KRAS mutations in cell-free DNA from preoperative and postoperative sera as a pancreatic cancer marker: a retrospective study

Association of preoperative and postoperative circulating tumour DNA (ctDNA) with PIK3CA gene mutation with risk of recurrence in patients with non-metastatic breast cancer

BACKGROUND

Circulating tumour DNA (ctDNA), contains tumour-specific gene mutation in blood circulation and could aid in postoperative risk stratification of non-metastatic breast cancer. In this study, we investigated the feasibility of detecting PIK3CA gene mutations in ctDNA in the preoperative (preop) and postoperative period (postop), and its prognostic significance in patients with breast cancer.

METHODS

A cohort of patients with breast cancer undergoing curative surgery with available blood samples preoperatively and postoperatively (Post op) at either Post op time period; week 1-2, week 3-4 or weeks 5-12 were enrolled. PIK3CA gene mutations at exons 9 and 20 were detected in ctDNA with High resolution melting (HRM) PCR and Allele specific fluorescence probe-based PCR.

RESULTS

A total of 62 patients (age, median (IQR), 51.50 (45.0-65.0) years), with a median follow-up of 90 months (interquartile range (IQR),60-120 months) were enrolled. In total, 25 (40.3%) and 22 (35%) patients with breast cancer had detectable PIK3CA gene mutations in ctDNA in preoperative and postoperative period, respectively. PIK3CA gene mutations in ctDNA in postoperative period (hazard ratio (H.R: 18.05, p = 0.001) were a negative prognostic factor for recurrencefree survival (RFS) and overall survival (OS) (H.R: 11.9, p = 0.01) in patients with breast cancer. Subgroup analysis of ctDNA indicate that positive ctDNA in both preoperative/postoperative period and post op period only were found to have prognostic effect on RFS and OS (RFS; p < 0.0001, O·S; p = 0.0007). Moreover, ctDNA-based detection preceded clinical detection of recurrence in patients with an average lead time of 12 months (IQR:20-28.5 months) across all the breast cancer subtypes.

CONCLUSION

We highlighted the prognostic ability of ctDNA in patients with breast cancer in perioperative period. However, future prospective studies are needed to assess the utility of ctDNA in clinical practice.

Evidence and Future Perspectives for Neoadjuvant Therapy for Resectable and Borderline Resectable Pancreatic Cancer: A Scoping Review

Pancreatic cancer (PC) is a lethal disease that requires innovative therapeutic approaches to enhance the survival outcomes. Neoadjuvant treatment (NAT) has gained attention for resectable and borderline resectable PC, offering improved resection rates and enabling early intervention and patient selection. Several retrospective studies have validated its efficacy. However, previous studies have lacked intention-to-treat analyses and appropriate resectability classifications. Randomized comparative trials may help to enhance the clinical applicability of evidence. Therefore, after searching the MEDLINE database, this scoping review presents a comprehensive summary of the evidence from published (n = 14) and ongoing (n = 12) randomized Phase II and III trials. Diverse regimens and their outcomes were explored for both resectable and borderline resectable PC. While some trials have supported the efficacy of NAT, others have demonstrated no clear survival benefits for patients with resectable PC. The utility of NAT has been confirmed in patients with borderline resectable PC, but the optimal regimens remain debatable. Ongoing trials are investigating novel regimens, including immunotherapy, thereby highlighting the dynamic landscape of PC treatment. Studies should focus on biomarker identification, which may enable precision in oncology. Future endeavors aim to refine treatment strategies, guided by precision oncology.

Next‑generation sequencing to identify genetic mutations in pancreatic cancer using intraoperative peritoneal washing fluid

The efficacy of next-generation sequencing (NGS) of tumor-derived DNA from intraoperative peritoneal washing fluid (IPWF) of patients with pancreatic ductal adenocarcinoma (PDAC) who intend to undergo curative resection remains unclear. The aim of the present study was to evaluate whether genomic mutations in tumor-derived DNA from IPWF samples of patients with PDAC who intend to undergo curative resection could be detected using NGS. A total of 12 such patients were included in this study. Cytology of IPWF (CY) was assessed and NGS of genomic tumor-derived DNA from the IPWF was performed to determine whether genomic mutations could be detected in these patient samples. A total of 2 patients (16.7%) had a CY(+) status and 1 patient (8.3%) showed intraoperative macro-peritoneal dissemination; 11 patients underwent radical surgery. Actionable gene alterations were detected in 8 (80.0%) out of the 10 patients with CY(-) status based on NGS of IPWF samples, and 3 (37.5%) patients among those with actionable gene mutations identified from IPWF samples underwent peritoneal dissemination after surgery within ~12 months. The most common genomic mutation was in KRAS (9 patients, 75.0%), followed by TP53 (3 patients, 25.0%), SMAD4 (1 patient, 8.3%) and CDKN2A (1 patient, 8.3%). These findings indicated that the genomic mutations identified in tumor-derived DNA from IPWF samples of patients with PDAC with a CY(-) status who intend to undergo curative resection are potential biomarkers for predicting the recurrence of early peritoneal dissemination.

Clinical Application of Liquid Biopsy in Pancreatic Cancer: A Narrative Review

Pancreatic ductal adenocarcinoma contributes significantly to global cancer-related deaths, featuring only a 10% survival rate over five years. The quest for novel tumor markers is critical to facilitate early diagnosis and tailor treatment strategies for this disease, which is key to improving patient outcomes. In pancreatic ductal adenocarcinoma, these markers have been demonstrated to play a crucial role in early identification, continuous monitoring, and prediction of its prognosis and have led to better patient outcomes. Nowadays, biopsy specimens serve to ascertain diagnosis and determine tumor type. However, liquid biopsies present distinct advantages over conventional biopsy techniques. They offer a noninvasive, easily administered procedure, delivering insights into the tumor's status and facilitating real-time monitoring. Liquid biopsies encompass a variety of elements, such as circulating tumor cells, circulating tumor DNA, extracellular vesicles, microRNAs, circulating RNA, tumor platelets, and tumor endothelial cells. This review aims to provide an overview of the clinical applications of liquid biopsy as a technique in the management of pancreatic cancer.

A Practical Approach to Interpreting Circulating Tumor DNA in the Management of Gastrointestinal Cancers

BACKGROUND

There is accumulating evidence supporting the clinical use of circulating tumor DNA (ctDNA) in solid tumors, especially in different types of gastrointestinal cancer. As such, appraisal of the current and potential clinical utility of ctDNA is needed to guide clinicians in decision-making to facilitate its general applicability.

CONTENT

In this review, we firstly discuss considerations surrounding specimen collection, processing, storage, and analysis, which affect reporting and interpretation of results. Secondly, we evaluate a selection of studies on colorectal, esophago-gastric, and pancreatic cancer to determine the level of evidence for the use of ctDNA in disease screening, detection of molecular residual disease (MRD) and disease recurrence during surveillance, assessment of therapy response, and guiding targeted therapy. Lastly, we highlight current limitations in the clinical utility of ctDNA and future directions.

SUMMARY

Current evidence of ctDNA in gastrointestinal cancer is promising but varies depending on its specific clinical role and cancer type. Larger prospective trials are needed to validate different aspects of ctDNA clinical utility, and standardization of collection protocols, analytical assays, and reporting guidelines should be considered to facilitate its wider applicability.

Prognostic utility of preoperative and postoperative KRAS-mutated circulating tumor DNA (ctDNA) in resected pancreatic ductal adenocarcinoma: A systematic review and meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a challenging disease, with surgery being the only possible cure. However, despite surgery, the majority of patients experience recurrence. Recent evidence suggests that perioperative KRAS-mutated circulating tumor DNA (ctDNA) may have prognostic value. Therefore, we conducted a systematic review and meta-analysis to explore the prognostic significance of preoperative and postoperative KRAS-mutated ctDNA testing in resected PDAC.

METHODS

We searched PubMed/MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases for studies that reported the effect of preoperative and postoperative KRAS-mutated ctDNA on overall survival (OS) and/or relapse-free survival (RFS) in resected PDAC. We used a random-effects model to determine the pooled OS and RFS hazard ratios (HR) and their corresponding 95 % confidence intervals (CI).

