene un diseño retrospectivo y un tamaño de muestra limitado.CONCLUSIONES:Un enfoque de hígado primero se asocia con una peor supervivencia libre de recurrencia en comparación con la resección primaria o simultánea, impulsada por la recurrencia extrahepática. Es necesario un estudio prospectivo sobre si el riesgo oncológico se asocia con dejar el primario in situ . Se recomienda la secuenciación del tratamiento multidisciplinario y una vigilancia posoperatoria mejorada para los pacientes que reciben una primera resección del hígado. (Traducción-Yesenia Rojas-Khalil ).

18F-FDG PET/CT for early prediction of pathological complete response in breast cancer neoadjuvant therapy: a retrospective analysis

BACKGROUND

Neoadjuvant treatment has been developed as a systematic approach for patients with early breast cancer and has resulted in improved breast-conserving rate and survival. However, identifying treatment-sensitive patients at the early phase of therapy remains a problem, hampering disease management and raising the possibility of disease progression during treatment.

METHODS

In this retrospective analysis, we collected 2-deoxy-2-[F-18] fluoro-d-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) images of primary tumor sites and axillary areas and reciprocal clinical pathological data from 121 patients who underwent neoadjuvant treatment and surgery in our center. The univariate and multivariate logistic regression analyses were performed to investigate features associated with pathological complete response (pCR). An 18F-FDG PET/CT-based prediction model was trained, and the performance was evaluated by receiver operating characteristic curves (ROC).

RESULTS

The maximum standard uptake values (SUVmax) of 18F-FDG PET/CT were a powerful indicator of tumor status. The SUVmax values of axillary areas were closely related to metastatic lymph node counts (R = 0.62). Moreover, the early SUVmax reduction rates (between baseline and second cycle of neoadjuvant treatment) were statistically different between pCR and non-pCR patients. The early SUVmax reduction rates-based model showed great ability to predict pCR (AUC = 0.89), with all molecular subtypes (HR+HER2-, HR+HER2+, HR-HER2+, and HR-HER2-) considered.

CONCLUSION

Our research proved that the SUVmax reduction rate of 18F-FDG PET/CT contributed to the early prediction of pCR, providing rationales for utilizing PET/CT in NAT in the future.

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.

Prognostic factors in pulmonary metastases resection from colorectal cancer: impact of right-sided colon cancer and early recurrence

OBJECTIVE

This retrospective cohort study aimed to explore the surgical outcomes and prognostic factors of resection of pulmonary metastases (PM) from colorectal cancer (CRC).

METHODS

Overall, 60 patients who underwent resection of PM from CRC between 2015 and 2021 at two institutions were reviewed. The primary outcome were overall survival (OS) and early recurrence after PM resection. The association between OS and right-sided colon cancer (RCC) was investigated. Early recurrence after PM resection was defined as recurrence within one year.

RESULTS

The 5-year OS after CRC resection was 83.8% (95% confidence interval [CI] 67.5-92.4) and after PM resection was 69.4% (95% CI 47.5-83.6). In total, 25 patients had recurrence after PM resection (16 within 1 year and 9 after 1 year). In multivariable analysis for OS, RCC (hazard ratio [HR] 4.370, 95% CI 1.020-18.73; p = 0.047) and early recurrence after resection of PM (HR 17.23, 95% CI 2.685-110.6; p = 0.003) were risk factors for poor OS. In multivariable analysis for early recurrence after PM resection, higher value of carcinoembryonic antigen (CEA) (> 5.0 mg/dL) before PM resection was a risk factor for early recurrence (HR 3.275, 95% CI 1.092-9.821; p = 0.034).

CONCLUSION

The RCC and early recurrence after PM resection were poor prognosis factors of OS. Higher value of CEA before PM resection was an independent risk factor for early recurrence after resection of PM. Comparitive study between surgery and nonsurgery is necessary in patients with higher CEA values.

Tumor therapeutics in the era of "RECIST": past, current insights, and future prospects

In recent years, advancements in medical treatment and imaging technologies have revolutionized the assessment of tumor response. However, the Response Evaluation Criteria in Solid Tumors (RECIST) has long been established as the gold standard for evaluating tumor treatment. As treatment modalities evolve, the need for continuous refinement and adaptation of RECIST becomes increasingly apparent. This review explores the historical evolution, current applications, limitations, and future directions of RECIST. It discusses the challenges of distinguishing true progression from pseudo-progression in ICIs (immune checkpoint inhibitors), the integration of advanced imaging tools, and the necessity for RECIST criteria tailored to specific therapies like neoadjuvant treatments. The review highlights the ongoing efforts to enhance RECIST's accuracy and reliability in clinical decision-making and the potential for developing new standards to better evaluate treatment efficacy in the rapidly evolving landscape of oncology.

Dynamics of RAS Mutations in Liquid Biopsies in Metastatic Colorectal Cancer Patients-Case Series and Literature Review

Liquid biopsies can accurately identify molecular alterations in patients with colorectal cancer with high concordance with tissue analysis and shorter turnaround times. Circulating tumor (ct) DNA analysis can be used for diagnosing and monitoring tumor evolution in patients with metastatic colorectal cancer who are treated with EGFR inhibitors. In this article, we reported three clinical cases to illustrate the relevance of RAS mutations identified in ctDNA samples of patients with wild-type metastatic colorectal cancer who received an EGFR inhibitor plus chemotherapy as first-line treatment. The identification of RAS mutations in these patients is one of the most frequently identified mechanisms of acquired resistance. However, detecting a KRAS mutation via liquid biopsy can be caused by inter-tumor heterogeneity or it can be a false positive due to clonal hematopoiesis. More research is needed to determine whether ctDNA monitoring may help guide therapy options in metastatic colorectal cancer patients. We performed a literature review to assess the technologies that are used for analysis of RAS mutations on ctDNA, the degree of agreement between tissue and plasma and the importance of tissue/plasma discordant cases.

Clinical features associated with NeoRAS wild-type metastatic colorectal cancer A SCRUM-Japan GOZILA substudy

"NeoRAS WT" refers to the loss of RAS mutations (MTs) following first-line treatment in metastatic colorectal cancer (mCRC). We evaluate the incidence and clinicopathological characteristics of NeoRAS WT mCRC using next-generation sequencing of plasma circulating tumor DNA. Patients with mCRC enrolled in the GOZILA study initially diagnosed with tissue RAS MT mCRC and received subsequent systemic therapy are eligible. NeoRAS WT is defined as the absence of detectable RAS MT in plasma and assessed in all eligible patients (Group A) and in a subgroup with at least one somatic alteration detected in plasma (Group B). Overall, 478 patients are included. NeoRAS WT prevalence is 19.0% (91/478) in Group A and 9.8% (42/429) in Group B. Absence of liver or lymph node metastasis and tissue RAS MTs other than KRAS exon 2 MTs are significantly associated with NeoRAS WT emergence. Overall, 1/6 and 2/6 patients with NeoRAS WT treated with anti-EGFR monoclonal antibodies (mAbs) show partial response and stable disease for ≥6 months, respectively. NeoRAS WT mCRC is observed at a meaningful prevalence, and anti-EGFR mAb-based therapy may be effective.

Clinical utility of the carcinoembryonic antigen level in patients with stage III colon cancer after surgery and adjuvant chemotherapy

PURPOSE

The association between perioperative and post-adjuvant carcinoembryonic antigen (CEA) levels and recurrence and prognosis remains unclear. We aimed to evaluate whether perioperative CEA levels are an integral component of the assessment of recurrence and prognosis of patients with stage III colon cancer (CC).

METHODS

This retrospective study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 2005 to 2013. We enrolled patients with stage III CC who underwent complete resection of a primary tumor and received adjuvant chemotherapy. We analyzed the association between perioperative and post-adjuvant CEA levels and recurrence-free survival (RFS) and overall survival (OS).

RESULTS

A total of 564 consecutive patients were included in the analysis. The RFS and OS of patients with high postoperative CEA levels were significantly worse than those of patients with normal postoperative CEA levels. In the multivariate analysis, high postoperative CEA levels were associated with shorter RFS and OS. The number of risk factors, postoperative CEA levels, and T/N-stage all had a cumulative effect on RFS and OS.

