A KRAS wild type mutational status confers a survival advantage in pancreatic ductal adenocarcinoma

Real-world genome profiling in Japanese patients with pancreatic ductal adenocarcinoma focusing on HRD implications

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges due to its high mortality, making it a critical area of research. This retrospective observational study aimed to analyze real-world data from comprehensive genome profiling (CGP) of Japanese patients with PDAC, mainly focusing on differences in gene detection rates among panels and the implications for homologous recombination deficiency (HRD) status. This study enrolled 2568 patients with PDAC who had undergone CGP between June 2019 and December 2021 using data from the nationwide Center for Cancer Genomics and Advanced Therapeutics database. Two types of CGP assays (tissue and liquid biopsies) were compared and a higher detection rate of genetic abnormalities in tissue specimens was revealed. HRD-related gene alterations were detected in 23% of patients, with BRCA1/2 mutations accounting for 0.9% and 2.9% of patients, respectively. Treatment outcome analysis indicated that patients with BRCA1/2 mutations had a longer time to treatment discontinuation with FOLFIRINOX than gemcitabine plus nab-paclitaxel as first-line therapy (9.3 vs. 5.6 months, p = 0.028). However, no significant differences were observed in the treatment response among the other HRD-related genes. Logistic regression analysis identified younger age and family history of breast, prostate, and ovarian cancers as predictive factors for HRD-related gene alterations. Despite the lack of progression-free survival data and the inability to discriminate between germline and somatic mutations, this study provides valuable insights into the clinical implications of CGP in Japanese patients with PDAC. Further research is warranted to optimize panel selection and elucidate the efficacy of platinum-based therapies depending on the HRD status.

Molecular Characterization and Therapeutic Opportunities in KRAS Wildtype Pancreatic Ductal Adenocarcinoma

PURPOSE

To investigate the molecular characteristics of and potential for precision medicine in KRAS wildtype pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

We investigated 27 patients with KRASWT PDAC at our institution. Clinical data were obtained via chart review. Tumor specimens for each subject were interrogated for somatic single nucleotide variants, insertion and deletions, and copy number variants by DNA sequencing. Gene fusions were detected from RNA-seq. A patient-derived organoid (PDO) was developed from a patient with a MET translocation and expanded ex vivo to predict therapeutic sensitivity prior to enrollment in a phase 2 clinical trial.

RESULTS

Transcriptomic analysis showed our cohort may be stratified by the relative gene expression of the KRAS signaling cascade. The PDO derived from our patient harboring a TFG-MET rearrangement was found to have in vitro sensitivity to the multi-tyrosine kinase inhibitor crizotinib. The patient was enrolled in the phase 2 SPARTA clinical trial and received monotherapy with vebrelitinib, a c-MET inhibitor, and achieved a partial and durable response.

CONCLUSIONS

KRASWT PDAC is molecularly distinct from KRASMUT and enriched with potentially actionable genetic variants. In our study, transcriptomic profiling revealed that the KRAS signaling cascade may play a key role in KRASWT PDAC. Our report of a KRASWT PDAC patient with TFG-MET rearrangement who responded to a cMET inhibitor further supports the pursuit of precision oncology in this sub-population. Identification of targetable mutations, perhaps through approaches like RNA-seq, can help enable precision-driven approaches to select optimal treatment based on tumor characteristics.

Evaluation of KRAS inhibitor-directed therapies for pancreatic cancer treatment

Despite significant advancements in the treatment of other cancers, pancreatic ductal adenocarcinoma (PDAC) remains one of the world's deadliest cancers. More than 90% of PDAC patients harbor a Kirsten rat sarcoma (KRAS) gene mutation. Although the clinical potential of anti-KRAS therapies has long been realized, all initial efforts to target KRAS were unsuccessful. However, with the recent development of a new generation of KRAS-targeting drugs, multiple KRAS-targeted treatment options for patients with PDAC have entered clinical trials. In this review, we provide an overview of current standard of care treatment, describe RAS signaling and the relevance of KRAS mutations, and discuss RAS isoform- and mutation-specific differences. We also evaluate the clinical efficacy and safety of mutation-selective and multi-selective inhibitors, in the context of PDAC. We then provide a comparison of clinically relevant KRAS inhibitors to second-line PDAC treatment options. Finally, we discuss putative resistance mechanisms that may limit the clinical effectiveness of KRAS-targeted therapies and provide a brief overview of promising therapeutic approaches in development that are focused on mitigating these resistance mechanisms.

Genomic determinants of biological aggressiveness and poor prognosis of pancreatic cancers: KRAS and beyond

INTRODUCTION

A marked histomolecular heterogeneity characterizes pancreatic cancer. Thus, different tumor histologies with divergent genomic profiles exist within the same category.

AREAS COVERED

Using data from PubMed, SCOPUS, and Embase (last search date: 04/04/2024), this expert-based, narrative review presents and discusses the essential molecular determinants of biological aggressiveness and poor prognosis in pancreatic cancer. First, KRAS mutation still represents one of the most critical difficulties in treating pancreatic cancers. In this district, it is mutated in > 90% of malignant tumors. Notably, actionable alterations for molecular-based therapies are typically lacking in KRAS-mutated pancreatic cancer. Furthermore, transcriptome-based studies clarified that the squamous phenotype is characterized by poorer prognosis and response to standard chemotherapy. We also discuss molecular biomarkers related to dismal prognosis in specific subsets of pancreatic cancer, such as SMAD4 in signet-ring cell carcinoma and TP53 in invasive cancers derived from intraductal tubulopapillary neoplasms.

EXPERT OPINION

The identification of the subgroups of pancreatic cancer with particularly unfavorable prognoses is a critical step for addressing specific research efforts. In addition to implementing and strengthening current precision oncology strategies, the decisive step for improving the survival of patients affected by pancreatic cancer must pass through targeting the KRAS gene.

The Clinical Implications of KRAS Mutations and Variant Allele Frequencies in Pancreatic Ductal Adenocarcinoma

The KRAS proto-oncogene is a major driver of pancreatic tumorigenesis and is nearly ubiquitously mutated in pancreatic ductal adenocarcinoma (PDAC). KRAS point mutations are detected in over 90% of PDAC cases, and these mutations have been shown to be associated with worse therapy response and overall survival. Pathogenic KRAS mutations are mostly limited to codons 12, 13 and 61, with G12D, G12V, G12R, Q61H, and G13D accounting for approximately 95% of the mutant cases. Emerging data have shown the importance of specific mutant subtypes, as well as KRAS variant allele frequency on clinical prognosis. Furthermore, novel technologies and therapies are being developed to target specific mutant subtypes, with encouraging early results. In this paper, we aim to review the recent studies regarding the relative impact of specific mutant KRAS subtypes on oncologic outcomes, the application of variant allele frequency in next generation sequencing analyses, and the ongoing research into therapies targeting specific mutant KRAS subtypes.

