Diagnostic intervals and pancreatic ductal adenocarcinoma (PDAC) resectability: a single-center retrospective analysis

Estimation and inference on the partial volume under the receiver operating characteristic surface

measures of biomarker accuracy that employ the receiver operating characteristic surface have been proposed for biomarkers that classify patients into one of three groups: healthy, benign, or aggressive disease. The volume under the receiver operating characteristic surface summarizes the overall discriminatory ability of a biomarker in such configurations, but includes cutoffs associated with clinically irrelevant true classification rates. Due to the lethal nature of pancreatic cancer, cutoffs associated with a low true classification rate for identifying patients with pancreatic cancer may be undesirable and not appropriate for use in a clinical setting. In this project, we study the properties of a more focused criterion, the partial volume under the receiver operating characteristic surface, that summarizes the diagnostic accuracy of a marker in the three-class setting for regions restricted to only those of clinical interest. We propose methods for estimation and inference on the partial volume under the receiver operating characteristic surface under parametric and non-parametric frameworks and apply these methods to the evaluation of potential biomarkers for the diagnosis of pancreatic cancer.

Defining and Understanding Diagnostic Delays Among Pancreatic Cancer Patients: A Retrospective Cohort Study

BACKGROUND AND AIMS

Pancreatic cancer is a lethal cancer of increasing incidence, presenting with several clinically detectable signals allowing for earlier diagnosis. However, there are limited data related to diagnostic process, including prevalence of diagnostic delays and their contributing factors. We aimed to develop a standardized definition of diagnostic delay, evaluate its prevalence, and identify its contributing factors among pancreatic cancer patients.

METHODS

We convened an expert panel who defined diagnostic delay among pancreatic cancer patients. We then conducted a retrospective cohort study among pancreatic adenocarcinoma patients consecutively diagnosed from 2007 to 2019 at a tertiary care Veterans Affairs medical center. We manually reviewed diagnostic delay instances for contributing factors. Secondary analyses, using multivariate logistic regression and Cox proportional hazards models, explored associations between diagnostic delays and cancer outcomes.

RESULTS

Diagnostic delay was defined as cancer diagnosis made ≥60 days after first clinical presence of predefined red flag(s). Among 197 pancreatic adenocarcinoma patients, 38.6% experienced a diagnostic delay. Among delay cases, the most common primary contributing factor was related to the patient-provider encounter (44.7% with lack of recognition of objective weight loss). Patients with delays were more likely to be diagnosed at advanced stage disease (adjusted odds ratio, 1.62; 95% confidence interval, 0.79-3.30) and less likely to receive potentially curative treatment (adjusted odds ratio, 0.72; 95% confidence interval, 0.28-1.84), although these trends did not reach statistical significance.

CONCLUSIONS

Over one-third of pancreatic cancer patients experienced a diagnostic delay, mostly due to inadequate recognition of red flag findings. Results can inform targeted interventions to reduce preventable diagnostic delays among pancreatic cancer patients.

Viscoelastic stiffening of gelatin hydrogels for dynamic culture of pancreatic cancer spheroids

