Risk factors for latent distant organ metastasis detected by staging laparoscopy in patients with radiologically defined locally advanced pancreatic ductal adenocarcinoma

Impact of endoscopic ultrasound-guided tissue acquisition on prognosis and peritoneal lavage cytology in resectable or borderline resectable pancreatic ductal adenocarcinoma

OBJECTIVES

This study aimed to evaluate the clinical impact of preoperative endoscopic ultrasound-guided tissue acquisition (EUS-TA) on the prognosis and incidence of positive peritoneal lavage cytology (PLC) during laparotomy or staging laparoscopy in patients with resectable (R) or borderline resectable (BR) pancreatic ductal adenocarcinoma (PDAC).

METHODS

We retrospectively collected data from patients diagnosed with body and tail PDAC with/without EUS-TA at our hospital from January 2006 to December 2021.

RESULTS

To examine the effect of EUS-TA on prognosis, 153 patients (122 in the EUS-TA group, 31 in the non-EUS-TA group) were analyzed. There was no significant difference in overall survival between the EUS-TA and non-EUS-TA groups after PDAC resection (P = 0.777). In univariate and multivariate analysis, preoperative EUS-TA was not identified as an independent factor related to overall survival after pancreatectomy [hazard ratio 0.96, 95 % confidence interval (CI) 0.54-1.70, P = 0.897]. Next, to examine the direct influence of EUS-TA on the results of PLC, 114 patients (83 in the EUS-TA group and 31 in the non-EUS-TA group) were analyzed. Preoperative EUS-TA was not statistically associated with positive PLC (odds ratio 0.73, 95 % CI 0.25-2.20, P = 0.583). After propensity score matching, overall survival and positive PLC were the same in both groups.

CONCLUSIONS

EUS-TA had no negative impact on postoperative survival and PLC-positive rates in R/BR PDAC.

Scoring system to predict positive peritoneal cytology in patients with resectable and borderline resectable pancreatic cancer

BACKGROUND

The aim of this study was to evaluate factors to predict positive peritoneal cytology, whcih would determine the indication for staging laparoscopy in pancreatic cancer.

METHODS

A total of 430 patients that underwent pancreatectomy for resectable and borderline resectable pancreatic cancer were retrospectively reviewed.

RESULTS

Among 430 patients, 36 had positive cytology (8.4%). Median survival time in negative cytology was 24.7 months, compared with 15.1 months in positive cytology (p = .004). Factors to predict positive cytology in pancreatic cancer according to multivariate analysis were tumor location (body, tail; OR 2.66; 95% CI: 1.21-5.85; p = .015), tumor size ≥30 mm (OR 2.95; 95% CI: 1.35-6.47; p = .007) and radiographic other-organ invasion (HR 2.79; 95% CI: 1.01-7.67; p = .047). Patients were scored 0 to 3 corresponding with these factors. Rates of positive cytology increases in each score were: score 0: 2.9%, score 1: 6.7%, score 2: 18.3%, score 3: 36.8%.

CONCLUSIONS

Tumor location (body or tail), tumor size ≥30 mm, and radiographic other-organ invasions were risk factors for positive cytology in pancreatic cancer. This scoring system might be a useful indicator to perform staging laparoscopy to diagnose positive cytology.

Can preoperative Carbohydrate Antigen 19-9 predict metastatic pancreatic cancer? Results of a systematic review and meta-analysis

BACKGROUND

To investigate the relationship between preoperative Carbohydrate Antigen19-9(CA19-9)and pancreatic cancer occult metastasis.

METHODS

Systematic search of MEDLINE, CENTRAL, Web of Science and bibliographic reference lists were conducted. All comparative observational studies investigating the predictive ability of preoperative CA 19-9 in patients with pancreatic cancer were considered. Mean CA-19-9 value in the pancreatic cancer patients with and without metastasis were evaluated. Best cut-off value of CA 19-9 for metastasis was determined using ROC analysis.

RESULTS

Ten comparative observational studies reporting a total of 1431 pancreatic cancer patients with (n = 496) and without (n = 935) metastasis were included. Subsequent meta-analysis demonstrated that mean preoperative CA 19-9 level was significantly higher in patients with metastases compared to those without (MD: 904.4; 95 % CI, 642.08-1166.74, P < 0.0001). The between-study heterogeneity was significant (I2: 99 %, P < 0.00001). ROC analysis yielded a cut-off CA 19-9 level of 336 with a sensitivity and specificity for predicting metastasis of 90 % and 80 %, respectively (AUC = 0.90).

CONCLUSIONS

CA 19-9 level is significantly higher in patients with metastatic pancreatic cancer. A preoperative CA 19-9 value of 336 should be considered as an acceptable cut-off value to design prospective studies.

