A novel immune checkpoint score system for prognostic evaluation in pancreatic adenocarcinoma.

BACKGROUND: Pancreatic adenocarcinoma (PAAD) remains a lethal malignancy making the detection of novel prognostic biomarkers urgent. Limited studies have investigated the predictive capability of immune checkpoints in PAAD. METHOD: Gene expression data and correlative clinical information of PAAD cohort were obtained from public databases, including TCGA, ICGC, GTEX and GEO databases. Risk factors were screened and used to establish a risk score model through LASSO and Cox regression analyses. The prognostic ability of the risk score model was demonstrated. The association between risk score with immune cells infiltration, immune checkpoint genes expression, immunogenic cell death, somatic mutations and signaling pathways enrichment were analysed. scRNA-seq data were collected to confirmed the immune checkpoints expression in PAAD samples. The prognosis prediction ability of OX40/TNFRSF4 was identified. The mRNA and protein expression of OX40 in our clinical specimens were examined by RT-PCR and IHC method and its prognosis ability was verified. RESULTS: First of all, the difference of immune microenvironment between pancreatic cancer and adjacent tissues was shown. A risk score system based on three immune checkpoints (OX40, TNFSF14 and KIR3DL1) was established. The risk score model was an independent prognostic factor and performed well regarding overall survival (OS) predictions among PAAD patients. A nomogram was established to facilitate the risk model application in clinical prognosis. Immune cells including naive B cells, CD8+ T cells and Tregs were negatively correlated with the risk score. The risk score was associated with expression of immune checkpoint genes, immunogenic cell death related genes and somatic mutations. Glycolysis processes, IL-2-STAT5, IL-6-STAT3, and mTORC1 signaling pathways were enriched in the high-risk score group. Furthermore, scRNA-seq data confirmed that TNFRSF4, TNFSF14 and KIR3DL1 were expressed on immune cells in PAAD samples. We then identified OX40 as an independent prognosis-related gene, and a higher OX40 expression was associated with increased survival rate and immune environment change. In 84 PAAD clinical specimens collected from our center, we confirmed that higher OX40 mRNA expression levels were related to a good prognosis. The protein expression of OX40 on tumor-infiltrating immune cells (TIICs), endothelial cells and tumor cells was verified in PAAD tissues by immunohistochemistry (IHC) method. CONCLUSIONS: Overall, our findings strongly suggested that the three-immune checkpoints score system might be useful in the prognosis and design of personalized treatments for PAAD patients. Finally, we identified OX40 as an independent potential biomarker for PAAD prognosis prediction.

Carbohydrate antigen 125 supplements carbohydrate antigen 19-9 for the prediction of invasive intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMNs) are characterized by their abundant mucin production and malignant potential. IPMNs of the pancreas are mainly managed according to their radiographic indications, but this approach lacks accuracy with regard to IPMN grading. Therefore, serological biomarkers such as CA19-9 and CA125 (MUC16) should be employed to assist in predicting the invasiveness of IPMNs. METHODS: We investigated the preoperative serum levels of CA19-9, CA125 and CEA in 381 surgical patients with a definite pathological diagnosis of IPMN from July 2010 to December 2019 at the Shanghai Cancer Center. We calculated the Youden indices of each point on the receiver operating characteristic (ROC) curves to identify the most appropriate cut-off values of CA19-9, CA125 and CEA for recognizing malignant IPMNs. Serological biomarker differences were correlated with clinicopathological features of IPMNs, and diagnostic indices of different scenarios were calculated to find the optimum strategy. RESULTS: The malignant group had higher serum levels of CA19-9, CA125 and CEA. According to the ROC curves, the cut-off values of CA19-9, CA125 and CEA were readjusted to 38.3 U/ml, 13.4 U/ml and 5.3 µg/L. CA19-9 elevation was significantly associated with vascular invasion and perineural infiltration. CA125 showed good efficacy in predicting invasive IPMN in the CA19-9-negative subgroup. CONCLUSIONS: Serological biomarkers are useful and sensitive indicators for recognizing invasive IPMNs. CA19-9 is the most important diagnostic index among all routinely measured serum biomarkers for differentiating malignant from benign IPMNs. CA19-9 should be combined with CA125 to enable more accurate predictions of IPMN malignancy.