RESULTS

We identified 15 studies (868 patients) eligible for analysis. In the preoperative setting, positive ctDNA correlated with worse RFS in 8 studies (HR, 2.067; 95 % CI, 1.346-3.174, P < 0.001) and worse OS in 10 studies (HR, 2.170; 95 % CI, 1.451-3.245, P < 0.001) compared to negative ctDNA. In the postoperative setting, positive ctDNA correlated with worse RFS across 9 studies (HR, 3.32; 95 % CI, 2.19-5.03, P < 0.001) and worse OS in 6 studies (HR, 6.62; 95 % CI, 2.18-20.16, P < 0.001) compared to negative ctDNA.

CONCLUSION

Our meta-analysis supports the utility of preoperative and postoperative KRAS-mutated ctDNA testing as a prognostic marker for resected PDAC. Further controlled studies are warranted to confirm these results and to investigate the potential therapeutic implications of positive KRAS-mutated ctDNA.

Long-term survival after surgical resection for bone metastasis from pancreatic cancer: A case report

INTRODUCTION

Pancreatic cancer (PC) is highly malignant and metastatic; however, bone metastases are rare. Although the effectiveness of conversion surgery for distant metastases of PC has been reported in a few cases, there are no reports on surgical resection for bone metastases. Here, we report a case of long-term survival after resection of bone metastasis from PC.

PATIENT CONCERNS

A 60-year-old woman underwent pancreaticoduodenectomy after neoadjuvant chemoradiotherapy for pancreatic head cancer. At 28 months after surgery, multiple lung metastases from PC were diagnosed, and chemotherapy was administered. After 59 months, chemotherapy was terminated because all target lesions had disappeared on imaging.

DIAGNOSIS

At 77 months after the initial surgery, bone metastasis in the left 9th rib was detected by positron emission tomography/computed tomography, which was performed due to elevated carbohydrate antigen 19-9 levels.

INTERVENTIONS

Chemotherapy was readministered as the initial treatment. Subsequently, due to the long-term well-controlled status of the recurrence site and the absence of other metastases, thoracoscopic-assisted partial resection of the left 9th rib was performed 128 months following pancreaticoduodenectomy. Pathological examination revealed adenocarcinoma metastasis from PC.

OUTCOMES

The patient is currently alive without recurrence 44 months after resection for bone metastasis and 172 months after the initial surgery.

CONCLUSION

Surgical resection may be favorable in patients with bone metastasis of PC that is well-controlled with chemotherapy.

Liquid biopsy after resection of pancreatic adenocarcinoma and its relation to oncological outcomes. Systematic review and meta-analysis

BACKGROUND

It has been hypothesised that manipulation during surgery releases tumoral components into circulation. We investigate the effect of surgery on plasma-borne DNA biomarkers and the oncological outcomes in resectable pancreatic ductal adenocarcinoma (PDAC). We also compare non-touch isolation techniques (NTIT) with standard techniques.

MATERIALS AND METHODS

We performed a systematic review and a meta-analysis of studies analysing liquid biopsy as circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), and messenger RNA (mRNA) in resectable PDAC patients who underwent surgery and its association with overall survival (OS) and disease-free survival (DFS). Research in EMBASE, Web of Science and PubMed was performed. The ctDNA shift negative-to-positive (ctDNA -/+) or ctDNA shift positive-to-negative (ctDNA +/-) before and after surgery was evaluated.

RESULTS

Twelve studies comprising 413 patients were included. Shorter OS and DFS were identified in patients with positive ctDNA status before (HR = 2.28, p = 0.005 and HR = 2.16, p = 0.006) or after surgery (HR = 3.88, p < 0.0001 and HR = 3.81, p = 0.03), respectively. Surgical resection increased the rate of ctDNA +/-. There were no differences in OS or DFS in the ctDNA +/- group compared with ctDNA +/+ or ctDNA -/+. However, there was a trend to shorter OS in the ctDNA -/+ group (HR = 5.00, p = 0.09). No differences between NTIT and standard techniques on liquid biopsy status were found.

CONCLUSION

Positive ctDNA in the perioperative period is associated with a worse prognosis. Surgical resection has a role in the negativisation of liquid biopsy status. More studies are needed to assess the potential of minimally invasive techniques on ctDNA dynamics.

Analysis of Plasma Circulating Tumor DNA in Borderline Resectable Pancreatic Cancer Treated with Neoadjuvant Modified FOLFIRINOX: Clinical Relevance of DNA Damage Repair Gene Alteration Detection

PURPOSE

There are no reliable biomarkers to guide treatment for patients with borderline resectable pancreatic cancer (BRPC) in the neoadjuvant setting. We used plasma circulating tumor DNA (ctDNA) sequencing to search biomarkers for patients with BRPC receiving neoadjuvant mFOLFIRINOX in our phase 2 clinical trial (NCT02749136).

MATERIALS AND METHODS

Among the 44 patients enrolled in the trial, patients with plasma ctDNA sequencing at baseline or post-operation were included in this analysis. Plasma cell-free DNA isolation and sequencing were performed using the Guardant 360 assay. Detection of genomic alterations, including DNA damage repair (DDR) genes, were examined for correlations with survival.

RESULTS

Among the 44 patients, 28 patients had ctDNA sequencing data qualified for the analysis and were included in this study. Among the 25 patients with baseline plasma ctDNA data, 10 patients (40%) had alterations of DDR genes detected at baseline, inclu-ding ATM, BRCA1, BRCA2 and MLH1, and showed significantly better progression-free survival than those without such DDR gene alterations detected (median, 26.6 vs. 13.5 months; log-rank p=0.004). Patients with somatic KRAS mutations detected at baseline (n=6) had significantly worse overall survival (median, 8.5 months vs. not applicable; log-rank p=0.003) than those without. Among 13 patients with post-operative plasma ctDNA data, eight patients (61.5%) had detectable somatic alterations.

CONCLUSION

Detection of DDR gene mutations from plasma ctDNA at baseline was associated with better survival outcomes of pati-ents with borderline resectable pancreatic ductal adenocarcinoma treated with neoadjuvant mFOLFIRINOX and may be a prognostic biomarker.

Electrical detection of RNA cancer biomarkers at the single-molecule level

Cancer is a significant healthcare issue, and early screening methods based on biomarker analysis in liquid biopsies are promising avenues to reduce mortality rates. Electrical detection of nucleic acids at the single molecule level could enable these applications. We examine the electrical detection of RNA cancer biomarkers (KRAS mutants G12C and G12V) as a single-molecule proof-of-concept electrical biosensor for cancer screening applications. We show that the electrical conductance is highly sensitive to the sequence, allowing discrimination of the mutants from a wild-type KRAS sequence differing in just one base. In addition to this high specificity, our results also show that these biosensors are sensitive down to an individual molecule with a high signal-to-noise ratio. These results pave the way for future miniaturized single-molecule electrical biosensors that could be groundbreaking for cancer screening and other applications.

Specific human leukocyte antigen class I genotypes predict prognosis in resected pancreatic adenocarcinoma: a retrospective cohort study

BACKGROUND

Patients with resected pancreatic adenocarcinoma (PAAD) often experience short-term relapse and dismal survival, suggesting an urgent need to develop predictive and/or prognostic biomarkers for these populations. Given the potential associations of the human leukocyte antigen class I ( HLA -I) genotype with oncogenic mutational profile and immunotherapy efficacy, we aimed to assess whether differential HLA -I genotype could predict the postoperative outcomes in resected PAAD patients.

MATERIALS AND METHODS

HLA -I ( A , B , and C ) genotyping and somatic variants of 608 Chinese PAAD patients were determined by targeted next-generation sequencing of matched blood cells and tumor tissues. HLA - A / B alleles were classified with the available definition of 12 supertypes. The Kaplan-Meier curves of disease-free survival (DFS) and multivariable Cox proportional-hazards regression analyses were performed to determine the survival difference in 226 selected patients with radical resection. Early-stage (I-II) patients constituted the majority (82%, 185/226) and some stage I-II individuals with high-quality tumor samples were analyzed by RNA-sequencing to examine immunophenotypes.

RESULTS

Patients with HLA-A02 + B62 + B44 - had significantly shorter DFS (median, 239 vs. 410 days; hazard ratio=1.65, P =0.0189) than patients without this genotype. Notably, stage I-II patients carrying HLA-A02 + B62 + B44 - had sharply shorter DFS than those without HLA-A02 + B62 + B44 - (median, 237 vs. 427 days; hazard ratio=1.85, P =0.007). Multivariate analysis revealed that HLA-A02 + B62 + B44 - was associated with significantly inferior DFS ( P =0.014) in stage I-II patients but not in stage III patients. Mechanistically, HLA-A02 + B62 + B44 - patients were associated with a high rate of KRAS G12D and TP53 mutations, lower HLA-A expression, and less inflamed T-cell infiltration.