The tumor microenvironment (TME) in pancreatic adenocarcinoma (PDAC) is a complex milieu of cellular and non-cellular components. Pancreatic cancer cells (PCC) and cancer-associated fibroblasts (CAF) are two major cell types in PDAC TME, whereas the non-cellular components are enriched with extracellular matrices (ECM) that contribute to high stiffness and fast stress-relaxation. Previous studies have suggested that higher matrix rigidity promoted aggressive phenotypes of tumors, including PDAC. However, the effects of dynamic viscoelastic matrix properties on cancer cell fate remain largely unexplored. The focus of this work was to understand the effects of such dynamic matrix properties on PDAC cell behaviors, particularly in the context of PCC/CAF co-culture. To this end, we engineered gelatin-norbornene (GelNB) based hydrogels with a built-in mechanism for simultaneously increasing matrix elastic modulus and viscoelasticity. Two GelNB-based macromers, namely GelNB-hydroxyphenylacetic acid (GelNB-HPA) and GelNB-boronic acid (GelNB-BA), were modularly mixed and crosslinked with 4-arm poly(ethylene glycol)-thiol (PEG4SH) to form elastic hydrogels. Treating the hybrid hydrogels with tyrosinase not only increased the elastic moduli of the gels (due to HPA dimerization) but also concurrently produced 1,2-diols that formed reversible boronic acid-diol bonding with the BA groups on GelNB-BA. We employed patient-derived CAF and a PCC cell line COLO-357 to demonstrate the effect of increasing matrix stiffness and viscoelasticity on CAF and PCC cell fate. Our results indicated that in the stiffened environment, PCC underwent epithelial-mesenchymal transition. In the co-culture PCC and CAF spheroid, CAF enhanced PCC spreading and stimulated collagen 1 production. Through mRNA-sequencing, we further showed that stiffened matrices, regardless of the degree of stress-relaxation, heightened the malignant phenotype of PDAC cells. STATEMENT OF SIGNIFICANCE: The pancreatic cancer microenvironment is a complex milieu composed of various cell types and extracellular matrices. It has been suggested that stiffer matrices could promote aggressive behavior in pancreatic cancer, but the effect of dynamic stiffening and matrix stress-relaxation on cancer cell fate remains largely undefined. This study aimed to explore the impact of dynamic changes in matrix viscoelasticity on pancreatic ductal adenocarcinoma (PDAC) cell behavior by developing a hydrogel system capable of simultaneously increasing stiffness and stress-relaxation on demand. This is achieved by crosslinking two gelatin-based macromers through orthogonal thiol-norbornene photochemistry and post-gelation stiffening with mushroom tyrosinase. The results revealed that higher matrix stiffness, regardless of the degree of stress relaxation, exacerbated the malignant characteristics of PDAC cells.

Advancements in Preclinical Models of Pancreatic Cancer

ABSTRACT

Pancreatic cancer remains one of the deadliest of all cancer types with a 5-year overall survival rate of just 12%. Preclinical models available for understanding the disease pathophysiology have evolved significantly in recent years. Traditionally, commercially available 2-dimensional cell lines were developed to investigate mechanisms underlying tumorigenesis, metastasis, and drug resistance. However, these cells grow as monolayer cultures that lack heterogeneity and do not effectively represent tumor biology. Developing patient-derived xenografts and genetically engineered mouse models led to increased cellular heterogeneity, molecular diversity, and tissues that histologically represent the original patient tumors. However, these models are relatively expensive and very timing consuming. More recently, the advancement of fast and inexpensive in vitro models that better mimic disease conditions in vivo are on the rise. Three-dimensional cultures like organoids and spheroids have gained popularity and are considered to recapitulate complex disease characteristics. In addition, computational genomics, transcriptomics, and metabolomic models are being developed to simulate pancreatic cancer progression and predict better treatment strategies. Herein, we review the challenges associated with pancreatic cancer research and available analytical models. We suggest that an integrated approach toward using these models may allow for developing new strategies for pancreatic cancer precision medicine.

Functional and Potential Therapeutic Implication of MicroRNAs in Pancreatic Cancer

The alarmingly low five-year survival rate for pancreatic cancer presents a global health challenge, contributing to about 7% of all cancer-related deaths. Late-stage diagnosis and high heterogeneity are the biggest hurdles in treating pancreatic cancer. Thus, there is a pressing need to discover novel biomarkers that could help in early detection as well as improve therapeutic strategies. MicroRNAs (miRNAs), a class of short non-coding RNA, have emerged as promising candidates with regard to both diagnostics and therapeutics. Dysregulated miRNAs play pivotal roles in accelerating tumor growth and metastasis, orchestrating tumor microenvironment, and conferring chemoresistance in pancreatic cancer. The differential expression profiles of miRNAs in pancreatic cancer could be utilized to explore novel therapeutic strategies. In this review, we also covered studies on recent advancements in various miRNA-based therapeutics such as restoring miRNAs with a tumor-suppressive function, suppressing miRNA with an oncogenic function, and combination with chemotherapeutic drugs. Despite several challenges in terms of specificity and targeted delivery, miRNA-based therapies hold the potential to revolutionize the treatment of pancreatic cancer by simultaneously targeting multiple signaling pathways.

