High KIT and PDGFRA are associated with shorter patients survival in gastroenteropancreatic neuroendocrine tumors, but mutations are a rare event

Nuclear survivin is a prognosticator in gastroenteropancreatic neuroendocrine neoplasms: a meta-analysis

Purpose

Gastroenteropancreatic neuroendocrine neosplasms (GEP-NEN) are biologically heterogenous tumors with an increasing incidence over the past decades. Although efforts have been made in the treatment of these tumors, survival rates in metastasized tumor stages remain frustrating. Thus, there is an urgent need to identify novel targets as alternative treatment options. In this regard, the inhibitor of apoptosis protein (IAP) family member survivin could be such an attractive target. Therefore, aim of our meta-analysis was to assess the role of survivin as a biomarker and predictor in GEP-NEN.

Methods

Medline, Web of Science and Scopus were screened for studies that fulfilled our selection criteria. Quality assessement of the studies was based on design, methodology, generalizability and results analysis. Meta-analyses were conducted using a random-effects model and effect size measures were expressed as pooled Hazard Ratio (HR) or Odds Ratio (OR) with 95% Confidence Interval (CI).

Results

Six eligible studies with 649 patients (range 77–132) assessed survivin expression in GEP-NEN by immunohistochemistry. High expression levels of nuclear survivin in GEP-NEN correlated with a shorter overall survival (HR 3.10; 95% CI 2.15–4.47; p < 0.0001). In contrast to cytoplasmic survivin (OR 1.24; CI 0.59–2.57; p = 0.57), nuclear survivin was also associated (OR 15.23; CI 3.61–64.23; p = 0.0002) with G3/poorly differentiated GEP-NEN.

Conclusion

Nuclear Survivin is highly expressed in more aggressive G3 GEP-NEN and correlates with a poor outcome. Survivin is therefore an interesting molecule for a targeted therapy, especially for patients with highly proliferative G3 GEP-NENs.

The emerging clinical relevance of genomic profiling in neuroendocrine tumours

Background

Neuroendocrine tumours (NETs) arise from hormone-producing or nervous system cells and can develop from anywhere in the body. They have heterogeneous origins from skin to gastrointestinal track and a complicated histology. Thus, there is an inevitable need for genomic profiling to determine the exact genetics of each tumour for prognosis and treatment strategies to overcome the disease’s complexity. For this purpose, next-generation-sequencing (NGS) is the most reliable methodology for both germ-line and somatic studies to make a clinical diagnosis. In this study, we analyse liquid biopsies, formalin fixed paraffin embedded (FFPE) tissues, and peripheral blood samples for their ability to provide information for actionability.

Methods

A customized multi-gene panel comprised of Succinate Dehydrogenase Complex Iron Sulfur Subunit B (SDHB), Succinate Dehydrogenase Complex Subunit C (SDHC), Cell Division Cycle 73(CDC73), Calcium Sensing Receptor (CASR), Platelet Derived Growth Factor Receptor Alpha (PDGFRA), Succinate Dehydrogenase Complex Flavoprotein Subunit A (SDHA), Ret Proto-Oncogene (RET), Succinate Dehydrogenase Complex Assembly Factor 2(SDHAF2), Menin 1(MEN1), Succinate Dehydrogenase Complex Subunit D (SDHD), MYC Associated Factor X (MAX) and Protein Kinase CAMP-Dependent Type I Regulatory Subunit Alpha (PRKAR1A) genes was constructed to assess multiple specimen types including: 3 liquid biopsies, 6 FFPE tissues, and 26 peripheral blood samples from 35 unique NET patients. Quality-control and bioinformatics analyses were performed using QCI-Analyze and QCI-Interpret.

Results

The three liquid biopsies and the 6 FFPE tissue samples were evaluated for somatic mutations; while the 26 peripheral blood samples were analysed using the germ-line pipeline. Five (55.6%) of the nine patients that were studied for somatic changes carried actionable mutations related to therapy sensitivities. Through the germ-line studies, we observed a 50% positivity rate for disease predisposition with 16 variants classified according to ACMG (American College of Medical Genetics) Standards and Guidelines.