Development and validation of a deep learning radiomics model with clinical-radiological characteristics for the identification of occult peritoneal metastases in patients with pancreatic ductal adenocarcinoma

BACKGROUND

Occult peritoneal metastases (OPM) in patients with pancreatic ductal adenocarcinoma (PDAC) are frequently overlooked during imaging. The authors aimed to develop and validate a computed tomography (CT)-based deep learning-based radiomics (DLR) model to identify OPM in PDAC before treatment.

METHODS

This retrospective, bicentric study included 302 patients with PDAC (training: n =167, OPM-positive, n =22; internal test: n =72, OPM-positive, n =9: external test, n =63, OPM-positive, n =9) who had undergone baseline CT examinations between January 2012 and October 2022. Handcrafted radiomics (HCR) and DLR features of the tumor and HCR features of peritoneum were extracted from CT images. Mutual information and least absolute shrinkage and selection operator algorithms were used for feature selection. A combined model, which incorporated the selected clinical-radiological, HCR, and DLR features, was developed using a logistic regression classifier using data from the training cohort and validated in the test cohorts.

RESULTS

Three clinical-radiological characteristics (carcinoembryonic antigen 19-9 and CT-based T and N stages), nine HCR features of the tumor, 14 DLR features of the tumor, and three HCR features of the peritoneum were retained after feature selection. The combined model yielded satisfactory predictive performance, with an area under the curve (AUC) of 0.853 (95% CI: 0.790-0.903), 0.845 (95% CI: 0.740-0.919), and 0.852 (95% CI: 0.740-0.929) in the training, internal test, and external test cohorts, respectively (all P <0.05). The combined model showed better discrimination than the clinical-radiological model in the training (AUC=0.853 vs. 0.612, P <0.001) and the total test (AUC=0.842 vs. 0.638, P <0.05) cohorts. The decision curves revealed that the combined model had greater clinical applicability than the clinical-radiological model.

CONCLUSIONS

The model combining CT-based DLR and clinical-radiological features showed satisfactory performance for predicting OPM in patients with PDAC.

Rim Enhancement and Peripancreatic Fat Stranding in Preoperative MDCT as Predictors for Occult Metastasis in PDAC Patients

RATIONALE AND OBJECTIVE

To identify the radiological features and clinical biomarkers that could predict the occult metastasis (OM) of pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

This retrospective study included PDAC patients who were radiologically diagnosed resectable (R) or borderline resectable (BR) and underwent surgical exploration from January 2018 to December 2021. Depending on whether distant metastases were found during the exploration, patients were divided into OM and non-OM groups. Univariate and multivariable logistic regression analyses were performed to determine the radiological and clinical predictive factors for occult metastasis. Model performance was determined by discrimination and calibration.

RESULTS

A total of 502 patients (median age, 64 years; interquartile range, 57-70 years; 294 men) were enrolled, among which 68 (13.5%) patients were found with distant metastases, with 45 liver-only, 19 peritoneal-only, four patients had both liver and peritoneal metastases. Rim enhancement and peripancreatic fat stranding were more frequent in the OM group than in the non-OM group. Tumor size (p = 0.028), tumor resectability (p = 0.031), rim enhancement (p < 0.001), peripancreatic fat stranding (p < 0.001) and level of CA125 (p = 0.021) were independent predictors of occult metastasis according to the multivariable analyses, and the areas under the curve (AUCs) of these characteristics were 0.703, 0.594, 0.638, 0.655, 0.631, respectively. The combined model showed the highest AUC of 0.823.

CONCLUSIONS

Rim enhancement, peripancreatic fat stranding, tumor size, tumor resectability and level of CA125 are risk factors for OM of PDAC. The combined model of radiological and clinical features may help the preoperative prediction of OM in PDAC.

Machine learning was used to predict risk factors for distant metastasis of pancreatic cancer and prognosis analysis

BACKGROUND

The mechanisms of distant metastasis in pancreatic cancer (PC) have not been elucidated, and this study aimed to explore the risk factors affecting the metastasis and prognosis of metastatic patients and to develop a predictive model.

METHOD

Clinical data from patients meeting criteria from 1990 to 2019 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database, and two machine learning methods, random forest and support vector machine, combined with logistic regression, were used to explore risk factors influencing distant metastasis and to create nomograms. The performance of the model was validated using calibration curves and ROC curves based on the Shaanxi Provincial People's Hospital cohort. LASSO regression and Cox regression models were used to explore the independent risk factors affecting the prognosis of patients with distant PC metastases.

RESULTS

We found that independent risk factors affecting PC distant metastasis were: age, radiotherapy, chemotherapy, T and N; the independent risk factors for patient prognosis were: age, grade, bone metastasis, brain metastasis, lung metastasis, radiotherapy and chemotherapy.

