Circulating tumor DNA dynamics and recurrence risk in patients undergoing curative intent resection of colorectal cancer liver metastases: A prospective cohort study

Circulating Tumor DNA Analysis Guiding Adjuvant Therapy in Stage II Colon Cancer

BACKGROUND

The role of adjuvant chemotherapy in stage II colon cancer continues to be debated. The presence of circulating tumor DNA (ctDNA) after surgery predicts very poor recurrence-free survival, whereas its absence predicts a low risk of recurrence. The benefit of adjuvant chemotherapy for ctDNA-positive patients is not well understood.

METHODS

We conducted a trial to assess whether a ctDNA-guided approach could reduce the use of adjuvant chemotherapy without compromising recurrence risk. Patients with stage II colon cancer were randomly assigned in a 2:1 ratio to have treatment decisions guided by either ctDNA results or standard clinicopathological features. For ctDNA-guided management, a ctDNA-positive result at 4 or 7 weeks after surgery prompted oxaliplatin-based or fluoropyrimidine chemotherapy. Patients who were ctDNA-negative were not treated. The primary efficacy end point was recurrence-free survival at 2 years. A key secondary end point was adjuvant chemotherapy use.

RESULTS

Of the 455 patients who underwent randomization, 302 were assigned to ctDNA-guided management and 153 to standard management. The median follow-up was 37 months. A lower percentage of patients in the ctDNA-guided group than in the standard-management group received adjuvant chemotherapy (15% vs. 28%; relative risk, 1.82; 95% confidence interval [CI], 1.25 to 2.65). In the evaluation of 2-year recurrence-free survival, ctDNA-guided management was noninferior to standard management (93.5% and 92.4%, respectively; absolute difference, 1.1 percentage points; 95% CI, -4.1 to 6.2 [noninferiority margin, -8.5 percentage points]). Three-year recurrence-free survival was 86.4% among ctDNA-positive patients who received adjuvant chemotherapy and 92.5% among ctDNA-negative patients who did not.

CONCLUSIONS

A ctDNA-guided approach to the treatment of stage II colon cancer reduced adjuvant chemotherapy use without compromising recurrence-free survival. (Supported by the Australian National Health and Medical Research Council and others; DYNAMIC Australian New Zealand Clinical Trials Registry number, ACTRN12615000381583.).

Effect of Co-mutation of RAS and TP53 on Postoperative ctDNA Detection and Early Recurrence after Hepatectomy for Colorectal Liver Metastases

BACKGROUND

Circulating tumor DNA (ctDNA) is a promising biomarker for patients undergoing hepatectomy for colorectal liver metastases (CLM). We hypothesized that post-hepatectomy ctDNA detection would identify patients at highest risk for early recurrence of CLM.

STUDY DESIGN

Patients with CLM who underwent curative-intent hepatectomy with ctDNA analysis within 180 days postoperatively (1/2013 and 6/2020) were included. Tissue somatic mutations and ctDNA analyses were performed by next-generation sequencing panels. Survival analyses determined factors associated with clinical recurrence 1 year or earlier after hepatectomy. Patients with primary tumors in situ and without 1-year follow-up were excluded. Median follow-up was 28.3 months.

RESULTS

Of 105 patients, 32 (30%) were ctDNA positive (ctDNA+) after curative-intent hepatectomy. Compared with ctDNA-negative patients, ctDNA+ patients had multiple CLM (84% vs 55%, p = 0.002) and co-mutated RAS/TP53 (47% vs 23%, p = 0.018). Multiple CLM (odds ration (OR), 5.43; p = 0.005) and co-mutated RAS/TP53 (OR, 3.30; p = 0.019) were independently associated with post-hepatectomy ctDNA. Although perioperative carcinoembryonic antigen levels were not prognostic, postoperative ctDNA+ (hazard ratio (HR), 2.04; p = 0.011) and extrahepatic disease (HR, 2.45, p = 0.004) were independently associated with worse recurrence-free survival. After adjusting for extrahepatic disease, preoperative chemotherapy, multiple CLM, tumor viability of 50% or greater, and co-mutated RAS/TP53, ctDNA+ within 180 days was the only independent risk factor for recurrence 1 year or earlier after hepatectomy (94% vs 49%; HR, 11.8; p = 0.003).

