Circulating tumor DNA as a predictive marker for occult metastases in pancreatic cancer patients with radiographically non-metastatic disease

Prognostic Significance of Biologic Factors in Patients with a Modest Radiologic Response to Neoadjuvant Treatment for Resectable and Borderline Resectable Pancreatic Cancers: Impact of the Combination Index of Sialyl-Lewis Antigen-Related Tumor Markers

BACKGROUND

Appropriate re-evaluation after neoadjuvant treatment (NAT) is important for optimal treatment selection. Nonetheless, determining the operative eligibility of patients with a modest radiologic response remains controversial. This study aimed to assess the prognostic significance of biologic factors for patients showing a modest radiologic response to NAT and investigate the tumor markers (TMs), CA19-9 alone, DUPAN-II alone, and their combination, to create an index that combines these sialyl-Lewis antigen-related TMs associated with treatment outcomes.

METHODS

This study enrolled patients deemed to have a "stable disease" by RECIST classification with slight progression (tumor size increase rate, ≤20%) as their radiologic response after NAT. A sialyl-Lewis-related index (sLe index), calculated by adding one fourth of the serum DUPAN-II value to the CA19-9 value, was created. The prognostic significances of CA19-9, DUPAN-II, and the sLe index were assessed in relation to postoperative outcomes.

RESULTS

An sLe index lower than the cutoff value (45.25) was significantly associated with favorable disease-free survival. Moreover, the post-NAT sLe index had a higher area under the curve value for recurrence within 24 months than the post-NAT levels of CA19-9 or DUPAN-II alone. Multivariable analysis showed that a post-NAT sLe index higher than 45.25 was the single independent predictive factor for recurrence within 24 months.

CONCLUSIONS

Additional evaluation of biologic factors can potentially enhance patient selection, particularly for patients showing a limited radiologic response to NAT. The authors' index is a simple indicator for the biologic evaluation of multiple combined sialyl-Lewis antigen-related TMs and may offer a better predictive significance.

Development of a radiomics-based model to predict occult liver metastases of pancreatic ductal adenocarcinoma: a multicenter study

BACKGROUND

Undetectable occult liver metastases block the long-term survival of pancreatic ductal adenocarcinoma (PDAC). This study aimed to develop a radiomics-based model to predict occult liver metastases and assess its prognostic capacity for survival.

MATERIALS AND METHODS

Patients who underwent surgical resection and were pathologically proven with PDAC were recruited retrospectively from five tertiary hospitals between January 2015 and December 2020. Radiomics features were extracted from tumors, and the radiomics-based model was developed in the training cohort using LASSO-logistic regression. The model's performance was assessed in the internal and external validation cohorts using the area under the receiver operating curve (AUC). Subsequently, the association of the model's risk stratification with progression-free survival (PFS) and overall survival (OS) was then statistically examined using Cox regression analysis and the log-rank test.

RESULTS

A total of 438 patients [mean (SD) age, 62.0 (10.0) years; 255 (58.2%) male] were divided into the training cohort ( n =235), internal validation cohort ( n =100), and external validation cohort ( n =103). The radiomics-based model yielded an AUC of 0.73 (95% CI: 0.66-0.80), 0.72 (95% CI: 0.62-0.80), and 0.71 (95% CI: 0.61-0.80) in the training, internal validation, and external validation cohorts, respectively, which were higher than the preoperative clinical model. The model's risk stratification was an independent predictor of PFS (all P <0.05) and OS (all P <0.05). Furthermore, patients in the high-risk group stratified by the model consistently had a significantly shorter PFS and OS at each TNM stage (all P <0.05).

CONCLUSION

The proposed radiomics-based model provided a promising tool to predict occult liver metastases and had a great significance in prognosis.

Prognostic value of preoperative circulating tumor DNA in non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Several recent studies have reported the increasing application of preoperative circulating tumor DNA (ctDNA) as a biomarker of tumor burden for guiding potential postoperative treatment strategies.