CONCLUSION

Together, our study provides a method for risk factors and prognostic assessment for patients with distant PC metastases. The nomogram we developed can be used as a convenient individualized tool to facilitate aid in clinical decision making.

Proton radiotherapy as a treatment strategy to increase survival in locally advanced pancreatic cancer in the body and tail: a retrospective study

BACKGROUND

Long-term outcomes and prognostic factors of proton radiotherapy for locally advanced pancreatic cancer (LAPC) in the body and tail are still unknown. The aim of this study was to determine the prognostic factors after proton radiotherapy in a large group of patients with LAPC in the body and tail.

METHODS

The medical records of 200 patients with LAPC in the body and tail who underwent proton radiotherapy between February 2009 and January 2021 at the Hyogo Ion Beam Medical Center were retrospectively reviewed to identify prognostic factors that contribute to long-term survival.

RESULTS

The overall survival rate at 1- and 2-year after PT was 69.6% and 35.4% with a median overall survival of 18.4 months. The 1- and 2-year local progression-free, and progression-free survival rates were 84.3% and 68.0%, and 44.3% and 19.4%, respectively. In multivariate analysis, superior mesenteric artery (SMA) invasion (SMA only invasion vs. celiac artery only invasion; P = 0.049: SMA and celiac artery invasion vs. celiac artery only invasion; P = 0.017), carbohydrate antigen 19-9 (CA 19-9) level ≥ 231.9 U/mL (P = 0.001), anterior peripancreatic invasion (P = 0.006), and incomplete scheduled concurrent chemotherapy (P = 0.009) were statistically significant prognostic factors for overall survival. There was no significant difference in local progression-free survival; however, distant metastasis-free survival was statistically worse in patients with prognostic factors than in those without.

CONCLUSIONS

Proton radiotherapy for LAPC in the body and tail may be a valuable multidisciplinary treatment option. Patients with SMA invasion, higher pre-proton radiotherapy serum CA 19-9 level, anterior peripancreatic invasion, or incomplete scheduled concurrent chemotherapy had worse overall survival because of worse distant metastasis-free survival, suggesting that distant metastases have a significant impact on overall survival in such patients.

TRIAL REGISTRATION

Retrospectively registered.

Is there any role of staging laparoscopy in pancreatic adenocarcinoma?

This is a letter to the editor on a study by Jambor et al. on the role of staging laparoscopy in identifying occult and distant metastases in pancreatic adenocarcinoma patients. In this study, inclusion of staging laparoscopy as an adjunct to computed tomography resulted in an absolute risk reduction of 12.5% for non-therapeutic laparotomy. The study found no correlation between the presence of occult and distant metastases, and serum CA 19-9 level, tumour size or location, which was in significant contrast to a number of other studies. This was likely due to the smaller sample size of the study and restriction to a single high-volume referral centre. It is also noted that staging laparoscopy cannot detect vascular invasion, lymph node involvement and deep hepatic metastases. The sensitivity of peritoneal lavage cytology in detecting occult metastases is low as well. Inclusion of biomarkers like peritoneal lavage tumour DNA may improve sensitivity. Hence, even as this study adds to the evidence supporting staging laparoscopy, further studies on improving the sensitivity of staging laparoscopy are warranted.

Advances in pre-treatment evaluation of pancreatic ductal adenocarcinoma: a narrative review

BACKGROUND AND OBJECTIVE

Despite advances in the multidisciplinary management of pancreatic cancer, overall prognosis remains poor, due to early progression of the disease. There is a need to also take action in staging, to make it increasingly accurate and complete, to define the setting of the therapeutic strategy. This review was planned to update the current status of pre-treatment evaluation for pancreatic cancer.

METHODS

We conducted an extensive review, including relevant articles dealing with traditional imaging, functional imaging and minimally invasive surgical procedures before treatment for pancreatic cancer. We searched articles written in English only. Data in the PubMed database, published in the period between January 2000 and January 2022, were retrieved. Prospective observational studies, retrospective analyses and meta-analyses were reviewed and analysed.

KEY CONTENT AND FINDINGS

Each imaging modality (endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography, computed tomography, positron emission tomography/computed tomography, staging laparoscopy) has its own diagnostic advantages and limitations. The sensitivity, specificity and accuracy for each image set are reported. Data that support the increasing role of neoadjuvant therapy (radiotherapy and chemotherapy) and the meaning of a patient-tailored treatment selection, based on tumour staging, are also discussed.

CONCLUSIONS

A multimodal pre-treatment workup should be searched as it improves staging accuracy, orienting patients with resectable tumors towards surgery, optimizing patient selection with locally advanced tumors to neoadjuvant or definite therapy and avoiding surgical resection or curative radiotherapy in those with metastatic disease.