CONCLUSIONS

High postoperative CEA levels and the number of risk factors are associated with recurrence and worse prognosis for patients with stage III CC.

A panorama of colon cancer in the era of liquid biopsy

Colon cancer (CC) is one of the most frequent cancers worldwide being responsible for over 500 thousand deaths in 2022. Its financial and human burden is expected to increase in the next decades accompanying the growing and aging of the global population. Much of this burden could be alleviated considering that the lethality of CC is mostly due to its late diagnosis and failure in the individualized management of patients. Coordinated government actions and implementation of better diagnostic tools capable of detecting CC earlier and of tracking tumoral evolution are mandatory to achieve a reduction in CC's social impact. CtDNA-based liquid biopsy (LB) has great potential to contribute to patients' screening adhesion, CC earlier detection, and to longitudinal tumor follow-up. In this review, we will discuss the latest epidemiological data on CC disease, diagnostic, subtypes, genetics, and treatment management focusing on the advantages and limitations of ctDNA-based LB, including important bottlenecks and solutions necessary for its clinical translation. The latest ctDNA-directed CC clinical trials will also be examined.

Waiting for the "liquid revolution" in the adjuvant treatment of colon cancer patients: a review of ongoing trials

Since colon cancer has a high rate of shedding of tumour fragments into the blood, several research efforts are now focused on the investigation of the minimal residual disease through the detection of ctDNA to tailor the adjuvant therapy of colon cancer patients and optimize its cost/effectiveness balance. The negative prognostic impact of detectable ctDNA in patients' blood after radical surgery for colon cancer is well established. Several clinical trials adopting heterogeneous designs and techniques are now ongoing to translate promises into daily practice by answering five general questions: i) is a ctDNA-guided decision making efficacious in the post-operative management of colon cancer patients? ii) are de-escalation strategies possible in ctDNA-negative cases? iii) are escalation strategies useful to improve the prognosis of ctDNA-positive patients? iv) when MRD is identified at the end of the adjuvant chemotherapy, is another post-adjuvant systemic therapy efficacious? v) can we exploit ctDNA technologies in the follow up of colon cancer patients? This review focuses on currently ongoing trials and how their results may affect the ctDNA "liquid revolution" of early colon cancer.

Colorectal Cancer: Genetic Underpinning and Molecular Therapeutics for Precision Medicine

Colorectal cancer (CRC) accounts for about 10% of all cancer cases and 9% of cancer-related deaths globally. In the United States alone, CRC represents approximately 12.6% of all cancer cases, with a mortality rate of about 8%. CRC is now the first leading cause of cancer death in men younger than age 50 and second in women younger than age 50. This review delves into the genetic landscape of CRC, highlighting key mutations and their implications in disease progression and treatment. We provide an overview of the current and emerging therapeutic strategies tailored to individual genomic profiles.

Efficacy, safety and genomic analysis of SCT200, an anti-EGFR monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type metastatic colorectal cancer: a phase Ⅱ study

BACKGROUND

Limited therapeutic options are available for metastatic colorectal cancer (mCRC) patients after failure of first- and second-line therapies, representing an unmet medical need for novel therapies.

METHODS

This is an open-label, single arm, multicenter, phase Ⅱ study aiming to perform the efficacy, safety and genomic analysis of SCT200, a noval fully humanized IgG1 anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type mCRC. SCT200 (6 mg/kg) was given weekly for the first six weeks, followed by a higher dose of 8 mg/kg every two weeks until disease progression or unacceptable toxicity. Primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) and secondary endpoints included ORR in patients with left-sided tumor, disease control rate (DCR), duration of response (DoR), time to response (TTR), progression-free survival (PFS), overall survival (OS) and safety.

FINDINGS

From February 12, 2018 to December 1, 2019, a total of 110 patients aged between 26 and 77 years (median: 55; interquartile range [IQR]: 47-63) with fluorouracil, oxaliplatin, and irinotecan refractory RAS and BRAF wild-type mCRC were enrolled from 22 hospitals in China. As the data cut-off date on May 15, 2020, the IRC-assessed ORR and DCR was 31% (34/110, 95% confidence interval [CI] 22-40%) and 75% (82/110, 95% CI 65-82%), respectively. Thirty one percent (34/110) patients achieved confirmed partial response (PR). The median PFS and median OS were 5.1 months (95% CI 3.4-5.2) and 16.2 months (95% CI 11.1-not available [NA]), respectively. The most common ≥ grade 3 treatment-related adverse events (TRAEs) were hypomagnesemia (17%, 19/110) and acneiform dermatitis (11%, 12/110). No deaths occurred. Genomic analysis suggested positive association between MYC amplification and patients' response (P = 0.0058). RAS/RAF mutation and MET amplification were the most frequently detected resistance mechanisms. Patients with high circulating tumor DNA (ctDNA) at baseline or without ctDNA clearance at the 7th week after the first dose of SCT200 administration before receiving SCT200 had worse PFS and OS.

INTERPRETATION

SCT200 exhibited promising clinical efficacy and manageable safety profiles in RAS and BRAF wild-type mCRC patients progressed on fluorouracil, irinotecan and oxaliplatin treatment. The baseline ctDNA and ctDNA clearance status at the 7th week after the first dose of SCT200 administration before receiving SCT200 could be a potential prognostic biomarker for RAS and BRAF wild-type mCRC patients with SCT200 therapy.

FUNDING

This study was sponsored by Sinocelltech Ltd., Beijing, China and partly supported by the National Science and Technology Major Project for Key New Drug Development (2019ZX09732001-006, 2017ZX09304015).

Sensitive and Specific Analyses of Colorectal Cancer Recurrence through Multiplex superRCA Mutation Detection in Blood Plasma

Mutation analysis of circulating tumor DNA (ctDNA) has applications in monitoring of colorectal cancer (CRC) patients for recurrence. Considering the low tumor fraction of ctDNA in cell-free DNA (cfDNA) isolated from blood plasma, the sensitivity of the detection method is important. Here, plasma DNA collected at diagnosis and follow-up from 25 CRC patients was analyzed using a multiplex superRCA mutation detection assay. The assay was also performed on genomic DNA (gDNA) from tumor and normal tissue from 20 of these patients. The lower limit of detection for most sequence variants was in the range of 10-5, while when analyzing cfDNA from plasma with a typical input of 33 ng, the practical detection limit was ~10-4 or 0.01% mutant allele frequency (MAF). In 17 of 19 patients with identified hotspot mutations in tumor gDNA, at least one hotspot mutation could be detected in plasma DNA at the time of diagnosis. The MAF increased at subsequent time points in four of the patients who experienced a clinical relapse. Multiplex superRCA analysis of the remaining six patients did not reveal any hotspot mutations. In conclusion, multiplex superRCA assays proved suitable for monitoring CRC patients by analyzing hotspot mutations in cfDNA, and dynamic changes in MAF were observed in patients with clinical relapse.

Prognostic value of circulating tumor cells in patients with recurrent and metastatic colorectal cancer: a systematic review and meta-analysis

BACKGROUND

The detection of circulating tumor cells (CTCs) has been employed in prognosticating the likelihood of recurrence and metastasis in colorectal cancer (CRC). Nonetheless, the findings remain enigmatic. This meta-analysis aims to systematically assess the predictive utility of CTCs detection in postoperative recurrence and metastasis among CRC patients.

METHODS

A comprehensive search of PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Cochrane Library was conducted from inception to March 2023. Pooled estimates including sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio, and summary receiver operating characteristic curve were computed to gauge the predictive value. The QUADAS-2 tool was employed to appraise bias risks in individual studies. The assessment of publication bias in the included literature was performed using Deek's funnel plot.