CONCLUSION

The current results suggest that a specific combination of germline HLA-A02/B62/B44 supertype, HLA-A02 + B62 + B44 - , was a potential predictor for DFS in early-stage PAAD patients after surgery.

Circulating Tumor DNA Is an Accurate Diagnostic Tool and Strong Prognostic Marker in Pancreatic Cancer

OBJECTIVE

The objectives of the study are to investigate the sensitivity and specificity of circulating tumor DNA (ctDNA) for the diagnosis of pancreatic cancer and to assess the utility of ctDNA as a prognostic marker in this disease.

METHODS

Cell-free DNA was extracted from plasma of patients who underwent endoscopic ultrasound fine-needle aspiration or surgical resections for pancreatic cancer. The cell-free DNA was then analyzed using droplet digital polymerase chain reaction for KRAS G12/13 mutations. Eighty-one patients with pancreatic cancer and 30 patients with benign pancreatic disease were analyzed.

RESULTS

ctDNA KRAS G12/13 mutations were detected in 63% of all patients with pancreatic cancer and in 76% of those patients who also had KRAS G12/13 mutations detected in the pancreatic primary. Specificity and tissue concordance were both 100%. Circulating tumor DNA corresponded with tumor size and stage, and high ctDNA was associated with significantly worse prognosis on both univariate and multivariate testing.

CONCLUSION

Our study shows that ctDNA is an accurate diagnostic tool and strong prognostic marker in patients with pancreatic cancer. The continued investigation of ctDNA will enable its implementation in clinical practice to optimize the care and survival outcomes of patients with pancreatic cancer.

State of the Art: ctDNA in Upper Gastrointestinal Malignancies

Circulating tumor DNA (ctDNA) has emerged as a promising non-invasive source to characterize genetic alterations related to the tumor. Upper gastrointestinal cancers, including gastroesophageal adenocarcinoma (GEC), biliary tract cancer (BTC) and pancreatic ductal adenocarcinoma (PADC) are poor prognostic malignancies, usually diagnosed at advanced stages when no longer amenable to surgical resection and show a poor prognosis even for resected patients. In this sense, ctDNA has emerged as a promising non-invasive tool with different applications, from early diagnosis to molecular characterization and follow-up of tumor genomic evolution. In this manuscript, novel advances in the field of ctDNA analysis in upper gastrointestinal tumors are presented and discussed. Overall, ctDNA analyses can help in early diagnosis, outperforming current diagnostic approaches. Detection of ctDNA prior to surgery or active treatment is also a prognostic marker that associates with worse survival, while ctDNA detection after surgery is indicative of minimal residual disease, anticipating in some cases the imaging-based detection of progression. In the advanced setting, ctDNA analyses characterize the genetic landscape of the tumor and identify patients for targeted-therapy approaches, and studies show variable concordance levels with tissue-based genetic testing. In this line, several studies also show that ctDNA serves to follow responses to active therapy, especially in targeted approaches, where it can detect multiple resistance mechanisms. Unfortunately, current studies are still limited and observational. Future prospective multi-center and interventional studies, carefully designed to assess the value of ctDNA to help clinical decision-making, will shed light on the real applicability of ctDNA in upper gastrointestinal tumor management. This manuscript presents a review of the evidence available in this field up to date.

KRAS mutation: The booster of pancreatic ductal adenocarcinoma transformation and progression

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. It has a poor response to conventional therapy and has an extremely poor 5-year survival rate. PDAC is driven by multiple oncogene mutations, with the highest mutation frequency being observed in KRAS. The KRAS protein, which binds to GTP, has phosphokinase activity, which further activates downstream effectors. KRAS mutation contributes to cancer cell proliferation, metabolic reprogramming, immune escape, and therapy resistance in PDAC, acting as a critical driver of the disease. Thus, KRAS mutation is positively associated with poorer prognosis in pancreatic cancer patients. This review focus on the KRAS mutation patterns in PDAC, and further emphases its role in signal transduction, metabolic reprogramming, therapy resistance and prognosis, hoping to provide KRAS target therapy strategies for PDAC.

Liquid biopsy leads to a paradigm shift in the treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most cancers. Its 5-year survival rate is very low. The recent induction of neoadjuvant chemotherapy and improvements in chemotherapy for patients with pancreatic cancer have resulted in improved survival outcomes. However, the prognosis of pancreatic cancer is still poor. To dramatically improve the prognosis, we need to develop more tools for early diagnosis, treatment selection, disease monitoring, and response rate evaluation. Recently, liquid biopsy (circulating free DNA, circulating tumor DNA, circulating tumor cells, exosomes, and microRNAs) has caught the attention of many researchers as a new biomarker that is minimally invasive, confers low-risk, and displays an overall state of the tumor. Thus, liquid biopsy does not employ the traditional difficulties of obtaining tumor samples from patients with advanced PDAC to investigate their molecular biological status. In addition, it allows for long-term monitoring of the molecular profile of tumor progression. These could help in identifying tumor-specific alterations that use the target structure for tailor-made therapy. Through this review, we highlighted the latest discoveries and advances in liquid biopsy technology in pancreatic cancer research and showed how it can be applied in clinical practice.

Circulating tumor DNA: a help to guide therapeutic strategy in patients with borderline and locally advanced pancreatic adenocarcinoma?

BACKGROUND

prognostic biomarkers could be useful to better select patients with borderline resectable (BR) or locally advanced (LA) pancreatic adenocarcinoma (PA) for chemoradiotherapy (CRT) and/or secondary resection.

AIMS

The main objective of this work was to study characteristics, received treatments and prognostic of patients with BR or LA PA according to their baseline circulating tumor DNA status and, for secondary objective, neutrophil-to-lymphocyte Ratio (NLR).

METHODS

ctDNA status at baseline was determined using Next Generation Sequencing in a consecutive monocentric cohort of patients with a BR or LA PA.

RESULTS

69 patients were included, 31 with BR PA and 38 with LA PA. 14 (20.3%) patients had baseline positive ctDNA. Five (7.8%) patients had NLR> 5. Patients with positive ctDNA had 3.7 months shorter progression free survival (p = 0.006). Patients with positive ctDNA had earlier progression after the beginning of CRT (4.4 vs 7.1 months; p = 0.068) and shorter relapse free survival after secondary resection (9.2 vs 22.9 months; p = 0.016).

CONCLUSIONS

positive ctDNA at baseline was associated with a worse prognosis in patients with BR or LA PA. These data are exploratory and must be confirmed in further prospective trials.

Circulating tumor DNA (ctDNA) to evaluate minimal residual disease (MRD), treatment response, and posttreatment prognosis in pancreatic adenocarcinoma

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as a blood-based test with multiple utilities in oncology. In the past few years, multiple studies of varying designs, methods, and quality have emerged which show promise for ctDNA as a tool to assess response to treatment and detect minimal residual disease (MRD) across various gastrointestinal (GI) malignancies. We aim to review the current literature for ctDNA as it pertains to assessing treatment response, MRD, prognosis, and risk of recurrence for pancreatic adenocarcinoma.

METHODS

PubMed was queried with a combination of terms regarding pancreatic adenocarcinoma, minimal residual disease, resection, and prognosis. All resultant articles were reviewed by the authors for appropriate fit with scope.

RESULTS

Fourteen articles were identified that fit with the scope of this review.

CONCLUSIONS

Detectable ctDNA after definitive resection, specifically mutated KRAS, correlates with shorter recurrence-free survival (RFS), overall survival (OS), and overall prognosis. Limited data also suggests ctDNA may provide a noninvasive means to assess response to chemotherapy. Whether this information is actionable in terms of altering neoadjuvant or postresection treatment regimens remains an open question requiring further study.

Is Cell-Free DNA Testing in Pancreatic Ductal Adenocarcinoma Ready for Prime Time?

Simple Summary

Pancreatic cancer is a deadly cancer with limited treatment options. It is often detected in most people at stages where cure is not possible. There is no good test to know if a person will respond to treatment or if there is any disease beyond what can be seen by available imaging tests. Genetic material from the tumor is expected to float in the blood. Studying the alterations in the genetic material could help detect the tumor early, give an idea about its aggressiveness and response to available treatments, and facilitate the discovery of newer therapies. The focus of the studies so far has been on only one kind of genetic aberration, mutations, which has not given us great results. There is a need to explore another type of change known as methylation that could hold answers for managing pancreatic cancers better.

