Search

In addition to being risk factors for pancreatic cancer, parameters such as smoking, diabetes, or obesity might also act as potential prognostic factors for the survival of patients initially diagnosed with pancreatic cancer. By implementing one of the largest retrospective study cohorts of 2323 pancreatic adenocarcinoma (PDAC) patients treated at a single high-volume center, potential prognostic factors for survival were evaluated on the basis of 863 cases. Since parameters such as smoking, obesity, diabetes, and hypertension can cause severe chronic kidney dysfunction, the glomerular filtration rate was also considered. In the univariate analyses, albumin (p < 0.001), active smoking (p = 0.024), BMI (p = 0.018), and GFR (p = 0.002) were identified as metabolic prognostic markers for overall survival. In multivariate analyses, albumin (p < 0.001) and chronic kidney disease stage 2 (GFR < 90 mL/min/1.37 m2; p = 0.042) were identified as independent metabolic prognostic markers for survival. Smoking presented a nearly statistically significant independent prognostic factor for survival with a p-value of 0.052. In summary, low BMI, status of active smoking, and reduced kidney function at the time of diagnosis were associated with lower overall survival. No prognostic association could be observed for presence of diabetes or hypertension.

Inflammatory properties are known to promote tumor progression leading to an impaired median overall survival (mOS). Various small studies have focused on a wide range of inflammation-based prognostic indicators. By using sufficient data from 1294 out of 2323 patients diagnosed with pancreatic cancer between 2009 and 2021 at our cancer center, inflammatory markers such as the neutrophil to lymphocyte ratio (NRL), the platelet to lymphocyte ratio (PLR), the lymphocyte to monocyte ratio (LMR) and the CRP to albumin ratio (CAR) were evaluated. We identified a new combined score, termed the inflammatory benchmark index (IBI). We performed univariate and multivariate overall survival analyses and identified optimal prognostic cut-off values for each parameter. In univariate analyses, advanced age (p < 0.001), gender (p < 0.001), tumor stage (p < 0.001), CA19-9 (p = 0.001), NLR (p = 0.001), LMR (p = 0.004), PLR (p = 0.004), CAR (p = 0.001) and IBI (p = 0.001) were identified as prognostic markers. In multivariate analyses advanced age (p < 0.001), gender (p = 0.001), tumor stage (p < 0.001), CA19-9 (p < 0.001), NLR (p = 0.001), LMR (p = 0.038), CAR (p < 0.001) and IBI (p < 0.001) were independent prognostic markers. These findings emphasize the impact of inflammation in pancreatic cancer, provide easily accessible prognostic values for the clinician, and may be useful as stratification parameters for trials aimed at patient inflammation or immune response.

Purpose:BRAFV600E mutations are associated with poor clinical prognosis in colorectal cancer (CRC). Although selective BRAF inhibitors are effective for treatment of melanoma, comparable efforts in CRC have been disappointing. Here, we investigated potential mechanisms underlying this resistance to BRAF inhibitors in BRAFV600E CRC.Experimental Design: We examined phosphoinositide 3-kinase (PI3K)/mTOR signaling in BRAFV600E CRC cell lines after BRAF inhibition and cell viability and apoptosis after combined BRAF and PI3K/mTOR inhibition. We assessed the efficacy of in vivo combination treatment using a novel genetically engineered mouse model (GEMM) for BRAFV600E CRC.Results: Western blot analysis revealed sustained PI3K/mTOR signaling upon BRAF inhibition. Our BRAFV600E GEMM presented with sessile serrated adenomas/polyps, as seen in humans. Combination treatment in vivo resulted in induction of apoptosis and tumor regression.Conclusions: We have established a novel GEMM to interrogate BRAFV600E CRC biology and identify more efficacious treatment strategies. Combination BRAF and PI3K/mTOR inhibitor treatment should be explored in clinical trials. Clin Cancer Res; 19(10); 2688–98. ©2013 AACR.

