A phase II study of erlotinib in gemcitabine refractory advanced pancreatic cancer

Small molecule inhibitor against onco-mucins disrupts Src/FosL1 axis to enhance gemcitabine efficacy in pancreatic ductal adenocarcinoma

Mucin MUC4 is an aberrantly expressed oncogene in pancreatic ductal adenocarcinoma (PDAC), yet no pharmacological inhibitors have been identified to target MUC4. Here, we adapted an in silico screening method using the Cancer Therapeutic Response Database (CTRD) to Identify Small Molecule Inhibitors against Mucins (SMIMs). We identified Bosutinib as a candidate drug to target oncogenic mucins among 126 FDA-approved drugs from CTRD screening. Functionally, Bosutinib treatment alone/and in combination with gemcitabine (Gem)/5' fluorouracil (5FU) reduced in vitro viability, migration, and colony formation in multiple PDAC cell lines as well as human PDAC organoid prolifertaion and growth and in vivo xenograft growth. Further, biochemical and molecular analyses showed that Bosutinib exhibited these functional effects by downregulating MUC4 mucin at both transcript and translation levels in a dose- and time-dependent manner. Mechanistically, global transcriptome analysis in PDAC cells upon treatment with Bosutinib revealed disruption of the Src-ERK/AKT-FosL1 pathway, leading to decreased expression of MUC4 and MUC5AC mucins. Taken together, Bosutinib is a promising, novel, and highly potent SMIMs to target MUC4/MUC5AC mucins. This mucin-targeting effect of Bosutinib can be exploited in the future with cytotoxic agents to treat mucinous tumors.

A randomized phase II study of SM-88 plus methoxsalen, phenytoin, and sirolimus in patients with metastatic pancreatic cancer treated in the second line and beyond

BACKGROUND

This trial explores SM-88 used with methoxsalen, phenytoin, and sirolimus (MPS) in pretreated metastatic pancreatic ductal adenocarcinoma (mPDAC) METHODS: Forty-nine patients were randomized to daily 460 or 920 mg oral SM-88 with MPS (SM-88 Regimen). The primary endpoint was objective response rate (RECIST 1.1).

RESULTS

Thirty-seven patients completed ≥ one cycle of SM-88 Regimen (response evaluable population). Disease control rate (DCR), overall survival (OS), and progression-free survival (PFS) did not differ significantly between dose levels. Stable disease was achieved in 9/37 patients (DCR, 24.3%); there were no complete or partial responses. Quality-of-life (QOL) was maintained and trended in favor of 920 mg. SM-88 Regimen was well tolerated; a single patient (1/49) had related grade 3 and 4 adverse events, which later resolved. In the intention-to-treat population of 49 patients, the median overall survival (mOS) was 3.4 months (95% CI: 2.7-4.9 months). Those treated in the second line had an mOS of 8.1 months and a median PFS of 3.8 months. Survival was higher for patients with stable versus progressive disease (any line; mOS: 10.6 months vs. 3.9 months; p = 0.01).

CONCLUSIONS

SM-88 Regimen has a favorable safety profile with encouraging QOL effects, disease control, and survival trends. This regimen should be explored in the second-line treatment of patients with mPDAC.

CLINICALTRIALS

gov Identifier: NCT03512756.

A special subtype: Revealing the potential intervention and great value of KRAS wildtype pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the predominant form of pancreatic cancer and has devastating consequences on affected families and society. Its dismal prognosis is attributed to poor specificity of symptoms during early stages. It is widely believed that PDAC patients with the wildtype (WT) KRAS gene benefit more from currently available treatments than those with KRAS mutations. The oncogenic genetic changes alternations generally found in KRAS wildtype PDAC are related to either the KRAS pathway or microsatellite instability/mismatch repair deficiency (MSI/dMMR), which enable the application of tailored treatments based on each patient's genetic characteristics. This review focuses on targeted therapies against alternative tumour mechanisms in KRAS WT PDAC.