RESULTS

The study encompassed 16 articles and 2037 patients. After synthesizing the pertinent indices, CTCs monitoring demonstrated sensitivity and specificity of 0.71 (95% confidence interval [CI], 0.62-0.79) and 0.71 (95% CI, 0.55-0.83), respectively. The corresponding values for positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 2.4 (95% CI, 1.5-4.0), 0.41 (95% CI, 0.29-0.58), and 6 (95% CI, 3-13). The summary receiver operating characteristic curve yielded an area under the curve of 0.76 (95% CI, 0.72-0.80). Deek's funnel plot analysis revealed no significant evidence of publication bias (P = .42).

CONCLUSION

This investigation underscores the potential of CTCs detection as a noninvasive modality to efficaciously prognosticate postoperative recurrence and metastasis in CRC.

Combined DNA Analysis from Stool and Blood Samples Improves Tumor Tracking and Assessment of Clonal Heterogeneity in Localized Rectal Cancer Patients

Objectives: In this study, stool samples were evaluated for tumor mutation analysis via a targeted next generation sequencing (NGS) approach in a small patient cohort suffering from localized rectal cancer. Introduction: Colorectal cancer (CRC) causes the second highest cancer-related death rate worldwide. Thus, improvements in disease assessment and monitoring that may facilitate treatment allocation and allow organ-sparing "watch-and-wait" treatment strategies are highly relevant for a significant number of CRC patients. Methods: Stool-based results were compared with mutation profiles derived from liquid biopsies and the gold standard procedure of tumor biopsy from the same patients. A workflow was established that enables the detection of de-novo tumor mutations in stool samples of CRC patients via ultra-sensitive cell-free tumor DNA target enrichment. Results: Notably, only a 19% overall concordance was found in mutational profiles across the compared sample specimens of stool, tumor, and liquid biopsies. Conclusion: Based on these results, the analysis of stool and liquid biopsy samples can provide important additional information on tumor heterogeneity and potentially on the assessment of minimal residual disease and clonal tumor evolution.

Tumor circulating biomarkers in colorectal cancer

CRC is a major global health concern and is responsible for a significant number of cancer-related deaths each year. The successful treatment of CRC becomes more difficult when it goes undetected until it has advanced to a later stage. Diagnostic biomarkers can play a critical role in the early detection of CRC, which leads to improved patient outcomes and increased survival rates. It is important to develop reliable biomarkers for the early detection of CRC to enable timely diagnosis and treatment. To date, CRC detection methods such as endoscopy, blood, and stool tests are imperfect and often only identify cases in the later stages of the disease. To overcome these limitations, researchers are turning to molecular biomarkers as a promising avenue for improving CRC detection. Diagnostic information can be provided more reliably through a noninvasive approach using biomarkers such as mRNA, circulating cell-free DNA, micro-RNA, long non-coding RNA, and proteins. These biomarkers can be found in blood, tissue, feces, and volatile organic compounds. The identification of molecular biomarkers with high sensitivity and specificity for early detection of CRC that are safe, cost-effective, and easily measurable remains a significant challenge for researchers. In this article, we will explore the latest advancements in blood-based diagnostic biomarkers for CRC and their potential impact on improving patient survival rates.

Current advances in detecting genetic and epigenetic biomarkers of colorectal cancer

Colorectal carcinoma (CRC) is the third most common cancer in terms of diagnosis and the second in terms of mortality. Recent studies have shown that various proteins, extracellular vesicles (i.e., exosomes), specific genetic variants, gene transcripts, cell-free DNA (cfDNA), circulating tumor DNA (ctDNA), microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and altered epigenetic patterns, can be used to detect, and assess the prognosis of CRC. Over the last decade, a plethora of conventional methodologies (e.g., polymerase chain reaction [PCR], direct sequencing, enzyme-linked immunosorbent assay [ELISA], microarray, in situ hybridization) as well as advanced analytical methodologies (e.g., microfluidics, electrochemical biosensors, surface-enhanced Raman spectroscopy [SERS]) have been developed for analyzing genetic and epigenetic biomarkers using both optical and non-optical tools. Despite these methodologies, no gold standard detection method has yet been implemented that can analyze CRC with high specificity and sensitivity in an inexpensive, simple, and time-efficient manner. Moreover, until now, no study has critically reviewed the advantages and limitations of these methodologies. Here, an overview of the most used genetic and epigenetic biomarkers for CRC and their detection methods are discussed. Furthermore, a summary of the major biological, technical, and clinical challenges and advantages/limitations of existing techniques is also presented.

Early changes in circulating tumor DNA (ctDNA) predict treatment response in metastatic KRAS-mutated colorectal cancer (mCRC) patients

The detection of RAS mutations and co-mutations in liquid biopsy offers a novel paradigm for the dynamic management of metastatic colorectal cancer (mCRC) patients. Expanding the results of the prospective OMITERC (OMIcs application from solid to liquid biopsy for a personalized ThERapy of Cancer) project, we collected blood samples at specific time points from patients who received a first-line chemotherapy (CT) for KRAS-mutated mCRC. CTC quantification was performed by CellSearch® system. Libraries from cfDNA were prepared using the Oncomine™ Colon cfDNA Assay to detect tumour-derived DNA in cfDNA. The analysis involved >240 hotspots in 14 genes. Twenty patients with KRAS-mutated mCRC treated at the Medical Oncology Unit of Careggi University Hospital were prospectively enrolled. Nine patients had available data for longitudinal monitoring of cfDNA. After 6 weeks of first-line CT an increase of KRAS-mutated clone was reported in the only patient who did not obtain disease control, while all patients with decrease of KRAS clones obtained disease control. Overall, in patients with a short (<9 months) progression-free survival (PFS) we registered, at 6 weeks, an increase in cfDNA levels and in KRAS mutations or other co-mutations, i.e. PIK3CA, FBXW7, GNAS, and TP53. In selected cases, co-mutations were able to better anticipate radiological progressive disease (PD) than the increase of KRAS-mutated clones. In conclusion, our study confirms plasma ctDNA as a crucial tool for anticipating PD at an early time point and highlights the value of a comprehensive assessment of clonal dynamics to improve the management of patients with mCRC.

Using oral tegafur/uracil (UFT) plus leucovorin as adjuvant chemotherapy in stage II colorectal cancer: a propensity score matching study from Taiwan

BACKGROUND

Early-stage colorectal cancer had excellent outcomes after curative resection, typically. However, a perplexing survival paradox between stage II and stage III was noted. This paradox could be influenced by the administration of routine postoperative adjuvant chemotherapy and the presence of high-risk factors in stage II CRC. The objective of the study was to investigate the influence of high-risk factors on patients with stage II CRC and assess the efficacy of oral tegafur/uracil (UFT) plus leucovorin as adjuvant chemotherapy for stage II CRC patients.

METHODS

A retrospective study was conducted using propensity score matching at a single medical institution. A total of 1544 patients with stage II colorectal cancer who underwent radical surgery between January 2004 and January 2009 were included. The intervention used was tegafur/uracil plus leucovorin as adjuvant chemotherapy. The main outcome measures were disease-free survival and overall survival.

RESULTS

After propensity score matching, 261 patients were included in three groups: no-treatment, half-year treatment, and one-year treatment. The clinical characteristics of each group tended to be more consistent. The Cox proportional hazard models showed that tegafur/uracil treatment or not was a significant independent factor for oncological outcome. Kaplan-Meier analysis also showed significantly better disease-free survival and overall survival. Further investigation revealed that tegafur/uracil duration was an independent factor for oncological outcome. While the survival curve did not reach statistical significance, the one-year UFT treatment group demonstrated the best treatment trend.

CONCLUSIONS

This study suggests that tegafur/uracil plus leucovorin is a feasible adjuvant chemotherapy regimen for patients with stage II colorectal cancer after curative surgical treatment. Prolonged tegafur/uracil plus leucovorin treatment for 12 months showed a trend towards better outcomes in patients with stage II colorectal cancer.

Early-stage sigmoid colon cancer resection followed by liver metastasis recurrence 1 year later and mesenteric recurrence more than 5 years later: a case report

BACKGROUND

Early-stage colorectal cancer (CRC) is often treated endoscopically, but additional surgical resection may be considered depending on pathological findings.