Conclusions

Genomic profiling medicine is an emerging area of clinical oncology and has become crucial for disease and patient management by providing a precision approach; this is especially true for rare diseases including rare cancers such as NETs. Notably, this study emphasized the relevance of multiple distinctive biological sample types for use in the genetic testing of cancers to help with the choice of therapy to maximize the likelihood of a positive clinical outcome.

Kinome Array Profiling of Patient-Derived Pancreatic Ductal Adenocarcinoma Identifies Differentially Active Protein Tyrosine Kinases

Pancreatic cancer remains one of the most difficult malignancies to treat. Minimal improvements in patient outcomes and persistently abysmal patient survival rates underscore the great need for new treatment strategies. Currently, there is intense interest in therapeutic strategies that target tyrosine protein kinases. Here, we employed kinome arrays and bioinformatic pipelines capable of identifying differentially active protein tyrosine kinases in different patient-derived pancreatic ductal adenocarcinoma (PDAC) cell lines and wild-type pancreatic tissue to investigate the unique kinomic networks of PDAC samples and posit novel target kinases for pancreatic cancer therapy. Consistent with previously described reports, the resultant peptide-based kinome array profiles identified increased protein tyrosine kinase activity in pancreatic cancer for the following kinases: epidermal growth factor receptor (EGFR), fms related receptor tyrosine kinase 4/vascular endothelial growth factor receptor 3 (FLT4/VEGFR-3), insulin receptor (INSR), ephrin receptor A2 (EPHA2), platelet derived growth factor receptor alpha (PDGFRA), SRC proto-oncogene kinase (SRC), and tyrosine kinase non receptor 2 (TNK2). Furthermore, this study identified increased activity for protein tyrosine kinases with limited prior evidence of differential activity in pancreatic cancer. These protein tyrosine kinases include B lymphoid kinase (BLK), Fyn-related kinase (FRK), Lck/Yes-related novel kinase (LYN), FYN proto-oncogene kinase (FYN), lymphocyte cell-specific kinase (LCK), tec protein kinase (TEC), hemopoietic cell kinase (HCK), ABL proto-oncogene 2 kinase (ABL2), discoidin domain receptor 1 kinase (DDR1), and ephrin receptor A8 kinase (EPHA8). Together, these results support the utility of peptide array kinomic analyses in the generation of potential candidate kinases for future pancreatic cancer therapeutic development.

Exploration of the relationships between tumor mutation burden with immune infiltrates in clear cell renal cell carcinoma

Background

Whether tumor mutation burden (TMB) correlated with improved survival outcomes or promotion of immunotherapies remained controversy in various malignancies. We aimed to investigate the prognosis of TMB and the potential association with immune infiltrates in clear cell renal cell carcinoma (ccRCC).

Methods

We downloaded the somatic mutation data of 336 ccRCC patients from the Cancer Genome Atlas (TCGA) database, and analyzed the mutation profiles with "maftools" package. TMB was calculated and we classified the samples into high-TMB and low-TMB group. Differential analysis was conducted to compare the expression profiles between two groups using "limma" package, and we identified the 9 hub TMB-related signature from batch survival analysis. Gene ontology (GO) analysis and Gene Set Enrichment Analysis (GSEA) were performed to screen significantly enriched pathways between two groups. Based on the TIMER database, we further assessed the relationships of the mutants of 9 TMB-related signature with immune infiltration levels in ccRCC. Besides, we utilized the "CIBERSORT" package to estimate the abundance of 22 immune fractions between low- and high-TMB groups, and the significant difference were determined by Wilcoxon rank-sum test. Furthermore, Cox regression model combined with survival analysis were used to evaluate the prognostic value of immune cells. Last, we constructed a Tumor Mutation Burden Prognostic Index (TMBPI) from multivariate Cox results and Receiver Operating Characteristic (ROC) curve was drawn to assess the predictive accuracy.