METHODS

A meta-analysis of prospective/retrospective cohort studies was conducted to compare the prognosis of preoperatively genetically positive and genetically negative NSCLC patients. The endpoints used in the included studies were overall survival (OS) and recurrence-free survival (RFS). The objective of the meta-analysis was to comprehensively explore the prognostic value of preoperative ctDNA for patients with non-small-cell lung cancer (NSCLC) and its significance in guiding postoperative adjuvant therapy (AT) in patients with NSCLC.

RESULTS

The preliminary analysis identified 1565 studies, among which only 11 studies fulfilled the eligibility criteria and were finally included in the present systematic review and meta-analysis. The statistical results revealed that the expression of preoperative ctDNA was associated with worse RFS (HR = 3.00; 95% CI 2.26-3.98; I2 = 0%) and OS (HR = 2.77; 95% CI 1.67-4.58; I2 = 0%), particularly in lung adenocarcinoma (LUAD) patients (RFS: HR = 3.46; 95% CI 2.37-5.05; I2 = 0%; OS: HR = 3.52; 95% CI 1.91-6.49; I2 = 0%) and patients with I-II stage of NSCLC (RFS: HR = 2.84; 95% CI 1.88-4.29; I2 = 0%; OS: HR = 2.60; 95% CI 1.43-4.74; I2 = 0%). Moreover, compared to patients with negative preoperative ctDNA, patients with positive preoperative ctDNA presented greater survival benefits (HR = 0.39; 95% CI 0.22-0.67; I2 = 2%) from postoperative AT.

CONCLUSION

The evaluation of the prognostic value of preoperative ctDNA revealed that preoperative ctDNA might be used as a prognostic biomarker for patients with LUAD or those with stage I-II NSCLC. In addition, postoperative AT is recommended for NSCLC patients with positive preoperative ctDNA, regardless of the disease stage and subtype.

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.

Importance of triple tumor markers as biomarkers in patients with pancreatic ductal adenocarcinoma

Aim

There is an urgent need to establish biomarkers for the treatment of pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to investigate the usefulness of the combined assessment of carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA), and duke pancreatic monoclonal antigen type 2 (DUPAN-2) in PDAC.

Methods

We retrospectively investigated the impact of three tumor markers on overall survival (OS) and recurrence-free survival (RFS). Patients were classified into two groups: upfront surgery (US) and neoadjuvant chemoradiation (NACRT) groups.

Results

In total, 310 patients were evaluated. In the US group, patients who had all three elevated markers showed a significantly worse prognosis than the others (median: 16.4 months, P = .005). In the NACRT group, patients who had elevated CA 19-9 and CEA levels after NACRT had significantly worse prognosis than the others (median: 26.2 months, P < .001). The elevated DUPAN-2 levels before NACRT were associated with significantly worse prognosis than normal levels (median: 44.0 vs 59.2 months, P = .030). Patients who had elevated DUPAN-2 levels before NACRT with elevated CA 19-9 and CEA levels after NACRT showed extremely poor RFS (median: 5.9 months). Multivariate analysis revealed that a modified triple-positive tumor marker indicating elevated DUPAN-2 levels before NACRT and elevated CA19-9 and CEA levels after NACRT was an independent prognostic factor of OS (hazard ratio: 2.49, P = .007) and RFS (hazard ration: 2.47, P = .007).

Conclusions

The combined evaluation of three tumor markers may provide useful information for the treatment of patients with PDAC.

Defining the Optimal Duration of Neoadjuvant Therapy for Pancreatic Ductal Adenocarcinoma: Time for a Personalized Approach?

ABSTRACT

Despite recent advances, pancreatic ductal adenocarcinoma (PDAC) continues to be associated with dismal outcomes, with a cure evading most patients. While historic treatment for PDAC has been surgical resection followed by 6 months of adjuvant therapy, there has been a recent shift toward neoadjuvant treatment (NAT). Several considerations support this approach, including the characteristic early systemic spread of PDAC, and the morbidity often surrounding pancreatic resection, which can delay recovery and preclude patients from starting adjuvant treatment. The addition of NAT has been suggested to improve margin-negative resection rates, decrease lymph node positivity, and potentially translate to improved survival. Conversely, complications and disease progression can occur during preoperative treatment, potentially eliminating the chance of curative resection. As NAT utilization has increased, treatment durations have been found to vary widely between institutions with an optimal duration remaining undefined. In this review, we assess the existing literature on NAT for PDAC, reviewing treatment durations reported across retrospective case series and prospective clinical trials to establish currently used approaches and seek the optimal duration. We also analyze markers of treatment response and review the potential for personalized approaches that may help clarify this important treatment question and move NAT toward a more standardized approach.