Targeting of promising transmembrane proteins for diagnosis and treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of cancer due to the relatively late diagnosis and the limited therapeutic options. Current treatment regimens mainly comprise the cytotoxic agents gemcitabine and FOLFIRINOX. These compounds have shown limited efficacy and severe side effects, highlighting the necessity for earlier detection and the development of more effective, and better-tolerated treatments. Although targeted therapies are promising for the treatment of several types of cancer, identification of suitable targets for early diagnosis and targeted therapy of PDAC is challenging. Interestingly, several transmembrane proteins are overexpressed in PDAC cells that show low expression in healthy pancreas and may therefore serve as potential targets for treatment and/or diagnostic purposes. In this review we describe the 11 most promising transmembrane proteins, carefully selected after a thorough literature search. Favorable features and potential applications of each target, as well as the results of the preclinical and clinical studies conducted in the past ten years, are discussed in detail.

Multikinase inhibitor-induced liver injury in patients with cancer: A review for clinicians

BACKGROUND

Multikinase inhibitors (MKI) are targeted molecular agents that have revolutionized cancer management. However, there is a paucity of data concerning MKI-related liver injury risk and clinical guidelines for the management of liver toxicity in patients receiving MKI for cancer are scarce.

DESIGN

We conducted a PubMed search of articles in English published from January 2000 to December 2018 related to hepatotoxicity of the 29 FDA-approved MKIs at doses used in clinical practice. The search terms were the international non-proprietary name of each agent cross-referenced with «hepatotoxicity», «hepatitis», «hepatic adverse event», or «liver failure», and «phase II clinical trial», «phase III clinical trial», or «case report».

RESULTS

Following this search, 140 relevant studies and 99 case reports were considered. Although asymptomatic elevation of aminotransferase levels has been frequently observed in MKI clinical trials, clinically significant hepatotoxicity is a rare event. In most cases, the interval between treatment initiation and the onset of liver injury is between one week and two months. Liver toxicity is often hepatocellular and less frequently mixed. Life-threatening MKI-induced hepatic injury has been described, involving fulminant liver failure or death. Starting from existing data, a description of MKI-related liver events, grading of hepatotoxicity risk, and recommendations for management are also given for various MKI molecules.

CONCLUSION

All MKIs can potentially cause liver injury, which is sometimes irreversible. As there is still no strategy available to prevent MKI-related hepatotoxicity, early detection remains crucial. The surveillance of liver function during treatment may help in the early detection of hepatotoxicity. Furthermore, the exclusion of potential causes of hepatic injury is essential to avoid unnecessary MKI withdrawal.

A Retrospective Look at Anti-EGFR Agents in Pancreatic Cancer Therapy

Background:

The introduction of Monoclonal Antibodies (mAbs) and small-molecule Tyrosine Kinase Inhibitors (TKIs) that target the Epidermal Growth Factor Receptor (EGFR), marks a huge step forward in the Pancreatic Cancer (PC) therapy. However, anti-EGFR therapy is found to be successful only in a fraction of patients. Although anti-EGFR agents have shown considerable clinical promise, a serious adverse event associated with anti- EGFR therapy has been challenging. At this juncture, there is still more to be done in the search for effective predictive markers with therapeutic applicability.

Methods:

A focused literature search was conducted to summarize the existing evidence on anti-EGFR agents in pancreatic cancer therapy.

Results:

This review discusses various anti-EGFR agents currently in use for PC therapy and potential adverse effects associated with it. Existing evidence on EGFR TKIs demonstrated better tolerant effects and outcomes with multiple toxic regimens. Anti-EGFR therapy in combination with chemotherapy is necessary to achieve the best clinical outcomes.

Conclusion:

Future prospective studies on the identification of additional biological agents and novel anti-EGFR agents are warranted.

Predictive role of skin rash in advanced pancreatic cancer patients treated with gemcitabine plus erlotinib: a systematic review and meta-analysis

Purpose

The survival benefit from gemcitabine plus erlotinib was on average marginal for advanced pancreatic cancer (APC) patients. Skin rash developed shortly after starting treatment seemed to be associated with better efficacy and might be used to assist clinical decision-making, but the results across studies were inconsistent. Thus, we conducted a systematic review and meta-analysis.

Methods

PubMed, Embase, Cochrane Central Register of Controlled Trials, three Chinese databases, and the abstracts of important conferences were searched for eligible studies. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS) and objective response. The random-effects model was used to pool results across studies if heterogeneity was substantial. Otherwise, the fixed-effect model was used.