Results

Single nucleotide polymorphism (SNP) occurred more frequently than insertion or deletion, and C>T was the most common of SNV in ccRCC. Higher TMB levels conferred poor survival outcomes, associated with higher tumor grades and advanced pathological stages. A total of 1,265 differentially expressed genes were obtained and top 19 immune-related genes were identified in Venn diagram. GSEA revealed that patients in higher TMB groups correlated with MAPK signaling pathway, Wnt signaling pathway and pathway in cancers. Moreover, we identified 9 hub TMB-related immune genes related with survival and mutants of 9 signature were associated with lower immune infiltrates. In addition, infiltration levels of CD8+ T cell, CD4+ memory resting T cell, M1 and M2 macrophages, as well as dendritic resting cells in high-TMB group were lower than that in low-TMB group, especially the level of CD8+ T cell and macrophage correlated negatively with prognosis of ccRCC. Last, the TMBPI was constructed and the AUC of ROC curve was 0.666.

Conclusions

Higher TMB correlated with poor survival outcomes and might inhibit the immune infiltrates in ccRCC. The mutants of 9 hub TMB-related immune signature conferred lower immune cells infiltration which deserved further validation.

PDGFRα expression as a novel therapeutic marker in well-differentiated neuroendocrine tumors

AIMS

To evaluate the biological significance of dense vascular networks associated with low-grade NENs, we assessed the impact of PDGFRα tissue expression in 77 GEP/NEN patients, associating PDGFRα expression with the morphological characterization in low-grade tumors.

METHODS AND RESULTS

Paraffin-embedded specimens of 77 GEP- NEN tissues, collected from January 2006 to March 2018, were evaluated for PDGFRα tissue expression and correlations with clinicopathological characteristics. PDGFRα tissue expression was significantly correlated with grade and the NEN growth pattern (p < 0.001) but not with gender, primary site or lymph nodes metastatic status. PDGFRα staining was mainly localized in the vascular pole of the neuroendocrine cells and in Enterochromaffin (EC) cells. In particular PDGFRα tissue expression was significantly more expressed in G2 (p < 0.001) than G1 and G3 cases (p 0.004; p < 0.0002;) and correlated with an insular growth pattern. PDGFRα tissue expression was associated with the Ki67 index and we found a significant negative trend of association with the Ki67 proliferation index (P < 0.001): thus PDGFRα expression is referred to morphological and not to proliferative data.

CONCLUSIONS

PDGFRα represents an effective target for new anti-angiogenic treatment in WD- GEP-NENs, in particular in G2 cases, and in G3 cases only when there is a mixed insular-acinar pattern. In this context, it is important to carefully delineate those tumors that might better respond to this type of treatment alone or in combination. Further investigation of the relationship between PD-L1 and PDGFRa is warranted, and may contribute to optimize the therapeutic approach in patients with GEP-NENs.

[Neuroendocrine neoplasia of the stomach : What is new?]

INTRODUCTION

Neuroendocrine Neoplasms are classified according to the new WHO classification in (1.) well differentiated neuroendocrine tumors G1 (NET G1, Ki67 ≤ 2 or mitosis count <2) and (2.) well differentiated neuroendocrine tumors G2 (NET G2, Ki67 3-20 or mitosis count 2-20) and (3.) poorly differentiated neuroendocrine carcinomas G3 (NEC G3, Ki67 > 20 or mitosis count >20).

MATERIAL AND METHODS

In this study 310 NENs of the Ludwig-Maximilians-University in Munich were reevaluated according to the new WHO classification.

RESULTS

7% of the analyzed NENs were presented as neoplasias of the stomach. In NENs of the stomach three distinct subtypes are recognized: (1) type 1 associated with autoimmune chronic atrophic gastritis (2) type 2, associated with multiple endocrine neoplasia (MEN1) and Zollinger-Ellison Syndrom; and (3) type 3, sporadic tumors.

DISCUSSION

Precursor lesions (i. e. hyperplasia of the ECL cells) are found in patients with hypergastrinaemia (type 1 and 2). This article should provide insights into the diagnosis of NENs of the stomach with emphasis on the new international standard.