CONCLUSION

Postoperative ctDNA detection is associated with early recurrence 1 year or earlier after curative-intent hepatectomy for CLM, and RAS/TP53 co-mutations result in a more than 3-fold increased risk for postoperative ctDNA positivity. This highlights the complementary effect of tumor tissue and circulating mutational profiling for patients with CLM.

Liquid biopsy at the frontier of detection, prognosis and progression monitoring in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide and a leading cause of carcinogenic death. To date, surgical resection is regarded as the gold standard by the operator for clinical decisions. Because conventional tissue biopsy is invasive and only a small sample can sometimes be obtained, it is unable to represent the heterogeneity of tumor or dynamically monitor tumor progression. Therefore, there is an urgent need to find a new minimally invasive or noninvasive diagnostic strategy to detect CRC at an early stage and monitor CRC recurrence. Over the past years, a new diagnostic concept called “liquid biopsy” has gained much attention. Liquid biopsy is noninvasive, allowing repeated analysis and real-time monitoring of tumor recurrence, metastasis or therapeutic responses. With the advanced development of new molecular techniques in CRC, circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), exosomes, and tumor-educated platelet (TEP) detection have achieved interesting and inspiring results as the most prominent liquid biopsy markers. In this review, we focused on some clinical applications of CTCs, ctDNA, exosomes and TEPs and discuss promising future applications to solve unmet clinical needs in CRC patients.

Tumour-agnostic circulating tumour DNA analysis for improved recurrence surveillance after resection of colorectal liver metastases: A prospective cohort study

PURPOSE

Nearly 50% of patients recur within two years after curatively intended resection of colorectal cancer liver metastasis (CRLM). The optimal surveillance strategy is unknown due to the lack of evidence. Here, we explored the potential for improving postoperative CRLM surveillance by performing serial circulating tumour DNA (ctDNA) assessments parallel to standard-of-care surveillance.

EXPERIMENTAL DESIGN

499 prospectively collected serial plasma samples from 96 patients undergoing CRLM resection were analysed using the tumour-agnostic methylation multiplex droplet-digital PCR test 'TriMeth'.

RESULTS

Patients with ctDNA postoperatively or post adjuvant chemotherapy experienced a significant lower recurrence-free survival than patients without ctDNA (hazard ratio (HR) 4.5; P < 0.0001 and HR 8.4, P < 0.0001). ctDNA status was a stronger predictor of recurrence than standard clinical risk factors and carcinoembryonic antigen. Serial TriMeth analysis detected ctDNA before radiological recurrence in 55.6% of ctDNA-positive patients, with up to 10.6 months lead-time (median 3.1 months). During surveillance, 24% of patients had inconclusive CT scans, which was associated with a significant delay in recurrence diagnosis (median 3.5 months versus 1.0 month, P < 0.0001). Uniquely, ctDNA status at the time of inconclusive CT scans predicted recurrence with positive and negative predictive values of 100%, and 75% (P = 0.0003). Serial TriMeth analysis allowed ctDNA growth rate assessment and revealed that fast ctDNA growth was associated with poor overall survival (HR: 1.6, P = 0.0052).

CONCLUSIONS

Serial postoperative ctDNA analysis has a strong prognostic value and is more sensitive for recurrence detection than standard-of-care CRLM surveillance tools. Altogether, TriMeth provides several opportunities for improving postoperative surveillance of CRLM patients.

Utility of Cell-Free DNA Detection in Transplant Oncology

Simple Summary

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-liver transplant stages, and evaluate transplant rejection. The use of ctDNA to evaluate transplant rejection has been extensively studied in non-hepatocellular carcinoma (HCC) diseases. Emerging studies have also investigated the use of ctDNA detection in evaluating HCC tumor burden pre-and post-surgery as well as transplant rejection. However, extensive studies still need to be conducted to evaluate the role of ctDNA detection in the medical management of transplant oncology patients.

Abstract

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. A critical concept that must be addressed to ensure the successful application of transplant oncology to patient care is efficient monitoring of tumor burden pre-and post-transplant and transplant rejection. Cell-free DNA (cfDNA) detection has emerged as a vital tool in revolutionizing the management of cancer patients who undergo organ transplantation. The advances in cfDNA technology have provided options to perform a pre-transplant evaluation of minimal residual disease (MRD) and post-transplant evaluation of cancer recurrence and transplant rejection. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-transplant stages, and evaluate transplant rejection.