Prognostic Impact of Positive Peritoneal Lavage Cytology on Resectable Pancreatic Body and Tail Cancer: A Retrospective Study

BACKGROUND

The prognostic impact of positive peritoneal lavage cytology on pancreatic cancer is unclear. Therefore, this study aimed to evaluate its impact in resectable pancreatic body and tail cancer.

METHODS

Between January 2006 and December 2019, 97 patients with pancreatic body and tail cancer underwent peritoneal lavage cytology and curative resection at our institution. We analyzed the impact of positive peritoneal lavage cytology on clinicopathological factors and on the prognosis of pancreatic body and tail cancer.

RESULTS

Malignant cells were detected in 14 patients (14.4%) using peritoneal lavage cytology. In these patients, the tumor diameter was significantly larger (p < 0.001) and anterior serosal invasion (p = 0.034), splenic artery invasion (p = 0.013), lympho-vessel invasion (p = 0.025), and perineural invasion (p = 0.008) were significantly more frequent. The R1 resection rate was also significantly higher in patients with positive peritoneal lavage cytology than in negative patients (p = 0.015). Positive peritoneal lavage cytology had a significantly poor impact on overall survival (p = 0.001) and recurrence-free survival (p < 0.001). This cytology was also an independent poor prognostic factor for recurrence (p = 0.022) and was associated with peritoneal dissemination and liver metastasis.

CONCLUSIONS

Positive peritoneal lavage cytology is considered to be indicative of more systemic disease in patients with resectable pancreatic body and tail cancer than in patients with negative peritoneal lavage cytology. Early detection of pancreatic cancer before it develops micrometastases is important to improve prognosis, and CY+ patients require more intensive multimodality treatment than standard treatment for resectable pancreatic cancer.

Synopsis of a clinical practice guideline for pancreatic ductal adenocarcinoma with peritoneal dissemination in Japan; Japan Peritoneal Malignancy Study Group

Patients with pancreatic ductal adenocarcinoma (PDAC) with peritoneal dissemination have a dismal prognosis because discontinuation of systemic chemotherapy is required for massive ascites or poor performance status. The natural history, diagnosis and treatment of PDAC with peritoneal dissemination have not been fully investigated. We systematically reviewed published information on the clinical diagnosis and treatment of PDAC with peritoneal dissemination using the PubMed database (2000-2020) and provided recommendations in response to clinical questions. This guideline was created according to the "Minds Clinical Practice Guideline Development Guide 2017". The literature quality and body of evidence were evaluated with the GRADE System and classified into four levels ("strong", "medium", "weak", "very weak"). The strength of each final recommendation was decided by a vote of committee members based on the GRADE Grid method. These guidelines address three subjects: diagnostic, chemotherapeutic, and surgical approaches. They include nine clinical questions and statements with recommendation strengths, evidence levels, and agreement rates, in addition to one "column". This is the English synopsis of the 2021 Japanese clinical practice guideline for PDAC with peritoneal dissemination. It summarizes the clinical evidence for the diagnosis and treatment of PDAC with peritoneal dissemination and provides future perspectives.

The clinical benefits of performing staging laparoscopy for pancreatic cancer treatment

BACKGROUND

The indications and benefits derived from staging laparoscopy (SL) for pancreatic cancer (PC) remain controversial.

METHODS

This study involved PC patients in whom resection had been considered possible between 2009 and 2020. We classified the patients into before 2014 (training set) and 2014 and later (validation set) groups, as SL was introduced in 2014, in our institution. In the training set, the predictors of non-curative factors were investigated, and reproducibility was confirmed in the validation set. In addition, the outcomes were compared between the datasets.

RESULTS

A total of 802 patients were classified into the training set (n = 241) and validation set (n = 561). In the training set, pancreatic body or tail tumors (odds ratio [OR]: 2.62: P = 0.039), CA19-9 > 88 U/ml (OR: 3.21: P = 0.018) and a tumor diameter >36 mm (OR: 6.07; P < 0.001) were independent predictors of non-curative factors. The increased rate of non-curative factors was confirmed as the number of predictors increased in the validation set. The curative resection (CR) rate was significantly higher in the validation set than in the training set (P = 0.035). Although there was no significant difference in the OS in the not-resected group (P = 0.895), the OS in the CR and non-CR group was significantly better in the validation set than in the training set (CR, P < 0.001; non-CR, P < 0.001).

CONCLUSION

The findings suggest potential candidates for SL and revealed improved outcomes by the advent of treatment strategies including SL.

Preoperative risk factors for positivity of peritoneal lavage cytology in patients with pancreatic ductal adenocarcinoma in the era of neoadjuvant therapy

BACKGROUND

The preoperative risk factors for positive peritoneal lavage cytology (CY) are unknown, especially in patients who received neoadjuvant therapy. In addition, the optimal indications for staging laparoscopy (SL) are still unclear. The aim of this study was to investigate the preoperative risk factors of CY positivity in patients with pancreatic ductal adenocarcinoma (PDAC) treated with surgical resection and to determine the optimal indications for SL.