Genes involved in angiogenesis and mTOR pathways are frequently mutated in Asian patients with pancreatic neuroendocrine tumors

Introduction: To address the issue of limited data on and inconsistent findings for genetic alterations in pancreatic neuroendocrine tumors (pNETs), we analyzed sequences of known pNET-associated genes for their impact on clinical outcomes in a Taiwanese cohort. Methods: Tissue samples from 40 patients with sporadic pNETs were sequenced using a customized sequencing panel that analyzed 43 genes with either an established or potential association with pNETs. Genetic mutations and clinical outcomes were analyzed for potential associations. Results: Thirty-three patients (82.5%) survived for a median 5.9 years (range, 0.3-18.4) of follow up. The median number of mutations per patient was 3 (range, 0-16). The most frequent mutations were in ATRX (28%), MEN1 (28%), ASCL1 (28%), TP53 (20%), mTOR (20%), ARID1A (20%), and VHL (20%). The mutation frequencies in the MEN1 (including MEN1/PSIP1/ARID1A), mTOR (including mTOR/PIK3CA/AKT1/PTEN /TS1/TSC2/ATM), DAXX/ATRX, and angiogenesis (including VHL/ANGPT1/ANGPT2 /HIF1A) pathways were 48%, 48%, 38%, and 45%, respectively. Mutations in ATRX were associated with WHO grade I pNET (vs. grade II or III, p = 0.043), and so were those in genes involved in angiogenesis (p = 0.002). Patients with mutated MEN1 and DAXX/ATRX pathways showed a trend toward better survival, compared to patients with the wild-type genes (p = 0.08 and 0.12, respectively). Conclusion: Genetic profiles of Asian patients with pNETs were distinct from Caucasian patient profiles. Asian patients with pNETs were more frequently mutated for the mTOR and angiogenesis pathways. This could partially explain the better outcome observed for targeted therapy in Asian patients with pNETs.

FOXM1: A novel drug target in gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are heterogeneous tumors that need to be molecularly defined to obtain novel therapeutic options. Forkheadbox protein M1 (FOXM1) is a crucial transcription factor in neoplastic cells and has been associated with differentiation and proliferation. We found that FOXM1 is strongly associated with tumor differentiation and occurrence of metastases in gastrointestinal NENs. In vitro inhibition by the FOXM1 inhibitor siomycin A led to down-regulation of mitotic proteins and resulted in a strong inhibitory effect. Siomycin A decreased mitosis rate, induced apoptosis in GEP-NEN cell lines and exerts synergistic effects with chemotherapy. FOXM1 is associated with clinical outcome and FOXM1 inhibition impairs survival in vitro. We therefore propose FOXM1 as novel therapeutic target in GEP-NENs.

A retrospective cohort study of pancreatic neuroendocrine tumors at single institution over 15 years: New proposal for low- and high-grade groups, validation of a nomogram for prognosis, and novel follow-up strategy for liver metastases

PURPOSE

Pancreatic neuroendocrine tumors (PNETs) exhibit various tumor behaviors and symptoms that are difficult for physicians to stage and predict prognosis. We assess prognostic factors combined with staging classifications to optimal the models and try to improve follow-up strategy to monitor liver metastases after surgery.

METHODS

Patients with PNETs treated at Sun Yat-sen Memorial Hospital between 2000 and 2015 were recruited. Patients were regrouped on the basis of functional status and mitotic rates. Nomograms to predict the prognostic values of classifications (AJCC, ENETS, and WHO) were constructed; the accuracy of the nomograms were quantified by the C-index and calibration plots.

RESULTS

We identified 78 PNETs patients with pathological reports. Correlations with OS in univariate analysis included nonfunctional status (P = 0.002), CgA>200 ng/ml (P < 0.001), Ki-67 (3-20%, P = 0.014; >20%, P < 0.001), and mitotic rate (3-20/10HPF, P = 0.011; >20/10HPF, P < 0.001). By multivariate analysis, nonfunctional status and mitotic rate maintained significance (P = 0.039; 3-20/10HPF, P = 0.015; >20/10HPF, P = 0.007). Evaluating the new proposed system, the difference in OS between low- and high-groups was statistically significant (P = 0.001). The C-index of the regrouped nomograms were higher than that of premise ones (AJCC cohort, 0.605 v 0.576, P < 0.01; ENETS cohort, 0.73 v 0.691, P < 0.01; WHO cohort, 0.678 v 0.603, P < 0.01).