Gemcitabine effects on tumor microenvironment of pancreatic ductal adenocarcinoma: Special focus on resistance mechanisms and metronomic therapies

Pancreatic ductal adenocarcinoma (PDAC) is considered one of the deadliest malignancies, with dismal survival rates and extremely prevalent chemoresistance. Gemcitabine is one of the primary treatments used in treating PDACs, but its benefits are limited due to chemoresistance, which could be attributed to interactions between the tumor microenvironment (TME) and intracellular processes. In preclinical models, certain schedules of administration of gemcitabine modulate the TME in a manner that does not promote resistance. Metronomic therapy constitutes a promising strategy to overcome some barriers associated with current PDAC treatments. This review will focus on gemcitabine's mechanism in treating PDAC, combination therapies, gemcitabine's interactions with the TME, and gemcitabine in metronomic therapies.

Recent onset diabetes is associated with better survival in pancreatic ductal adenocarcinoma-An analysis of preoperative symptoms within the DGAV StuDoQ|Pancreas Registry

BACKGROUND

This multicenter study analyzed the relationship between preoperative symptoms and postsurgical outcomes utilizing the German national DGAV StuDoQ|Pancreas database.

METHODS

This retrospective study included 2,643 pancreatic ductal adenocarcinoma patients undergoing pancreatic head resection from 2013-2017 within the German pancreatic surgery registry (DGAV StuDoQ|Pancreas). The association of preoperative symptoms with overall survival was analyzed using Kaplan-Meier and Cox regression analysis.

RESULTS

Preoperative symptoms were common, with 2,380 of 2,643 (90%) patients presenting with any one or more of the following symptoms: jaundice (40%), biliary obstruction treated with biliary stent (41%), pain (37%), weight loss (29%), nausea (18%), diabetes (31%), emesis (6%), and recent onset diabetes (5%). Patients were separated into 3 groups: no symptoms (n = 293), symptoms (n = 2,229), and recent onset diabetes (n = 121). The 3 groups differed in body mass index and nodal staging, where patients with recent onset diabetes had the highest values (body mass index: no symptoms: 24.5 kg/m2, symptoms: 25.1 kg/m2; recent-onset diabetes: 26.3 kg/m2, P = .007), (no symptoms: N1: 55%, N2: 10%; symptoms: N1: 53%, N2: 17%; recent-onset diabetes: N1: 56%, N2: 16%, P = .023). Other pathological characteristics, carbohydrate antigen 19-9 levels, and adjuvant chemotherapy receival did not differ between the groups. Interestingly, recent-onset diabetes was associated with better survival compared with the other groups (Median overall survival: 28 months [no symptoms at all], 22 months [symptoms] versus not reached [recent onset diabetes group], and 5-year overall survival rates of 28%, 11%, and 57%, respectively [log rank, P = .013]). Multivariable analysis revealed that recent-onset diabetes and preoperative symptoms were independently associated with overall survival (recent-onset diabetes, relative risk 0.052 P = .027, >5 symptoms relative risk 3.66, P < .001).

CONCLUSION

Pancreatic ductal adenocarcinoma symptoms occured in up to 90% of patients with resectable pancreatic ductal adenocarcinoma. In addition, PDAC symptoms were associated with overall survival and might identify unique pancreatic ductal adenocarcinoma subtypes.