Abnormalities in the KRAS Gene and Treatment Options for NSCLC Patients with the G12C Mutation in This Gene-A Literature Review and Single-Center Experience

Mutations in the KRAS gene are among the most common mutations observed in cancer cells, but they have only recently become an achievable goal for targeted therapies. Two KRAS inhibitors, sotorasib and adagrasib, have recently been approved for the treatment of patients with advanced non-small cell lung cancer with the KRAS G12C mutation, while studies on their efficacy are still ongoing. In this work, we comprehensively analyzed RAS gene mutations' molecular background, mutation testing, KRAS inhibitors' effectiveness with an emphasis on non-small cell lung cancer, the impact of KRAS mutations on immunotherapy outcomes, and drug resistance problems. We also summarized ongoing trials and analyzed emerging perspectives on targeting KRAS in cancer patients.

Precision medicine for KRAS wild-type pancreatic adenocarcinomas

BACKGROUND

KRAS mutation is the most common molecular alteration in pancreatic adenocarcinoma (PDAC), and around 10% of patients harbor KRAS wild-type tumors (KRASWT).

METHODS

A retrospective chart review of clinical/molecular data was performed including all PDAC patients with a determined KRAS status (tumor molecular profiling on tissue or liquid biopsy).

RESULTS

342 patients were included with 54 KRASWT PDAC (16%) compared to 288 patients with KRASm PDAC. Median age was 61 years [IQR:54.0;67.0] and 164 pts (48%) were female. At diagnosis, KRASWT patients (63%) were more frequently diagnosed at a non-metastatic stage compared to KRASm patients (41%) (p = 0.003). Regarding metastatic sites, liver was less frequent in KRASWT (39%, p < 0.0001). Median overall survival (mOS) from initial diagnosis was significantly higher in the KRASWT group compared to KRASm (50.8 months, CI95% [32.0-NR] vs 21.1 months, CI95% [18.9-23.4] (p < 0.004 after adjustment on age, ECOG and stage at diagnosis). In first-line systemic treatment, (mostly FOLFIRINOX) progression-free survival (PFS) was also higher in KRASWT. Based on ESCAT classification, a putative actionable alteration (ESCAT I-III) was identified in 19 (36%) KRASWT pts and 46 (16%) KRASm patients (p < 0.0001) with more alterations in FGFR2, BRAF(V600E), NRTK and more MSI tumors. KRASWT harbored also fewer alterations in TP53, CDKN2A, and SMAD4. 12 KRASWT patients received a molecularly-matched treatment with clinical benefit and improved outcomes compared to KRASm patients.

CONCLUSIONS

KRASWT patients display distinct disease characteristics and outcomes with prolonged overall survival. KRASWT patients also harbor more actionable molecular alterations, leading to higher survival rates after receiving molecularly matched treatments.

Targeting KRAS-Mutated Gastrointestinal Malignancies with Small-Molecule Inhibitors: A New Generation of Breakthrough Therapies

Kirsten rat sarcoma virus (KRAS) is one of the most important and frequently mutated oncogenes in cancer and the mutational prevalence is especially high in many gastrointestinal malignancies, including colorectal cancer and pancreatic ductal adenocarcinoma. The KRAS protein is a small GTPase that functions as an "on/off" switch to activate downstream signaling, mainly through the mitogen-activated protein kinase pathway. KRAS was previously considered undruggable because of biochemical constraints; however, recent breakthroughs have enabled the development of small-molecule inhibitors of KRAS G12C. These drugs were initially approved in lung cancer and have now shown substantial clinical activity in KRAS G12C-mutated pancreatic ductal adenocarcinoma as well as colorectal cancer when combined with anti-EGFR monoclonal antibodies. Early data are encouraging for other gastrointestinal cancers as well and many other combination strategies are being investigated. Several new KRAS G12C inhibitors and novel inhibitors of other KRAS alterations have recently entered the clinic. These molecules employ a variety of innovative mechanisms and have generated intense interest. These novel drugs are especially important as KRAS G12C is rare in gastrointestinal malignancies compared with other KRAS alterations, representing potentially groundbreaking advances. Soon, the rapidly evolving landscape of novel KRAS inhibitors may substantially shift the therapeutic landscape for gastrointestinal cancers and offer meaningful survival improvements.

Identification of an optimal mutant allele frequency to detect activating KRAS, NRAS, and BRAF mutations in a commercial cell-free DNA next-generation sequencing assay in colorectal and pancreatic adenocarcinomas

Background

Evaluation for activating mutations in KRAS, NRAS, and BRAF in colorectal cancer (CRC) and in KRAS in pancreatic ductal adenocarcinoma (PDAC) is essential for clinical care. Plasma cell-free DNA (cfDNA) next-generation sequencing (NGS) allows convenient assessment of a tumor's molecular profile, however low tumor DNA shedding limits sensitivity. We investigated mutant allele frequency (MAF) of other oncogenic dominant genes to identify a threshold for accurate detection of KRAS, NRAS, and BRAF (RAS/RAF) mutations in cfDNA.

Methods

Molecular and clinical data were obtained from the Duke Molecular Registry of Tumors and the SCRUM-Japan GOZILA study. Patients with CRC or PDAC and a KRAS, NRAS, or BRAF activating single nucleotide variant (SNV) present on tissue NGS and with available cfDNA assays were included. Recursive partitioning and Wilcoxon-rank statistics methods identified potential cut-points for discriminative MAF values.

Results

One hundred and thirty-five CRC and 30 PDAC cases with 198 total cfDNA assays met criteria. Greatest non-RAS/RAF dominant gene MAF of 0.34% provided maximum discrimination for predicting RAS/RAF SNV detection. Sensitivity for RAS/RAF SNVs increased with dominant gene MAF, with MAF ≥1% predicting sensitivity >98%, MAF between 0.34 and 1% predicting sensitivity of 84.0%, and MAF £0.34% predicting sensitivity of 50%. For 43 cfDNA assays that did not detect RAS/RAF SNVs, 18 assays detected 34 other oncogenic variants, of which 80.6% were not also detected on tissue.

Conclusions

Non-RAS/RAF dominant oncogenic mutation MAF ≥1% on cfDNA NGS predicts high sensitivity to detect RAS/RAF oncogenic SNVs in CRC and PDAC. MAF £0.34% indicates an assay may not reliably detect RAS/RAF SNVs, despite detection on tissue testing. Most variants from assays that did not detect RAS/RAF had MAF <1% and were not detected on tissue, suggesting potential confounding. These data suggest a practical approach to determining cfDNA assay adequacy, with implications for guiding clinical decisions in CRC and PDAC.

Targeting KRAS in Pancreatic Ductal Adenocarcinoma: The Long Road to Cure

Pancreatic ductal adenocarcinoma (PDAC) remains an important cause of cancer-related mortality, and it is expected to play an even bigger part in cancer burden in the years to come. Despite concerted efforts from scientists and physicians, patients have experienced little improvement in survival over the past decades, possibly because of the non-specific nature of the tested treatment modalities. Recently, the discovery of potentially targetable molecular alterations has paved the way for the personalized treatment of PDAC. Indeed, the central piece in the molecular framework of PDAC is starting to be unveiled. KRAS mutations are seen in 90% of PDACs, and multiple studies have demonstrated their pivotal role in pancreatic carcinogenesis. Recent investigations have shed light on the differences in prognosis as well as therapeutic implications of the different KRAS mutations and disentangled the relationship between KRAS and effectors of downstream and parallel signaling pathways. Additionally, the recognition of other mechanisms involving KRAS-mediated pathogenesis, such as KRAS dosing and allelic imbalance, has contributed to broadening the current knowledge regarding this molecular alteration. Finally, KRAS G12C inhibitors have been recently tested in patients with pancreatic cancer with relative success, and inhibitors of KRAS harboring other mutations are under clinical development. These drugs currently represent a true hope for a meaningful leap forward in this dreadful disease.