Results

A total of 16 studies with 1,776 patients were included. Patients who developed skin rash during treatment had longer OS (8.9 vs 4.9 months, HR=0.57, 95% CI 0.50–0.64) and longer PFS (4.5 vs 2.4 months, HR=0.53, 95% CI 0.40–0.68) than those who did not. A dose– response relationship was also observed for both OS (HR=0.64 for grade-1 rash vs no rash and HR=0.46 for ≥grade-2 rash vs no rash) and PFS (HR=0.72 for grade-1 rash vs no rash and HR=0.43 for ≥grade-2 rash vs no rash).

Conclusion

Skin rash was associated with better OS and PFS in APC patients treated with gemcitabine plus erlotinib. It might be used as a marker for efficacy to guide clinical decision-making toward a more precise and personalized treatment.

Current status and dilemma of second-line treatment in advanced pancreatic cancer: is there a silver lining?

Pancreatic cancer remains one of the most lethal malignant diseases worldwide. The majority of patients present with advanced disease and, therefore, need palliative chemotherapy. Some chemotherapeutic regimens have been well established as first-line therapies and have been shown to increase survival; however, almost all patients with advanced pancreatic cancer will experience disease progression after first-line therapy. Nevertheless, many patients who retain good performance status after initial treatment remain good candidates for additional therapy. Historically, few studies have assessed second-line therapy, with most reports representing small phase II trials with variable findings; however, clinical research for second-line treatment has increased in the past decade, and several randomized controlled trials using different regimens have been published. The current literature shows varying results on treatment efficacy and tolerability. Thus, we reviewed the published data on the use of chemotherapy in the second-line setting for the treatment of advanced pancreatic cancer.

Combination Cancer Therapy Can Confer Benefit via Patient-to-Patient Variability without Drug Additivity or Synergy

Combination cancer therapies aim to improve the probability and magnitude of therapeutic responses and reduce the likelihood of acquired resistance in an individual patient. However, drugs are tested in clinical trials on genetically diverse patient populations. We show here that patient-to-patient variability and independent drug action are sufficient to explain the superiority of many FDA-approved drug combinations in the absence of drug synergy or additivity. This is also true for combinations tested in patient-derived tumor xenografts. In a combination exhibiting independent drug action, each patient benefits solely from the drug to which his or her tumor is most sensitive, with no added benefit from other drugs. Even when drug combinations exhibit additivity or synergy in pre-clinical models, patient-to-patient variability and low cross-resistance make independent action the dominant mechanism in clinical populations. This insight represents a different way to interpret trial data and a different way to design combination therapies.

A phase II trial of erlotinib monotherapy in advanced pancreatic cancer as a first- or second-line agent

INTRODUCTION

Pancreatic adenocarcinoma carries a grim prognosis. In 2007, gemcitabine with erlotinib emerged as an appropriate treatment option for patients with advanced inoperable or metastatic disease (APC). In this phase II trial we sought to evaluate the efficacy of erlotinib monotherapy in patients with APC who had disease refractory to or ineligibility for gemcitabine-based therapy.

METHODS

Eligible patients who had received 0 or 1 non-EGFR inhibitor containing gemcitabine-based chemotherapy for APC were recruited prospectively and treated with erlotinib 150 mg orally daily until unacceptable toxicity or disease progression. Primary endpoint was progression-free survival (PFS). Correlations of clinical response with smoking, rash, steady-state concentration of erlotinib and its metabolite (OSI-420) as well as the nicotine metabolite cotinine were performed.

RESULTS

The trial was terminated early for futility. Eighteen of the 34 planned subjects were recruited. Median PFS and OS were 42 and 95 days, respectively. Best response was stable disease (21%). There was a trend for improved PFS and OS in never smokers compared to current and past smokers (128.5, 39, 42 days and 173, 100, 88 days, respectively). Past/current smokers had lower steady-state concentrations of erlotinib and OSI-420 compared to never smokers. There was evidence of recent smoking exposure in 30% of patients self-identified as past smokers. Rash was infrequent, with no cases of grade III/IV rash and it was not related to treatment outcomes.