METHODS

We retrospectively analyzed 493 patients with PDAC, including 356 treated with upfront surgery and 137 treated with neoadjuvant chemotherapy (NAC). The preoperative risk factor for CY positivity was investigated along with stratification according to NAC.

RESULTS

Among the 493 patients, 36 (7.3%) were CY-positive. The CY-positive frequency in patients who received and did not receive NAC was 9 (6.6%) and 27 (7.6%), respectively. In the multivariate analyses, no independent preoperative predictive factor was found in patients who received NAC, whereas body and tail PDAC were identified as an independent risk factor for CY positivity in patients who did not receive NAC.

CONCLUSIONS

The preoperative risk factors of CY-positive PDAC are body and tail PDAC in 356 patients who did not receive NAC. However, there is no useful predictive factor for CY positivity in patients treated with NAC. Based on these results, it was difficult to determine the optimal indication for SL especially in NAC cases.

Neoadjuvant Treatment Strategies in Resectable Pancreatic Cancer

Simple Summary

Only 10–20% of patients with newly diagnosed resectable pancreatic adenocarcinoma have potentially resectable disease. Upfront surgery is the gold standard, but it is rarely curative. After surgical extirpation of tumors, up to 80% of patients will develop cancer recurrence, and the initial relapse is metastatic in 50–70% of these patients. Adjuvant chemotherapy offers the best strategy to date to improve overall survival but faces real challenges; some patients will experience rapid disease progression within 3 months of surgery and patients who do not receive all planned cycles of chemotherapy have unfavourable oncological outcomes. The neoadjuvant approach is therefore logical but requires further investigation. This approach shows favourable trends regarding disease-free survival and overall survival but, in the absence of rigorous published phase III trials, is not validated to date. Here, we intend to provide a comprehensive analysis of the literature to provide direction for future studies.

Abstract

Complete surgical resection is the cornerstone of curative therapy for resectable pancreatic adenocarcinoma. Upfront surgery is the gold standard, but it is rarely curative. Neoadjuvant treatment is a logical option, as it may overcome some of the limitations of adjuvant therapy and has already shown some encouraging results. The main concern regarding neoadjuvant therapy is the risk of disease progression during chemotherapy, meaning the opportunity to undergo the intended curative surgery is missed. We reviewed all recent literature in the following areas: major surveys, retrospective studies, meta-analyses, and randomized trials. We then selected the ongoing trials that we believe are of interest in this field and report here the results of a comprehensive review of the literature. Meta-analyses and randomized trials suggest that neoadjuvant treatment has a positive effect. However, no study to date can be considered practice changing. We considered design, endpoints, inclusion criteria and results of available randomized trials. Neoadjuvant treatment appears to be at least a feasible strategy for patients with resectable pancreatic cancer.

Impact of sarcopenia on recurrent biliary obstruction after insertion of self-expandable metallic stent in patients with malignant biliary obstruction

BACKGROUND/PURPOSE

Recurrent biliary obstruction (RBO) after self-expandable metallic stent (SEMS) insertion is a big problem in patients with unresectable malignant biliary obstruction (MBO). Sarcopenia is associated with poor prognosis in patients with malignancies. The purpose of this study is to clarify the relationship between RBO and sarcopenia.

METHODS

Forty-six patients with normal psoas muscle mass index (PMI) and 55 with low PMI were enrolled, based on PMI cut-off values. We analyzed the cumulative incidences and predictors of RBO, considering death without RBO to be a competing risk.

RESULTS

In the Kaplan-Meier analysis, the 60-, 180-, and 360-day cumulative incidence rates of RBO were 0.0%, 12.2%, and 22.0% in the normal PMI group, as compared to 4.0%, 31.1%, and 55.0% in the low PMI group, respectively (log-rank P = .003). In competing risk analysis, the incidences were 2.9%, 2.9%, and 7.1% in the normal PMI group, as compared to 13.7%, 34.8%, and 51.7% in the low PMI group, respectively (P < .001). In multivariate Cox regression and Fine-Gray's analyses, hazard ratios of low PMI for RBO were 4.593 (95% confidence interval 1.673-12.61, P = .003) and 4.980 (2.045-12.13, P < .001), respectively.

CONCLUSIONS

Sarcopenia in MBO was an independent risk factor for RBO.

Staging laparoscopy is mandatory for the treatment of pancreatic cancer to avoid missing radiologically negative metastases

PURPOSE

Staging laparoscopy is considered useful for determining treatment plans for advanced pancreatic cancer. However, the indications for staging laparoscopy are not clear. This study aimed to evaluate the safety of staging laparoscopy and its usefulness for detecting distant metastases in patients with pancreatic cancer.