An analysis of time to treatment in patients with pancreatic adenocarcinoma

BACKGROUND

Currently, no guidelines exist regarding the appropriate time from diagnosis to treatment among pancreatic adenocarcinoma patients. Herein, we aim to define the median time to treatment in pancreatic adenocarcinoma, factors associated with treatment delay, and prognostic significance.

METHODS

We conducted a retrospective study of pancreatic adenocarcinoma patients, stage I-IV, at a tertiary referral center (2017-2020). We subdivided time to treatment (days) into 4 components: (1) Ti: symptom onset to initial provider evaluation, (2) Tii: initial provider evaluation to diagnosis, (3) Tiii: diagnosis to specialist consultation, (4) Tiv: specialist visit to treatment.

RESULTS

In total, 217 patients met the inclusion criteria. The median Ti, Tii, Tiii, and Tiv were 20, 12, 4, and 14 days, respectively. The total time to treatment was 75 days. Patients with weight loss had longer Ti (β = 108.6). More frequent hospitalizations (β = 19.5) and misdiagnosis (β = 33.4) were associated with longer Tii. Patients with a history of malignancy (β = 15) or active treatment of a second disease (β = 19.4) had longer Tiii. Poor performance status (β = 6.2) or private insurance (β = 50.2) were associated with a longer Tiv. Black patients had longer Ti+ii+iii+iv (β = 100). Time to treatment was not associated with overall survival (P > .05).

CONCLUSION

It takes a median time of less than a month for a patient with pancreatic adenocarcinoma to start treatment, even after they visit a primary provider. The greatest opportunity to shorten the overall time to treatment is by having patients seek medical attention earlier (Ti).

Tumor microenvironment interactions with cancer stem cells in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer in the United States. Additionally, the low survival rate makes PDAC the third-leading cause of cancer-related mortality in the United States, and it is projected that by 2030, it will become the second-leading cause of cancer mortality. Several biological factors contribute to PDAC aggressiveness, and their understanding will narrow the gap from biology to clinical care of PDAC, leading to earlier diagnoses and the development of better treatment options. In this review, we describe the origins of PDAC highlighting the role of cancer stem cells (CSC). CSC, also known as tumor initiating cells, which exhibit a unique metabolism that allows them to maintain a highly plastic, quiescent, immune- and therapy-evasive state. However, CSCs can exit quiescence during proliferation and differentiation, with the capacity to form tumors while constituting a small population in tumor tissues. Tumorigenesis depends on the interactions between CSCs and other cellular and non-cellular components in the microenvironment. These interactions are fundamental to support CSC stemness and are maintained throughout tumor development and metastasis. PDAC is characterized by a massive desmoplastic reaction, which result from the deposition of high amounts of extracellular matrix components by stromal cells. Here we review how this generates a favorable environment for tumor growth by protecting tumor cells from immune responses and chemotherapy and inducing tumor cell proliferation and migration, leading to metastasis formation ultimately leading to death. We emphasize the interactions between CSCs and the tumor microenvironment leading to metastasis formation and posit that better understanding and targeting of these interactions will improve patient outcomes.

Circulating tumor DNA: toward evolving the clinical paradigm of pancreatic ductal adenocarcinoma

Over a decade of sequencing-based genomics research has unveiled a diverse somatic mutation landscape across patients with pancreatic ductal adenocarcinoma (PDAC), and the identification of druggable mutations has aligned with the development of novel targeted therapeutics. However, despite these advances, direct translation of years of PDAC genomics research into the clinical care of patients remains a critical and unmet need. Technologies that enabled the initial mapping of the PDAC mutation landscape, namely whole-genome and transcriptome sequencing, remain overly expensive in terms of both time and financial resources. Consequentially, dependence on these technologies to identify the relatively small subset of patients with actionable PDAC alterations has greatly impeded enrollment for clinical trials testing novel targeted therapies. Liquid biopsy tumor profiling using circulating tumor DNA (ctDNA) generates new opportunities by overcoming these challenges while further addressing issues particularly relevant to PDAC, namely, difficulty of obtaining tumor tissue via fine-needle biopsy and the need for faster turnaround time due to rapid disease progression. Meanwhile, ctDNA-based approaches for tracking disease kinetics with respect to surgical and therapeutic interventions offer a means to elevate the current clinical management of PDAC toward higher granularity and accuracy. This review provides a clinically focused summary of ctDNA advances, limitations, and opportunities in PDAC and postulates ctDNA sequencing technology as a catalyst for evolving the clinical decision-making paradigm of this disease.