Supplementary Figure 1 PDF file 118K, Development a GEMM for BRAFV600E CRC

Supplementary Figure 2 PDF file 152K, APC tumors do not recapitulate the sessile serrated CRC pathway

Supplementary Figure Legends PDF file 89K, Supplementary Figure Legends for Supplementary Figure 1 and Supplementary Figure 2

Upfront KRAS and NRAS gene testing (‘RAS’) is the standard of care for metastatic colorectal cancer (mCRC), to guide first-line treatment. The presence of RAS mutation (MT) is a negative predictor for the efficacy of anti-EGFR antibodies and the use of cetuximab and panitumumab is restricted to RAS wild-type (WT) mCRC. Conversion from RAS WT to RAS MT mCRC after treatment with anti-EGFR antibodies is a known and well-described acquired resistance mechanism. The by far less frequent ‘NeoRAS wild-type’ phenomenon (reversion from RAS MT to RAS WT) has recently drawn attention. The proposed effect of chemotherapy on RAS status in mCRC patients is not fully understood. Because of the intriguing biological consequence of a RAS MT to RAS WT reversion, subsequent treatment of NeoRAS WT patients with anti-EGFR antibodies is increasingly being discussed. Here, we report three clinical cases of NeoRAS WT mCRC patients, which received standard-of-care regimens for RAS MT mCRC. Anti-EGFR antibodies were used in two out of three patients after progression of the disease. One of the patients had a long-term response. In line with our observations, NeoRAS WT phenomenon occurs in clinical practice. Retesting of RAS status during treatment should be discussed in patients with unusual long-term clinical courses of RAS MT mCRC to optimise treatment strategy and to evaluate the use of anti-EGFR antibodies.

Since metastatic colorectal cancer (CRC) is a leading cause of cancer-related death, therapeutic approaches overcoming primary and acquired therapy resistance are an urgent medical need. In this study, the efficacy and toxicity of high-affinity inhibitors targeting antiapoptotic BCL-2 proteins (BCL-2, BCL-XL, and MCL-1) were evaluated. By RNA sequencing analysis of a pan-cancer cohort comprising >1500 patients and subsequent prediction of protein activity, BCL-XL was identified as the only antiapoptotic BCL-2 protein that is overactivated in CRC. Consistently, pharmacologic and genetic inhibition of BCL-XL induced apoptosis in human CRC cell lines. In a combined treatment approach, targeting BCL-XL augmented the efficacy of chemotherapy in vitro, in a murine CRC model, and in human ex vivo derived CRC tissue cultures. Collectively, these data show that targeting of BCL-XL is efficient and safe in preclinical CRC models, observations that pave the way for clinical translation.

In recent years treatment options for esophageal cancer were expanding as randomized trials have shown a beneficial effect of preoperative chemotherapy and of chemoradiotherapy (1-7). However, it is unclear whether early stage cancers also benefit from preoperative therapy since the number of patients included in such randomized trials is small (8-10). In a more recently published randomized trial, Mariette et al. (11) investigated the benefit of preoperative chemoradiotherapy in stage I and II esophageal carcinomas. A total of 195 patients were randomized between primary surgery and preoperative chemoradiotherapy (cisplatin/5- FU +45 Gy), followed by surgery. Despite of a significant downstaging and a pathologic complete remission (pCR) in 33.3% of cases in the chemoradiotherapy group, no improvement of neither R0 resection rate nor overall survival were observed. Moreover, there was no difference in postoperative complications but there was an increase in hospital mortality in the chemoradiotherapy group (11.1% vs. 3.4%), which may have affected the overall outcome of the trial. Due to these results neoadjuvant treatment for T2 esophageal cancer remains highly controversial.