Circulating tumor DNA for prognosis assessment and postoperative management after curative-intent resection of colorectal liver metastases

The recurrence rate of colorectal liver metastases (CRLM) patients treated with curative intent is above 50%. Standard of care surveillance includes intensive computed tomographic (CT) imaging as well as carcinoembryonic antigen (CEA) measurements. Nonetheless, relapse detection often happens too late to resume curative treatment. This longitudinal cohort study enrolled 115 patients with plasma samples (N = 439) prospectively collected before surgery, postoperatively at day 30 and every third month for up to 3 years. Droplet digital PCR (ddPCR) was used to monitor serial plasma samples for somatic mutations. Assessment of ctDNA status either immediately after surgery, or serially during surveillance, stratified the patients into groups of high and low recurrence risk (hazard ratio [HR], 7.6; 95% CI, 3.0-19.7; P < .0001; and HR, 4.3; 95% CI, 2.3-8.1; P < .0001, respectively). The positive predictive value (PPV) of ctDNA was 100% in all postoperative analyses. In multivariable analyses, postoperative ctDNA status was the only consistently significant risk marker associated with relapse (P < .0001). Indeterminate CT findings were observed for 30.8% (21/68) of patients. All patients (9/21) that were ctDNA positive at the time of the indeterminate CT scan later relapsed, contrasting 42.6% (5/12) of those ctDNA negative (P = .0046). Recurrence diagnoses in patients with indeterminate CT findings were delayed (median 2.8 months, P < .0001). ctDNA status is strongly associated with detection of minimal residual disease and early detection of relapse. Furthermore, ctDNA status can potentially contribute to clinical decision-making in case of indeterminate CT findings, reducing time-to-intervention.

Circulating DNA in patients undergoing loco-regional treatment of colorectal cancer metastases: a systematic review and meta-analysis

Background

Loco-regional treatment strategies of colorectal cancer (CRC) metastases are evolving, but biological markers that can benefit patients and assist physicians in clinical decisions are lacking. The primary objective of this systematic review and meta-analysis is to investigate the current knowledge on circulating DNA and its clinical utility in predicting outcomes in patients undergoing loco-regional treatment of CRC metastases.

Methods

A systematic search of PubMed, Embase, and Cochrane Central Register of Controlled Trials was conducted on March 22, 2022. We included studies on patients undergoing loco-regional treatment of CRC metastases reporting the predictive or prognostic value of circulating DNA in the blood. Hazard ratios (HR) were pooled in separate random-effects meta-analyses to investigate if pre- or post-ablation measurements of circulating DNA were associated with survival. The risk of bias was assessed according to the Quality in Prognosis Studies tool.

Results

Twenty-eight studies with 2868 patients were included, of which 16 studies were eligible for meta-analyses. As expected in this new research field, a majority of included studies (n = 21/28) had a high risk of bias in at least one domain. Circulating DNA above the cutoff in a plasma sample taken before loco-regional treatment was associated with a short recurrence-free survival [pooled HR = 2.8, 95% confidence interval (CI) 1.4-5.7, n = 162] and overall survival (pooled HR = 4.7, 95% CI 1.1-20.6, n = 105). Circulating DNA above the cutoff in a plasma sample taken after loco-regional treatment was associated with a short recurrence-free survival (pooled HR = 4.5, 95% CI 3.4-6.1, n = 569) and overall survival (pooled HR = 7.5, 95% CI 2.0-27.3, n = 161). There was limited data on the association between dynamics in circulating DNA and outcome.

Conclusions

Measurements of circulating DNA can be valuable when selecting and monitoring patients undergoing loco-regional treatment of CRC metastases. Studies designed to investigate the true clinical utility of circulating DNA in the context of various ablation modalities are warranted.The review has been registered at PROSPERO (ID: CRD42022320032).

Liquid biopsies for residual disease and recurrence

Detection of minimal residual disease in patients with cancer, who are in complete remission with no cancer cells detectable, has the potential to improve recurrence-free survival through treatment selection. Studies analyzing circulating tumor DNA (ctDNA) in patients with solid tumors suggest the potential to accurately predict and detect relapse, enabling treatment strategies that may improve clinical outcomes. Over the past decade, assays for ctDNA detection in plasma samples have steadily increased in sensitivity and specificity. These are applied for the detection of residual disease after treatment and for earlier detection of recurrence. Novel clinical trials are now assessing how assays for "residual disease and recurrence" (RDR) may influence current treatment paradigms and potentially change the landscape of risk classification for cancer recurrence. In this review, we appraise the progress of RDR detection using ctDNA and consider the emerging role of liquid biopsy in the monitoring and management of solid tumors.