The Mutation Portraits of Oncogenes and Tumor Supressor Genes in Predicting the Overall Survival in Pancreatic Cancer: A Bayesian Network Meta-Analysis

INTRODUCTION

In pancreatic cancer, the carcinogenesis can not be separated from genetics mutations. The portraits of genes alterations majorily including oncogenes (KRAS, HER2, PD-L1) and tumor supressor genes (P53, CDKN2A, SMAD4). Besides being notorious a screening marker, the genetic mutations were related to the prognosis of pancreatic cancer. The aim of this study is to determine the genetic mutations portrait in predicting the overall survival in pancreatic cancer.

METHODS

The network meta analysis (NMA) was registered in PROSPERO (CRD42023397976) and conducted in accordance with the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) in addition of NMA extension guidance. Comprehensive searches were done including all studies which reported the overall survival of pancreatic cancer subjects with KRAS, HER2, PD-L1, P53, CDKN2A, SMAD4. Data were collected and analysis will be done based on Bayesian method, Markov Chain Monte Carlo algorithm, using BUGSnet package in R studio. Transivity was controlled by methods and consistency of the NMA will be fitted by deviance information criterion. Data analysis in NMA were presented in Sucra plot, league table, and forest plot.

RESULTS

Twenty-four studies were included in this NMA with 4613 total subjects. The NMA was conducted in random-effects, consistent, and convergence model. Relative to control, the genetic mutation of SMAD4 (HR 1.84; 95%CI 1.39-2.46), HER2 (HR 1.76; 95%CI 1.14-2.71), and KRAS (HR 1.7; 95%CI 1.19-2.48) were significant to have worse survival. The mutations of PD-L1, P53, and CDKN2A also showed poor survival, but not statistically significant compared to control.

CONCLUSION

In pancreatic cancer, the mutation of SMAD4 predicted the worst overall survival, compared to control, also mutation of HER2, KRAS, PD-L1, P53, and CDKN2A.

Pancreatic cancer in young adults - an evolving entity?

The incidence of early-onset pancreatic cancer (EOPC) among young population (<50 years) is rising in the last decade, with gender, medical overtreatment, and genetic factors as the risk factors in EOPC. Nevertheless, the role of genetic factors in the development of EOPC needs further exploration since the studies were carried out with small sample size and ambiguous evidence. Notable, the high incidence of pathogenic germline variant (PGV) appears to be involved in EOPC. Compared with average-age-onset pancreatic cancer (AOPC), EOPC patients display a distinctive genomic feature on several well-known tumor suppressor and oncogenic genes including, including SMAD4, RAS wild wild-type, CDKN2A BRCA1, BRCA2 and FOXC2, which is different from the findings of studies with AOPC and LOPC, suggesting the dynamic evolving entity of EOPC. In addition, the potential gender-related incidence found in several countries also suggests the involvement of genetic or socioenvironmental factors in the development of AOPC. Therefore, further prospective epidemiological and molecular studies are warranted to elucidate the shifting epidemiology of this disease and, most importantly, to better exploit the opportunities for the early diagnosis of the disease.

[Preclinical study of T cell receptor specifically reactive with KRAS G12V mutation in the treatment of malignant tumors]

OBJECTIVE

KRAS gene is one of the most common mutations of proto-oncogenes in human tumors, G12V is one of the most common mutation types for KRAS. It's challenging to chemically acquire the targeted drug for this mutation. Recent studies reported that this mutation peptides can form a neoepitope for T cell recognition. Our study aims to clone the T cell receptor (TCR) which specifically recognizes the neoepitope for KRAS G12V mutation and constructs TCR engineered T cells (TCR-T), and to investigate if TCR-Ts have strong antitumor response ability.

METHODS

In this study, tumor infiltrating lymphocytes were obtained from one colorectal cancer patient carrying KRAS G12V mutation. Tumor-reactive TCR was obtained by single-cell RT-5' rapid-amplification of cDNA ends PCR analysis and introduced into peripheral blood lymphocytes to generate TCR-Ts.

RESULTS

We obtained a high-affinity TCR sequence that specifically recognized the HLA-A^*11:01-restricted KRAS G12V_8-16 epitope: KVA11-01. KVA11-01 TCR-T could significantly kill various tumor cells such as PANC-1, SW480 and HeLa (overexpressing HLA-A^*11:01 and KRAS G12V), and secreting high levels of interferon-γ (IFN-γ). Non-specific killing experiments suggested KVA11-01 specifically recognized tumor cells expressing both mutant KRAS G12V and HLA-A^*11:01. In vivo assay, tumor inhibition experiments demonstrated that infusion of approximately 1E7 KVA11-01 TCR-T could significantly inhibit the growth of subcuta-neously transplanted tumors of PANC-1 and HeLa (overexpressing HLA-A^*11:01 and KRAS G12V) cells in nude mice. No destruction of the morphologies of the liver, spleen and brain were observed. We also found that KVA11-01 TCR-T could significantly infiltrate into tumor tissue and had a better homing ability.

CONCLUSION

KVA11-01 TCR-T cells can effectively target a variety of malignant tumor cells carrying KRAS G12V mutation through in vitro and in vivo assay. KVA11-01 TCR-T cells have excellent biological activity, high specificity of target antigen and homing ability into solid tumor tissue. KVA11-01 TCR-T is expected to be an effective treatment for patients with KRAS G12V mutant solid malignancies.

Therapeutic advances in metastatic pancreatic cancer: a focus on targeted therapies

Mortality from pancreatic ductal adenocarcinoma (PDAC) is increasing worldwide and effective new treatments are urgently needed. The current treatment of metastatic PDAC in fit patients is based on two chemotherapy combinations (FOLFIRINOX and gemcitabine plus nab-paclitaxel) which were validated more than 8 years ago. Although almost all treatments targeting specific molecular alterations have failed so far when administered to unselected patients, encouraging results were observed in the small subpopulations of patients with germline BRCA 1/2 mutations, and somatic gene fusions (neurotrophic tyrosine receptor kinase, Neuregulin 1, which are enriched in KRAS wild-type PDAC), KRAS G12C mutations, or microsatellite instability. While targeted tumor metabolism therapies and immunotherapy have been disappointing, they are still under investigation in combination with other drugs. Optimizing pharmacokinetics and adapting available chemotherapies based on molecular signatures are other promising avenues of research. This review evaluates the current expectations and limits of available treatments and analyses the existing trials. A permanent search for actionable vulnerabilities in PDAC tumor cells and microenvironments will probably result in a more personalized therapeutic approach, keeping in mind that supportive care must also play a major role if real clinical efficacy is to be achieved in these patients.