METHODS

A total of 146 patients with pancreatic cancer who underwent staging laparoscopy between 2013 and 2019 were analyzed. Staging laparoscopy was performed in all pancreatic cancer patients in whom surgery was considered possible.

RESULTS

In this cohort, 42 patients (29%) were diagnosed with malignant cells on peritoneal lavage cytology, 9 (6%) had peritoneal dissemination, and 11 (8%) had liver metastases. A total of 48 (33%) had radiologically negative metastases. On a multivariate analysis, body and tail cancer [odds ratio (OR) 5.00, 95% confidence interval (CI) 2.15-11.6, p < 0.001], high CA19-9 level [OR 4.04, 95% CI 1.74-9.38, p = 0.001], and a resectability status of unresectable (OR 2.31, 95% CI 1.03-5.20, p = 0.04) were independent risk factors for radiologically negative metastases.

CONCLUSIONS

Staging laparoscopy can be safely performed and is useful for the diagnosis of radiologically negative metastases. Staging laparoscopy should be routinely performed for the accurate diagnosis of pancreatic cancer patients before pancreatectomy and/or local treatment, such as radiotherapy.

Comparable prevalence of distant metastasis and survival of different primary site for LN + pancreatic tumor

Background

Few studies have delved into the prevalence of distant metastasis (DM +) and survival for patients with lymph node metastases (LN +) by primary site. We aimed to detect differences in distant metastasis and prognosis between pancreatic head and bodytail tumors for LN + patients.

Methods

Patients with chemotherapy, histologically diagnosed, primary site between 2004 and 2016 were included from the SEER (Surveillance, Epidemiology, and End Results) database. Pancreatic head tumors were compared with pancreatic bodytail tumors using the odds ratio (OR) for rates of distant metastasis, hazard ratios (HR) for overall survival (OS) and cancer-specific survival (CSS). The competing risk model and propensity score matching (PSM) were performed to further explore.

Results

Of 5726 LN + patients identified from the SEER database, pancreatic head tumors account for 85.2% (4877 of 5726) and 14.8% (849 of 5726) were pancreatic bodytail tumors. The incidence of DM was lower in pancreatic head than in pancreatic bodytail tumors (OR, 0.29; 95% CI 0.23–0.37; P < 0.001). The multivariate Cox regression show pancreatic head tumors have a significantly shorter survival rate relative to pancreatic bodytail (HR, 1.12; 95% CI 1.03–1.22; P = 0.008), but the primary site was not a significant independent risk factor for prognosis by log-rank test (P = 0.39) and multivariate competing risk model [subdistribution HR (SHR), 1.08; 95% CI 0.98–1.19; P = 0.087].We then examined our conclusion by 1:1 propensity score matching, and the result reflected pancreatic head tumors have a lower risk of DM compared with pancreatic bodytail tumors (OR, 0.22; 95% CI 0.15–0.34; P < 0.001), but the primary site of pancreatic tumors was not associated with LN + patient survival based on univariate Cox regression (HR, 1.04; 95% CI 0.93–1.17; P = 0.435) and competing risk analysis (SHR, 1.01; 95% CI 0.89–1.12; P = 0.947).

Conclusions

LN + pancreatic head tumors were significantly lower risk of DM relative to pancreatic bodytail tumors. Survival outcome in LN + pancreatic tumors didn’t exist significant differences split by primary site, which indicates that the prognosis of LN + patients with chemotherapy isn’t associated with the primary site of metastasis, but with the occurrence of metastasis.

Performance of Multiparametric Functional Imaging and Texture Analysis in Predicting Synchronous Metastatic Disease in Pancreatic Ductal Adenocarcinoma Patients by Hybrid PET/MR: Initial Experience