Abstract

Cell-free DNA (cfDNA) testing currently does not have a significant role in PDA management: it is insufficient to diagnose PDA, and its use is primarily restricted to identifying targetable mutations (if tissue is insufficient or unavailable). cfDNA testing has the potential to address critical needs in PDA management, such as pre-operative risk stratification (POR), prognostication, and predicting (and monitoring) treatment response. Prior studies have focused primarily on somatic mutations, specifically KRAS variants, and have shown limited success in addressing prognosis and POR. Recent studies have demonstrated the importance of other less prevalent mutations (ERBB2 and TP53), but no studies have provided reliable mutation panels for clinical use. Methylation aberrations in cfDNA (epigenetic markers) in PDA have been relatively less explored. However, early evidence has suggested they offer diagnostic and, to some extent, prognostic value. The inclusion of epigenetic markers of cfDNA adds another dimension to genomic testing and may open new therapeutic avenues beyond addressing critical areas of need in PDA treatment. For cfDNA to substantially influence PDA management, concerted efforts are required to include less frequent mutations and epigenetic markers. Furthermore, relying on KRAS mutations for PDA management will always be inadequate.

Circulating tumour DNA: a challenging innovation to develop "precision onco-surgery" in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the third leading cause of cancer-related mortality within the next decade. Management of PDAC remains challenging with limited effective treatment options and a dismal long-term prognosis. Liquid biopsy and circulating biomarkers seem to be promising to improve the multidisciplinary approach in PDAC treatment. Circulating tumour DNA (ctDNA) is the most studied blood liquid biopsy analyte and can provide insight into the molecular profile and individual characteristics of the tumour in real-time and in advance of standard imaging modalities. This could pave the way for identifying new therapeutic targets and markers of tumour response to supplement diagnostic and provide enhanced stratified treatment. Although its specificity seems excellent, the current sensitivity of ctDNA remains a limitation for clinical use, especially in patients with a low tumour burden. Increasing evidence suggests that ctDNA is a pertinent candidate biomarker to assess minimal residual disease after surgery but also a strong independent prognostic biomarker. This review explores the current knowledge and recent developments in ctDNA as a screening, diagnostic, prognostic and predictive biomarker in the management of resectable PDAC but also technical and analytical challenges that must be overcome to move toward "precision onco-surgery."

Approach to Resectable Gastric Cancer: Evolving Paradigm of Neoadjuvant and Adjuvant Treatment

OPINION STATEMENT

Recent therapeutic advances have prolonged survival in patients with metastatic gastric cancer, though the prognosis for patients with locally advanced resectable gastric cancer remains poor. Long-term survival after resection of locally advanced gastric adenocarcinoma is dependent on early eradication of micrometastatic disease and optimal surgical resection. Preoperative therapy with a docetaxel-containing three-drug regimen has recently been shown to be superior to an anthracycline-containing three-drug regimen or two-drug therapy with a fluoropyrimidine and platinum. Chemoradiation is not essential and is reserved for patients with suboptimal resection. Emerging research strategies include introduction of pre- and postoperative checkpoint blockade and biomarker-directed therapy.

Circulating Tumor DNA: An Emerging Tool in Gastrointestinal Cancers

Circulating tumor DNA (ctDNA) is tumor-derived fragmented DNA in the bloodstream that has come from primary or metastatic cancer sites. Neoplasm-specific genetic and epigenetic abnormalities are increasingly being identified through liquid biopsy: a novel, minimally invasive technique used to isolate and analyze ctDNA in the peripheral circulation. Liquid biopsy and other emerging ctDNA technologies represent a paradigm shift in cancer diagnostics because they allow for the detection of minimal residual disease in patients with early-stage disease, improve risk stratification, capture tumor heterogeneity and genomic evolution, and enhance ctDNA-guided adjuvant and palliative cancer therapy. Moreover, ctDNA can be used to monitor the tumor response to neoadjuvant and postoperative therapy in patients with metastatic disease. Using clearance of ctDNA as an endpoint for escalation/de-escalation of adjuvant chemotherapy for patients considered to have high-risk disease has become an important area of research. The possibility of using ctDNA as a surrogate for treatment response-including for overall survival, progression-free survival, and disease-free survival-is an attractive concept; this surrogate will arguably reduce study duration and expedite the development of new therapies. In this review, we summarize the current evidence on the applications of ctDNA for the diagnosis and management of gastrointestinal tumors. Gastrointestinal cancers-including tumors of the esophagus, stomach, colon, liver, and pancreas-account for one-quarter of global cancer diagnoses and contribute to more than one-third of cancer-related deaths. Given the prevalence of gastrointestinal malignancies, ctDNA technology represents a powerful tool to reduce the global burden of disease.

Circulating Nucleic Acids as Novel Biomarkers for Pancreatic Ductal Adenocarcinoma

Despite considerable advancements in the clinical management of PDAC it remains a significant cause of mortality. PDAC is often diagnosed at advanced stages due to vague symptoms associated with early-stage disease and a lack of reliable diagnostic biomarkers. Late diagnosis results in a high proportion of cases being ineligible for surgical resection, the only potentially curative therapy for PDAC. Furthermore, a lack of prognostic biomarkers impedes clinician's ability to properly assess the efficacy of therapeutic interventions. Advances in our ability to detect circulating nucleic acids allows for the advent of novel biomarkers for PDAC. Tumor derived circulating and exosomal nucleic acids allow for the detection of PDAC-specific mutations through a non-invasive blood sample. Such biomarkers could expand upon the currently limited repertoire of tests available. This review outlines recent developments in the use of molecular techniques for the detection of these nucleic acids and their potential roles, alongside current techniques, in the diagnosis, prognosis and therapeutic governance of PDAC.

Prognostic role of cell-free DNA biomarkers in pancreatic adenocarcinoma: A systematic review and meta-analysis

This systematic review and meta-analysis evaluated the prognostic role of cell-free DNA (cfDNA) in pancreatic ductal adenocarcinoma (PDAC). Eligible studies reported differences in overall (OS) and progression-free survival (PFS) by cfDNA status. The random effect model yielded the pooled hazard ratios (HRs) and 95 % confidence intervals (CI). Detection of circulant-tumor DNA (ctDNA), KRAS mutations and other cfDNA alterations constitute detectable cfDNA biomarkers. Altogether, 38 studies (3,318 patients) were eligible. Progression-free and overall survival were decreased with detectable ctDNA (HR = 1.92, 95 %CI:(1.29,2.86); HR = 2.25, 95 %CI:(1.73,2.92)) and KRAS mutations (HR = 1.88, CI:1.22,2.92,); HR = 1.52, 95 %CI:(1.22,1.90)) respectively, across various stages. In unresectable cases, ctDNA (HR = 2.50, 95 %CI:(1.94,3.23)), but not KRAS mutations (HR = 1.16, 95 %CI:(0.46,2.94)) signaled risk for progression. Detectable cfDNA biomarkers correlated with worse prognosis in resectable cases and if detected during treatment. In conclusion, cfDNA biomarkers indicate accelerated progression and decreased survival in PDAC. Significance of KRAS mutations detection in unresectable cases is to be determined.

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 dynamics analysis in a xenograft mouse model with esophageal squamous cell carcinoma

BACKGROUND

It remains unclear which factors, such as tumor volume and tumor invasion, influence circulating tumor DNA (ctDNA), and the origin of ctDNA in liquid biopsy is always problematic. To use liquid biopsies clinically, it will be very important to address these questions.

AIM

To assess the origin of ctDNA, clarify the dynamics of ctDNA levels, assess ctDNA levels by using a xenograft mouse after treatment, and to determine whether tumor volume and invasion are related to ctDNA levels.

METHODS

Tumor xenotransplants were established by inoculating BALB/c-nu/nu mice with the TE11 cell line. Groups of mice were injected with xenografts at two or four sites and sacrificed at the appropriate time point after xenotransplantation for ctDNA analysis. Analysis of ctDNA was performed by droplet digital PCR, using the human telomerase reverse transcriptase (hTERT) gene.

RESULTS

Mice given two-site xenografts were sacrificed for ctDNA at week 4 and week 8. No hTERT was detected at week 4, but it was detected at week 8. However, in four-site xenograft mice, hTERT was detected both at week 4 and week 6. These experiments revealed that both tumor invasion and tumor volume were associated with the detection of ctDNA. In resection experiments, hTERT was detected at resection, but had decreased by 6 h, and was no longer detected 1 and 3 d after resection.