The CCTG PA.7 phase II trial of gemcitabine and nab-paclitaxel with or without durvalumab and tremelimumab as initial therapy in metastatic pancreatic ductal adenocarcinoma

Immunotherapy-based monotherapy treatment in metastatic pancreatic ductal adenocarcinoma (mPDAC) has shown limited benefit outside of the mismatch repair deficiency setting, while safety and efficacy of combining dual-checkpoint inhibitor immunotherapy with chemotherapy remains uncertain. Here, we present results from the CCTG PA.7 study (NCT02879318), a randomized phase II trial comparing gemcitabine and nab-paclitaxel with and without immune checkpoint inhibitors durvalumab and tremelimumab in 180 patients with mPDAC. The primary endpoint was overall survival. Secondary endpoints included progression-free survival and objective response rate. Results of the trial were negative as combination immunotherapy did not improve survival among the unselected patient population (p = 0.72) and toxicity was limited to elevation of lymphocytes in the combination immunotherapy group (p = 0.02). Exploratory baseline circulating tumor DNA (ctDNA) sequencing revealed increased survival for patients with KRAS wildtype tumors in both the combination immunotherapy (p = 0.001) and chemotherapy (p = 0.004) groups. These data support the utility of ctDNA analysis in PDAC and the prognostic value of ctDNA-based KRAS mutation status.

Autophagy: A Key Player in Pancreatic Cancer Progression and a Potential Drug Target

Pancreatic cancer is known to have the lowest survival outcomes among all major cancers, and unfortunately, this has only been marginally improved over last four decades. The innate characteristics of pancreatic cancer include an aggressive and fast-growing nature from powerful driver mutations, a highly defensive tumor microenvironment and the upregulation of advantageous survival pathways such as autophagy. Autophagy involves targeted degradation of proteins and organelles to provide a secondary source of cellular supplies to maintain cell growth. Elevated autophagic activity in pancreatic cancer is recognized as a major survival pathway as it provides a plethora of support for tumors by supplying vital resources, maintaining tumour survival under the stressful microenvironment and promoting other pathways involved in tumour progression and metastasis. The combination of these features is unique to pancreatic cancer and present significant resistance to chemotherapeutic strategies, thus, indicating a need for further investigation into therapies targeting this crucial pathway. This review will outline the autophagy pathway and its regulation, in addition to the genetic landscape and tumor microenvironment that contribute to pancreatic cancer severity. Moreover, this review will also discuss the mechanisms of novel therapeutic strategies that inhibit autophagy and how they could be used to suppress tumor progression.

Early-onset pancreatic cancer: a review of molecular mechanisms, management, and survival

OBJECTIVES

Early-onset pancreatic cancer (EOPC) - defined as pancreatic cancer diagnosed before the age of 50 years - is associated with a poor prognosis as compared to later-onset pancreatic cancer (LOPC). Emerging evidence suggests that EOPC may exhibit a genetic signature and tumor biology that is distinct from that of LOPC. We review genetic mutations that are more prevalent in EOPC relative to LOPC and discuss the potential impact of these mutations on treatment and survival.

MATERIALS AND METHODS

Using PubMed and Medline, the following terms were searched and relevant citations assessed: "early onset pancreatic cancer," "late onset pancreatic cancer," "pancreatic cancer," "pancreatic cancer genes," and "pancreatic cancer targeted therapy."

RESULTS

Mutations in CDKN2, FOXC2, and SMAD4 are significantly more common in EOPC as compared to LOPC. In addition, limited data suggest that PI3KCA mutations are more frequently observed in EOPC as compared to LOPC. KRAS mutations are relatively rare in EOPC.

CONCLUSIONS

Genetic mutations associated with EOPC are distinct from those of LOPC. The preponderance of the evidence suggest that poor outcomes in EOPC are related both to advanced stage of presentation and unique tumor biology. The molecular and genetic features of EOPC warrant further investigation in order to optimize management.

Molecular Characterization of KRAS Wild-type Tumors in Patients with Pancreatic Adenocarcinoma

PURPOSE

KRAS mutation (MT) is a major oncogenic driver in pancreatic ductal adenocarcinoma (PDAC). A small subset of PDACs harbor KRAS wild-type (WT). We aim to characterize the molecular profiles of KRAS WT PDAC to uncover new pathogenic drivers and offer targeted treatments.

EXPERIMENTAL DESIGN

Tumor tissue obtained from surgical or biopsy material was subjected to next-generation DNA/RNA sequencing, microsatellite instability (MSI) and mismatch repair status determination.

RESULTS

Of the 2,483 patients (male 53.7%, median age 66 years) studied, 266 tumors (10.7%) were KRAS WT. The most frequently mutated gene in KRAS WT PDAC was TP53 (44.5%), followed by BRAF (13.0%). Multiple mutations within the DNA-damage repair (BRCA2, ATM, BAP1, RAD50, FANCE, PALB2), chromatin remodeling (ARID1A, PBRM1, ARID2, KMT2D, KMT2C, SMARCA4, SETD2), and cell-cycle control pathways (CDKN2A, CCND1, CCNE1) were detected frequently. There was no statistically significant difference in PD-L1 expression between KRAS WT (15.8%) and MT (17%) tumors. However, KRAS WT PDAC were more likely to be MSI-high (4.7% vs. 0.7%; P < 0.05), tumor mutational burden-high (4.5% vs. 1%; P < 0.05), and exhibit increased infiltration of CD8+ T cells, natural killer cells, and myeloid dendritic cells. KRAS WT PDACs exhibited gene fusions of BRAF (6.6%), FGFR2 (5.2%), ALK (2.6%), RET (1.3%), and NRG1 (1.3%), as well as amplification of FGF3 (3%), ERBB2 (2.2%), FGFR3 (1.8%), NTRK (1.8%), and MET (1.3%). Real-world evidence reveals a survival advantage of KRAS WT patients in overall cohorts as well as in patients treated with gemcitabine/nab-paclitaxel or 5-FU/oxaliplatin.

CONCLUSIONS

KRAS WT PDAC represents 10.7% of PDAC and is enriched with targetable alterations, including immuno-oncologic markers. Identification of KRAS WT patients in clinical practice may expand therapeutic options in a clinically meaningful manner.

Significance of KRAS mutation testing in biliary brushing cytology specimens: A 10-year retrospective review

BACKGROUND

Biliary strictures can be caused by benign and malignant conditions. A biliary duct brushing diagnosis can be challenging because of low cellularity and overlapping morphology among different entities, leading to a variable reported sensitivity. This study aimed to assess the value of KRAS mutation testing in adding cytological diagnosis of biliary duct brushings.

METHODS

With institutional review board approval, biliary duct brushing cytology specimens were collected from 269 patients with extrahepatic biliary stenosis between August 2011 and July 2021. The results of cytology and KRAS mutational analyses were evaluated in view of corresponding cytology examination and histopathological/clinical follow-up.