CONCLUSIONS

Overall, erlotinib monotherapy failed to improve outcomes compared to historical controls in patients with APC after 0-1 prior systemic therapies. There was a trend for improved PFS and OS in never smokers.

Next generation sequencing of pancreatic ductal adenocarcinoma: right or wrong?

Pancreatic ductal adenocarcinoma (PDAC) has the highest mortality rate of all epithelial malignancies and a paradoxically rising incidence rate. Clinical translation of next generation sequencing (NGS) of tumour and germline samples may ameliorate outcomes by identifying prognostic and predictive genomic and transcriptomic features in appreciable fractions of patients, facilitating enrolment in biomarker-matched trials. Areas covered: The literature on precision oncology is reviewed. It is found that outcomes may be improved across various malignancies, and it is suggested that current issues of adequate tissue acquisition, turnaround times, analytic expertise and clinical trial accessibility may lessen as experience accrues. Also reviewed are PDAC genomic and transcriptomic NGS studies, emphasizing discoveries of promising biomarkers, though these require validation, and the fraction of patients that will benefit from these outside of the research setting is currently unknown. Expert commentary: Clinical use of NGS with PDAC should be used in investigational contexts in centers with multidisciplinary expertise in cancer sequencing and pancreatic cancer management. Biomarker directed studies will improve our understanding of actionable genomic variation in PDAC, and improve outcomes for this challenging disease.

Targeting the Epidermal Growth Factor Receptor in Addition to Chemotherapy in Patients with Advanced Pancreatic Cancer: A Systematic Review and Meta-Analysis

Overexpression of epidermal growth factor receptors (EGFR) occurs in >90% of pancreatic ductal adenocarcinomas (PDACs) and is associated with a poorer prognosis. A systematic review of electronic databases identified studies exploring the addition of EGFR-targeted treatment to chemotherapy in patients with locally advanced (LA)/metastatic PDAC. Efficacy, safety and tolerability of EGFR-targeted therapy were explored using meta-analysis of randomised controlled trials (RCTs). Meta-regression was utilised to explore factors associated with improved prognosis (all studies) and benefit from EGFR-targeted therapy (RCTs). Twenty-eight studies (7 RCTs and 21 cohort studies) comprising 3718 patients were included. The addition of EGFR-targeted treatment to chemotherapy did not improve progression-free (pooled hazard ratio (HR): 0.90, p = 0.15) or overall survival (HR: 0.94, p = 0.18). EGFR-targeted therapy was associated with increased treatment-related deaths (pooled odds ratio (OR): 5.18, p = 0.007), and grade (G)3/4 rash (OR: 4.82, p = 0.03). There was a borderline significant increase in G3/4 diarrhoea (OR: 1.75, p = 0.06), but no effect on treatment discontinuation without progression (OR: 0.87, p = 0.25). Neither G3/4 rash nor diarrhoea were associated with increased survival benefit from EGFR-targeted therapy. The effect of EGFR-targeted therapy on overall survival (OS) appeared greater in studies with a greater proportion of LA rather than metastatic patients (R = -0.69, p < 0.001). Further studies in unselected patients with advanced PDAC are not warranted. The benefit from EGFR inhibitors may be limited to patient subgroups not yet clearly defined.

Key biological processes driving metastatic spread of pancreatic cancer as identified by multi-omics studies

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy, characterized by a high metastatic burden, already at the time of diagnosis. The metastatic potential of PDAC is one of the main reasons for the poor outcome next to lack of significant improvement in effective treatments in the last decade. Key mutated driver genes, such as activating KRAS mutations, are concordantly expressed in primary and metastatic tumors. However, the biology behind the metastatic potential of PDAC is not fully understood. Recently, large-scale omic approaches have revealed new mechanisms by which PDAC cells gain their metastatic potency. In particular, genomic studies have shown that multiple heterogeneous subclones reside in the primary tumor with different metastatic potential. The development of metastases may be correlated to a more mesenchymal transcriptomic subtype. However, for cancer cells to survive in a distant organ, metastatic sites need to be modulated into pre-metastatic niches. Proteomic studies identified the influence of exosomes on the Kuppfer cells in the liver, which could function to prepare this tissue for metastatic colonization. Phosphoproteomics adds an extra layer to the established omic techniques by unravelling key functional signaling. Future studies integrating results from these large-scale omic approaches will hopefully improve PDAC prognosis through identification of new therapeutic targets and patient selection tools. In this article, we will review the current knowledge on the biology of PDAC metastasis unravelled by large scale multi-omic approaches.