CONCLUSION

We clarified the origin and dynamics of ctDNA, showing that tumor volume is an important factor. We also found that when the tumor was completely resected, ctDNA was absent after one or more days.

Mutations in key driver genes of pancreatic cancer: molecularly targeted therapies and other clinical implications

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, with a minimal difference between its incidence rate and mortality rate. Advances in oncology over the past several decades have dramatically improved the overall survival of patients with multiple cancers due to the implementation of new techniques in early diagnosis, therapeutic drugs, and personalized therapy. However, pancreatic cancers remain recalcitrant, with a 5-year relative survival rate of <9%. The lack of measures for early diagnosis, strong resistance to chemotherapy, ineffective adjuvant chemotherapy and the unavailability of molecularly targeted therapy are responsible for the high mortality rate of this notorious disease. Genetically, PDAC progresses as a complex result of the activation of oncogenes and inactivation of tumor suppressors. Although next-generation sequencing has identified numerous new genetic alterations, their clinical implications remain unknown. Classically, oncogenic mutations in genes such as KRAS and loss-of-function mutations in tumor suppressors, such as TP53, CDNK2A, DPC4/SMAD4, and BRCA2, are frequently observed in PDAC. Currently, research on these key driver genes is still the main focus. Therefore, studies assessing the functions of these genes and their potential clinical implications are of paramount importance. In this review, we summarize the biological function of key driver genes and pharmaceutical targets in PDAC. In addition, we conclude the results of molecularly targeted therapies in clinical trials and discuss how to utilize these genetic alterations in further clinical practice.

Plasma KRAS mutations predict the early recurrence after surgical resection of pancreatic cancer

BACKGROUND

The technique to analyze circulating tumor DNA (ctDNA) in body fluid (so-called "liquid biopsy") is recently developed.

AIMS

Our aim was to assess the utility of liquid biopsy for predicting progression of pancreatic ductal adenocarcinoma (PDAC) after surgical resection or chemotherapy.

METHODS

A total of 72 patients with PDAC were retrospectively enrolled for this study, 33 treated surgically and 39 given chemotherapy, either FOLFIRINOX (oxaliplatin/irinotecan/fluorouracil/leucovorin) or gemcitabine plus nab-paclitaxel. Prior to treatment, patients were screened for the presence of KRAS mutations (G12D and G12V) in plasma using droplet digital polymerase chain reaction, and outcomes were compared.

RESULTS

KRAS mutations were identified in plasma samples of 12 patients (36%) underwent surgical resection. Patients with plasma KRAS mutations had significantly shorter disease-free survival (DFS) and overall survival (p < .01 and p = .01, respectively). Of 10 clinical variables analyzed, plasma KRAS mutation was the factor predictive of DFS in multivariate analysis (RR = 3.58, 95% CI: 1.36-9.60; p = .01). Although 12 patients (31%) given chemotherapy tested positive for plasma KRAS mutations, there was no demonstrable relation between plasma KRAS mutations and progression-free survival (PFS) or overall survival (OS) (p = .35 and p = .68, respectively).

CONCLUSIONS

In patients with PDAC, detection of KRAS mutations in plasma proved independently predictive of early recurrence after surgical resection but did not correlate with PFS following chemotherapy.

Role of Circulating Tumor DNA in Gastrointestinal Cancers: Current Knowledge and Perspectives

Gastrointestinal (GI) cancers are major health burdens worldwide and biomarkers are needed to improve the management of these diseases along their evolution. Circulating tumor DNA (ctDNA) is a promising non-invasive blood and other bodily-fluid-based biomarker in cancer management that can help clinicians in various cases for the detection, diagnosis, prognosis, monitoring and personalization of treatment in digestive oncology. In addition to the well-studied prognostic role of ctDNA, the main real-world applications appear to be the assessment of minimal residual disease to further guide adjuvant therapy and predict relapse, but also the monitoring of clonal evolution to tailor treatments in metastatic setting. Other challenges such as predicting response to treatment including immune checkpoint inhibitors could also be among the potential applications of ctDNA. Although the level of advancement of ctDNA development in the different tumor localizations is still inhomogeneous, it might be now reliable enough to be soon used in clinical routine for colorectal cancers and shows promising results in other GI cancers.

Perioperative cell-free mutant KRAS dynamics in patients with pancreatic cancer

This prospective observational biomarker trial evaluated the diagnostic and prognostic value of circulating KRAS mutations (cmKRAS) and their perioperative dynamics in patients with resectable pancreatic ductal adenocarcinoma (PDAC). Plasma cmKRAS samples (G12D, G12V, G12R, and G12C) were analysed by droplet digital PCR in 51 patients with resectable PDAC, 20 with advanced PDAC, and 34 with non-malignant pancreatic pathology. Preoperative detection of cmKRAS alone did not correlate with poorer overall and disease-free survival in this patient cohort. However, a perioperative change in cmKRAS, particularly accurate when an intraoperative sample was included, was identified as a new and useful marker for prediction of prolonged survival.

Promising biomarker

Meta-Analysis of Circulating Cell-Free DNA's Role in the Prognosis of Pancreatic Cancer

Simple Summary

Pancreatic cancer is an aggressive disease with a poor prognosis. The analysis of cell-free DNA (cfDNA) for genetic abnormalities is a promising new approach for the diagnosis and prognosis of pancreatic cancer patients. In this study, we conducted a systematic review and meta-analysis of studies that reported cfDNA in pancreatic ductal adenocarcinoma (PDAC). In total, 48 studies were included in the qualitative synthesis, while 44 were assessed in the quantitative synthesis, including 3524 PDAC patients. An overall negative impact of cfDNA and KRAS mutations on the overall (OS) and progression free survival (PFS) (HR = 2.42, 95% CI: 1.95–2.99 and HR = 2.46, 95% CI: 2.01–3.00, respectively) were found. The performance of molecular studies to assess the presence of KRAS mutation by liquid biopsy may support global efforts to improve outcomes for PDAC patients.

Abstract

Introduction: The analysis of cell-free DNA (cfDNA) for genetic abnormalities is a promising new approach for the diagnosis and prognosis of pancreatic cancer patients. Insights into the molecular characteristics of pancreatic cancer may provide valuable information, leading to its earlier detection and the development of targeted therapies. Material and Methods: We conducted a systematic review and a meta-analysis of studies that reported cfDNA in pancreatic ductal adenocarcinoma (PDAC). The studies were considered eligible if they included patients with PDAC, if they had blood tests for cfDNA/ctDNA, and if they analyzed the prognostic value of cfDNA/ctDNA for patients’ survival. The studies published before 22 October 2020 were identified through the PubMED, EMBASE, Web of Science and Cochrane Library databases. The assessed outcomes were the overall (OS) and progression-free survival (PFS), expressed as the log hazard ratio (HR) and standard error (SE). The summary of the HR effect size was estimated by pooling the individual trial results using the Review Manager, version 5.3, Cochrane Collaboration. The heterogeneity was assessed using the Cochran Q test and I² statistic. Results: In total, 48 studies were included in the qualitative review, while 44 were assessed in the quantitative synthesis, with the total number of patients included being 3524. Overall negative impacts of cfDNA and KRAS mutations on OS and PFS in PDAC (HR = 2.42, 95% CI: 1.95–2.99 and HR = 2.46, 95% CI: 2.01–3.00, respectively) were found. The subgroup analysis of the locally advanced and metastatic disease presented similar results (HR = 2.51, 95% CI: 1.90–3.31). In the studies assessing the pre-treatment presence of KRAS, there was a moderate to high degree of heterogeneity (I² = 87% and I² = 48%, for OS and PFS, respectively), which was remarkably decreased in the analysis of the studies measuring post-treatment KRAS (I² = 24% and I² = 0%, for OS and PFS, respectively). The patients who were KRAS positive before but KRAS negative after treatment had a better prognosis than the persistently KRAS-positive patients (HR = 5.30, 95% CI: 1.02–27.63). Conclusion: The assessment of KRAS mutation by liquid biopsy can be considered as an additional tool for the estimation of the disease course and outcome in PDAC patients.

Postoperative transient elevation of serum cancer antigen 125 in non-small cell lung cancer patients

OBJECTIVE

The aim of this retrospective study was to investigate the correlation of transiently elevated postoperative serum cancer antigen 125 levels and prognosis in patients with non-small cell lung cancer.

METHODS

A total of 181 non-small cell lung cancer patients with normal levels of preoperative serum cancer antigen 125 were statistically summarized in this study.