Transabdominal ultrasound of pancreatic ductal adenocarcinoma: A multi-centered population-based study in sensitivity, associated diagnostic intervals, and survival

OBJECTIVES

To determine the sensitivity of ultrasound (US) in detecting pancreatic ductal adenocarcinoma in our region, to identify factors associated with US test result, and assess the impact on the diagnostic interval and survival.

METHODS

Patients diagnosed between January 1, 2014 and December 31, 2015 in Nova Scotia, Canada were identified by a cancer registry. US performed prior to diagnosis were retrospectively graded as true positive (TP), indeterminate or false negative (FN). Amongst US results, differences in age, weight and tumor size were assessed [one-way analysis of variance (ANOVA)]. Associations between result and sex, tumor location (proximal/distal), clinical suspicion of malignancy, and visualization of the pancreas, tumor, secondary signs and liver metastases were assessed (Chi-square). Mean follow-up imaging, diagnostic, and survival intervals were assessed (one-way ANOVA).

RESULTS

One hundred thirteen US of 107 patients (54 women; mean 70 ± 13 years) were graded as follows: 48/113 (42.5%) TPs; 42/113 (37.2%) indeterminates; and 23/113 (20.4%) FNs. Sensitivity was 48/71(67.6%). There was no difference in age, weight or tumor size amongst US result (P > 0.5). FNs had proportionally more men (P = 0.011) and lacked clinical suspicion of malignancy (P = 0.0006); TPs had proportionally more proximal tumors (P = 0.017). US result was associated with visualization of the pancreas, tumor, secondary signs and liver metastases (P < 0.005). FNs had longer mean follow-up imaging (P < 0.0001) and diagnostic (P = 0.0007) intervals, and worse mean survival (P = 0.034).

CONCLUSIONS

In our region, the sensitivity of US in detecting pancreatic ductal adenocarcinoma is 67.6%. A false negative US is associated with delayed diagnostic work-up and worse mean survival.

Impact of multicentre diagnostic workup in patients with pancreatic cancer on repeated diagnostic investigations, time-to-diagnosis and time-to-treatment: A nationwide analysis

BACKGROUND

Due to the centralization of pancreatic surgery, patients with suspected pancreatic cancer may undergo diagnostic workup in both a non-pancreatic centre and a pancreatic centre, i.e. multicentre workup. This retrospective study assessed whether multicentre diagnostic workup is associated with repeated diagnostics, delayed time-to-diagnosis, delayed time-to-treatment, survival and whether variation existed among pancreatic cancer networks.

METHODS

This nationwide study included all patients diagnosed with non-metastatic pancreatic ductal adenocarcinoma (PDAC) in 2015, registered by the Netherlands Cancer Registry. A delayed time-to-diagnosis was defined as ≥3 weeks from initial hospital visit to final diagnosis. A delayed time-to-treatment was defined as ≥6 weeks from the first hospital visit to start of first tumour treatment. Multilevel logistic regression analyses and survival analyses were performed.

RESULTS

In total, 931 patients with non-metastatic PDAC were included. Overall, 175 patients (19%) underwent a multicentre diagnostic workup, which was significantly associated with repeated diagnostic investigations (OR = 6.31, 95% CI 4.13-9.64, P < 0.0001), a delayed time-to-diagnosis (OR = 2.66 95% CI 1.74-4.06, P < 0.001), and a delayed time-to-treatment (OR = 1.93 95% CI 1.12-3.31, P = 0.02), but not with decreased survival (HR = 1.09 95% CI 0.83-1.44; P = 0.532). Variation in outcomes per network was observed, especially for time-to-treatment, though the ICC was not statistically significant (P = 0.065).