Predictive Values of Preoperative Markers for Resectable Pancreatic Body and Tail Cancer Determined by MDCT to Detect Occult Metastases.

BACKGROUND: To evaluate the clinical value of preoperative markers in predicting occult metastases in resectable pancreatic body and tail cancer judged by a recent multidetector computed tomography (MDCT) scan of the abdomen. METHODS: The data from a retrospective collected database from 2010 to 2019 with 699 patients who had MDCT scan predicted resectable mass in pancreatic body and tail and were pathological confirmed as adenocarcinoma after surgery. Receiver operating characteristic (ROC) curve was plotted for serum CA19-9, CA125, CEA and tumor size measured by MDCT. The optimal cut-off point-related sensitivity and specificity were calculated, respectively. RESULTS: Occult metastases were found in 73 (73/699, 10.4%) pancreatic body and tail cancer patients underwent exploration. The area under curve (AUC) for CA19-9, CA125, CEA and tumor size were 0.624, 0.733, 0.561 and 0.697, respectively. The optimal cut-off for CA19-9, CA125 and tumor size is 226 U/ml, 22.1 U/ml and 3.3 cm, respectively. The sensitivity and specificity of CA19-9 for predicting occult metastases were 67.1% and 60.4%, 72.6% and 64.7% for CA125, 80.8% and 51.4% for tumor size. CONCLUSION: CA125 is superior to CA19-9 and tumor size for predicting occulting metastases in MDCT scan suggested resectable pancreatic body and tail cancer. The high level of CA125 (≥ 22.1 U/ml) is regarded as high risk for occulting metastases, and laparoscopy should be applied for these patients.

High GFPT1 expression predicts unfavorable outcomes in patients with resectable pancreatic ductal adenocarcinoma.

BACKGROUND: Glutamine-fructose-6-phosphate transaminase 1 (GFPT1) is the first rate-limiting enzyme of the hexosamine biosynthesis pathway (HBP), which plays a pivotal role in the progression of pancreatic ductal adenocarcinoma (PDAC). Therefore, we investigated the prognostic significance of GFPT1 expression in patients with resectable PDAC. METHODS: We analyzed public datasets to compare GFPT1 expression in tumor tissues and normal/adjacent pancreatic tissues. We measured the relative GFPT1 expression of 134 resected PDAC specimens in our institution, using real-time polymerase chain reaction (PCR). Survival was compared between high and low GFPT1 expression groups using Kaplan-Meier curves and log-rank tests. Multivariate analyses were estimated using Cox regression and logistic regression models. RESULTS: GFPT1 is generally upregulated in PDAC tissues, according to the analysis of public datasets. The data from our institution shows that high GFPT1 expression was correlated with a high rate of lymph node (LN) metastasis (p = 0.038) and was an independent risk factor for LN metastasis (odds ratio (OR) = 3.14, 95% confidence interval (CI) = 1.42 to 6.90, P = 0.005). High GFPT1 expression was significantly associated with poor overall survival (OS; P = 0.019) in patients with resected PDAC. The multivariable-adjusted hazard ratio (HR) for mortality when comparing patients with high and low GFPT1 expression was 2.54 (95% CI = 1.35 to 4.79, P = 0.004). CONCLUSIONS: GFPT1 is generally upregulated in PDAC tissue and is associated with a high risk of LN metastasis and an unfavorable outcome in patients with resectable PDAC, suggesting its crucial role in PDAC progression.

Prognostic Value of the C-Reactive Protein/Lymphocyte Ratio in Pancreatic Cancer.