CONCLUSION

An prognostic model based on mitotic rates and functional status correlates strongly with survival. PNETs should return visits every 2 months for the first half years, and every 3 months as followed until 2 years after surgery.

PDGF receptors in tumor biology: prognostic and predictive potential

PDGF receptors (PDGFRs) exert cell type-specific effects in many different tumor types. They are emerging as key regulators of mesenchymal cells of the tumor microenvironment, and of many common malignancies, such as cancer of the breast, colon and prostate. In some tumor types PDGFRs are genetically activated and are thus directly involved in stimulation of malignant cell growth. Recent studies have uncovered clinically relevant variations in stromal PDGFR expression. High stromal PDGFRβ expression or activation is associated with poor prognosis in breast and prostate cancer. Indications of prognostic significance of stromal PDGFRβ expression in various GI tract tumor types also exist. The prognostic significance of PDGFRα and β in malignant cells of common epithelial tumor types should be further studied. Collectively data suggest that continued characterization of PDGFR expression in human tumors should present opportunities for improved accuracy in prognosis and also allow novel biomarker-based clinical studies exploring the efficacy of PDGFR-directed tumor therapies.

Neuroendocrine Carcinomas of the Gastroenteropancreatic System: A Comprehensive Review

To date, empirical literature has generally been considered lacking in relation to neuroendocrine carcinomas (NECs), the highly malignant subgroup of neuroendocrine neoplasms. NECs are often found in the lungs or the gastroenteropancreatic (GEP) system and can be of small or large cell type. Concentrating on GEP-NECs, we can conclude that survival times are poor, with a median of only 4–16 months depending on disease stage and primary site. Further, this aggressive disease appears to be on the rise, with incidence numbers increasing while survival times are stagnant. Treatment strategies concerning surgery are often undecided and second-line chemotherapy is not yet established. After an analysis of over 2600 articles, we can conclude that there is indeed more empirical literature concerning GEP-NECs available than previously assumed. This unique review is based on 333 selected articles and contains detailed information concerning all aspects of GEP-NECs. Namely, the classification, histology, genetic abnormalities, epidemiology, origin, biochemistry, imaging, treatment and survival of GEP-NECs are described. Also, organ-specific summaries with more detail in relation to disease presentation, diagnosis, treatment and survival are presented. Finally, key points are discussed with directions for future research priorities.

Platelet-derived growth factors induced lymphangiogenesis: evidence, unanswered questions and upcoming challenges

Crosstalk between angiogenesis and lymphangiogenesis in embryonic development continues during postnatal life and has specific mechanisms involving factors that initiate activation of the intracellular cascade for their specific receptors. Platelet-derived growth factors (PDGFs) and their corresponding receptors (PDGFRs) are known as important regulators of blood vessel development in both normal and pathologic angiogenesis. Despite some recent papers which reported a potential role of the PDGF/PDGFR axis in lymphatic spread of tumor cells, a few papers have suggested the potential role of PDGFs in tumor lymphangiogenesis development. The present paper summarizes the potential lymphangiogenic role of the PDGF/PDGFR axis, underlying upcoming challenges in the field.

Comparison of tumor markers for predicting outcomes after resection of nonfunctioning pancreatic neuroendocrine tumors

BACKGROUND

This study compares the predictability of 5 tumor markers for distant metastasis and mortality in pancreatic neuroendocrine tumors (PNETs).

METHODS

A total of 128 patients who underwent pancreatectomy for nonfunctioning PNETs between 1998 and 2011 were evaluated. Tumor specimens were stained via immunochemistry for cytoplasmic and nuclear survivin, cytokeratin 19 (CK19), c-KIT, and Ki67. Univariate and multivariate regression analyses and receiver operating characteristics curve were used to evaluate the predictive value of these markers.