CONCLUSION

Multicentre diagnostic workup for patients with PDAC is associated with repeated diagnostic investigations, a delayed time-to-diagnosis and delayed time-to-treatment compared to patients with monocentre workup. To reduce costs and improve treatment times, efforts should be made to improve network coordination, for example via network care pathways.

Time to Neoadjuvant Chemotherapy Initiation Is not Associated With Survival in Pancreatic Cancer

INTRODUCTION

Not all patients with pancreatic adenocarcinoma (PDAC) tolerate multiagent neoadjuvant chemotherapy (NAC). We utilized institutional data and the National Cancer Database (NCDB) to investigate if time from diagnosis to NAC initiation is associated with survival.

METHODS

Patients who received NAC and underwent pancreatectomy at our institution (2010-2021) or within the NCDB (2010-2016) were identified. Time from diagnosis to NAC was grouped: <21, 21-35, and >35 d. Recurrence-free (RFS) and overall survival (OS) was compared.

RESULTS

At our institution, 122 patients received NAC before pancreatectomy (<21 d: n = 36; 21-35 d: n = 61; >35 d: n = 25). Demographics, performance status, and anatomic resectability were similar. There was no difference in RFS (13.3 versus 12.4 versus 11.9 mo) or OS (26.7 versus 25.8 versus 26.1 mo) based on NAC timing. Patients who received FOLFIRINOX had an improvement in RFS (14.4 versus 12.2 versus 6.8 mo, P = 0.05) and OS (39.2 versus 21.4 versus 17.3 mo, P = 0.01) compared to gemcitabine with nab-paclitaxel or other regimens. Within the NCDB, 6713 patients were included (<21 d: n = 2087; 21-35 d: n = 2656; >35 d: n = 1970). There was no difference in OS (21.6 versus 20.9 versus 22.2 mo). Multiagent NAC was associated with improved OS compared to single-agent (22.6 versus 18.8 mo, P < 0.001).

CONCLUSIONS

Delay in NAC initiation for PDAC is not associated with survival. Patient optimization could be considered with the goal of improving tolerance of multiagent chemotherapy.

The tumor microenvironment in pancreatic ductal adenocarcinoma: current perspectives and future directions

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies and is characterized by a unique tumor microenvironment (TME) consisting of an abundant stromal component. Many features contained with the PDAC stroma contribute to resistance to cytotoxic and immunotherapeutic regimens, as well as the propensity for this tumor to metastasize. At the cellular level, PDAC cells crosstalk with a complex mixture of non-neoplastic cell types including fibroblasts, endothelial cells, and immune cells. These intricate interactions fuel the progression and therapeutic resistance of this aggressive cancer. Moreover, data suggest the polarization of these cell types, in particular immune and fibroblast populations, dictate how PDAC tumors grow, metastasize, and respond to therapy. As a result, current research is focused on how to best target these populations to render tumors responsive to treatment. Herein, we summarize the cell populations implicated in providing a supporting role for the development and progression of PDAC. We focus on stromal fibroblasts and immune subsets that have been widely researched. We discuss factors which govern the phenotype of these populations and provide insight on how they have been targeted therapeutically. This review provides an overview of the tumor microenvironment and postulates that cellular and soluble factors within the microenvironment can be specifically targeted to improve patient outcomes.