BACKGROUND: Many inflammatory markers can be used for the prognostication of pancreatic cancer, but which combination of inflammatory factors may be the best remains unclear. This study focused on the potential feasibility of the newly discovered C-reactive protein (CRP)/lymphocyte ratio (CLR) as a prognostic biomarker for patients with pancreatic cancer. METHODS: The study enrolled 997 patients with pancreatic cancer. Six combinations of inflammatory markers, namely, the neutrophil/lymphocyte ratio (NLR), the platelet/lymphocyte ratio (PLR), the CRP/albumin ratio (CAR), the neutrophil/albumin ratio (NAR), the platelet/albumin ratio (PAR), and CLR, were examined to determine which combination offers the highest accuracy for predicting poor survival by receiver operating characteristic curve analysis. The prognostic value of the CLR was analyzed by uni- and multivariate analyses. RESULTS: The newly developed CLR was more accurate than the NLR, PLR, CAR, NAR, and PAR in predicting survival. The optimal cutoff value for the CLR was calculated to be 1.8 for survival. A CLR higher than 1.8 was associated with poor survival in both the univariate (hazard ratio [HR] 2.00; P < 0.001) and multivariate (HR 1.73; P < 0.001) analyses. In addition, a CLR higher than 1.8 was an independent risk factor for patients with stage 2 (HR 1.85; P = 0.001), stage 3 (HR 1.83; P = 0.001), or stage 4 (HR 1.70; P < 0.001) disease. CONCLUSIONS: Pretreatment CLR can be considered a feasible biomarker for the prognostic prediction of pancreatic cancer. An elevated CLR was an independent risk factor for poor survival, with a cutoff value of 1.8.

Prior history of acute pancreatitis predicts poor survival in patients with resectable pancreatic ductal adenocarcinoma.

BACKGROUND/OBJECTIVES: Mounting evidence has suggested that acute pancreatitis (AP) is a risk factor for pancreatic ductal adenocarcinoma (PDAC), but its role in survival in PDAC patients was rarely investigated. The objective was to investigate the association of a history of AP with survival among PDAC patients who underwent surgical resection. METHODS: A retrospective cohort study comprising 632 patients who were diagnosed with resectable PDAC was conducted. Survival was evaluated by history of AP prior to a diagnosis of PDAC using Kaplan-Meier methods and log-rank tests. Multivariate analyses for mortality were estimated using the Cox proportional hazards model. Propensity score matching methods were used to balance the difference of clinical characteristics between patients with and without AP history. RESULTS: The log-rank tests showed that patients with a history of AP had a worse overall survival than those without a history of AP (p = 0.006). The multivariable-adjusted hazard ratio (HR) for mortality comparing participants with AP to those without AP was 1.808 (95% CI: 1.241-2.632, p = 0.002). Patients with a recent history of AP (<2 years), rather than patients with a remote history of AP (≥2 years), were found to have significantly worse survival (p = 0.014) than those without a history of AP. After adjusted for PSM, history of AP remained an independent survival predictor of PDAC following surgical resection. CONCLUSIONS: Our findings indicate that a history of AP, especially a recent history of AP, is associated with poor survival among patients with resectable pancreatic ductal adenocarcinoma.

Resected Pancreatic Cancer With N2 Node Involvement Is Refractory to Gemcitabine-Based Adjuvant Chemotherapy.

Lymphatic metastasis is a major determinant of the outcome of resected pancreatic cancer. Gemcitabine-based adjuvant chemotherapy can improve the outcome of resected pancreatic cancer. However, the efficacy of gemcitabine against pancreatic cancer stratified by nodal involvement is unclear. In this study, patients who had undergone curative resection of pancreatic adenocarcinoma (612 cases) were included. The efficacy of adjuvant gemcitabine-based regimen, stratified by nodal status (negative, positive) or N substage (N0, no nodal involvement; N1, 1-3-node involvement; N2, ≥4-node involvement), was examined. Both the node-negative (hazard ratio [HR] = 0.62, 95% confidence interval [CI], 0.44-0.87, P = .006) and node-positive subgroups (HR = 0.45, 95% CI, 0.33-0.62, P < .001) benefited from gemcitabine-based adjuvant chemotherapy. Patients with N0 (ie, the node-negative subgroup) or N1 (HR = 0.36, 95% CI, 0.25-0.52, P < .001) disease benefited from gemcitabine-based chemotherapy. However, patients with N2 tumors (HR = 0.95, 95% CI, 0.50-1.78, P = .867) had poor response to gemcitabine-based treatment. Therefore, we postulate that resected pancreatic cancer with N2 node involvement is refractory to gemcitabine-based adjuvant chemotherapy. A more intensive adjuvant regimen may be required for N2 subgroup patients.