Objectives: To assess the imaging biomarkers of glucose metabolic activity and diffusion-weighted imaging (DWI) derived from pretreatment integrated ¹⁸F-fluorodeoxyglucose positron emission tomography-magnetic resonance (¹⁸F-FDG PET/MR) imaging as potential predictive factors of metastasis in patients with pancreatic ductal adenocarcinoma (PDAC). Patients and Methods: We retrospectively included 17 consecutive patients with pathologically confirmed PDAC by pretreatment ¹⁸F-FDG PET/MR. The study subjects were divided into a non-metastatic group (M0, six cases) and a metastatic group (M1, 11 cases). The ¹⁸F-FDG PET/MR images were reviewed independently by two board certificated nuclear medicine physicians and one radiologist. Conventional characteristics and quantitative parameters from both PET and apparent diffusion coefficient (ADC) were assessed. The texture features were extracted from LIFEx packages (www.lifexsoft.org), and a 3D tumor volume of interest was manually drawn on fused PET/ADC images. Chi-square tests, independent-samples t-tests and Mann-Whitney U-tests were used to compare the differences in single parameters between the two groups. A logistic regression analysis was performed to determine independent predictors. A receiver operating characteristic (ROC) curve analysis was performed to assess the discriminatory power of the selected parameters. Correlations between metabolic parameters and ADC features were calculated with Spearman's rank correlation coefficient test. Results: For conventional parameters, univariable analysis demonstrated that the M1 group had a significantly larger size and a higher peak of standardized uptake value (SUV_peak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) than those of the M0 group (p < 0.05 for all). TLG remained significant predictor in the multivariable analysis, but there were no significant differences for the area under the ROC curve (AUC) among the four conventional features in differential diagnoses (p > 0.05 for all). For the texture features, there were four features from the PET image and 13 from the ADC map that showed significant differences between the two groups. Multivariate analysis indicated that one feature from PET and three from the ADC were significant predictors. TLG was associated with ADC-GLRLM_GLNU (r = 0.659), ADC-GLRLM_LRHGE (r = 0.762), and PET-GLRLM_LRHGE (r = 0.806). Conclusions: Multiple parameters and texture features of primary tumors from ¹⁸F-FDG PET/MR images maybe reliable biomarkers to predict synchronous metastatic disease for the pretreatment PDAC.

Quantitative monitoring of circulating tumor DNA in patients with advanced pancreatic cancer undergoing chemotherapy

According to cancer genome sequences, more than 90% of cases of pancreatic ductal adenocarcinoma (PDAC) harbor active KRAS mutations. Digital PCR (dPCR) enables accurate detection and quantification of rare mutations. We assessed the dynamics of circulating tumor DNA (ct-DNA) in patients with advanced PDAC undergoing chemotherapy using dPCR. KRAS G12/13 mutation was assayed by dPCR in 47 paired tissue- and ct-DNA samples. The 21 patients were subjected to quantitative ct-DNA monitoring at 4 to 8-week intervals during chemotherapy. KRAS mutation was detected in 45 of those 47 patients using tissue DNA. In the KRAS mutation-negative cases, next-generation sequencing revealed KRAS Q61K and NRAS Q61R mutations. KRAS mutation was detected in 23/45 cases using ct-DNA (liver or lung metastasis, 18/19; mutation allele frequency [MAF], 0.1%-31.7%; peritoneal metastasis, 3/9 [0.1%], locally advanced, 2/17 [0.1%-0.2%]). In the ct-DNA monitoring, the MAF value changed in concordance with the disease state. In the 6 locally advanced cases, KRAS mutation appeared concurrently with liver metastasis. Among the 6 cases with liver metastasis, KRAS mutation disappeared during the duration of stable disease or a partial response, and reappeared at the time of progressive disease. The median progression-free survival was longer in cases in which KRAS mutation disappeared after an initial course of chemotherapy than in those in which it was continuously detected (248.5 vs 50 days, P < .001). Therefore, ct-DNA monitoring enables continuous assessment of disease state and could have prognostic utility during chemotherapy.

A prospective single-center protocol for using near-infrared fluorescence imaging with indocyanine green during staging laparoscopy to detect small metastasis from pancreatic cancer

Background

Pancreatic resection and radiotherapy are powerful tools in the multidisciplinary local treatment of pancreatic ductal adenocarcinoma (PDAC). However, 10–20% of patients with preoperatively resectable PDAC have radiographically occult metastases, which results in laparotomy without resection. This study aims to explore the utility of intraoperative near-infrared (NIR) imaging with indocyanine green (ICG) during staging laparoscopy to detect PDAC metastasis.

Methods

This prospective study will evaluate patients with radiographically non-metastatic PDAC before they undergo planned pancreatic resection or chemoradiotherapy. Enrolled patients will receive ICG intravenously (0.5 mg/kg) before the staging laparoscopy. During the staging laparoscopy, the abdominal cavity will be observed using standard white-light laparoscopic imaging and then using NIR-ICG imaging. Suspicious lesions that are detected using standard imaging and/or NIR-ICG imaging will be examined intraoperatively using frozen sections and permanent specimens. We will evaluate the benefit of NIR-ICG imaging based on its ability to identify additional liver or peritoneal lesions that were not detected during standard white-light imaging.

Discussion

This study will help establish the clinical utility of NIR-ICG imaging to more precisely identify metastases from radiographically non-metastatic PDAC. This approach may help avoid needless major surgery or radiotherapy.

Trial registration

This protocol was registered on April 1, 2017 on the UMIN Clinical Trials Registry: UMIN000025900 and February 26, 2019 on the Japan Registry of Clinical Trials: jRCT1051180076.

Predictors of distant metastasis on exploration in patients with potentially resectable pancreatic cancer

BACKGROUND

Patients with potentially resectable pancreatic ductal adenocarcinoma (PDAC) are frequently found to be unresectable on exploration due to small distant metastasis. This study was to investigate predictors of small distant metastasis in patients with potentially resectable PDAC.