Review of clinical and emerging biomarkers for early diagnosis and treatment management of pancreatic cancer: towards personalised medicine

Background:

Pancreatic cancer is the 12th most commonly diagnosed cancer and the 3rd leading cause of cancer mortality and accounts for approximately 2·7% of all newly diagnosed cancer cases and 6·4% of all cancer mortalities in Canada. It has a very poor survival rate mainly due to the difficulty of detecting the disease at an early stage. Consequently, in the advancement of disease management towards the concept of precision medicine that takes individual patient variabilities into account, several investigators have focused on the identification of effective clinical biomarkers with high specificity and sensitivity, capable of early diagnosis of symptomatic patients and early detection of the disease in asymptomatic individuals at high risk for developing pancreatic cancer.

Materials and methods:

We searched several databases from August to December 2020 for relevant studies published in English between 2000 and 2020 and reporting on biomarkers for the management of pancreatic cancer. In this narrative review paper, we describe 13 clinical and emerging biomarkers for pancreatic cancers used in screening for early detection and diagnosis, to identify patients’ risk for metastatic disease and subsequent relapse, to monitor patient response to specific treatment and to provide clinicians the possibility of prospectively identifying groups of patients who will benefit from a particular treatment.

Conclusions:

Current and emerging biomarkers for pancreatic cancer with high specificity and sensitivity has the potential to account for individual patient variabilities, for early detection of disease before the onset of metastasis to improve treatment outcome and patients’ survival, help screen high-risk populations, predict prognosis, provide accurate information of patient response to specific treatment and improve patients monitoring during treatment. Thus, the future holds promise for the use of effective clinical biomarkers or a panel of biomarkers for personalised patient-specific targeted medicine for pancreatic cancer.

Disparities in access to health care system as determinant of survival for patients with pancreatic cancer in the State of São Paulo, Brazil

Little is known about the features and outcomes of Brazilian patients with pancreatic cancer. We sought to describe the socio-economic characteristics, patterns of health care access, and survival of patients diagnosed with malignant pancreatic tumors from 2000 to 2014 in São Paulo, Brazil. We included patients with malignant exocrine and non-classified pancreatic tumors according to the International Classifications of Disease (ICD)-O-2 and -O-3, diagnosed from 2000 to 2014, who were registered in the FOSP database. Prognostic factors for overall survival (OS) in the subgroup of patients with ductal or non-specified (adeno)carcinoma were evaluated using Cox proportional hazard model. The study population consists of 6855 patients. Median time from the first visit to diagnosis and treatment were 13 (Interquartile range [IQR] 4-30) and 24 (IQR 8-55) days, respectively. Both intervals were longer for patients treated in the public setting. Median OS was 4.9 months (95% confidence interval [95% CI] 4.7-5.2). Increasing age, male gender, lower educational level, treatment in the public setting, absence of treatment, advanced stage, and treatment from 2000 to 2004 were associated with inferior OS. From 2000-2004 to 2010-2014, no improvement in OS was seen for patients treated in the public setting. Survival of patients with malignant pancreatic tumors remains dismal. Socioeconomical variables, especially health care funding, are major determinants of survival. Further work is necessary to decrease inequalities in access to medical care for patients with pancreatic cancer in Brazil.

Pancreatic Adenocarcinoma: Unconventional Approaches for an Unconventional Disease

This review highlights current treatments, limitations, and pitfalls in the management of pancreatic cancer and discusses current research in novel targets and drug development to overcome these clinical challenges. We begin with a review of the clinical landscape of pancreatic cancer, including genetic and environmental risk factors, as well as limitations in disease diagnosis and prevention. We next discuss current treatment paradigms for pancreatic cancer and the shortcomings of targeted therapy in this disease. Targeting major driver mutations in pancreatic cancer, such as dysregulation in the KRAS and TGFβ signaling pathways, have failed to improve survival outcomes compared with nontargeted chemotherapy; thus, we describe new advances in therapy such as Ras-binding pocket inhibitors. We then review next-generation approaches in nanomedicine and drug delivery, focusing on preclinical advancements in novel optical probes, antibodies, small-molecule agents, and nucleic acids to improve surgical outcomes in resectable disease, augment current therapies, expand druggable targets, and minimize morbidity. We conclude by summarizing progress in current research, identifying areas for future exploration in drug development and nanotechnology, and discussing future prospects for management of this disease.