HNF-1a promotes pancreatic cancer growth and apoptosis resistance via its target gene PKLR.

Pancreatic ductal adenocarcinoma is one of the deadliest malignant tumors, and many genes play important roles in its development. The hepatocyte nuclear factor-1a (HNF-1a) gene encodes HNF-1a, which is a transcriptional activator. HNF-1a regulates the tissue-specific expression of multiple genes, especially in pancreatic islet cells and in the liver. However, the role of the HNF-1a gene in the development of pancreatic cancer is still unclear. Here, we used immunohistochemical staining and real-time PCR to analyze HNF-1a expression in pancreatic cancer tissue. Stable cell lines with HNF-1a knockdown or overexpression were established to analyze the role of HNF-1a in pancreatic cancer cell proliferation and apoptosis by colony formation assay and flow cytometry. We also analyzed the L-type pyruvate kinase (PKLR) promoter sequence to identify the regulatory effect of HNF-1a on PKLR transcription and confirmed the HNF-1a binding site in the PKLR promoter via a chromatin immunoprecipitation assay. HNF-1a was found to be overexpressed in pancreatic cancer and promoted proliferation while inhibiting apoptosis in pancreatic cancer cells. PKLR was identified as the downstream target gene of HNF-1a and binding of HNF-1a at two sites in PKLR (-1931/-1926 and -966/-961) regulated PKLR transcription. In conclusion, HNF-1a is overexpressed in pancreatic cancer, and the transcription factor HNF-1a can promote pancreatic cancer growth and apoptosis resistance via its target gene PKLR.

Atypical Mucin Expression Predicts Worse Overall Survival in Resectable Pancreatic Ductal Adenocarcinoma.

Background: Pancreatic ductal adenocarcinoma (PDAC) displays a typical mucin expression pattern which is characterized by MUC1 positive, MUC2 negative, and MUC5AC positive. More and more evidences show that mucins are involved in the development of pancreatic diseases. However, the relationship between mucin expression and prognosis of PDAC patients has been controversial in the past decades; therefore, we aim to figure out the association of mucin expression with survival in PDAC patients who underwent radical resection. Methods: We performed immunohistochemistry (IHC) to detect the expression of MUC1, MUC2, and MUC5AC in resected PDAC specimens from Shanghai Cancer Center, Fudan University (FUSCC, n = 427) and obtained the corresponding clinical statistical data for retrospective study. Kaplan-Meier methods and Mantel-Cox tests were used to compare the survival curves, and the Cox regression model was employed for multivariate analyses to determine the independent risk factors. Survival analysis was also performed in the Queensland Centre for Medical Genomics (QCMG, n = 70) PDAC cohort to verify the conclusion. Results: Both the FUSCC cohort and the QCMG cohort demonstrated that MUC1 absence was significantly correlated with worse overall survival (OS). The presence of MUC2 showed marginal significance in predicting shorter OS of PDAC patients, while MUC5AC had no prognostic value. In the FUSCC cohort, MUC1 absence was associated with increased proportion of stage III PDAC (p = 0.011), and MUC1 absence and MUC2 presence were associated with tumour perineural aggression (p = 0.011 and p = 0.030, respectively). Multivariable adjusted hazard ratios (HRs) for mortality of MUC1 and MUC2 were 0.492 (95% CI: 0.274-0.883, p = 0.017) and 1.596 (95% CI: 1.061-2.401, p = 0.025), respectively. Conclusions: MUC1 absence or MUC2 presence is independently associated with poor OS among patients with resectable PDAC. MUC5AC absence tended to be associated with short-term death.