CASE PRESENTATION

A 73-year-old man was found to have early-stage sigmoid colon cancer by colonoscopy during a medical examination, and endoscopic mucosal resection (EMR) was performed. The lesion was a 7-mm-sized sessile polyp, and the pathological diagnosis was well-differentiated tubular adenocarcinoma, pT1 (submucosal invasion of 400 μm), with no lymphovascular invasion, low budding grade, and negative horizontal and vertical margins. Therefore, the patient was observed without postoperative treatment. One year later, a computed tomography (CT) scan showed multiple liver metastases. After five courses of preoperative chemotherapy with folinic acid, 5-fluorouracil and oxaliplatin (FOLFOX) and panitumumab, liver metastases were reduced. The patient underwent extended right hepatic lobectomy. The pathological finding was well-to-moderately differentiated tubular adenocarcinoma, and immunohistochemistry findings were consistent with liver metastases from sigmoid colon cancer. Postoperatively, the patient received five courses adjuvant chemotherapy with FOLFOX. Although the patient had been recurrence-free for 5 years after liver resection, a CT scan revealed a nodular lesion in the sigmoid mesentery. Positron emission tomography (PET) showed abnormal accumulation in the same lesion. Therefore, the mesenteric nodules diagnosed as lymph metastasis and recurrence of sigmoid colon cancer and performed laparoscopic sigmoid colon resection with lymph node dissection. The pathological findings showed that the recurrent lesion in the mesentery formed a nodular infiltrate with venous, lymphatic, and neural invasion, but lymph node structures were not found, and it was assumed to be metastasis or recurrence due to lymphovascular invasion. The pathologic specimen of the sigmoid colon had no neoplastic lesions, which are considered to be a local recurrence on the mucosal surface. After sigmoid colectomy, adjuvant chemotherapy with CapeOX was conducted, and the patient has been recurrence-free for 13 months at present.

CONCLUSION

Even early-stage CRCs that have no pathological indications for additional resection have risks of metastases and recurrences, and we may need to consider that the criteria for additional resection should not be limited to pathological findings alone.

Clinical application of circulating tumor DNA in metastatic cancers

INTRODUCTION

Advances in genomics have facilitated the application of cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA) in phase II and phase III clinical trials. The various mutations of cfDNA/ctDNA have been correlated with clinical features. Advances in next-generation sequencing (NGS) and digital droplet PCR have paved the way for identifying cfDNA/ctDNA mutations.

AREAS COVERED

Herein, the biology of ctDNA and its function in clinical application in metastasis, which may lead to improved clinical management of metastatic cancer patients, are comprehensively reviewed.

EXPERT OPINION

Metastatic cancer ctDNA shows the greatest frequency of mutations in TP53, HER-2, KRAS, and EGFR genes (alteration frequency of > 50%). Therefore, identifying key mutations frequently present in metastatic cancers can help identify patients with pre-malignant tumors before cancer progression. Studying ctDNA can help determine the prognosis and select appropriate treatments for affected patients. Nevertheless, the obstacles to detecting and analyzing ctDNA should be addressed before translation into routine practice. Also, more clinical trials should be conducted to study the significance of ctDNA in commonly diagnosed malignancies. Given the recent advances in personalized anti-neoplastic treatments, further studies are needed to detect a panel of ctDNA and patient-specific ctDNA for various cancers.

A multi-institutional observational study evaluating the incidence and the clinicopathological characteristics of NeoRAS wild-type metastatic colorectal cancer

PURPOSE

As circulating tumor DNA (ctDNA) measurement becomes more widespread, the "NeoRAS" phenomenon, where tissue rat sarcoma viral oncogene homolog (RAS) status converts from mutant (MT) to wild-type (WT) after treatment in metastatic colorectal cancer (mCRC), is gaining attention because ineffective epidermal growth factor receptor (EGFR) inhibitors may made effective. This study investigated its incidence and clinicopathological characteristics.

PATIENTS AND METHODS

In total, 107 mCRC patients (refractory or intolerant to previous chemotherapies) with tissue RAS MT were enrolled in four institutions from June 2021 to August 2022. The RAS status in ctDNA was assessed using OncoBEAM™ RAS CRC assay. Clinicopathologic features were compared between patients according to their RAS status in ctDNA, whether WT conversion was noted or not.

RESULTS

The incidence rate of NeoRAS WT mCRC was 21.5% (23/107). According to tissue RAS mutation sites, NeoRAS WT frequency in patients with KRAS mutation in exon 2 was significantly lower than those in exon 3 and 4 or NRAS (18.2% [18/99] vs 62.5% [5/8], P = 0.011). Regarding clinical background, there were significant differences in NeoRAS WT frequency between male vs female patients (30.6% [19/62] vs 8.9% [4/45], P = 0.008), and absence vs presence of liver metastasis (38.6% [17/44] vs 9.5% [6/63], P < 0.001). Comparing the two groups divided by the median value, NeoRAS WT was associated with smaller tumor diameter (>60.9 mm vs ≤, 3.8% [2/53] vs 38.9% [21/54], P < 0.001), lower carcinoembryonic antigen level (>38.2 ng/ml vs ≤, 11.3% [6/53] vs 31.5% [17/54], P = 0.018), and lower carbohydrate antigen 19-9 level (>158.0 U/ml vs ≤, 9.4% [5/53] vs 33.3% [18/54], P = 0.004). In the logistic regression multivariate analysis, liver metastasis absence (Odds ratio [OR], 4.62; P = 0.019), smaller tumor diameter (OR, 7.92; P = 0.012), and tissue RAS MT in other than KRAS exon 2 (OR, 9.04; P = 0.026) were significantly related to the conversion to NeoRAS WT in ctDNA.

CONCLUSIONS

Original RAS variants in tissue, tumor diameter, and liver metastasis are related to conversion to NeoRAS WT mCRC in ctDNA.

Relationship between circulating tumour DNA and skeletal muscle stores at diagnosis of pancreatic ductal adenocarcinoma: a cross-sectional study

Low skeletal muscle index (SMI) and low skeletal muscle radiodensity (SMD) are associated with reduced survival time in pancreatic ductal adenocarcinoma (PDAC). The negative prognostic impact of low SMI and low SMD is often reported as independent of cancer stage when using traditional clinical staging tools. Therefore, this study sought to explore the relationship between a novel marker of tumour burden (circulating tumour DNA) and skeletal muscle abnormalities at diagnosis of PDAC. A retrospective cross-sectional study was conducted in patients who had plasma and tumour tissue samples stored in the Victorian Pancreatic Cancer Biobank (VPCB) at diagnosis of PDAC, between 2015 and 2020. Circulating tumour DNA (ctDNA) of patients with G12 and G13 KRAS mutations was detected and quantified. Pre-treatment SMI and SMD derived from analysis of diagnostic computed tomography imaging was tested for its association to presence and concentration of ctDNA, as well as conventional staging, and demographic variables. The study included 66 patients at PDAC diagnosis; 53% female, mean age 68.7 years (SD ± 10.9). Low SMI and low SMD were present in 69.7% and 62.1% of patients, respectively. Female gender was an independent risk factor for low SMI (OR 4.38, 95% CI 1.23-15.55, p = 0.022), and older age an independent risk factor for low SMD (OR 1.066, 95% CI 1.002-1.135, p = 0.044). No association between skeletal muscle stores and concentration of ctDNA (SMI r = - 0.163, p = 0.192; SMD r = 0.097, p = 0.438) or stage of disease according to conventional clinical staging [SMI F(3, 62) = 0.886, p = 0.453; SMD F(3, 62) = 0.717, p = 0.545] was observed. These results demonstrate that low SMI and low SMD are highly prevalent at diagnosis of PDAC, and suggest they are comorbidities of cancer rather than related to the clinical stage of disease. Future studies are needed to identify the mechanisms and risk factors for low SMI and low SMD at diagnosis of PDAC to aid screening and intervention development.

Circulating tumour DNA in colorectal cancer management

Circulating tumour DNA analysis can be performed using two opposing paradigms: tumour-informed and tumour-agnostic approaches. The first requires sequencing data from the primary tumour sample to identify tumour DNA in circulation, whereas the latter occurs without previous primary tumour genetic profiling.