RESULTS

A total of 116 tumors (91%) were positive for cytoplasmic survivin, 95 (74%) for nuclear survivin, 85 (66.4%) for CK19, 3 for c-KIT, and 41 (32%) for Ki67 >3%. Twelve (9%) tumors expressed none of the markers. Survivin, CK19, and c-KIT had no substantial effect on distant metastasis or mortality. Age >55 years, grade 3 histology, distant metastasis, and Ki67 >3% were associated with mortality (P < .05). A cut-off of Ki67 >3% was the best predictor (83%) of mortality with an area under the curve of 0.85. Ki67 >3% also predicted occurrence of distant metastases with odds ratio of 9.22 and 95% confidence interval of 1.55-54.55 (P < .015).

CONCLUSION

Of the 5 markers studied, only Ki67 >3% was greatly associated with distant metastasis and death. Survivin, CK19, and c-KIT had no prognostic value in nonfunctioning PNETs.

The role of targeted therapy for gastrointestinal tumors

Many targeted drugs have been studied to target the molecular pathways involved in the development of gastrointestinal cancers. Anti-VEGF, anti-EGFR agents, and recently also multi-kinase inhibitor regorafenib, have already been available for the treatment of metastatic colorectal cancer patients. To date, Her-2 positive, gastric cancer patients, are also treated with trastuzumab, while the multi-targeted inhibitor, sorafenib, represents the standard treatment for hepatocellular carcinoma patients. Finally, sunitinib and everolimus, have been approved for the treatment of the neuroendocrine gastroenteropancreatic tumors. Actually a great number of further drugs are under preclinical and clinical development. The aim of this review is to provide a comprehensive overview of the state of art, focusing on the new emerging strategies in the personalized treatment of gastrointestinal tumors.

Altered interphase fluorescence in situ hybridization profiles of chromosomes 4, 8q24, and 9q34 in pancreatic ductal adenocarcinoma are associated with a poorer patient outcome

Most patients with pancreatic ductal adenocarcinoma (PDAC) die within 6 months of diagnosis. However, 20% to 25% patients undergoing total tumor resection remain alive and disease-free 5 years after diagnostic surgery. Few studies on tumor markers have predicted patient prognosis and/or survival. We evaluated the effect of tumor cytogenetic copy number changes detected by interphase fluorescence in situ hybridization on overall survival (OS) of 55 PDAC patients. The prognostic value of copy number changes showing an effect on OS was validated in an external cohort of 44 surgically resected PDAC patients by comparative genomic hybridization arrays, and the genes coded in altered chromosomes with prognostic value were identified by high-density single-nucleotide polymorphism arrays in 20 cases. Copy number changes of chromosomes 4 and 9q34 with gains of 8q24 were independently associated with shorter OS. On the basis of these three chromosomal alterations, a score is proposed that identifies patients with significantly different (P < 0.001) 5-year OS rates: 60% ± 20%, 16% ± 8%, and 0% ± 0%, respectively. Our results show an association between tumor cytogenetics and OS of PDAC patients and provide the basis for further prognostic stratification of patients undergoing complete tumor resection. Further studies to identify specific genes coded in these chromosomes and their functional consequences are necessary to understand the clinical effect of these changes.

The search for the primary tumor in metastasized gastroenteropancreatic neuroendocrine neoplasm

Gastroenteropancreatic neuroendocrine tumors (NETs) often present as liver metastasis from a carcinoma of unknown primary. We recently showed that primary NETs from the pancreas, small intestine and stomach as well as their respective liver metastases differ from each other by the expression profile of the three genes CD302, PPWD1 and ABHB14B. The gene and protein expression of CD302, PPWD1, and ABHB14B was studied in abdominal NET metastases to identify the site of the respective primary tumors. Cryopreserved tissue from NET metastases collected in different institutions (group A: 29, group B: 50, group C: 132 specimens) were examined by comparative genomic hybridization (Agilent 105 K), gene expression analysis (Agilent 44 K) (groups A and B) and immunohistochemistry (group C). The data were blindly evaluated, i.e. without knowing the site of the primary. Gene expression analysis correctly revealed the primary in the ileum in 94 % of the cases of group A and in 58 % of group B. A pancreatic primary was predicted in 83 % (group A) and 20 % (group B), respectively. The combined sensitivity of group A and B was 75 % for ileal NETs and 38 % for pancreatic NETs. Immunohistochemical analysis of group C revealed an overall sensitivity of 80 %. Gene and protein expression analysis of CD302 and PPWD1 in NET metastases correctly identifies the primary in the pancreas or the ileum in 80 % of the cases, provided that the tissue is well preserved. Immunohistochemical profiling revealed CD302 as the best marker for ileal and PPWD1 for pancreatic detection.