RESULTS

KRAS mutations were identified in 50 of 269 biliary stricture brushing cases (19%). Among the cases with available follow-up, 72% (34 of 47) of biliary brushings had confirmed malignancy when there were KRAS mutations. The overall specificity and sensitivity of KRAS mutation testing was 92% and 36%, respectively. KRAS mutation was significantly more enriched in pancreatic duct adenocarcinoma than in cholangiocarcinoma (66% vs 5%, P < .001). The absolute risk of malignancy was 3%, 28%, and 71%, respectively, in negative, atypical, and suspicious cytological diagnostic categories and the risks increased to 14%, 68%, and 95% in corresponding categories with KRAS mutation.

CONCLUSIONS

Our results suggested that KRAS mutational analysis can be considered supplementary to cytology diagnosis of biliary duct brushing for patients with extrahepatic biliary stenosis in clinical practice.

Circulating Cell-Free Tumor DNA in Advanced Pancreatic Adenocarcinoma Identifies Patients With Worse Overall Survival

Background

Plasma-based circulating cell-free tumor DNA (ctDNA) genomic profiling by next-generation sequencing (NGS)is an emerging diagnostic tool for pancreatic cancer (PC). The impact of detected genomic alterations and variant allele fraction (VAF) in tumor response to systemic treatments and outcomes is under investigation.

Methods

Patients with advanced PC who had ctDNA profiled at time of initial diagnosis were retrospectively evaluated. We considered the somatic alteration with the highest VAF as the dominant clone allele frequency (DCAF). ctDNA NGS results were related to clinical demographics, progression-free survival (PFS) and overall survival (OS).

Results

A total of 104 patients were evaluated. Somatic alterations were detected in 84.6% of the patients. Patients with ≥ 2 detectable genomic alterations had worse median PFS (p < 0.001) and worse median OS (p = 0.001). KRAS was associated with disease progression to systemic treatments (80.4% vs 19.6%, p = 0.006), worse median PFS (p < 0.001) and worse median OS (p = 0.002). TP53 was associated with worse median PFS (p = 0.02) and worse median OS (p = 0.001). The median DCAF was 0.45% (range 0-55%). DCAF >0.45% was associated with worse median PFS (p<0.0001) and median OS (p=0.0003). Patients that achieved clearance of KRAS had better PFS (p=0.047), while patients that achieved clearance of TP53 had better PFS (p=0.0056) and OS (p=0.037).

Conclusions

Initial detection of ctDNA in advanced PC can identify somatic alterations that may help predict clinical outcomes. The dynamics of ctDNA are prognostic of outcomes and should be evaluated in prospective studies.

Kras Gene Analysis Using Liquid-Based Cytology Specimens Predicts Therapeutic Responses and Prognosis in Patients with Pancreatic Cancer

Simple Summary

New therapeutic strategies are needed to improve the prognosis of pancreatic ductal adenocarcinoma (PDAC) and developing biomarkers that can guide individualized treatment decisions is an important part of these strategies. In this study, we found that unresectable PDAC patients harboring wild-type Kras had significantly longer progression-free survival (PFS) and overall survival (OS) than those harboring mutant Kras after undergoing first-line gemcitabine and nab-paclitaxel (GA) therapy and that wild-type Kras was a significant predictor of longer PFS and OS. This is the first report suggesting that Kras gene analysis has the potential to predict therapeutic responses to GA and the prognosis of unresectable PDAC.

Abstract

Background: Although several molecular analyses have shown that the Kras gene status is related to long-term survival of patients with pancreatic ductal adenocarcinoma (PDAC), the results remain controversial. Here, we examined the Kras gene status in a cohort of unresectable PDAC patients who underwent first-line therapy with gemcitabine and nab-paclitaxel (GA) and assessed differences in chemotherapy responses and survival. Methods: Patients with a histological diagnosis of PDAC (based on EUS-guided fine-needle aspiration) from 2017 to 2019 were enrolled. Tumor genomic DNA was extracted from residual liquid-based cytology specimens and Kras mutations were assessed using the quenching probe method. The relationships between the Kras status and progression-free survival (PFS) and overall survival (OS) were assessed. Results: Of the 110 patients analyzed, 15 had wild-type Kras. Those with the wild-type gene showed significantly longer PFS and OS than those with mutant Kras (6.9/5.3 months (p = 0.044) vs. 19.9/11.8 months (p = 0.037), respectively). Multivariate analyses identified wild-type Kras as a significant independent factor associated with longer PFS and OS (HR = 0.53 (p = 0.045) and HR = 0.35 (p = 0.007), respectively). Conclusions: The analysis of the Kras gene status could be used to predict therapeutic responses to GA and prognosis in unresectable PDAC patients.

EUS-FNA Biopsies to Guide Precision Medicine in Pancreatic Cancer: Results of a Pilot Study to Identify KRAS Wild-Type Tumours for Targeted Therapy

Background

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer death and lacks effective treatment options. Diagnostic endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsies represent an appealing source of material for molecular analysis to inform targeted therapy, as they are often the only available tissue for patients presenting with PDAC irrespective of disease stage. However, EUS-FNA biopsies are typically not used to screen for precision medicine studies due to concerns about low tissue yield and quality. Epidermal growth factor receptor (EGFR) inhibition has shown promise in clinical trials of unselected patients with advanced pancreatic cancer, but has not been prospectively tested in KRAS wild-type patients. Here, we examine the clinical utility of EUS-FNA biopsies for molecular screening of KRAS wild-type PDAC patients for targeted anti-EGFR therapy to assess the feasibility of this approach.

Patients and Methods

Fresh frozen EUS-FNA or surgical biopsies from PDAC patient tumours were used to screen for KRAS mutations. Eligible patients with recurrent, locally advanced, or metastatic KRAS wild-type status who had received at least one prior line of chemotherapy were enrolled in a pilot study (ACTRN12617000540314) and treated with panitumumab at 6mg/kg intravenously every 2 weeks until progression or unacceptable toxicity. The primary endpoint was 4-month progression-free survival (PFS).

Results

275 patient biopsies were screened for KRAS mutations, which were detected in 88.3% of patient samples. 8 eligible KRAS wild-type patients were enrolled onto the interventional study between November 2017 and December 2020 and treated with panitumumab. 4-month PFS was 14.3% with no objective tumour responses observed. The only grade 3/4 treatment related toxicity observed was hypomagnesaemia.

Conclusions

This study demonstrates proof-of-principle feasibility to molecularly screen patients with pancreatic cancer for targeted therapies, and confirms diagnostic EUS-FNA biopsies as a reliable source of tumour material for molecular analysis. Single agent panitumumab was safe and tolerable but led to no objective tumour responses in this population.

Impact of somatic mutations on clinical and pathologic outcomes in borderline resectable and locally advanced pancreatic cancer treated with neoadjuvant chemotherapy and stereotactic body radiotherapy followed by surgical resection

PURPOSE

The purpose of this study was to determine if somatic mutations are associated with clinical and pathologic outcomes in patients with borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) who were treated with neoadjuvant chemotherapy and stereotactic body radiotherapy (SBRT).