Several preanalytical and laboratory considerations need to be taken into account before proceeding with in-house circulating tumour DNA analysis.

Detection of circulating tumour DNA after curative resection is associated with a significant risk of recurrence. For those with stage II disease and detectable postoperative circulating tumour DNA, administration of adjuvant chemotherapy results in a reduction in the number of patients receiving chemotherapy while providing non-inferior recurrence-free survival compared with standard histopathological decision-making algorithms.

Monitoring circulating tumour DNA during post-treatment surveillance may provide a significantly earlier diagnosis of recurrence.

Private Payer and Medicare Coverage Policies for Use of Circulating Tumor DNA Tests in Cancer Diagnostics and Treatment

BACKGROUND

Circulating tumor DNA (ctDNA) is used to select initial targeted therapy, identify mechanisms of therapeutic resistance, and measure minimal residual disease (MRD) after treatment. Our objective was to review private and Medicare coverage policies for ctDNA testing.

METHODS

Policy Reporter was used to identify coverage policies (as of February 2022) from private payers and Medicare Local Coverage Determinations (LCDs) for ctDNA tests. We abstracted data regarding policy existence, ctDNA test coverage, cancer types covered, and clinical indications. Descriptive analyses were performed by payer, clinical indication, and cancer type.

RESULTS

A total of 71 of 1,066 total policies met study inclusion criteria, of which 57 were private policies and 14 were Medicare LCDs; 70% of private policies and 100% of Medicare LCDs covered at least one indication. Among 57 private policies, 89% specified a policy for at least 1 clinical indication, with coverage for ctDNA for initial treatment selection most common (69%). Of 40 policies addressing progression, coverage was provided 28% of the time, and of 20 policies addressing MRD, coverage was provided 65% of the time. Non-small cell lung cancer (NSCLC) was the cancer type most frequently covered for initial treatment (47%) and progression (60%). Among policies with ctDNA coverage, coverage was restricted to patients without available tissue or in whom biopsy was contraindicated in 91% of policies. MRD was commonly covered for hematologic malignancies (30%) and NSCLC (25%). Of the 14 Medicare LCD policies, 64% provided coverage for initial treatment selection and progression, and 36% for MRD.

CONCLUSIONS

Some private payers and Medicare LCDs provide coverage for ctDNA testing. Private payers frequently cover testing for initial treatment, especially for NSCLC, when tissue is insufficient or biopsy is contraindicated. Coverage remains variable across payers, clinical indications, and cancer types despite inclusion in clinical guidelines, which could impact delivery of effective cancer care.

Advances in liquid biopsy-based markers in NSCLC

Lung cancer is the second most-frequently occurring cancer and the leading cause of cancer-associated deaths worldwide. Non-small cell lung cancer (NSCLC), the most common type of lung cancer is often diagnosed in middle or advanced stages and have poor prognosis. Diagnosis of disease at an early stage is a key factor for improving prognosis and reducing mortality, whereas, the currently used diagnostic tools are not sufficiently sensitive for early-stage NSCLC. The emergence of liquid biopsy has ushered in a new era of diagnosis and management of cancers, including NSCLC, since analysis of circulating tumor-derived components, such as cell-free DNA (cfDNA), circulating tumor cells (CTCs), cell-free RNAs (cfRNAs), exosomes, tumor-educated platelets (TEPs), proteins, and metabolites in blood or other biofluids can enable early cancer detection, treatment selection, therapy monitoring and prognosis assessment. There have been great advances in liquid biopsy of NSCLC in the past few years. Hence, this chapter introduces the latest advances on the clinical application of cfDNA, CTCs, cfRNAs and exosomes, with a particular focus on their application as early markers in the diagnosis, treatment and prognosis of NSCLC.

Rs11479 in Thymidine Phosphorylase Associated with Prognosis of Patients with Colorectal Cancer Who Received Capecitabine-Based Adjuvant Chemotherapy

Objective

Thymidine Phosphorylase (TYMP) gene was of potential significance in the process of colorectal cancer (CRC) development and played an important role in capecitabine metabolism. This study was to identify the association between TYMP polymorphism and prognosis of postoperative patients with CRC who received capecitabine-based adjuvant chemotherapy.

Methods

A total of 218 patients with CRC who were treated with surgical resection and capecitabine-based adjuvant chemotherapy were included in this study retrospectively. Peripheral blood and peripheral blood mononuclear cell (PBMC) specimen of the patients were collected for the genotyping of TYMP polymorphism and TYMP mRNA expression, respectively. Univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, Cox regression analysis was adopted in multivariate analysis. The mRNA expression of TYMP according to genotype status was analyzed using non-parameter test.

Results

Prevalence of rs11479 in TYMP among the 218 patients exhibited that minor allele frequency of rs11479 was 0.20 (GG 141 cases, GA 68 cases and AA 9 cases), which was in accordance with Hardy-Weinberg equilibrium (P=0.825). Association analysis suggested that the median disease-free survival (DFS) of patients with GG genotype and GA/AA genotype was 3.1 and 6.1 years, respectively (P=0.004). Furthermore, the median overall survival of patients with GG genotype and GA/AA genotype was 5.0 and 7.0 years, respectively (P=0.033). Multivariate Cox regression analysis exhibited that rs11479 polymorphism was an independent factor for DFS (HR = 1.64, P=0.009). Additionally, of the 65 PBMC specimens, mRNA expression results indicated that patients with GA/AA genotypes conferred significantly higher mRNA expression of TYMP than that of patients with GG genotype (P<0.001).

Conclusion

Polymorphism rs11479 in TYMP gene might predict the prognosis of patients with CRC who received capecitabine-based adjuvant chemotherapy through mediation of the mRNA expression of TYMP. The conclusion of this study should be validated in prospective clinical trials subsequently.

The utility of ctDNA in colorectal cancer with peritoneal metastases

BACKGROUND

The development of peritoneal metastases (PM) in patients with colorectal cancer (CRC) connotates a poor prognosis. Circulating tumour (ctDNA) is a promising tumour biomarker in the management CRC. This systematic review aimed to summarize the role of ctDNA in patients with CRC and PM.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, a systematic review of the literature until June 2022 was performed. Studies reporting on the utility of ctDNA in colorectal PM were included. A total of eight eligible studies were identified including a total of 167 patients.

RESULTS

The findings from this review suggest an evolving role for ctDNA in CRC with PM. ctDNA can be isolated from both plasma and peritoneal fluid, with peritoneal fluid preferred as the liquid biopsy of choice with higher mutation detection rates. Concordance rates between tissue and plasma/peritoneal ctDNA mutation detection can vary, but is generally high. ctDNA has a potential role in monitoring anti-EGFR treatment response and resistance, as well as in predicting future prognosis and recurrence. The detection of ctDNA in plasma of patients with isolated PM is also possibly suggestive of occult systemic disease, and patients exhibiting such ctDNA positivity may benefit from systemic treatment. Limitations to ctDNA mutation detection may include the size of peritoneal lesions, as well as the fact that PM poorly shed ctDNA.

CONCLUSION

While these findings are promising, further large-scale studies are needed to better evaluate the utility of ctDNA in this subset of patients.

Circulating Tumor DNA: The Dawn of a New Era in the Optimization of Chemotherapeutic Strategies for Metastatic Colo-Rectal Cancer Focusing on RAS Mutation

Genotyping of tumor tissues to assess RAS and BRAF V600E mutations enables us to select optimal molecularly targeted therapies when considering treatment strategies for patients with metastatic colorectal cancer. Tissue-based genetic testing is limited by the difficulty of performing repeated tests, due to the invasive nature of tissue biopsy, and by tumor heterogeneity, which can limit the usefulness of the information it yields. Liquid biopsy, represented by circulating tumor DNA (ctDNA), has attracted attention as a novel method for detecting genetic alterations. Liquid biopsies are more convenient and much less invasive than tissue biopsies and are useful for obtaining comprehensive genomic information on primary and metastatic tumors. Assessing ctDNA can help track genomic evolution and the status of alterations in genes such as RAS, which are sometimes altered following chemotherapy. In this review, we discuss the potential clinical applications of ctDNA, summarize clinical trials focusing on RAS, and present the future prospects of ctDNA analysis that could change daily clinical practice.