Prognostic Significance of Intraoperative Peritoneal Lavage Cytology in Patients with Pancreatic Ductal Adenocarcinoma: A Single-Center Experience and Systematic Review of the Literature

BACKGROUND

The prognostic significance of peritoneal lavage cytology (PLC) in patients with pancreatic ductal adenocarcinoma (PDAC) remains controversial. The purpose of this study was to evaluate the prognostic impact of PLC status in PDAC patients.

METHODS

Patients intending to undergo resection for PDAC between 2007 and 2020 were included. Survival was compared among patients who underwent resection with negative or positive PLC status and those who did not undergo resection. Univariable and multivariable analyses were conducted to evaluate the prognostic impact of positive PLC status. A systematic literature review was performed to evaluate the correlation between prognosis and the positive PLC rate.

RESULTS

A total of 480 patients formed the study cohort and were divided as follows: 438 in the negative PLC group, 18 in the positive PLC group, and 24 in the no resection group. Although the median survival time significantly differed between the negative and positive PLC groups (35.7 vs. 13.6 months, P < 0.001), it did not significantly differ between the positive PLC and no resection groups (13.6 vs. 12.2 months, P = 0.605). Multivariable analyses demonstrated that positive PLC status (hazard ratio = 3.54, 95% confidence interval = 1.97-6.38, P < 0.001) was the strongest poor prognostic factor. Based on statistical analyses for the systematic review, the prognostic impact of positive PLC status weakened significantly as the institutional positive PLC rate increased (P = 0.044).

CONCLUSIONS

Resection did not improve the prognosis of patients with positive PLC status in our cohort. The institutional positive PLC rate may be a good reference for surgical indication in these patients.

Circulating tumor DNA correlates with tumor burden and predicts outcome in pancreatic cancer irrespective of tumor stage

INTRODUCTION

Circulating tumor DNA (ctDNA) represents a promising tool for diagnosis, prognosis and treatment monitoring of several malignancies. Its association with tumor burden in pancreatic ductal cancer (PDAC), especially in localized disease, is not fully explored yet. We aimed to investigate the association of pretherapeutic ctDNA levels in localized and metastatic PDAC with tumor volume and clinical outcomes.

MATERIAL AND METHODS

Liquid biopsy for ctDNA detection was prospectively obtained from patients with localized or disseminated PDAC prior to either resection or systemic treatment. Detection rates and levels of ctDNA (digital droplet PCR) were correlated to tumor volume, relapse rate and survival.

RESULTS

60 patients with localized and 47 patients with metastatic PDAC were included. ctDNA was detected in 10% of localized and 57.4% of metastasized PDAC samples. In localized disease, ctDNA detection significantly correlated with the numbers of involved locoregional lymph nodes (p = 0.030). Primary tumor volume did not correlate with ctDNA levels in neither localized (p = 0.573) nor metastasized disease (p = 0.878). In disseminated disease, ctDNA levels correlated with total tumor volume (p = 0.026) and especially with liver metastases volume (p = 0.004), but not with other metastases. Detection of pretherapeutic ctDNA was associated with shorter DFS in localized (3.3 vs. 18.1 months, p = 0.000), whereas ctDNA levels were associated with worse survival in metastatic PDAC (5.7 vs. 7.8 months, p = 0.036).

CONCLUSION

ctDNA positivity indicates major nodal involvement or even presence of undetected distant metastases associated with early recurrence in localized PDAC. Moreover, it predicts worse clinical outcome in both localized and metastatic disease.