The implications of missed or misinterpreted cases of pancreatic ductal adenocarcinoma on imaging: a multi-centered population-based study

OBJECTIVES

To assess the proportion of missed/misinterpreted imaging examinations of pancreatic ductal adenocarcinoma (PDAC), and their association with the diagnostic interval and survival.

METHODS

Two hundred fifty-seven patients (mean age, 71.8 years) diagnosed with PDAC in 2014-2015 were identified from the Nova Scotia Cancer Registry. Demographics, stage, tumor location, and dates of initial presentation, diagnosis, and, if applicable, surgery and death were recorded. US, CT, and MRI examinations during the diagnostic interval were independently graded by two radiologists using the RADPEER system; discordance was resolved in consensus. Mean diagnostic interval and survival were compared amongst RADPEER groups (one-way ANOVA). Kaplan-Meier analysis was performed for age (< 65, 65-79, ≥ 80), sex, tumor location (proximal/distal), stage (I-IV), surgery (yes/no), chemotherapy (yes/no), and RADPEER score (1-3). Association between these covariates and survival was assessed (multivariate Cox proportion hazards model).

RESULTS

RADPEER 1-3 scores were assigned to 191, 27, and 39 patients, respectively. Mean diagnostic intervals were 53, 86, and 192 days, respectively (p = 0.018). There were only 3/257 (1.2%) survivors. Mean survival was not different between groups (p = 0.43). Kaplan-Meier analysis showed worse survival in RADPEER 1-2 (p = 0.007), older age (p < 0.001), distal PDAC (p = 0.016), stage (p < 0.0001), and no surgery (p < 0.001); survival was not different with sex (p = 0.083). Cox analysis showed better survival in RADPEER 3 (p = 0.005), women (p = 0.002), surgical patients (p < 0.001), and chemotherapy (p < 0.001), and worse survival in stage IV (p = 0.006).

CONCLUSION

Imaging-related delays occurred in one-fourth of patients and were associated with longer diagnostic intervals but not worse survival, potentially due to overall poor survival in the cohort.

KEY POINTS

• One-fourth of patients (66/257, 25.7%) with pancreatic ductal adenocarcinoma (PDAC) underwent imaging examinations that demonstrated manifestations of the disease, but findings were either missed or misinterpreted; RADPEER 2 and 3 scores were assigned to 10.5% and 15.2% of patients, respectively. • Patients with imaging examinations assigned RADPEER 3 scores were associated with significantly longer diagnostic intervals (192 ± 323 days) than RADPEER 1 (53 ± 86 days) and RADPEER 2 (86 ± 120 days) (p < 0.001). • Imaging-related diagnostic delays were not associated with worse survival; however, this may have been confounded by the overall poor survival in our cohort (only 3/257 (1.2%) survivors).

Benefits Of Timely Care In Pancreatic Cancer: A Systematic Review To Navigate Through The Contradictory Evidence

The evidence base of policies that improve the timeliness of cancer care is under ongoing debate. Pancreatic cancer is frequently diagnosed in a stage when curative therapy is not feasible; hence, it is an important target for timelier healthcare interventions. The objectives of our research were to identify all clinical studies on pancreatic cancer care delays via a systematic literature review, to assess the study methodologies for possible biases, to conclude on the available evidence, and to formulate research recommendations on evidence gaps. Nineteen studies were identified and eight reported multivariate analyses. Although many sources of bias shifted the results towards negative or paradoxical findings, a statistically significant association of shorter delays with better clinical outcomes was demonstrated in the majority of studies reporting multivariate analyses. Noninferiority analyses were not published. Further efforts to provide timely care for pancreatic cancer patients are encouraged, and studies on the associations of delay with patient experience and healthcare resource utilization are warranted.