Identification of liquid biopsy-based mutations in colorectal cancer by targeted sequencing assays

Recently, liquid biopsy, as a promising approach was introduced for the analysis of different tumor-derived circulating markers including tumor DNA and cell free DNA (ct/cfDNA). Identification of mutations in cfDNA may allow the early detection of tumors, as well as predicting and monitoring treatment responses in a minimally invasive way. In the present study, we used commercially available gene panels to verify the mutation overlap between liquid biopsy and abnormalities detected in colorectal tumor tissue. The two panels (Archer®VariantPlex®Solid Tumor and LIQUIDPlexTM ctDNA) overlap in 23 genes, which enables a comprehensive view of tumor-plasma mutational status by next generation sequencing. We successfully analyzed 16 plasma and 16 tumor samples. We found that 87% of tumor tissues contained 44 mutations in 12 genes and 43.8% of cfDNA harbored 13 mutations in 5 genes. To verify whether the mutation pattern of the tumor DNA could be consistently detected in plasma cfDNA, we compared the alterations between cfDNA and matched tissue DNA in nine patients. Six of the 9 tumor tissues harbored mutations in TP53, KRAS or MET genes, those were not detectable by the ctDNA kit, even eventhough the exons of these genes overlap in both panels. Comparing the mutational patterns of the matched samples, we found that only one cfDNA had the same mutations (KRAS, SMAD4 and TP53) in the paired tissue. The results of the comparison between tumor tissue DNA and matched plasma cfDNA underline the importance of studying the paired solid tumor and plasma samples together.

DUSP4 inhibits autophagic cell death and apoptosis in colorectal cancer by regulating BCL2-Beclin1/Bax signaling

BACKGROUND

The DUSP4 gene plays an important role in the carcinogenesis of colorectal cancer (CRC). However, the underlying mechanism of DUSP4-regulated colorectal carcinogenesis is unknown. DUSP4 is a negative regulator of the MAP kinase (MAPK) JNK, and JNK-mediated BCL2 phosphorylation is associated with apoptosis and autophagic cell death. Our study aimed to explore the significance of BCL2 phosphorylation-dependent autophagy and apoptosis in DUSP4-promoted colorectal carcinogenesis.

METHODS

We first investigated the roles of DUSP4 in the survival of HCT116 and SW480 CRC cell lines using gene-silencing and -overexpression techniques. Next, we explored the effects of DUSP4 on the BCL2 phosphorylation, autophagy and apoptosis of HCT116 and SW480 cells. Ultimately, with the help of pharmacological inhibitors of Beclin1 and BCL2 (spautin-1 and ABT-737), the relationship between BCL2-Beclin1/Bax signaling and DUSP4-regulated autophagy, apoptosis, survival and migration in HCT116 cells was clarified.

RESULTS

Our results first confirmed the contribution of DUSP4 to the survival of HCT116 and SW480 cells. In addition, DUSP4 silencing resulted in BCL2 phosphorylation and the enhancement in autophagy and apoptosis in HCT116 and SW480 cells, while DUSP4 overexpression showed the opposite effect. Moreover, DUSP4 silencing inhibited the protein interaction between BCL2 and Beclin1 or Bax in HCT116 cells. Moreover, the survival and migration of HCT116 cells inhibited by DUSP4 silencing were blocked by autophagy inhibition with spautin-1. Notably, the survival and migration of HCT116 cells promoted by DUSP4 overexpression were reversed by ABT-737.

CONCLUSIONS

It was indicated that DUSP4 can maintain the survival and function of CRC cells by inhibiting BCL2 phosphorylation-dependent autophagic cell death and apoptosis.

Microsatellite instability assessment is instrumental for Predictive, Preventive and Personalised Medicine: status quo and outlook

A form of genomic alteration called microsatellite instability (MSI) occurs in a class of tandem repeats (TRs) called microsatellites (MSs) or short tandem repeats (STRs) due to the failure of a post-replicative DNA mismatch repair (MMR) system. Traditionally, the strategies for determining MSI events have been low-throughput procedures that typically require assessment of tumours as well as healthy samples. On the other hand, recent large-scale pan-tumour studies have consistently highlighted the potential of massively parallel sequencing (MPS) on the MSI scale. As a result of recent innovations, minimally invasive methods show a high potential to be integrated into the clinical routine and delivery of adapted medical care to all patients. Along with advances in sequencing technologies and their ever-increasing cost-effectiveness, they may bring about a new era of Predictive, Preventive and Personalised Medicine (3PM). In this paper, we offered a comprehensive analysis of high-throughput strategies and computational tools for the calling and assessment of MSI events, including whole-genome, whole-exome and targeted sequencing approaches. We also discussed in detail the detection of MSI status by current MPS blood-based methods and we hypothesised how they may contribute to the shift from conventional medicine to predictive diagnosis, targeted prevention and personalised medical services. Increasing the efficacy of patient stratification based on MSI status is crucial for tailored decision-making. Contextually, this paper highlights drawbacks both at the technical level and those embedded deeper in cellular/molecular processes and future applications in routine clinical testing.

Circulating tumor nucleic acids: biology, release mechanisms, and clinical relevance

BACKGROUND

Despite advances in early detection and therapies, cancer is still one of the most common causes of death worldwide. Since each tumor is unique, there is a need to implement personalized care and develop robust tools for monitoring treatment response to assess drug efficacy and prevent disease relapse.

MAIN BODY

Recent developments in liquid biopsies have enabled real-time noninvasive monitoring of tumor burden through the detection of molecules shed by tumors in the blood. These molecules include circulating tumor nucleic acids (ctNAs), comprising cell-free DNA or RNA molecules passively and/or actively released from tumor cells. Often highlighted for their diagnostic, predictive, and prognostic potential, these biomarkers possess valuable information about tumor characteristics and evolution. While circulating tumor DNA (ctDNA) has been in the spotlight for the last decade, less is known about circulating tumor RNA (ctRNA). There are unanswered questions about why some tumors shed high amounts of ctNAs while others have undetectable levels. Also, there are gaps in our understanding of associations between tumor evolution and ctNA characteristics and shedding kinetics. In this review, we summarize current knowledge about ctNA biology and release mechanisms and put this information into the context of tumor evolution and clinical utility.

CONCLUSIONS

A deeper understanding of the biology of ctDNA and ctRNA may inform the use of liquid biopsies in personalized medicine to improve cancer patient outcomes.

A Micro-Costing Framework for Circulating Tumor DNA Testing in Dutch Clinical Practice

Circulating tumor DNA (ctDNA) is a promising new biomarker with multiple potential applications in cancer care. Estimating total cost of ctDNA testing is necessary for reimbursement and implementation, but challenging because of variations in workflow. We aimed to develop a micro-costing framework for consistent cost calculation of ctDNA testing. First, the foundation of the framework was built, based on the complete step-wise diagnostic workflow of ctDNA testing. Second, the costing method was set up, including costs for personnel, materials, equipment, overhead, and failures. Third, the framework was evaluated by experts and applied to six case studies, including PCR-, mass spectrometry-, and next-generation sequencing-based platforms, from three Dutch hospitals. The developed ctDNA micro-costing framework includes the diagnostic workflow from blood sample collection to diagnostic test result. The framework was developed from a Dutch perspective and takes testing volume into account. An open access tool is provided to allow for laboratory-specific calculations to explore the total costs of ctDNA testing specific workflow parameters matching the setting of interest. It also allows to straightforwardly assess the impact of alternative prices or assumptions on the cost per sample by simply varying the input parameters. The case studies showed a wide range of costs, from €168 to €7638 ($199 to $9124) per sample, and generated information. These costs are sensitive to the (coverage of) platform, setting, and testing volume.