A phase I study of olaratumab, an anti-platelet-derived growth factor receptor alpha (PDGFRα) monoclonal antibody, in patients with advanced solid tumors

PURPOSE

The platelet-derived growth factor receptor (PDGFR) has an important role in tumorigenesis and tumor progression. Olaratumab (IMC-3G3) is a fully human monoclonal antibody that selectively binds human PDGFRα and blocks ligand binding. This phase I study assessed the safety, maximum tolerated dose (MTD), recommended phase II dose (RP2D), pharmacokinetics, and preliminary antitumor activity of olaratumab in patients with advanced solid tumors.

METHODS

Patients were enrolled into five dose-escalating cohorts of 3-6 patients each. Olaratumab was administered intravenously weekly at 4, 8, or 16 mg/kg (cohorts 1-3) or once every other week at 15 or 20 mg/kg (cohorts 4-5), with 4 weeks/cycle.

RESULTS

Nineteen patients were treated in five cohorts. There were no dose-limiting toxicities; the MTD was not identified with the doses studied. The most common olaratumab-related adverse events (AE) were fatigue and infusion reactions (10.5 % each). With the exception of 1 patient (20 mg/kg) experiencing two grade 3 drug-related AEs after the dose-limiting toxicity assessment period, all drug-related AEs were grade 1 or 2. The trough concentrations (C min) for 16 mg/kg weekly and 20 mg/kg biweekly were higher than 155 μg/mL, and the concentration found to be efficacious in preclinical xenograft models. Twelve patients (63.2 %) had a best response of stable disease [median duration of 3.9 months (95 % CI 2.3-8.7)].

CONCLUSIONS

Olaratumab was well tolerated and showed preliminary antitumor activity. RP2Ds are 16 mg/kg weekly and 20 mg/kg biweekly. Phase II studies of olaratumab as monotherapy and in combination are ongoing in several tumor types.

Safety and efficacy of sunitinib in patients with unresectable pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are becoming increasingly common, with the majority of patients presenting with either lymph node involvement or metastatic disease, thus requiring systemic therapy. Targeted therapy is a type of medication that blocks the growth of cancer cells by interfering with specific targeted molecules needed for carcinogenesis and tumor growth rather than by simply interfering with rapidly dividing cells (eg, with traditional chemotherapy). In this review article, pharmacologic inhibition of multiple targets including vascular endothelial growth factor receptor (VEGF-R), platelet-derived growth factor receptor (PDGF-R), stem cell factor receptor (c-KIT-R), FML-like tyrosine kinase-3 receptor (FLT3-R), colony stimulating factor 1 receptor (CSF1-R), and glial cell-line derived neurotrophic factor receptor (RET-R) with sunitinib in patients with unresectable PNETs is discussed. Phase III data indicate that additional treatment with sunitinib can improve prognosis in these patients.

Pulmonary well-differentiated fetal adenocarcinoma with platelet-derived growth factor receptor (PDGFR)α expression

Well-differentiated fetal adenocarcinoma (WDFA) is a rare pulmonary malignancy. Biomarkers of tumor biology has rarely been studied in WDFA. Here, we report two WDFA patients. Both patients had blood-streaked sputum or mild hemoptysis at presentation. They underwent lobectomy and systematic mediastinal lymphadenectomy. Expression of PDGFRα on the plasma membrane was demonstrated by immunohistochemistry (IHC) in the resected tumor specimens. Further IHC examination showed intense immunostaining of β-catenin in both patients but negative staining for TP53, CEA, CD56, EGFR, CK5/6, HER2, S-100, ER, PR, BCL2, and NSE. Both patients had no recurrence to date after more than 3 years of follow up. Herein, we reviewed this rare disease with special emphasis on the clinico-pathological features, treatment and potential role of PDGFRα.