METHODS

Patients who underwent surgical exploration for potentially resectable PDAC from 2013 to 2014 were reviewed retrospectively and divided into two groups according to whether distant metastases were encountered on exploration. Then, univariate and multivariate logistic regression analyses were used to identify predictors of distant metastasis. A scoring system to predict distant metastasis of PDAC on exploration was constructed based on the regression coefficient of a multivariate logistic regression model.

RESULTS

A total of 235 patients were included in this study. Mean age of the study population was 61.7 ± 10.4 years old. Upon exploration, distant metastases were found intraoperatively in 62 (26.4%) patients, while the remaining 173 were free of distant metastases. Multivariate logistic regression analysis identified that age ≤ 62 years old (p < 0.001), male sex (p = 0.011), tumor size ≥4.0 cm (p < 0.001), alanine aminotransferase level (ALT) < 125 U/L (p < 0.001), and carbohydrate antigen (CA19-9) level ≥ 385 U/mL (p < 0.001) were independent risk factors for occult distant metastasis of PDAC. A preoperative scoring system (0-8 points) for distant metastasis on exploration was constructed using these five factors. The receiver operating characteristic curves showed that the area under the curve of this score was 0.85. A score of 6 points was suggested to be the optimal cut-off value, and the sensitivity and specificity were 85% and 69%, respectively.

CONCLUSIONS

Distant metastasis is still frequently encountered on exploration for patients with potentially resectable PDAC. Younger age, male sex, larger tumor size, low ALT level and high CA19-9 level are independent predictors of unexpected distant metastasis on exploration.

Incidence and risk factors for abdominal occult metastatic disease in patients with pancreatic adenocarcinoma

BACKGROUND

The incidence of occult metastatic disease (OMD) in pancreatic ductal adenocarcinoma (PDAC) and associated risk factors are largely unknown.

METHODS

We identified all patients with PDAC, who had an aborted oncologic operation due to OMD within a 10-year period. The cases were matched to a cohort of resected PDAC patients on a 1:3 ratio, based on age and sex, for comparison of preoperative clinical characteristics and potential risk factors for OMD.

RESULTS

In the studied period, 117 patients with OMD were identified in 1423 pancreatectomies performed for PDAC (8%). Liver metastases were the most common finding (79%) followed by peritoneal implants (16%). When compared with non-OMD cases, patients with OMD presented more often with abdominal pain (P < 0.001), and higher preoperative carbohydrate antigen 19-9 (CA 19-9) values ( P = 0.007). Additionally, indeterminate liver lesions on preoperative computed tomography (CT) were identified in 40% of OMD versus 17% of non-OMD patients ( P < 0.001). Multivariable analysis distinguished four independent predictors for OMD: indeterminate lesions on preoperative CT, tumor size > 30 mm, abdominal pain, and preoperative CA 19-9 > 192 U/mL.

CONCLUSIONS

Occurrence of OMD in PDAC accounts for 8% of cases. Preoperative CA 19-9 > 192 U/mL, primary tumor size > 30 mm, and identification of indeterminate lesions in preoperative CT may indicate the need for diagnostic laparoscopy.

Survival benefit of intravenous and intraperitoneal paclitaxel with S-1 in pancreatic ductal adenocarcinoma patients with peritoneal metastasis: a retrospective study in a single institution

BACKGROUND

We evaluated the clinical efficacy of intravenous (i.v.) and intraperitoneal (i.p.) paclitaxel (PTX) combined with S-1 in patients with chemotherapy-naïve pancreatic ductal adenocarcinoma (PDAC) with peritoneal metastasis.

METHODS

Forty-nine patients were diagnosed with peritoneal metastasis during 2007-2014; 29 received gemcitabine or S-1-based chemo(radio)therapy from 2007 to 2011 (control group), and the remaining 20 received i.v. (50 mg/m² ) and i.p. (20 mg/m² ) PTX on days 1 and 8, and S-1 at 80 mg/m² per day for 14 consecutive days, followed by 7 days of rest from 2012 to 2014 (study group).

RESULTS

The median survival time in the study group was significantly longer than that in the control group (20 vs. 10 months, respectively; P = 0.004). At 1 year after initial treatment, a significant difference in ascites development on CT was found between the study (5/20 patients) and the control group (18/29 patients, P = 0.009). The frequency of objective response (9/20 patients) and conversion surgery (6/20 patients) in the study group was higher than those in the control group (8/29 and 2/29, respectively). Patients who underwent conversion surgery had improved survival in both groups.

CONCLUSION

Implementation of the S-1+i.v./i.p. PTX regimen was closely associated with improved overall survival in PDAC patients with peritoneal metastasis.