Integrated analysis of necroptosis-related genes for evaluating immune infiltration and colon cancer prognosis

Background

Colon cancer (CC) is the second most common gastrointestinal malignancy. About one in five patients have already developed distant metastases at the time of initial diagnosis, and up to half of patients develop distant metastases from initial local disease, which leads to a poor prognosis for CC patients. Necroptosis plays a key role in promoting tumor growth in different tumors. The purpose of this study was to construct a prognostic model composed of necroptosis-related genes (NRGs) in CC.

Methods

The Cancer Genome Atlas was used to obtain information on clinical features and gene expression. Gene expression differential analysis, weighted gene co-expression network analysis, univariate Cox regression analysis and the least absolute shrinkage and selection operator regression algorithm were utilized to identify prognostic NRGs. Thereafter, a risk scoring model was established based on the NRGs. Biological processes and pathways were identified by gene ontology and gene set enrichment analysis (GSEA). Further, protein-protein interaction and ceRNA networks were constructed based on mRNA-miRNA-lncRNA. Finally, the effect of necroptosis related risk score on different degrees of immune cell infiltration was evaluated.

Results

CALB1, CHST13, and SLC4A4 were identified as NRGs of prognostic significance and were used to establish a risk scoring model. The time-dependent receiver operating characteristic curve analysis revealed that the model could well predict the 1-, 3-, and 5-year overall survival (OS). Further, GSEA suggested that the NRGs may participate in biological processes, such as the WNT pathway and JAK-Stat pathway. Eight key hub genes were identified, and a ceRNA regulatory network, which comprised 1 lncRNA, 5 miRNAs and 3 mRNAs, was constructed. Immune infiltration analysis revealed that the low-risk group had significantly higher immune-related scores than the high-risk group. A nomogram of the model was constructed based on the risk score, necroptosis, and the clinicopathological features (age and TNM stage). The calibration curves implied that the model was effective at predicting the 1-, 3-, and 5-year OS of CC.

Conclusion

Our NRG-based prognostic model can assist in the evaluation of CC prognosis and the identification of therapeutic targets for CC.

Predictive biomarkers of colon cancer immunotherapy: Present and future

Immunotherapy has revolutionized colon cancer treatment. Immune checkpoint inhibitors (ICIs) have shown clinical benefits for colon cancer patients, especially those with high microsatellite instability (MSI-H). In 2020, the US Food and Drug Administration (FDA)-approved ICI pembrolizumab as the first-line treatment for metastatic MSI-H colon cancer patients. Additionally, neoadjuvant immunotherapy has presented efficacy in treating early-stage colon cancer patients. Although MSI has been thought of as an effective predictive biomarker for colon cancer immunotherapy, only a small proportion of colon cancer patients were MSI-H, and certain colon cancer patients with MSI-H presented intrinsic or acquired resistance to immunotherapy. Thus, further search for predictive biomarkers to stratify patients is meaningful in colon cancer immunotherapy. Except for MSI, other biomarkers, such as PD-L1 expression level, tumor mutation burden (TMB), tumor-infiltrating lymphocytes (TILs), certain gut microbiota, ctDNA, and circulating immune cells were also proposed to be correlated with patient survival and ICI efficacy in some colon cancer clinical studies. Moreover, developing new diagnostic techniques helps identify accurate predictive biomarkers for colon cancer immunotherapy. In this review, we outline the reported predictive biomarkers in colon cancer immunotherapy and further discuss the prospects of technological changes for biomarker development in colon cancer immunotherapy.

Clinical Applications of Liquid Biopsy in Colorectal Cancer Screening: Current Challenges and Future Perspectives

Colorectal cancer (CRC) represents the third most prevalent cancer worldwide and a leading cause of mortality among the population of western countries. However, CRC is frequently a preventable malignancy due to various screening tests being available. While failing to obtain real-time data, current screening methods (either endoscopic or stool-based tests) also require disagreeable preparation protocols and tissue sampling through invasive procedures, rendering adherence to CRC screening programs suboptimal. In this context, the necessity for novel, less invasive biomarkers able to identify and assess cancer at an early stage is evident. Liquid biopsy comes as a promising minimally invasive diagnostic tool, able to provide comprehensive information on tumor heterogeneity and dynamics during carcinogenesis. This review focuses on the potential use of circulating tumor cells (CTCs), circulating nucleic acids (CNAs) and extracellular vesicles as emerging liquid biopsy markers with clinical application in the setting of CRC screening. The review also examines the opportunity to implement liquid biopsy analysis during everyday practice and provides highlights on clinical trials researching blood tests designed for early cancer diagnosis. Additionally, the review explores potential applications of liquid biopsies in the era of immunotherapy.

Circulating Tumor DNA as a Marker of Minimal Residual Disease After Radical Resection of Colorectal Liver Metastases

PURPOSE

Prognostic tools to estimate the risk of relapse for patients with liver-limited metastatic colorectal cancer (LL-mCRC) undergoing resection with curative intent are needed. Circulating tumor DNA (ctDNA) as a surrogate of postsurgical minimal residual disease is a promising marker in localized CRC. We explored the role of postoperative ctDNA as a marker of minimal residual disease in patients with radically resected LL-mCRC.

MATERIALS AND METHODS

Seventy-six patients with LL-mCRC were retrospectively included. DNA from tumor tissue was sequenced, and one somatic mutation was then assessed by digital droplet polymerase chain reaction in plasma samples collected after surgery to identify the persistence of ctDNA. Relapse-free survival and postresection overall survival were compared between patients with positive vs negative postoperative ctDNA.

RESULTS

ctDNA was found in 39 (51%) of 76 patients with LL-mCRC. At a median follow-up of 77 months, 33 of 39 ctDNA-positive patients and 20 of 37 ctDNA-negative patients experienced disease relapse ( P = .008). ctDNA-positive patients reported significantly shorter RFS than ctDNA-negative ones (median RFS 12.7 v 27.4 months hazard ratio, 2.09, P = .008). In the multivariable model including other prognostic covariates, this association was still significant ( P = .046) and a trend toward shorter overall survival among ctDNA-positive patients was reported (hazard ratio, 1.65, P = .183).

CONCLUSION

The detection of postsurgical ctDNA is an independent negative prognostic marker and identifies patients at high risk of relapse after liver metastases resection.

Integrated Tissue and Blood miRNA Expression Profiles Identify Novel Biomarkers for Accurate Non-Invasive Diagnosis of Breast Cancer: Preliminary Results and Future Clinical Implications

We aimed to identify miRNAs that were closely related to breast cancer (BRCA). By integrating several methods including significance analysis of microarrays, fold change, Pearson’s correlation analysis, t test, and receiver operating characteristic analysis, we developed a decision-tree-based scoring algorithm, called Optimized Scoring Mechanism for Primary Synergy MicroRNAs (O-PSM). Five synergy miRNAs (hsa-miR-139-5p, hsa-miR-331-3p, hsa-miR-342-5p, hsa-miR-486-5p, and hsa-miR-654-3p) were identified using O-PSM, which were used to distinguish normal samples from pathological ones, and showed good results in blood data and in multiple sets of tissue data. These five miRNAs showed accurate categorization efficiency in BRCA typing and staging and had better categorization efficiency than experimentally verified miRNAs. In the Protein-Protein Interaction (PPI) network, the target genes of hsa-miR-342-5p have the most regulatory relationships, which regulate carcinogenesis proliferation and metastasis by regulating Glycosaminoglycan biosynthesis and the Rap1 signaling pathway. Moreover, hsa-miR-342-5p showed potential clinical application in survival analysis. We also used O-PSM to generate an R package uploaded on github (SuFei-lab/OPSM accessed on 22 October 2021). We believe that miRNAs included in O-PSM could have clinical implications for diagnosis, prognostic stratification and treatment of BRCA, proposing potential significant biomarkers that could be utilized to design personalized treatment plans in BRCA patients in the future.