A systematic review and meta-analysis of the association between circulating tumor DNA (ctDNA) and prognosis in pancreatic cancer

Pancreatic cancer is a deadly disease with limited therapeutic options. Several strategies are being investigated to improve disease management, including the early diagnosis of recurrences and treatment tailoring by better prognosis estimation. Circulating tumor DNA (ctDNA) could be a promising tool in this regard, although the data is limited. Therefore, we conducted a systemical review and meta-analysis of the published studies on the association of ctDNA and survival outcomes in pancreatic cancer. In the pooled analysis, positive preoperative or postoperative ctDNA was associated with lower RFS/PFS (HR: 2.27, 95 % CI: 1.59-3.24, p < 0.001) and OS (HR: 2.04, 95 % CI: 1.29-3.21, p = 0.002) in localized pancreatic cancer. Similarly, positive baseline ctDNA was associated with lower RFS/PFS (HR: 2.61, 95 % CI: 1.94-3.51, p < 0.001) and OS (HR: 2.41, 95 % CI: 1.74-3.34, p < 0.001) in advanced pancreatic cancer. In conclusion, ctDNA could be a promising tool to individualize treatment planning and to improve outcomes in pancreatic cancer.

Circulating Tumor DNA and Minimal Residual Disease (MRD) in Solid Tumors: Current Horizons and Future Perspectives

Circulating tumor DNA (ctDNA) is cell-free DNA (cfDNA) fragment in the bloodstream that originates from malignant tumors or circulating tumor cells. Recently, ctDNA has emerged as a promising non-invasive biomarker in clinical oncology. Analysis of ctDNA opens up new avenues for individualized cancer diagnosis and therapy in various types of tumors. Evidence suggests that minimum residual disease (MRD) is closely associated with disease recurrence, thus identifying specific genetic and molecular alterations as novel MRD detection targets using ctDNA has been a research focus. MRD is considered a promising prognostic marker to identify individuals at increased risk of recurrence and who may benefit from treatment. This review summarizes the current knowledge of ctDNA and MRD in solid tumors, focusing on the potential clinical applications and challenges. We describe the current state of ctDNA detection methods and the milestones of ctDNA development and discuss how ctDNA analysis may be an alternative for tissue biopsy. Additionally, we evaluate the clinical utility of ctDNA analysis in solid tumors, such as recurrence risk assessment, monitoring response, and resistance mechanism analysis. MRD detection aids in assessing treatment response, patient prognosis, and risk of recurrence. Moreover, this review highlights current advancements in utilizing ctDNA to monitor the MRD of solid tumors such as lung cancer, breast cancer, and colon cancer. Overall, the clinical application of ctDNA-based MRD detection can assist clinical decision-making and improve patient outcomes in malignant tumors.

ctDNA: An emerging neoadjuvant biomarker in resectable solid tumors

Christopher Abbosh and Charles Swanton discuss circulating tumor DNA as a potential biomarker for neoadjuvant treatment response in solid tumors.

Cancer Special Issue: Early detection and minimal residual disease

Beryne Odeny discusses PLOS Medicine's Special Issue on early cancer detection and minimal residual disease.

Clinical Applications of Minimal Residual Disease Assessments by Tumor-Informed and Tumor-Uninformed Circulating Tumor DNA in Colorectal Cancer

Simple Summary

Circulating tumor DNA, or ctDNA, are fragments of tumor DNA that can be detected in the blood of patients with colorectal cancer. Measuring ctDNA levels in the blood has shown the potential to provide important information that can be helpful in the clinical care of patients with colorectal cancer. For example, in patients with colon cancer that has been removed by surgery, measuring ctDNA in the blood can predict the likelihood of cancer recurrence, while in those with metastatic colorectal cancer, measuring ctDNA can inform the clinician whether chemotherapy is effective at earlier timepoints than currently available tests. In this review, we discuss the results from ongoing studies describing the utility of ctDNA measurements across all stages of colorectal cancer. We also discuss the various clinical scenarios that ctDNA may have the most immediate impact in colorectal cancer management.