MATERIALS AND METHODS

Patients treated with neoadjuvant chemotherapy and SBRT followed by surgical resection from August 2016 to January 2019 and who underwent next generation sequencing of their primary tumor were included in the study. Next-generation sequencing was performed either in-house with a Solid Tumor Panel or with FoundationOne CDx. Univariate (UVA) and multivariable analyses (MVA) were performed to determine associations between somatic mutations and pathologic and clinical outcomes.

RESULTS

Thirty-five patients were included in the study. Chemotherapy consisted of modified FOLFIRINOX, gemcitabine and nab-paclitaxel, or gemcitabine and capecitabine. Patients were treated with SBRT in 33 Gy in 5 fractions. On UVA and MVA, tumors with KRAS G12V mutation demonstrated better pathologic tumor regression grade (TRG) to neoadjuvant therapy when compared to tumors with other KRAS mutations (odds ratio = 0.087; 95% confidence interval [CI], 0.009-0.860; p = 0.036). On UVA and MVA, mutations in NOTCH1/2 were associated with worse overall survival (hazard ratio [HR] = 4.15; 95% CI, 1.57-10.95; p = 0.004) and progression-free survival (HR = 3.61; 95% CI, 1.41-9.28; p = 0.008). On UVA, only mutations in NOTCH1/2 were associated with inferior distant metastasis-free survival (HR = 3.38; 95% CI, 1.25-9.16; p = 0.017).

CONCLUSION

In BRPC and LAPC, the KRAS G12V mutation was associated with better TRG following chemotherapy and SBRT. Additionally, NOTCH1/2 mutations were associated with worse overall survival, distant metastasis-free survival, and progression-free survival.

Analysis of KRAS Mutation Subtype in Tissue DNA and Cell-Free DNA Using Droplet Digital PCR and the Function of Cell-Free DNA as a Recurrence Predictive Marker in Pancreatic Cancer

KRAS mutation is a major regulator in the tumor progression of pancreatic cancer. Here, we compared the frequency and mutation burden of KRAS mutation subtypes with paired tumor tissue and blood in patients and examined their clinical significance. DNA from tumor tissues and cell-free DNA (cfDNA) from preoperative blood were obtained from 70 patients with pancreatic cancer. Subtypes and mutation burdens of KRAS G12D and G12V mutations were evaluated using droplet digital PCR. Comparing the presence of mutations in tissue, accumulative and simultaneous mutations of G12D or G12V were identified of 67 (95.7%), and 48 patients (68.6%). Conversely, in blood, they were only identified in 18 (25.7%) and four (5.7%) patients; respectively. Next, comparing the mutation burden in tissue, the mutation burden varied from less than 0.1 to more than five, whereas that of cfDNA in blood was mostly between one and five, as cases with a mutation burden lower than 0.1 and higher than five were rare. Finally, the presence of the G12V mutation alone in cfDNA and the combination of the G12V mutation with elevated CA 19-9 levels were associated with poor recurrence-free survival. These fundamental data on the KRAS mutation subtypes and their clinical significance could support their potential as predictive markers for postoperative recurrence.

The value of comprehensive genomic sequencing to maximize the identification of clinically actionable alterations in advanced cancer patients: a case series

PURPOSE

We present seven cases of advanced cancer patients who initially underwent tumor testing utilizing smaller, panel-based tests, followed by a variety of therapeutic treatments which ultimately resulted in progression of their disease. These cases demonstrate the value of utilizing WES/RNA seq and characterization following disease progression in these patients and the determination of clinically targetable alterations as well as acquired resistance mutations.

MATERIALS AND METHODS

All patients are part of an IRB approved observational study. WES and RNA sequencing were performed, using GEM ExTra® on tumor and blood samples obtained during routine clinical care. To accurately determine somatic versus germline alterations the test was performed with paired normal testing from peripheral blood.

RESULTS

The presented cases demonstrate the clinical impact of actionable findings uncovered using GEM ExTra® in patients with advanced disease who failed many rounds of treatment. Unique alterations were identified resulting in newly identified potential targeted therapies, mechanisms of resistance, and variation in the genomic characterization of the primary versus the metastatic tumor.

CONCLUSIONS

Taken together our results demonstrate that GEM ExTra® maximizes detection of actionable mutations, thus allowing for appropriate treatment selection for patients harboring both common and rare genomic alterations.

The potential targeted drugs for fusion genes including NRG1 in pancreatic cancer

Pancreatic cancer (PC) remains an incurable disease with few treatment options Recently, promising targets have been identified and novel therapeutic drugs are currently under development in KRAS wild-type PC. It has been reported that KRAS wild-type PC has the genomic alterations such as oncogenic derivers and kinase fusions. NRG1 fusion, which encodes the neuregulin 1 and is the main ligands for ERRB3, has been identified in approximately half of younger patients with PC with KRAS wild-type tumors by RNA sequencing. There are several promising targeted therapies for NRG1 fusion-positive tumors, such as EGFR-tyrosine kinase inhibitor, HER3, HER2 antibodies. BRAF, NTRK, and ALK fusion are also potentially actionable alterations in KRAS wild-type PC and novel therapies targeting certain aberrations have shown activity in clinical trials.

Circulating TP53 mutations are associated with early tumor progression and poor survival in pancreatic cancer patients treated with FOLFIRINOX

Background:

Biomarkers predicting treatment response may be used to stratify pancreatic ductal adenocarcinoma (PDAC) patients for therapy. The aim of this study was to identify circulating tumor DNA (ctDNA) mutations that associate with tumor progression during FOLFIRINOX chemotherapy, and overall survival (OS).

Methods:

Circulating cell-free DNA was analyzed with a 57 gene next-generation sequencing panel using plasma samples of 48 PDAC patients of all disease stages. Patients received FOLFIRINOX as initial treatment. Chemotherapy response was determined on CT scans as disease control (n = 30) or progressive disease (n = 18) within eight cycles of FOLFIRINOX, based on RECIST 1.1 criteria.

Results:

Detection of a TP53 ctDNA mutation before start of FOLFIRINOX [odds ratio (OR) 10.51, 95% confidence interval (CI) 1.40–79.14] and the presence of a homozygous TP53 Pro72Arg germline variant (OR 6.98, 95% CI 1.31–37.30) were predictors of early tumor progression during FOLFIRINOX in multivariable analysis. Five patients presented with the combination of a TP53 ctDNA mutation before start of FOLFIRINOX and the homozygous Pro72Arg variant. All five patients showed progression during FOLFIRINOX. The combination of the TP53 mutation and TP53 germline variant was associated with shorter survival (median OS 4.4 months, 95% CI 2.6–6.2 months) compared with patients without any TP53 alterations (median OS 13.0 months, 95% CI 8.6–17.4 months).

Conclusion:

The combination of a TP53 ctDNA mutation before start of FOLFIRINOX and a homozygous TP53 Pro72Arg variant is a promising biomarker, associated with early tumor progression during FOLFIRINOX and poor OS. The results of this exploratory study need to be validated in an independent cohort.