Inappropriate activation of epidermal growth factor receptor (EGFR) plays a causal role in many cancers including colon cancer. The activation of EGFR by phosphorylation is balanced by receptor kinase and protein tyrosine phosphatase activities. However, the mechanisms of negative EGFR regulation by tyrosine phosphatases remain largely unexplored. Our previous results indicate that protein tyrosine phosphatase receptor type O (PTPRO) is down-regulated in a subset of colorectal cancer (CRC) patients with a poor prognosis. Here we identified PTPRO as a phosphatase that negatively regulates SRC by directly dephosphorylating Y416 phosphorylation site. SRC activation triggered by PTPRO down-regulation induces phosphorylation of both EGFR at Y845 and the c-CBL ubiquitin ligase at Y731. Increased EGFR phosphorylation at Y845 promotes its receptor activity, whereas enhanced phosphorylation of c-CBL triggers its degradation promoting EGFR stability. Importantly, hyperactivation of SRC/EGFR signaling triggered by loss of PTPRO leads to high resistance of colon cancer to EGFR inhibitors. Our results not only highlight the PTPRO contribution in negative regulation of SRC/EGFR signaling but also suggest that tumors with low PTPRO expression may be therapeutically targetable by anti-SRC therapies.

Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies are currently used for treatment of metastatic colorectal cancer. Although they have improved clinical outcome for these metastatic patients, only a small percentage benefit from the treatment. This limited efficacy is related to the lack of validated biomarkers that could aid better selection of the patients most likely to benefit. Although several biomarkers have been identified in recent years, we still do not know how to administer these drugs in a “personalized, targeted manner”. The purpose of this review is to summarize the state of the art of biomarker discovery and the steps to follow to optimize treatment.

Precision oncology aims to distinguish which patients are eligible for a specific treatment in order to achieve the best possible outcome. In the last few years, genetic screens have shown their potential to find the new targets and drug combinations as well as predictive biomarkers for response and/or resistance to cancer treatment. In this review, we outline how precision oncology is changing over time and describe the different applications of genetic screens. Finally, we present some practical examples that describe the utility and the limitations of genetic screens in precision oncology.

The RAS/RAF/MEK/MAPK and the PTEN/PI3K/AKT/mTOR pathways are key regulators of proliferation and survival in human cancer cells. Selective inhibitors of different transducer molecules in these pathways have been developed as molecular targeted anti-cancer therapies. The in vitro and in vivo anti-tumor activity of pimasertib, a selective MEK 1/2 inhibitor, alone or in combination with a PI3K inhibitor (PI3Ki), a mTOR inhibitor (everolimus), or with multi-targeted kinase inhibitors (sorafenib and regorafenib), that block also BRAF and CRAF, were tested in a panel of eight human lung and colon cancer cell lines. Following pimasertib treatment, cancer cell lines were classified as pimasertib-sensitive (IC50 for cell growth inhibition of 0.001 µM) or pimasertib-resistant. Evaluation of basal gene expression profiles by microarrays identified several genes that were up-regulated in pimasertib-resistant cancer cells and that were involved in both RAS/RAF/MEK/MAPK and PTEN/PI3K/AKT/mTOR pathways. Therefore, a series of combination experiments with pimasertib and either PI3Ki, everolimus, sorafenib or regorafenib were conducted, demonstrating a synergistic effect in cell growth inhibition and induction of apoptosis with sustained blockade in MAPK- and AKT-dependent signaling pathways in pimasertib-resistant human colon carcinoma (HCT15) and lung adenocarcinoma (H1975) cells. Finally, in nude mice bearing established HCT15 and H1975 subcutaneous tumor xenografts, the combined treatment with pimasertib and BEZ235 (a dual PI3K/mTOR inhibitor) or with sorafenib caused significant tumor growth delays and increase in mice survival as compared to single agent treatment. These results suggest that dual blockade of MAPK and PI3K pathways could overcome intrinsic resistance to MEK inhibition.