Pancreatic cancer: from bench to bedside

Pancreatic cancer is recognized as the king of carcinoma, and the gap between basic research and clinical practice is difficult to improve the treatment effect. Translational medicine builds an important bridge between pancreatic cancer basic research and clinical practice from the pathogenesis, early diagnosis of pancreatic carcinoma, drug screening, treatment strategies and metastasis prediction. This article will carry on the concrete elaboration to the above several aspects.

Pancreatic cancer: New hopes after first line treatment

Pancreatic cancer is the fourth leading cause of cancer-related death worldwide. Extensive research has yielded advances in first-line treatment strategies, but there is no standardized second-line therapy. In this review, we examine the literature trying to establish a possible therapeutic algorithm.

A phase II study of the HSP90 inhibitor AUY922 in chemotherapy refractory advanced pancreatic cancer

OBJECTIVES

AUY922 is a novel heat shock protein inhibitor with preclinical activity in pancreatic cancer. This phase II study evaluated the efficacy of AUY922 in patients with advanced pancreatic cancer previously treated with chemotherapy.

METHODS

In this single-arm, Simon two-stage phase II trial, patients with metastatic or locally advanced pancreatic ductal adenocarcinoma who had progressed on at least one line of chemotherapy and were of good performances status (ECOG 0 or 1) were treated with AUY922 at a dose of 70 mg/m(2) IV weekly. The primary endpoint was disease control rate (objective response and stable disease ≥16 weeks).

RESULTS

Twelve patients were accrued, all of whom received treatment. At least possibly related ≥grade 3 adverse events included fatigue (8 %) and AST elevation (8 %). Ten patients were evaluable for response with 1 (10 %) having stable disease and 9 (90 %) progressive disease. The median progression-free survival was 1.6 months, and the median overall survival was 2.9 months.

CONCLUSIONS

AUY922 was not associated with significant efficacy in previously treated patients with advanced pancreatic cancer.

The Prognostic and Predictive Role of Epidermal Growth Factor Receptor in Surgical Resected Pancreatic Cancer

The data regarding the prognostic significance of EGFR (epidermal growth factor receptor) expression and adjuvant therapy in patients with resected pancreatic cancer are insufficient. We retrospectively investigated EGFR status in 357 resected PDAC (pancreatic duct adenocarcinoma) patients using tissue immunohistochemistry and validated the possible role of EGFR expression in predicting prognosis. The analysis was based on excluding the multiple confounding parameters. A negative association was found between overall EGFR status and postoperative survival (p = 0.986). Remarkably, adjuvant chemotherapy and radiotherapy were significantly associated with favorable postoperative survival, which prolonged median overall survival (OS) for 5.8 and 10.2 months (p = 0.009 and p = 0.006, respectively). Kaplan-Meier analysis showed that adjuvant chemotherapy correlated with an obvious survival benefit in the EGFR-positive subgroup rather than in the EGFR-negative subgroup. In the subgroup analyses, chemotherapy was highly associated with increased postoperative survival in the EGFR-negative subgroup (p = 0.002), and radiotherapy had a significant survival benefit in the EGFR-positive subgroup (p = 0.029). This study demonstrated that EGFR expression is not correlated with outcome in resected pancreatic cancer patients. Adjuvant chemotherapy and radiotherapy were significantly associated with improved survival in contrary EGFR expressing subgroup. Further studies of EGFR as a potential target for pancreatic cancer treatment are warranted.