Modulating p-AMPK/mTOR Pathway of Mitochondrial Dysfunction Caused by MTERF1 Abnormal Expression in Colorectal Cancer Cells

Human mitochondrial transcription termination factor 1 (MTERF1) has been demonstrated to play an important role in mitochondrial gene expression regulation. However, the molecular mechanism of MTERF1 in colorectal cancer (CRC) remains largely unknown. Here, we found that MTERF1 expression was significantly increased in colon cancer tissues compared with normal colorectal tissue by Western blotting, immunohistochemistry, and tissue microarrays (TMA). Overexpression of MTERF1 in the HT29 cell promoted cell proliferation, migration, invasion, and xenograft tumor formation, whereas knockdown of MTERF1 in HCT116 cells appeared to be the opposite phenotype to HT29 cells. Furthermore, MTERF1 can increase mitochondrial DNA (mtDNA) replication, transcription, and protein synthesis in colorectal cancer cells; increase ATP levels, the mitochondrial crista density, mitochondrial membrane potential, and oxygen consumption rate (OCR); and reduce the ROS production in colorectal cancer cells, thereby enhancing mitochondrial oxidative phosphorylation (OXPHOS) activity. Mechanistically, we revealed that MTERF1 regulates the AMPK/mTOR signaling pathway in cancerous cell lines, and we also confirmed the involvement of the AMPK/mTOR signaling pathway in both xenograft tumor tissues and colorectal cancer tissues. In summary, our data reveal an oncogenic role of MTERF1 in CRC progression, indicating that MTERF1 may represent a new therapeutic target in the future.

Application progress of liquid biopsy in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors globally. Guiding the individualized treatment of GC is the focus of research. Obtaining representative biological samples to study the biological characteristics of GC is the focus of diagnosis and treatment of GC. Liquid biopsy technology can use high-throughput sequencing technology to detect biological genetic information in blood. Compared with traditional tissue biopsy, liquid biopsy can determine the dynamic changes of tumor. As a noninvasive auxiliary diagnostic method, liquid biopsy can provide diagnostic and prognostic information concerning the progression of the disease. Liquid biopsy includes circulating tumor cells, circulating tumor DNA, circulating tumor RNA, tumor educated platelets, exosomes, and cytokines. This article describes the classification of liquid biopsy and its application value in the occurrence, development, and therapeutic efficacy of GC.

Multicentre single-arm phase II trial evaluating the safety and effiCacy of Panitumumab and iRinOtecan in NeoRAS Wild-type mEtaStatic colorectal cancer patientS (C-PROWESS trial): study protocol

INTRODUCTION

A new concept of 'NeoRAS wild-type (WT)', which means conversion of RAS status from RAS mutant to RAS WT after treatment, has been reported. Previous observational and proof-of-concept studies have demonstrated the efficacy of epidermal growth factor receptor inhibitors in patients with NeoRAS WT metastatic colorectal cancer (mCRC). Moreover, posthoc biomarker analyses of these studies have suggested that not only the RAS status in the circulating tumour DNA (ctDNA) but also other gene mutational status may be useful as biomarkers of epidermal growth factor receptor inhibitors for NeoRAS WT mCRC.

METHODS AND ANALYSIS

This trial is a multicentre, single-arm, phase II trial to assess the efficacy and safety of panitumumab plus irinotecan therapy for patients with NeoRAS mCRC. The key eligibility criteria include RAS mutant mCRC initially proven in tumour tissue refractory or intolerant to fluoropyrimidine, oxaliplatin and irinotecan; RAS WT in ctDNA (defined as plasma mutant allele frequencies of all RAS ≤0.1%) within 28 days before enrolment and Eastern Cooperative Oncology Group performance status ≤2. The primary endpoint is the response rate. The target sample size is 30 patients. Biomarker analyses are planned to be performed using next-generation sequencing-based ctDNA analysis.

ETHICS AND DISSEMINATION

This study was approved by the certified review board of National Cancer Center Hospital. The main results of the trial will be presented in international meetings and in medical journals.

TRIAL REGISTRATION NUMBER

s031210565.

Liquid Biopsies in Colorectal Liver Metastases: Towards the Era of Precision Oncologic Surgery

Tumor mutational analysis has been incorporated into the management of patients with CRLM since it can provide valuable prognostic information as well as guide peri-operative systemic treatment. Unlike tumor biopsy, liquid biopsy has emerged as a promising, non-invasive alternative that can detect cell-derived markers from a variety of body fluids and might better characterize all subclones present at a specific time point and allow sequential monitoring of disease evolution. Although not currently considered standard of care, an increasing number of cancer centers are nowadays routinely using liquid biopsies in the treatment of CRLM patients with promising results. The current review provides an overview of liquid biopsies in cancer therapeutics and focuses on the application of this relatively new approach on patients with CRLM.

Comprehensive exploration of tumor immune microenvironment feature and therapeutic response in colorectal cancer based on a novel immune-related long non-coding RNA prognostic signature

Colorectal cancer (CRC) is one of the most common malignant tumors with a high incidence rate and mortality. LncRNA is an important regulator of the immune system. It is of great significance to study immune-related lncRNAs (IR-lncRNAs) for CRC. In this study, we screened IR-lncRNAs differentially expressed in normal and CRC tissues, and Univariate Cox regression and the Least Absolute Shrinkage and Selection Operator were applied to construct IR-lncRNA prognostic signature in TCGA training dataset, and its predictive capability for the prognosis of CRC patients was verified in GSE39582 validation dataset. The novel signature was identified as an independent predictor of prognosis in CRC patients. In addition, the signature could accurately predict the feature of the immune microenvironment and therapeutic response in CRC patients. The CMap database was adopted to screen for small molecule candidate drugs that can reverse and treat high-risk CRC patients. Finally, the expression of six IR-lncRNAs were verified by qRT-PCR in clinical specimens from our patient cohort. In conclusion, we construct an IR-lncRNA prognostic signature, which is a powerful biomarker of CRC and can accurately predict the prognosis, immune microenvironment feature, and therapeutic response of CRC patients.

Liquid biopsy for KRAS, NRAS and BRAF mutation testing in advanced colorectal cancer patients: the Argentinean experience

Objective: To analyze the frequency of KRAS, NRAS and BRAF hotspot mutations in circulating tumor DNA (ctDNA) from patients with metastatic colorectal cancer (mCRC). Methods: Observational, descriptive and retrospective study in mCRC patients with available ctDNA-based genotype of KRAS, NRAS and BRAF. Results: The frequencies of plasma mutations for KRAS, NRAS and BRAF were 34% (± 7), 4% (± 3) and 4% (± 3), respectively. Median overall survival of plasma-tested RAS/BRAF-mutated patients was 26.6 months (95% CI: 14.4-not estimable [NE]), while RAS/BRAF wild-type patients did not reach the median survival during follow-up. Median progression-free survival for RAS/BRAF wild-type and RAS/BRAF-mutated patients was 12 (95% CI: 7-NE) and 4 months (95% CI: 4-NE), respectively. Conclusion: Our work supports the utility of KRAS, NRAS and BRAF analysis in liquid biopsy from mCRC patients.

Liquid Biopsy and Circulating Biomarkers for the Diagnosis of Precancerous and Cancerous Oral Lesions

Oral cancer is one of the most common malignancies worldwide, accounting for 2% of all cases annually and 1.8% of all cancer deaths. To date, tissue biopsy and histopathological analyses are the gold standard methods for the diagnosis of oral cancers. However, oral cancer is generally diagnosed at advanced stages with a consequent poor 5-year survival (~50%) due to limited screening programs and inefficient physical examination strategies. To address these limitations, liquid biopsy is recently emerging as a novel minimally invasive tool for the early identification of tumors as well as for the evaluation of tumor heterogeneity and prognosis of patients. Several studies have demonstrated that liquid biopsy in oral cancer could be useful for the detection of circulating biomarkers including circulating tumor DNA (ctDNA), microRNAs (miRNAs), proteins, and exosomes, thus improving diagnostic strategies and paving the way to personalized medicine. However, the application of liquid biopsy in oral cancer is still limited and further studies are needed to better clarify its clinical impact. The present manuscript aims to provide an updated overview of the potential use of liquid biopsy as an additional tool for the management of oral lesions by describing the available methodologies and the most promising biomarkers.