RESULTS

Out of the analyzed patients, 22 (12.2%) showed elevation of serum cancer antigen 125 within one month after surgery. Serum cancer antigen 125 level decreased to normal at three months postoperation. Serum cancer antigen 125 was positively correlated with pro-brain natriuretic peptide in non-small cell lung cancer postoperative patients (p=0.00035). Univariate analysis did not find significant difference in disease progression survival between those who experienced cancer antigen 125 elevation in the early postoperation and those who did not (p=0.646).

CONCLUSIONS

In conclusion, transient elevation of cancer antigen 125 is associated to pro-brain natriuretic peptide increase after pulmonary surgery in non-small cell lung cancer patients.

Plasma vs. serum in circulating tumor DNA measurement: characterization by DNA fragment sizing and digital droplet polymerase chain reaction

Background Choosing the specimen type is the first step of the pre-analytical process. Previous reports suggested plasma as the optimal specimen for circulating tumor DNA (ctDNA) analysis. However, head-to-head comparisons between plasma and serum using platforms with high analytical sensitivity, such as droplet digital polymerase chain reaction (ddPCR), are limited, and several recent studies have supported the clinical utility of serum-derived ctDNA. This study aimed to compare the DNA profiles isolated from plasma and serum, characterize the effects of the differences between specimens on ctDNA measurement, and determine the major contributors to these differences. Methods We isolated cell-free DNA (cfDNA) from 119 matched plasma/serum samples from cancer patients and analyzed the cfDNA profiles by DNA fragment sizing. We then assessed KRAS mutations in ctDNA from matched plasma/serum using ddPCR. Results The amount of large DNA fragments was increased in serum, whereas that of cfDNA fragments (<800 bp) was similar in both specimens. ctDNA was less frequently detected in serum, and the KRAS-mutated fraction in serum was significantly lower than that in plasma. The differences in ctDNA fractions between the two specimen types correlated well with the amount of large DNA fragments and white blood cell and neutrophil counts. Conclusions Our results provided detailed insights into the differences between plasma and serum using DNA fragment sizing and ddPCR, potentially contributing to ctDNA analysis standardization. Our study also suggested that using plasma minimizes the dilution of tumor-derived DNA and optimizes the sensitivity of ctDNA analysis. So, plasma should be the preferred specimen type.

Circulating Cell-Free DNA as a Prognostic Biomarker in Resectable Ampullary Cancer

Simple Summary

Circulating cell-free DNA (cfDNA) in patients with ampullary cancer was measured to clarify the correlation between cfDNA and clinicopathological factors and the impact of cfDNA on survival outcomes. The level of cfDNA was significantly higher in patients with lymph node involvement, lymphovascular invasion, abnormal serum carcinoembryonic antigen level, and stage II and III cancer. The 1- and 5-year survival rates were 92.0% and 66.5%, respectively, for patients with low cfDNA levels ≤ 6687 copies/mL as compared with 84.0% and 49.9%, respectively, for patients with high cfDNA levels > 6687 copies/mL (p < 0.001). After multivariate analysis, only the cfDNA level and cancer stage were independent factors in determining the prognosis of the ampullary cancer. The cfDNA level could act as a surrogate marker of both disease extent and biological aggressiveness of ampullary cancer. Moreover, cfDNA plays a significant role in determining the prognosis of resectable ampullary cancer.

Abstract

Circulating cell-free DNA (cfDNA) in ampullary cancer patients was measured to clarify the correlation between cfDNA and clinicopathological factors and the impact of cfDNA on survival outcomes. Patients with ampullary cancer undergoing pancreaticoduodenectomy were included. Correlations between cfDNA and clinicopathological and prognostic factors were determined. The cfDNA levels in patients ranged from 1282 to 21,674 copies/mL, with a median of 6687 copies/mL. The cfDNA level was significantly higher in patients with lymph node involvement, lymphovascular invasion, abnormal serum carcinoembryonic antigen (CEA) level, and stage II and III cancer. Poor prognostic factors for ampullary cancer included high cfDNA > 6687 copies/mL, lymph node involvement, abnormal serum CEA > 5 ng/mL, and advanced stage II and III cancer. The 1- and 5-year survival rates were 92.0% and 66.5%, respectively, for patients with low cfDNA < 6687 copies/mL and 84.0% and 49.9%, respectively, for patients with high cfDNA > 6687 copies/mL (p < 0.001). After multivariate analysis, only the cfDNA level and stage were independent prognostic factors of ampullary cancer. Thus, the cfDNA level could act as a surrogate marker of both disease extent and biological aggressiveness of ampullary cancer. Moreover, cfDNA plays a significant role in the prognosis of resectable ampullary cancer.

Molecular profiling of ctDNA in pancreatic cancer: Opportunities and challenges for clinical application

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related mortality within the next decade, with limited effective treatment options and a dismal long-term prognosis for patients. Genomic profiling has not yet manifested clinical benefits for diagnosis, treatment or prognosis in PDAC, due to the lack of available tissues for sequencing and the confounding effects of low tumour cellularity in many biopsy specimens. Increasing focus is now turning to the use of minimally invasive liquid biopsies to enhance the characterisation of actionable PDAC tumour genomes. Circulating tumour DNA (ctDNA) is the most comprehensively studied liquid biopsy analyte in blood and can provide insight into the molecular profile and biological characteristics of individual PDAC tumours, in real-time and in advance of traditional imaging modalities. This can pave the way for identification of new therapeutic targets, novel risk variants and markers of tumour response, to supplement diagnostic screening and provide enhanced scrutiny in treatment stratification. In the roadmap towards the application of precision medicine for clinical management in PDAC, ctDNA analyses may serve a leading role in streamlining candidate biomarkers for clinical integration. In this review, we highlight recent developments in the use of ctDNA-based liquid biopsies for PDAC and provide new insights into the technical, analytical and biological challenges that must be overcome for this potential to be realised.

Circulating Cell-Free DNA in Pancreatic Head Adenocarcinoma Undergoing Pancreaticoduodenectomy

OBJECTIVE

Circulating cell-free DNA (cfDNA) analysis is recently reported as a promising prognostic biomarker in various types of cancer. This study aimed to evaluate the role of cfDNA in pancreatic head adenocarcinoma.

METHODS

Data for pancreatic head adenocarcinoma undergoing pancreaticoduodenectomy were studied for cfDNA. Prognostic factors were determined, and their correlation with cfDNA level was evaluated.

RESULTS

The median of cfDNA for 97 cases was 7724 copies/mL, with a mean of 10,467, and ranging from 1856 to 44,203. Cell-free DNA was significantly higher in positive lymph node involvement and advanced stage III. Poor prognostic factors included high cfDNA level (>7724 copies/mL), abnormal carbohydrate antigen 19-9, abnormal carcinoembryonic antigen, and advanced stage. The 1- and 5-year survivals for those with high cfDNA were poorer, 70.2% and 21.2%, respectively, as compared with 93.4% and 23.7% for those with low cfDNA level. Only cfDNA level and stage were independent prognostic factors after multivariate analysis.

CONCLUSIONS

The level of cfDNA was correlated with tumor burden. Therefore, it could be an emerging survival predictor for resectable pancreatic head adenocarcinoma, and its detection might be a promising liquid biopsy to monitor both tumor progression and treatment response.

Peritoneal dissemination of pancreatic cancer caused by endoscopic ultrasound-guided fine needle aspiration: A case report and literature review

BACKGROUND

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a biopsy technique widely used to diagnose pancreatic tumors because of its high sensitivity and specificity. Although needle-tract seeding caused by EUS-FNA has been recently reported, dissemination of pancreatic cancer cells is generally considered to be a rare complication that does not affect patient prognosis. However, the frequency of dissemination and needle-tract seeding appears to have been underestimated. We present a case of peritoneal dissemination of pancreatic cancer due to preoperative EUS-FNA.

CASE SUMMARY

An 81-year-old man was referred to the Department of Surgery of our hospital in Japan owing to the detection of a pancreatic mass on computed tomography during medical screening. Trans-gastric EUS-FNA revealed that the mass was an adenocarcinoma; hence laparoscopic distal pancreatectomy with lympha-denectomy was performed. No intraoperative peritoneal dissemination and liver metastasis were visually detected, and pelvic lavage cytology was negative for carcinoma cells. The postoperative surgical specimen was negative for carcinoma cells at the dissected margin and the cut end margin; however, pathological findings revealed adenocarcinoma cells on the peritoneal surface proximal to the needle puncture site, and the cells were suspected to be disseminated via EUS- FNA. Hence, the patient received adjuvant therapy with S-1 (tegafur, gimeracil, and oteracil potassium); however, computed tomography performed 5 mo after surgery revealed liver metastasis and cancerous peritonitis. The patient received palliative therapy and died 8 mo after the operation.