K-Ras mutation detection in liquid biopsy and tumor tissue as prognostic biomarker in patients with pancreatic cancer: a systematic review with meta-analysis

K-Ras gene mutations have been found in most pancreatic cancers; however, conflicting data on the prognostic value of K-Ras mutations in pancreatic cancer have been published. We conducted a meta-analysis to assess its prognostic significance. Literature searches of PubMed, EMBASE, Cochrane Library, Web of Science and Google Scholar were performed through December 2015 to identify publications exploring the association of K-Ras mutation with overall survival. Forty eligible studies involving 3427 patients with pancreatic cancer were included in the present meta-analysis. Our analysis showed a hazard ratio (HR) of negative association with survival of 1.61 [95 % confidence interval (CI) 1.36-1.90; p < 0.01] in K-Ras mutant pancreatic cancer patients. In subgroup analyses, K-Ras mutations detected in tumor tissues and in liquid biopsies had HRs of 1.37 (95 % CI 1.20-1.57; p < 0.01) and 3.16 (95 % CI 2.1-4.71; p < 0.01), respectively. In addition, the HR was higher when K-Ras mutations were detected in fresh frozen samples (HR = 2.01, 95 % CI 1.28-3.16, p = 0.002) than in formalin-fixed, paraffin-embedded (FFPE) samples (HR = 1.29, 95 % CI 1.12-1.49, p < 0.01). Though K-Ras alterations are more frequent among non-East Asian individuals than East Asian individuals, there were no significant differences in HRs of survival between the two ethnic subgroups. In conclusion, this meta-analysis suggests that K-Ras mutations are associated with a worse overall survival in pancreatic cancer patients, especially when mutations are detected in liquid biopsies or fresh frozen tumor tissue samples.

A novel schedule of erlotinib/capecitabine (7/7) as salvage therapy in previously treated advanced pancreatic adenocarcinoma: a case series

BACKGROUND

The objective of this study was to report a case series on the efficacy and safety of capecitabine 7/7 schedule combined with erlotinib (CAP-ERL) in patients with advanced pancreatic cancer (APC) who have failed prior therapies.

METHODS

We retrospectively evaluated 13 patients with locally advanced or metastatic pancreatic cancer previously treated with gemcitabine or oxaliplatin-irinotecan-based first-line regimens. Treatment consisted of capecitabine (Xeloda) at a flat dose of 1000 mg orally twice daily on days 1-7 out of 14 days (7/7 schedule) and erlotinib (Tarceva) 100 mg orally once daily until unacceptable toxicity or disease progression. Tumor assessments were repeated every two cycles (8 weeks) and serum tumor markers were measured every 4 weeks.

RESULTS

All patients (median age: 63 years; 7 female/3 male) had various previous lines of treatments of chemotherapies. Median number of cycles with CAP-ERL was 4 (range 2-12). The overall response rate was 20%. CA19-9 was reduced more than 25% in 40% patients. The median overall survival and progression-free survival from the start of CAP-ERL were 4.5 months (range 3-7.5) and 2 months (range 1.5-4), respectively. The most common grade 3 toxicities included hand-foot syndrome, nausea, vomiting, diarrhea, rash, and fatigue.

CONCLUSIONS

Our result suggests that the combination of a fixed low dose of CAP-ERL 7/7 schedule was tolerated with manageable toxicity and showed encouraging activity as salvage treatment in patients with refractory APC with ECOG performance status 0-2. Further prospective studies are warranted to evaluate this combination.

Prolonged complete response following gemcitabine-erlotinib combined therapy in advanced pancreatic cancer

Pancreatic cancer is one of the most lethal types of malignant solid tumor and is typically associated with a poor prognosis. The majority of patients are diagnosed with advanced-stage disease, therefore, the median survival period is <6 months. Recently, a number of basic research projects and clinical trials were undertaken with the aim of improving treatment outcomes in pancreatic cancer; however, only one agent, erlotinib, passed the clinical trials. Erlotinib is an inhibitor of epidermal growth factor receptor, which when overexpressed in cancer, promotes angiogenesis, cell proliferation and inhibits apoptosis. The US Food and Drug Administration and European Medicines Agency approved erlotinib in combination with gemcitabine for the first-line treatment of advanced pancreatic cancer. To the best of our knowledge, the current study is the first to report a case of pancreatic cancer treated with this regimen alone to achieve a complete response (CR). A 40-year-old male with a medical history of chronic pancreatitis and hypertension was diagnosed with medically inoperable adenocarcinoma of the pancreas. Following palliative surgery, the patient began palliative gemcitabine and erlotinib chemotherapy. After three months, this treatment strategy resulted in a CR, as determined by imaging studies. Therapy was discontinued after 14 months due to the development of peritoneal metastases and the patient was referred for treatment with the folinic acid, 5-fluorouracil, irinotecan and oxaliplatin regimen. A CR is rarely reported in pancreatic cancer, however, a treatment strategy of gemcitabine and erlotinib may induce rapid regression of advanced-stage disease.