Aberrant APOBEC3C expression induces characteristic genomic instability in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a well-known lethal and heterogeneous disease. Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC) is an important mutagenic driver that has seldom been investigated in PDAC. Therefore, this study investigated the significance of APOBEC3C in PDAC. First, cytosine deamination-associated mutation signatures were identified in the PDAC cohorts from TCGA and Fudan University Shanghai Cancer Center (FUSCC) datasets, and C > X-enriched kataegis regions were identified in the FUSCC cohort (12 to 27 counts per sample). Patients were stratified according to APOBEC3C expression, and high APOBEC3C expression was found to correlate with a higher motif enrichment score of 5'-CC-3' and an elevated kataegis count within PCSK5 and NES genes. Second, we compared APOBEC expression in PDAC and normal pancreatic tissues and found that APOBEC3C was substantially upregulated in PDAC. APOBEC3C-overexpressing cell lines were generated to substantiate the effects of APOBEC3C on PDAC genome, including alterations in single-nucleotide variant (SNV) classes (higher proportion of C > T conversions) and the formation of kataegis regions (newly occurring kataegis regions detected in ACHE and MUC6 genes). Three different PDAC cohorts (FUSCC, TCGA, and QCMG) were analysed to evaluate the prognostic value of APOBEC3C, and APOBEC3C overexpression predicted shorter survival. Finally, the APOBEC3C overexpression correalted with the PDAC tumour microenvironment (TME) remodelling, APOBEC3C expression was associated with the invasion of CD4 + T lymphocytes and CD8 + T lymphocytes (cytotoxic T lymphocytes, CTLs), indicating enhanced immune activity and validating the practicality of APOBEC3C for guiding immunotherapy.

Roles of CA19-9 in pancreatic cancer: Biomarker, predictor and promoter.

Carbohydrate antigen 19-9 (CA19-9) is the best validated biomarker and an indicator of aberrant glycosylation in pancreatic cancer. CA19-9 functions as a biomarker, predictor, and promoter in pancreatic cancer. As a biomarker, the sensitivity is approximately 80%, and the major challenges involve false positives in conditions of inflammation and nonpancreatic cancers and false negatives in Lewis-negative Individuals. Lewis antigen status should be determined when using CA19-9 as a biomarker. CA19-9 has screening potential when combined with symptoms and/or risk factors. As a predictor, CA19-9 could be used to assess stage, prognosis, resectability, recurrence, and therapeutic efficacy. Normal baseline levels of CA19-9 are associated with long-term survival. As a promoter, CA19-9 could be used to evaluate the biology of pancreatic cancer. CA19-9 can accelerate pancreatic cancer progression by glycosylating proteins, binding to E-selectin, strengthening angiogenesis, and mediating the immunological response. CA19-9 is an attractive therapeutic target for cancer, and strategies include therapeutic antibodies and vaccines, CA19-9-guided nanoparticles, and inhibition of CA19-9 biosynthesis.

Fibrinogen/Albumin Ratio as a Promising Marker for Predicting Survival in Pancreatic Neuroendocrine Neoplasms.

BACKGROUND: The fibrinogen/albumin ratio (FAR) has been widely reported to be a possible biomarker for predicting prognosis in several types of tumors, but the prognostic value of the FAR in pancreatic neuroendocrine neoplasms (Pan-NENs) has not been systematically studied. PATIENTS AND METHODS: In total, 324 patients with Pan-NENs were recruited. The patients were divided into 2 subgroups according to the FAR cutoff value, and clinicopathological characteristics of the 2 subgroups were compared. Overall survival (OS) was the primary endpoint, and progression-free survival (PFS) was the secondary endpoint. The prognostic value of the FAR was analyzed in univariate and multivariate analyses. RESULTS: The optimal cutoff value for the FAR was calculated to be 0.08 for OS. The patients with a FAR ≥0.08 had higher proportions of nonfunctioning tumors, Pan-NECs, grade 3 tumors, and stage IV tumors than those with a FAR <0.08. In the univariate analysis, a FAR ≥ 0.08 was associated with poor OS (hazard ratio (HR) = 2.37, P < 0.001) and PFS (HR = 2.37, P < 0.001). In the multivariate analysis, a FAR ≥0.08 was an independent risk factor for poor OS (HR = 4.70, P < 0.001) and PFS (HR = 1.80, P = 0.006). CONCLUSION: The pretreatment FAR, which includes fibrinogen and albumin, was a feasible and predictive biomarker for prognosis in patients with Pan-NENs. An elevated FAR, based on a cutoff value of 0.08, was an independent risk factor for poor OS and PFS.

High pre-operative fasting blood glucose levels predict a poor prognosis in patients with pancreatic neuroendocrine tumour.