Relevance of circulating hybrid cells as a non-invasive biomarker for myriad solid tumors

Metastatic progression defines the final stages of tumor evolution and underlies the majority of cancer-related deaths. The heterogeneity in disseminated tumor cell populations capable of seeding and growing in distant organ sites contributes to the development of treatment resistant disease. We recently reported the identification of a novel tumor-derived cell population, circulating hybrid cells (CHCs), harboring attributes from both macrophages and neoplastic cells, including functional characteristics important to metastatic spread. These disseminated hybrids outnumber conventionally defined circulating tumor cells (CTCs) in cancer patients. It is unknown if CHCs represent a generalized cancer mechanism for cell dissemination, or if this population is relevant to the metastatic cascade. Herein, we detect CHCs in the peripheral blood of patients with cancer in myriad disease sites encompassing epithelial and non-epithelial malignancies. Further, we demonstrate that in vivo-derived hybrid cells harbor tumor-initiating capacity in murine cancer models and that CHCs from human breast cancer patients express stem cell antigens, features consistent with the potential to seed and grow at metastatic sites. Finally, we reveal heterogeneity of CHC phenotypes reflect key tumor features, including oncogenic mutations and functional protein expression. Importantly, this novel population of disseminated neoplastic cells opens a new area in cancer biology and renewed opportunity for battling metastatic disease.

Pancreatic ductal adenocarcinoma in the era of precision medicine

The paradigm for treatment of PDAC is shifting from a "one size fits all" of cytotoxic therapy to a precision medicine approach based on specific predictive biomarkers for a subset of patients. As the genomic landscape of pancreatic carcinogenesis has become increasingly defined, several oncogenic alterations have emerged as actionable targets and their use has been validated in novel approaches such as targeting mutated germline DNA damage response genes (BRCA) and mismatch deficiency (dMMR/MSI-H) or blockade of rare somatic oncogenic fusions. Chemotherapy selection based on transcriptomic subtypes and developing stroma- and immune-modulating strategies have yielded encouraging results and may open therapeutic refinement to a broader PDAC population. Notwithstanding, a series of negative late-stage trials over the last year continue to underscore the inherent challenges in the treatment of PDAC. Multifactorial therapy resistance warrants further exploration in PDAC "omics" and tumor-stroma-immune cells crosstalk. Herein, we discuss precision medicine approaches applied to the treatment of PDAC, its current state and future perspective.

Germline and somatic genetic alterations in two first-degree relatives with appendiceal low-grade mucinous carcinoma peritonei

Comparing genetic mutations of first-degree relatives with appendiceal pseudomyxoma peritonei may explain clinical outcomes and disease pathogenesis. Molecular profiling of mucinous tumors may identify improved treatments to traditional chemotherapy.

Challenges and Therapeutic Opportunities of Autophagy in Cancer Therapy

Simple Summary

Autophagy is a physiological process characterized by the degradation of the cell components through lysosomes due to stimuli/stress. In this study, we review the challenges and therapeutic opportunities that autophagy presents in the treatment of cancer. We discussed the results of several studies that evaluated autophagy as a therapeutic strategy in cancer, both through the modulation of therapeutic resistance and the death of cancer cells. Moreover, we discussed the role of autophagy in the biology of cancer stem cells and the inhibition of this process as a strategy to overcome resistance and progression of cancer stem cells.

Abstract

Autophagy is a physiological cellular process that is crucial for development and can occurs in response to nutrient deprivation or metabolic disorders. Interestingly, autophagy plays a dual role in cancer cells—while in some situations, it has a cytoprotective effect that causes chemotherapy resistance, in others, it has a cytotoxic effect in which some compounds induce autophagy-mediated cell death. In this review, we summarize strategies aimed at autophagy for the treatment of cancer, including studies of drugs that can modulate autophagy-mediated resistance, and/or drugs that cause autophagy-mediated cancer cell death. In addition, the role of autophagy in the biology of cancer stem cells has also been discussed.

KRAS wild-type pancreatic ductal adenocarcinoma: molecular pathology and therapeutic opportunities

Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease, whose main molecular trait is the MAPK pathway activation due to KRAS mutation, which is present in 90% of cases.The genetic landscape of KRAS wild type PDAC can be divided into three categories. The first is represented by tumors with an activated MAPK pathway due to BRAF mutation that occur in up to 4% of cases. The second includes tumors with microsatellite instability (MSI) due to defective DNA mismatch repair (dMMR), which occurs in about 2% of cases, also featuring a high tumor mutational burden. The third category is represented by tumors with kinase fusion genes, which marks about 4% of cases. While therapeutic molecular targeting of KRAS is an unresolved challenge, KRAS-wild type PDACs have potential options for tailored treatments, including BRAF antagonists and MAPK inhibitors for the first group, immunotherapy with anti-PD-1/PD-L1 agents for the MSI/dMMR group, and kinase inhibitors for the third group.This calls for a complementation of the histological diagnosis of PDAC with a routine determination of KRAS followed by a comprehensive molecular profiling of KRAS-negative cases.

Integrated clinicomolecular characterization identifies RAS activation and CDKN2A deletion as independent adverse prognostic factors in cancer of unknown primary

Cancer of unknown primary (CUP) denotes a malignancy with histologically confirmed metastatic spread while the primary tumor remains elusive. Here, we address prognostic and therapeutic implications of mutations and copy number variations (CNVs) detected in tumor tissue in the context of a comprehensive clinical risk assessment. Targeted panel sequencing was performed in 252 CUP patients. 71.8% of patients had unfavorable CUP according to ESMO guidelines. 74.7% were adeno- and 13.7% squamous cell carcinomas. DNA was extracted from microdissected formalin-fixed, paraffin-embedded tissues. For library preparation, mostly multiplex PCR-based Ion Torrent AmpliSeq™ technology with Oncomine comprehensive assays was used. Most frequent genetic alterations were mutations/deletions of TP53 (49.6%), CDKN2A (19.0%) and NOTCH1 (14.1%) as well as oncogenic activation of KRAS (23.4%), FGFR4 (14.9%) and PIK3CA (10.7%). KRAS activation was predominantly found in adenocarcinomas (p = 0.01), PIK3CA activation in squamous cell carcinomas (p = 0.03). Male sex, high ECOG score, unfavorable CUP, higher number of involved organs and RAS activation predicted decreased event-free and overall survival in multivariate analysis. Deletions of CDKN2A were prognostically adverse regarding overall survival. TP53 mutations did not significantly influence prognosis in the overall cohort, but worsened prognosis in otherwise favorable CUP subtypes. Although not standard in CUP, for 17/198 (8.6%) patients molecularly targeted treatment was recommended and 10 patients (5.1%) were treated accordingly. In conclusion, besides the identification of drug targets, panel sequencing in CUP is prognostically relevant, with RAS activation and CDKN2A deletion emerging as novel independent risk factors in a comprehensive assessment with clinicopathological data.

Effect of Gemcitabine and nab-Paclitaxel With or Without Hydroxychloroquine on Patients With Advanced Pancreatic Cancer: A Phase 2 Randomized Clinical Trial

Importance

Autophagy is a mechanism of treatment resistance to chemotherapy that has a role in the maintenance of pancreatic cancer. Hydroxychloroquine sulfate (HCQ) is an inhibitor of autophagy that inhibits the fusion of the autophagosome to the lysosome.