Comparative Gene Expression Analyses Identify Luminal and Basal Subtypes of Canine Invasive Urothelial Carcinoma That Mimic Patterns in Human Invasive Bladder Cancer

More than 160,000 people are expected to die from invasive urothelial carcinoma (iUC) this year worldwide. Research in relevant animal models is essential to improving iUC management. Naturally-occurring canine iUC closely resembles human iUC in histopathology, metastatic behavior, and treatment response, and could provide a relevant model for human iUC. The molecular characterization of canine iUC, however, has been limited. Work was conducted to compare gene expression array results between tissue samples from iUC and normal bladder in dogs, with comparison to similar expression array data from human iUC and normal bladder in the literature. Considerable similarities between enrichment patterns of genes in canine and human iUC were observed. These included patterns mirroring basal and luminal subtypes initially observed in human breast cancer and more recently noted in human iUC. Canine iUC samples also exhibited enrichment for genes involved in P53 pathways, as has been reported in human iUC. This is particularly relevant as drugs targeting these genes/pathways in other cancers could be repurposed to treat iUC, with dogs providing a model to optimize therapy. As part of the validation of the results and proof of principal for evaluating individualized targeted therapy, the overexpression of EGFR in canine bladder iUC was confirmed. The similarities in gene expression patterns between dogs and humans add considerably to the value of naturally-occurring canine iUC as a relevant and much needed animal model for human iUC. Furthermore, the finding of expression patterns that cross different pathologically-defined cancers could allow studies of dogs with iUC to help optimize cancer management across multiple cancer types. The work is also expected to lead to a better understanding of the biological importance of the gene expression patterns, and the potential application of the cross-species comparisons approach to other cancer types as well.

Recent advances for the treatment of pancreatic and biliary tract cancer after first-line treatment failure

Here, we evaluate clinical trials on chemotherapy for patients with pancreatic or biliary tract cancer after first-line treatment failure. Clinical trials on conventional and innovative medical treatments for progressive pancreatic and biliary cancer were analyzed. Metronomic chemotherapy, which consists of the administration of continuative low-dose of anticancer drugs, was also considered. A significant extension of overall survival was achieved with second-line, regimens in patients with gemcitabine-refractory pancreatic cancer. Moreover, many Phase II studies, including chemotherapy and target molecules and immunotherapy, have reported promising results, in both pancreatic and biliary cancer. However, data in these patients' setting are very heterogeneous, and only few randomized studies are available.

New targeted therapies in pancreatic cancer

Patients with pancreatic cancer have a poor prognosis with a median survival of 4-6 mo and a 5-year survival of less than 5%. Despite therapy with gemcitabine, patient survival does not exceed 6 mo, likely due to natural resistance to gemcitabine. Therefore, it is hoped that more favorable results can be obtained by using guided immunotherapy against molecular targets. This review summarizes the new leading targeted therapies in pancreatic cancers, focusing on passive and specific immunotherapies. Passive immunotherapy may have a role for treatment in combination with radiochemotherapy, which otherwise destroys the immune system along with tumor cells. It includes mainly therapies targeting against kinases, including epidermal growth factor receptor, Ras/Raf/mitogen-activated protein kinase cascade, human epidermal growth factor receptor 2, insulin growth factor-1 receptor, phosphoinositide 3-kinase/Akt/mTOR and hepatocyte growth factor receptor. Therapies against DNA repair genes, histone deacetylases, microRNA, and pancreatic tumor tissue stromal elements (stromal extracellular matric and stromal pathways) are also discussed. Specific immunotherapies, such as vaccines (whole cell recombinant, peptide, and dendritic cell vaccines), adoptive cell therapy and immunotherapy targeting tumor stem cells, have the role of activating antitumor immune responses. In the future, treatments will likely include personalized medicine, tailored for numerous molecular therapeutic targets of multiple pathogenetic pathways.