BACKGROUND: Hyperglycaemia has been indicated as a pro-tumoural factor; however, the prognostic role of diabetes mellitus (DM) in pancreatic neuroendocrine tumours (panNETs) remains ambiguous, partly due to the effects of anti-diabetic drugs. We hypothesise that the blood sugar level per se affects the outcome of panNETs, and thus, we investigated the prognostic significance of the fasting blood glucose (FBG) level in resected panNET patients with no pre-existing DM. METHODS: A retrospective cohort study comprising 201 patients with radically resected non-functional panNETs was conducted. A total of 164 patients without pre-existing DM were further studied. An FBG level greater than 5.6 mmol/L was defined as high (otherwise, normal). Survival was evaluated using Kaplan-Meier methods and log-rank tests. Multivariate analyses for survival were performed using the Cox regression model. RESULTS: High FBG levels were significantly associated with poor overall survival (OS; p = 0.019) and recurrence-free survival (RFS; p = 0.011) in resected patients with panNET who had no pre-existing DM. The multivariable-adjusted hazard ratios (HRs) for mortality and recurrence comparing patients with high and normal FBG levels were 12.19 (95% confidence interval (CI) = 1.15-128.78, p = 0.038) and 2.43 (95% CI = 1.03-5.72, p = 0.042), respectively. CONCLUSION: A pre-operative FBG level greater than 5.6 mmol/L is associated with poor OS and RFS metastasis for patients with panNET who undergo radical surgical resection.

Absolute Counts of Peripheral Lymphocyte Subsets Correlate with the Progression-Free Survival and Metastatic Status of Pancreatic Neuroendocrine Tumour Patients.

PURPOSE: Pancreatic neuroendocrine tumours (panNETs) are rare tumours of pancreas. Lymphocyte subsets in the peripheral blood are reported to reflect tumour prognosis and progression. The objective of the study is to investigate the hypotheses that the levels of peripheral lymphocytes may reflect tumour progression and may predict the prognosis of pancreatic neuroendocrine tumours (panNETs). PATIENTS AND METHODS: A retrospective cohort study consisting of 73 patients diagnosed with panNETs was conducted. Kaplan-Meier methods and Log rank tests were used to compare the survival rates, and a Cox regression model was used to perform multivariate analyses. RESULTS: panNET patients with distant metastasis were associated with lower peripheral total T cell (p = 0.039) and CD4+ T cell (p = 0.006) counts. Lower peripheral B cells (p = 0.007) and higher peripheral NK cell (p = 0.001) counts indicated worse progression-free survival (PFS) in Log rank tests. In multivariate analyses, low B cell count (hazard ratio (HR): 6.769, 95% confidence interval (CI): 2.158 to 21.228, p = 0.001) and high NK cell count (HR: 3.715, 95% CI: 1.164 to 11.855, p = 0.027) were independent risk factors for progression. NK cells and B cells were also significantly associated with PFS following radical surgical resection. CONCLUSION: Peripheral total T cell and CD4+ T cell counts may reflect the distant metastasis status in panNET patients. The absolute count of peripheral B cells and NK cells may independently predict the progression of panNET patients, making them promising prognostic indicators and potential targets for treatment of panNETs.

Clinical implication of serum CA125 for the prediction of malignancy in mucinous cystic neoplasms of the pancreas.

Mucinous cystic neoplasms (MCNs) of the pancreas have malignant potential. Carbohydrate antigen 125 (CA125) is a common widely used biomarker for cancers. However, the role of CA125 in predicting the malignant change of MCNs is currently unidentified. Patients with resected and pathologically confirmed MCN were identified from a prospectively maintained database. The predictive role of serum CA125 in assessing malignant change of MCNs was analyzed and compared with serum carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA). This study included 164 patients with MCN (low/moderate grade, 153 cases; high grade and invasive, 11 cases). The serum levels of CA125 in the high grade and invasive group (45.1±42.1 U/ml) was significantly higher than those in the low/moderate grade group (21.0±46.2 U/ml, P=0.006). The area under the receiver operating characteristic (ROC) curve of CA125 (0.75) for predicting malignancy of MCNs was higher than that of CA19-9 (0.68) or CEA (0.72). The prediction value of CA125 was improved when combined with CEA (CA125 alone, sensitivity 36.4%, specificity 90.6%, accuracy 86.6%; combined with CEA, sensitivity 45.5%, specificity 88.2%, accuracy 85.0%). It was concluded that serum CA125 shows value in predicting the malignant change of MCNs, especially when combined with serum CEA.