CONCLUSION

The indications of EUS-FNA should be carefully considered to avoid iatrogenic dissemination, especially for cancers in the pancreatic body or tail.

Adjuvant Pancreatic Cancer Management: Towards New Perspectives in 2021

Adjuvant chemotherapy is currently used in all patients with resected pancreatic cancer who are able to begin treatment within 3 months after surgery. Since the recent publication of the PRODIGE 24 trial results, modified FOLFIRINOX has become the standard-of-care in the non-Asian population with localized pancreatic adenocarcinoma following surgery. Nevertheless, there is still a risk of toxicity, and feasibility may be limited in heavily pre-treated patients. In more frail patients, gemcitabine-based chemotherapy remains a suitable option, for example gemcitabine or 5FU in monotherapy. In Asia, although S1-based chemotherapy is the standard of care it is not readily available outside Asia and data are lacking in non-Asiatic patients. In patients in whom resection is not initially possible, intensified schemes such as FOLFIRINOX or gemcitabine-nabpaclitaxel have been confirmed as options to enhance the response rate and resectability, promoting research in adjuvant therapy. In particular, should oncologists prescribe adjuvant treatment after a long sequence of chemotherapy +/- chemoradiotherapy and surgery? Should oncologists consider the response rate, the R0 resection rate alone, or the initial chemotherapy regimen? And finally, should they take into consideration the duration of the entire sequence, or the presence of limited toxicities of induction treatment? The aim of this review is to summarize adjuvant management of resected pancreatic cancer and to raise current and future concerns, especially the need for biomarkers and the best holistic care for patients.

Prognostic value of circulating tumor DNA in pancreatic cancer: a systematic review and meta-analysis

Increasing evidence has revealed the potential correlation between circulating tumor DNA (ctDNA) and the prognosis of pancreatic cancer, but inconsistent findings have been reported. Therefore, a meta-analysis was performed to evaluate the prognostic value of ctDNA in pancreatic cancer. The Embase, MEDLINE, and Web of Science databases were searched for relevant articles published until April 2020. Articles reporting the correlation between ctDNA and the prognosis of pancreatic cancer were identified through database searches. The pooled hazard ratios (HRs) for prognostic data were calculated and analyzed using Stata software. A total of 2326 patients pooled from 25 eligible studies were included in the meta-analysis to evaluate the prognostic value of ctDNA in pancreatic cancer. Patients with mutations detected or high concentrations of ctDNA had a significantly poorer overall survival (OS) (univariate: HR = 2.54; 95% CI, 2.05-3.14; multivariate: HR = 2.07; 95% CI, 1.69-2.54) and progression-free survival (PFS) (univariate: HR = 2.18; 95% CI, 1.41-3.37; multivariate: HR = 2.20; 95% CI, 1.38-3.52). In conclusion, the present meta-analysis indicates that mutations detected or high concentrations of ctDNA are significant predictors of OS and PFS in patients with pancreatic cancer.

Serial Circulating Tumor DNA Mutational Status in Patients with KRAS-Mutant Metastatic Colorectal Cancer from the Phase 3 AIO KRK0207 Trial

BACKGROUND

We assessed the usefulness of circulating tumor DNA (ctDNA) pre- or post-treatment initiation for outcome prediction and treatment monitoring in metastatic colorectal cancer (mCRC).

METHODS

Droplet digital PCR was used to measure absolute mutant V-Ki-ras2 Kirsten rat sarcoma viral oncogene ((mut)KRAS) ctDNA concentrations in 214 healthy controls (plasma and sera) and in 151 tissue-based mutKRAS positive patients with mCRC from the prospective multicenter phase 3 trial AIO KRK0207. Serial mutKRAS ctDNA was analyzed prior to and 2-3 weeks after first-line chemotherapy initiation with fluoropyrimidine, oxaliplatin, and bevacizumab in patients with mCRC and correlated with clinical parameters.

RESULTS

mut KRAS ctDNA was detected in 74.8% (113/151) of patients at baseline and in 59.6% (90/151) at follow-up. mutKRAS ctDNA at baseline and follow-up was associated with poor overall survival (OS) (hazard ratio [HR] =1.88, 95% confidence interval [CI] 1.20-2.95; HR = 2.15, 95% CI 1.47-3.15) and progression-free survival (PFS) (HR = 2.53, 95% CI 1.44-4.46; HR = 1.90, 95% CI 1.23-2.95), respectively. mutKRAS ctDNA clearance at follow-up conferred better disease control (P = 0.0075), better OS (log-rank P = 0.0018), and PFS (log-rank P = 0.0018). Measurable positive mutKRAS ctDNA at follow-up was the strongest and most significant independent prognostic factor on OS in multivariable analysis (HR = 2.31, 95% CI 1.40-3.25).

CONCLUSIONS

Serial analysis of circulating mutKRAS concentrations in mCRC has prognostic value. Post treatment mutKRAS concentrations 2 weeks after treatment initiation were associated with therapeutic response in multivariable analysis and may be an early response predictor in patients receiving first-line combination chemotherapy.

CLINICALTRIALSGOV IDENTIFIER

NCT00973609.

Implementing biological markers as a tool to guide clinical care of patients with pancreatic cancer

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A major obstacle for the effective treatment of PDAC is its molecular heterogeneity.

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Stratification of PDAC using markers highly specific, reproducible, sensitive, easily measurable and inexpensive is necessary.

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At the early stages, clinician’s priority lies in rapid diagnosis, so that the patient receives surgery without delay.

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At advanced disease stages, priority is to determine the tumor subtype and select a suitable effective treatment.

A major obstacle for the effective treatment of pancreatic ductal adenocarcinoma (PDAC) is its molecular heterogeneity, reflected by the diverse clinical outcomes and responses to therapies that occur. The tumors of patients with PDAC must therefore be closely examined and classified before treatment initiation in order to predict the natural evolution of the disease and the response to therapy. To stratify patients, it is absolutely necessary to identify biological markers that are highly specific and reproducible, and easily measurable by inexpensive sensitive techniques. Several promising strategies to find biomarkers are already available or under development, such as the use of liquid biopsies to detect circulating tumor cells, circulating free DNA, methylated DNA, circulating RNA, and exosomes and extracellular vesicles, as well as immunological markers and molecular markers. Such biomarkers are capable of classifying patients with PDAC and predicting their therapeutic sensitivity. Interestingly, developing chemograms using primary cell lines or organoids and analyzing the resulting high-throughput data via artificial intelligence would be highly beneficial to patients. How can exploiting these biomarkers benefit patients with resectable, borderline resectable, locally advanced, and metastatic PDAC? In fact, the utility of these biomarkers depends on the patient's clinical situation. At the early stages of the disease, the clinician's priority lies in rapid diagnosis, so that the patient receives surgery without delay; at advanced disease stages, where therapeutic possibilities are severely limited, the priority is to determine the PDAC tumor subtype so as to estimate the clinical outcome and select a suitable effective treatment.

Recent Discoveries of Diagnostic, Prognostic and Predictive Biomarkers for Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a dismal prognosis that is frequently diagnosed at an advanced stage. Although less common than other malignant diseases, it currently ranks as the fourth most common cause of cancer-related death in the European Union with a five-year survival rate of below 9%. Surgical resection, followed by adjuvant chemotherapy, remains the only potentially curative treatment but only a minority of patients is diagnosed with locally resectable, non-metastatic disease. Patients with advanced disease are treated with chemotherapy but high rates of treatment resistance and unfavorable side-effect profiles of some of the used regimens remain major challenges. Biomarkers reflect pathophysiological or physiological processes linked to a disease and can be used as diagnostic, prognostic and predictive tools. Thus, accurate biomarkers can allow for better patient stratification and guide therapy choices. Currently, the only broadly used biomarker for PDAC, CA 19-9, has multiple limitations and the need for novel biomarkers is urgent. In this review, we highlight the current situation, recent discoveries and developments in the field of biomarkers of PDAC and their potential clinical applications.