Abstract

Emerging data suggest that circulating tumor DNA (ctDNA) can detect colorectal cancer (CRC)-specific signals across both non-metastatic and metastatic settings. With the development of multiple platforms, including tumor-informed and tumor-agnostic ctDNA assays and demonstration of their provocative analytic performance to detect minimal residual disease, there are now ongoing, phase III randomized clinical trials to evaluate their role in the management paradigm of CRC. In this review, we highlight landmark studies that have formed the basis for ongoing studies on the clinically applicability of plasma ctDNA assays in resected, stage I–III CRC and metastatic CRC. We discuss clinical settings by which ctDNA may have the most immediate impact in routine clinical practice. These include the potential for ctDNA to (1) guide surveillance and intensification or de-intensification strategies of adjuvant therapy in resected, stage I–III CRC, (2) predict treatment response to neoadjuvant therapy in locally advanced rectal cancer inclusive of total neoadjuvant therapy (TNT), and (3) predict response to systemic and surgical therapies in metastatic disease. We end by considering clinical variables that can influence our ability to reliably interpret ctDNA dynamics in the clinic.

Predictive Nomogram for the Prediction of Early Recurrence of Colorectal Cancer

Aim

The prognosis of colorectal cancer (CRC) individuals after curative resection is not satisfactory due to the early recurrence. We sought to identify the affecting features of early recurrence in CRC patients.

Methods

A total of 3500 CRC patients underwent curative resection were retrospectively incorporated into our study. Among them, 246 patients exhibited tumor recurrence: 121 had early recurrence (≤1 year after operation) and 125 had late recurrence (>1 year after operation). A total of 246 CRC patients with recurrence were randomly assigned into the training group (N=177) or validation group (N=69) based on the ratio of 7:3. LASSO COX regression and support vector machine (SVM) were utilized to screen for the significant clinical indexes associated with the presence of early recurrence. Recurrent nomogram was created based on the above informative parameters to predict the probability of early recurrence.

Results

Proportion of advanced TNM stage, platelet count, systemic immune-inflammation index (SII), mean corpuscular hemoglobin concentration (MCHC), CA-199, CA-125, lactate dehydrogenase, total bile acid (TBA), urea nitrogen were significantly higher in early recurrence group compared with that in late recurrence group. Results from LASSO COX regression and support vector machine (SVM) revealed that TNM stage, CA-199, CA125, SII and TBA were strong predictors for the presence of early recurrence among postoperative CRC patients in the training group. The recurrent nomogram based on the five predictors exhibited good predictive performance as calculated by C-index (0.846, 95% CI 0.789-0.902 in the training group and 0.799, 95% CI 0.697-0.902 in the validation group) for the prediction of early recurrence. Moreover, the recurrent nomogram exhibited not only encouraging calibration ability, but also great clinical utility both in the training group and validation group.

Conclusion

TNM stage, CA-199, CA125, SII and TBA were closely correlated with the presence of early recurrence of CRC patients. The recurrent nomogram held well predictive ability for the identification of CRC patients with early recurrence.

Current Status of Next-Generation Sequencing-Based Cancer Genome Profiling Tests in Japan and Prospects for Liquid Biopsy

Next-generation sequencing-based comprehensive genome profiling (CGP) testing, OncoGuide NCC Oncopanel System, and FoundationOne CDx Cancer Genomic Profile have been covered by the Japanese national health insurance system since June 2019. Because CGP was initially developed to enroll patients into an early-phase clinical trial for solid tumors, its approved indications have been limited to patients who have completed the standard chemotherapy treatment. Approximately 14,000 cases have been registered with the Center for Cancer Genomics and Advanced Therapeutics as of March 2021. Measuring the drug access rate is not enough due to patients' deteriorating condition during CGP analysis and due to the limited number of ongoing clinical trials available, although tumor-agnostic therapies, such as the use of pembrolizumab in high microsatellite-instable solid tumors and in conditions with a high tumor mutational burden (≥10 mut/Mb) as well as the use of entrectinib and larotrectinib in NTRK fusion-positive tumors have been approved in Japan. Moreover, since this analysis is performed using DNA derived from tumor tissue, it is difficult to perform CGP in cases in which an insufficient amount of tissue exists. Thus, noninvasive blood-based assays have been developed, and CGP panels using circulating tumor DNA from blood were approved in March 2021. However, cost, timing, and the number of tests allowed by the health system have not yet been determined. Therefore, in this review, we outline the current status and issues of CGP testing using tumor tissues as well as the expectations and limitations of liquid biopsy for use in Japanese clinical practice.