Molecular alterations and targeted therapy in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a malignancy characterized by a poor prognosis and high mortality rate. Genetic mutations and altered molecular pathways serve as targets in precise therapy. Using next-generation sequencing (NGS), these aberrant alterations can be identified and used to develop strategies that will selectively kill cancerous cells in patients with PDAC. The realization of targeted therapies in patients with PDAC may be summarized by three approaches. First, because oncogenes play a pivotal role in tumorigenesis, inhibition of dysregulated oncogenes is a promising method (Table 3). Numerous researchers are developing strategies to target oncogenes, such as KRAS, NRG1, and NTRK and related molecules, although most of the results are unsatisfactory. Accordingly, emerging strategies are being developed to target these oncogenes, including simultaneously inhibiting multiple molecules or pathways, modification of mutant residues by small molecules, and RNA interference. Second, researchers have attempted to reactivate inactivated tumour suppressors or modulate related molecules. TP53, CDKN2A and SMAD4 are three major tumour suppressors involved in PDAC. Advances have been achieved in clinical and preclinical trials of therapies targeting these three genes, and further investigations are warranted. The TGF-ß-SMAD4 signalling pathway plays a dual role in PDAC tumorigenesis and participates in mediating tumour-stroma crosstalk and modulating the tumour microenvironment (TME); thus, molecular subtyping of pancreatic cancer according to the SMAD4 mutation status may be a promising precision oncology technique. Finally, genes such as KDM6A and BRCA have vital roles in maintaining the structural stability and physiological functions of normal chromosomes and are deficient in some patients with PDAC, thus serving as potential targets for correcting these deficiencies and precisely killing these aberrant tumour cells. Recent clinical trials, such as the POLO (Pancreas Cancer Olaparib Ongoing) trial, have reported encouraging outcomes. In addition to genetic event-guided treatment, immunotherapies such as chimeric antigen receptor T cells (CAR-T), antibody-drug conjugates, and immune checkpoint inhibitors also exhibit the potential to target tumours precisely, although the clinical value of immunotherapies as treatments for PDAC is still limited. In this review, we focus on recent preclinical and clinical advances in therapies targeting aberrant genes and pathways and predict the future trend of precision oncology for PDAC.

Lewis antigen­negative pancreatic cancer: An aggressive subgroup.

Carbohydrate antigen 19­9 (CA19­9) is the most important biomarker for pancreatic cancer. Approximately 5­10% of individuals are Lewis antigen negative with scarce secretion of CA19­9 and fucosylation deficiency. However, the characteristics of Lewis­negative pancreatic cancer are unidentified. Clinicopathological characteristics of 853 patients with pancreatic cancer were examined. Pancreatic cancer cell lines were sequenced for Lewis status. Morphological and molecular features of pancreatic cancer cells were compared. Orthotopic animal modes were established. Lewis­negative patients had poorer outcome (P<0.001), higher metastatic rate (P=0.004), lower CA19­9 expression (P<0.001) and higher MUC16 expression (P<0.001) than Lewis­positive patients. Lewis­negative cells (CaPan­1, MiaPaCa­2 and Panc­1) showed a shuttle shape with scarce pseudopods. Overall, Lewis­negative cells had higher proliferation rate, higher migration ability, lower fucosylation, lower CA19­9 expression and higher MUC16 expression than Lewis­positive cells (BxPC­3, SU8686, SW1990). Lewis­negative cell line MiaPaCa­2 corresponded to larger orthotopic tumor than Lewis­positive cells SU8686. Potential proteoglycans were identified in Lewis­positive cancer, including EGFR, HSPG2, ADAM17, GPC1, ITGA2, CD40, IL6ST and GGT1. Therefore, Lewis­negative pancreatic cancer is an aggressive subgroup with special clinical and molecular features.