Clinical Implications of Pre- and Postoperative Circulating Tumor DNA in Patients with Resected Pancreatic Ductal Adenocarcinoma

BACKGROUND

The clinical implications of pre- and postoperative KRAS-mutated circulating tumor DNA (ctDNA) present in patients with pancreatic ductal adenocarcinoma (PDAC) have remained an unresolved issue. This study sought to investigate the clinical significance of pre- and postoperative ctDNA analyses and their impact on the prognosis of PDAC patients.

METHODS

Digital droplet polymerase chain reaction detected ctDNA in pre- and postoperative plasma samples prospectively obtained from patients with resectable and borderline-resectable PDAC. Its associations with recurrence-free survival (RFS) and overall survival (OS) were analyzed. The patients were sorted according to the presence of pre- and postoperative ctDNA, and its ability to stratify prognosis was evaluated.

RESULTS

The study analyzed 97 patients. Both pre- and postoperative ctDNA were detected in 9 patients, and neither was detected in 55 patients. Whereas 15 patients harbored only preoperative ctDNA, 18 patients had only postoperative ctDNA. The multivariate analysis showed that the presence of preoperative ctDNA was associated with poorer OS (P = 0.008) and that postoperative ctDNA was not associated with either RFS or OS. Survival did not differ significantly between the patients with a positive shift in ctDNA status and those without detectable pre- or postoperative ctDNA.

CONCLUSIONS

For the patients with PDAC, the presence of preoperative ctDNA was significantly associated poor OS, whereas postoperative ctDNA was not associated with poor survival. A positive change in ctDNA did not affect patients' survival.

Current Status of Circulating Tumor DNA Liquid Biopsy in Pancreatic Cancer

Pancreatic cancer is a challenging disease with a low 5-year survival rate. There are areas for improvement in the tools used for screening, diagnosis, prognosis, treatment selection, and assessing treatment response. Liquid biopsy, particularly cell free DNA liquid biopsy, has shown promise as an adjunct to our standard care for pancreatic cancer patients, but has not yet been universally adopted into regular use by clinicians. In this publication, we aim to review cfDNA liquid biopsy in pancreatic cancer with an emphasis on current techniques, clinical utility, and areas of active investigation. We feel that researchers and clinicians alike should be familiar with this exciting modality as it gains increasing importance in the care of cancer patients.

O-Glycan-Altered Extracellular Vesicles: A Specific Serum Marker Elevated in Pancreatic Cancer

Simple Summary

Pancreatic cancer (PC) is among the most lethal malignancies due to an often delayed and difficult initial diagnosis. Therefore, the development of a novel, early stage, diagnostic PC marker in liquid biopsies is of great significance. In this study, we analyzed the differential glycomic profiling of extracellular vesicles (EVs) derived from serum using lectin microarray. The glyco-candidates of PC-specific EVs were quantified using a high-sensitive exosome-counting system, ExoCounter. An absolute quantification system for altered glycan-containing EVs elevated in PC serum was established. EVs recognized by O-glycan-binding lectins ABA or ACA were identified as candidate markers by lectin microarray. Quantitative analyses using ExoCounter revealed that the ABA- or ACA-positive EVs were significantly increased in the serum of PC patients. These specific EVs with O-glycans can act as potential biomarkers in a liquid biopsy for PC patients screening.

Abstract

Pancreatic cancer (PC) is among the most lethal malignancies due to an often delayed and difficult initial diagnosis. Therefore, the development of a novel, early stage, diagnostic PC marker in liquid biopsies is of great significance. In this study, we analyzed the differential glycomic profiling of extracellular vesicles (EVs) derived from serum (two cohorts including 117 PC patients and 98 normal controls) using lectin microarray. The glyco-candidates of PC-specific EVs were quantified using a high-sensitive exosome-counting system, ExoCounter. An absolute quantification system for altered glycan-containing EVs elevated in PC serum was established. EVs recognized by O-glycan-binding lectins ABA or ACA were identified as candidate markers by lectin microarray. Quantitative analyses using ExoCounter revealed that the ABA- or ACA-positive EVs were significantly increased in the culture of PC cell lines or in the serum of PC patients including carbohydrate antigen 19-9 negative patients with high area under curve values. The elevated numbers of EVs in PC serum returned to normal levels after pancreatectomy. Histological examination confirmed that the tumors stained with ABA/ACA. These specific EVs with O-glycans recognized by ABA/ACA are elevated in PC sera and can act as potential biomarkers in a liquid biopsy for PC patients screening.

Combination of KRAS and SMAD4 mutations in formalin-fixed paraffin-embedded tissues as a biomarker for pancreatic cancer

Formalin‐fixed paraffin‐embedded (FFPE) tissues used for routine pathological diagnosis are valuable for cancer genomic analysis; however, the association between mutation status derived from these specimens and prognosis in pancreatic ductal adenocarcinoma (PDAC) remains unclear. We analyzed 50 cancer‐related gene mutations including driver genes in PDAC, using next‐generation sequencing (NGS) to clarify the association between gene mutations and prognosis. DNA was extracted from FFPE tissues obtained from 74 patients with untreated resectable PDAC who underwent surgery at our institution between 2013 and 2018. Fifty of the 74 patients with DNA extracts from FFPE samples suitable for NGS were analyzed. The prevalence of driver gene mutations was as follows: 84% for KRAS, 62% for TP53, 32% for SMAD4, and 18% for CDKN2A. There were no cases of single SMAD4 mutations; its rate of coincidence with KRAS or TP53 mutations was 30% and 2%, respectively. The combination of KRAS and SMAD4 mutations resulted in significantly shorter relapse‐free survival (RFS; median survival time [MST], 12.3 vs. 28.9 months, P = .014) and overall survival (OS; MST, 22.3 months vs. not reached, P = .048). On multivariate analysis, the combination of KRAS and SMAD4 mutations was an independent prognostic factor for RFS (hazard ratio [HR] 4.218; 95% confidence interval [CI], 1.77‐10.08; P = .001) and OS (HR 6.730; 95% CI, 1.93‐23.43; P = .003). The combination of KRAS and SMAD4 mutations in DNA obtained from FFPE tissues is an independent poor prognostic factor in PDAC.

Plasma circulating tumor DNA in pancreatic adenocarcinoma for screening, diagnosis, prognosis, treatment and follow-up: A systematic review

While no biomarker is currently recommended for the management of pancreatic adenocarcinoma (PA), circulating tumor DNA (ctDNA) seems promising but little is known on how it may help to manage our patients in the near future. This systematic review of literature was designed to explore the current knowledge on ctDNA as a screening, diagnostic, prognostic, predictive and theranostic biomarker in the management of PA. We retrieved 62 full-text articles, 3 meta-analyses, 2 clinical trials, 1 abstract and 13 ongoing trials. Results were categorized into sections about screening, diagnosis, prognosis and follow-up of localized and advanced PA together with possible theranostics applications. Although its specificity is excellent, the current sensitivity of ctDNA remains a limitation especially in patients without metastatic disease. Therefore, this biomarker cannot be currently used as a screening or diagnostic tool. Increasing evidence suggests that ctDNA is a relevant candidate biomarker to assess minimal residual disease after radical surgery, but also a strong independent biomarker linked to a poor prognosis in advanced PA. Some recent data also indicates that ctDNA is an attractive biomarker for longitudinal follow-up and possibly early treatment adaptation. Its role in tumor profiling in advanced disease to decide targeted treatments remains to be explored. Altogether, ctDNA appears to be a reliable prognostic tool. Though promising results have been reported, further studies are still needed to define exactly how ctDNA can help physicians in the screening, diagnosis and treatment, as PA is expected to become a major cause of cancer-related deaths in the forthcoming decade.

Impact of circulating tumor DNA in hepatocellular and pancreatic carcinomas

Hepatocellular carcinoma (HCC) and pancreatic cancer (PC) belong to the most lethal malignancies worldwide. Despite advances in surgical techniques and perioperative multidisciplinary management, the prognosis of both carcinoma entities remains poor mainly because of rapid tumor progression and early dissemination with diagnosis in advanced tumor stages with poor sensitivity to current therapy regimens. Both highly heterogeneous visceral carcinomas exhibit unique somatic alterations, but share common driver genes and mutations as well. Recently, circulating tumor DNA (ctDNA) could be identified as a liquid biopsy tool with huge potential as non-invasive biomarker in early diagnosis and prognosis. CtDNA released from necrotic or apoptotic cells of primary tumors, metastasis, and circulating tumor cells can reveal genetic and epigenetic alterations with tumor-specific and individual mutation and methylation profiles. In this article, we focus on clinical impact of ctDNA as potential biomarker in patients with HCC and PC.