Objective

To determine whether HCQ improves overall survival at 1 year in combination with gemcitabine hydrochloride and nab-paclitaxel (GA) among patients with metastatic pancreatic cancer.

Design, Setting, and Participants

Open-label, phase 2 randomized clinical trial conducted between March 18, 2013, and November 16, 2017, at the University of Pennsylvania, HonorHealth, and The Johns Hopkins University among 112 patients with previously untreated metastatic or advanced pancreatic ductal adenocarcinoma, Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate marrow and organ function. All efficacy analyses were performed for the intention-to-treat population.

Interventions

Patients were randomized in a 1:1 ratio to receive GA with or without HCQ. All patients received standard doses of GA, and those randomized to receive HCQ were treated continuously with 600 mg orally twice daily.

Main Outcome and Measure

Overall survival at 1 year.

Results

A total of 112 patients (45 women and 67 men; median age, 65 years; range, 43-86 years) were enrolled; 55 were randomized to receive GA plus HCQ, and 57 to receive GA. Overall survival at 12 months was 41% (95% CI, 27%-53%) in the HCQ group and 49% (95% CI, 35%-61%) in the non-HCQ group. Median progression-free survival was 5.7 months (95% CI, 4.0-9.3 months) in the HCQ group and 6.4 months (95% CI, 4.5-7.6 months) in the non-HCQ group. Median overall survival was 11.1 months (95% CI, 9.0-14.2 months) in the HCQ group and 12.1 months (95% CI, 9.3-15.5 months) in the non-HCQ group. Overall response rate was 38.2% (n = 21) in the HCQ group and 21.1% (n = 12) in the non-HCQ group (P = .047). Treatment-related grade 3 or 4 adverse events that differed between the HCQ and non-HCQ groups were neutropenia (23 of 54 [42.6%] vs 12 of 53 [22.6%]), anemia (2 of 54 [3.7%] vs 9 of 53 [17.0%]), fatigue (4 of 54 [7.4%] vs 0), nausea (5 of 54 [9.3%] vs 0), peripheral neuropathy (7 of 54 [13.0%] vs 3 of 53 [5.7%]), visual changes (3 of 54 [5.6%] vs 0), and neuropsychiatric symptoms (3 of 54 [5.6%] vs 0).

Conclusions and Relevance

The addition of HCQ to block autophagy did not improve the primary end point of overall survival at 12 months. These data do not support the routine use of GA plus HCQ for metastatic pancreatic cancer in the absence of a biomarker. However, improvement seen in the overall response rate with HCQ may indicate a role for HCQ in the locally advanced setting, where tumor response may permit resection.

Trial Registration

ClinicalTrials.gov identifier: NCT01506973.

Kirsten Rat Sarcoma Viral Oncogene Homologue (KRAS) Mutations in the Occurrence and Treatment of Pancreatic Cancer

Pancreatic cancer is a highly malignant tumor with a 5-year survival rate of less than 6%, and incidence increasing year by year globally. Pancreatic cancer has a poor prognosis and a high recurrence rate, almost the same as the death rate. However, the available effective prevention and treatment measures for pancreatic cancer are still limited. The genome variation is one of the main reasons for the development of pancreatic cancer. In recent years, with the development of gene sequencing technology, in-depth research on pancreatic cancer gene mutation presents that a growing number of genetic mutations are confirmed to be in a close relationship with invasion and metastasis of pancreatic cancer. Among them, KRAS mutation is a special one. Therefore, it is particularly important to understand the mechanism of the KRAS mutation in the occurrence and development of pancreatic cancer, and to explore the method of its transformation into clinical tumor molecular targeted treatment sites, to further improve the therapeutic effect on pancreatic cancer. Therefore, to better design chemical drugs, this review based on the biological functions of KRAS, summarized the types of KRAS mutations and their relationship with pancreatic cancer and included the downstream signaling pathway Raf-MEK-ERK, PI3K-AKT, RalGDS-Ral of KRAS and the current medicinal treatment methods for KRAS mutations. Moreover, drug screening and clinical treatment for KRAS mutated cell and animal models of pancreatic cancer are also reviewed along with the prospect of targeted medicinal chemistry therapy for precision treatment of pancreatic cancer in the future.

RAS in pancreatic cancer

The pancreas is a gland composed mainly by endocrine and exocrine cells, giving rise to three main tumour types. Pancreatic neuroendocrine tumour or PNET arise from the endocrine portion of the pancreas. On the contrary, pancreatic exocrine neoplasms include pancreatic ductal adenocarcinoma (PDAC) and acinar cell carcinoma. PDAC is the most common type of pancreatic cancer and one of the leading causes of cancer-related death. It has been shown that less than 3% of PDAC patients have an overall survival of up to 5 years in the U.K. This mainly arises since the majority of patients diagnosed with PDAC present with advanced unresectable disease, which is highly resistant to all forms of chemotherapy and radiotherapy. Activating mutations of an isoform of the RAS protein, KRAS, are found in almost all PDAC cases and occur during early stages of malignant transformation. KRAS mutations play a critical role as they are involved in both initiating and maintaining PDAC development. The interaction of RAS with GDP/GTP along with its recruitment to the membrane affects transduction of its activating signals to downstream effectors. In this review, we aim to summarise different mutations of RAS and their prevalence in pancreatic cancer along with other RAS-induced tumours. In addition, we briefly discuss the genetically engineered mouse models that have been developed to study KRAS-mutated adenocarcinomas in the pancreas. These provide an opportunity to also address the importance of targeting RAS for better treatment response in PDAC patients along with the challenges incurred herein.

Bioinformatic evidences and analysis of putative biomarkers in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human cancers. Aberrant expression of genes plays important role in the procession of PDAC. The analysis of gene expression profile will contribute to the research of carcinoma mechanism.

OBJECTIVE

This present study is focused to investigate the differentially expressed genes (DEGs) from 3 PDAC microarray datasets, which would provide candidate genes for putative biomarkers to understand the mechanism of PDAC and potential targets of treatment.

METHOD

Based on the overlap genes obtained from 3 GEO datasets, the hub genes were identified using STRING and Cytoscape plugin MCODE. The enrichment and function analysis were applied using DAVID. The protein-protein interaction network was performed using cBioPortal and UCSC Xena. The Oncomine was finally used to determine the candidate gene by analyzing their expression between pancreas sample and PDAC sample.

RESULTS

25 hub genes were selected from a total of 1006 DEGs from 3 GEO datasets, consisting of 14 upregulated genes and 11 downregulated genes. The overall decline of hub gene expression enriched in G1 phase of cell cycle in other subtypes of pancreatic cancer. Oncomine database was ultimately performed to determine the 8 candidate genes, including CXCL5, CCL20, NMU, F2R, ANXA1, EDNRA, LPAR6, and GNA15.

CONCLUSIONS

Conclusively, 8 candidate genes would become the potential PDAC combined biomarkers for diagnosis and therapeutic strategies.