Purpose: BRAFV600E mutations are associated with poor clinical prognosis in colorectal cancer (CRC). Although selective BRAF inhibitors are effective for treatment of melanoma, comparable efforts in CRC have been disappointing. Here, we investigated potential mechanisms underlying this resistance to BRAF inhibitors in BRAFV600E CRC. Experimental Design: We examined phosphoinositide 3-kinase (PI3K)/mTOR signaling in BRAFV600E CRC cell lines after BRAF inhibition and cell viability and apoptosis after combined BRAF and PI3K/mTOR inhibition. We assessed the efficacy of in vivo combination treatment using a novel genetically engineered mouse model (GEMM) for BRAFV600E CRC. Results: Western blot analysis revealed sustained PI3K/mTOR signaling upon BRAF inhibition. Our BRAFV600E GEMM presented with sessile serrated adenomas/polyps, as seen in humans. Combination treatment in vivo resulted in induction of apoptosis and tumor regression. Conclusions: We have established a novel GEMM to interrogate BRAFV600E CRC biology and identify more efficacious treatment strategies. Combination BRAF and PI3K/mTOR inhibitor treatment should be explored in clinical trials. Clin Cancer Res; 19(10); 2688–98. ©2013 AACR.

BRAF(V600E) mutant colon cancers (CCs) have a characteristic gene expression signature that is also found in some tumors lacking this mutation. Collectively, they are referred to as "BRAF-like" tumors and represent some 20% of CCs. We used a shRNA-based genetic screen focused on genes upregulated in BRAF(V600E) CCs to identify vulnerabilities of this tumor subtype that might be exploited therapeutically. Here, we identify RANBP2 (also known as NUP358) as essential for survival of BRAF-like, but not for non-BRAF-like, CC cells. Suppression of RANBP2 results in mitotic defects only in BRAF-like CC cells, leading to cell death. Mechanistically, RANBP2 silencing reduces microtubule outgrowth from the kinetochores, thereby inducing spindle perturbations, providing an explanation for the observed mitotic defects. We find that BRAF-like CCs display far greater sensitivity to the microtubule poison vinorelbine both in vitro and in vivo, suggesting that vinorelbine is a potential tailored treatment for BRAF-like CCs.

Background: MEK is activated in ∼40% colorectal cancer (CRC) and 20–30% non-small cell lung cancer (NSCLC). Selumetinib is a selective inhibitor of MEK1/2, which is currently in clinical development. Methods: We evaluated the effects of selumetinib in vitro and in vivo in CRC and NSCLC cell lines to identify cancer cell characteristics correlating with sensitivity to MEK inhibition. Results: Five NSCLC and six CRC cell lines were treated with selumetinib and classified according to the median inhibitory concentration (IC50) values as sensitive (⩽1 μℳ) or resistant (>1 μℳ). In selumetinib-sensitive cancer cell lines, selumetinib treatment induced G1 cell-cycle arrest and apoptosis and suppression of tumour growth as xenografts in immunodeficient mice. Evaluation of intracellular effector proteins and analysis of gene mutations showed no correlation with selumetinib sensitivity. Microarray gene expression profiles revealed that the activation of cAMP-dependent protein kinase A (PKA) was associated with MEK inhibitor resistance. Combined targeting of both MEK and PKA resulted in cancer cell growth inhibition of MEK inhibitor-resistant cancer cell lines in vitro and in vivo. Conclusion: This study provides molecular insights to explain resistance to an MEK inhibitor in human cancer cell lines.

The introduction in clinical practice of anti-epidermal growth factor receptor (EGFR) antibodies has improved the clinical outcome of metastatic colorectal cancer (mCRC) patients. Nevertheless, only 10% of mCRC tumors respond to these treatments, thus rendering the efforts made to maximize their therapeutic index justified. Although several biomarkers have been identified, we do not know yet how to administer these drugs in colorectal cancer patients in a “personalized–targeted manner.” With this review we will try to demonstrate that we need to go beyond the assumption of a binary relationship between one genetic event and response or resistance to anti-EGFR drugs and that several factors can influence the response to these agents. Therefore, the introduction in future approaches of a holistic genomic discovery plan instead of an individual and specific identification of alterations is needed.

Anti-Epidermal Growth Factor Receptor (EGFR) therapies have been recently developed for the treatment of multiple cancer types. At the time when they were introduced in clinical practice, there was little knowledge of the molecular bases of tumor sensitivity and resistance to these novel targeted compounds. By using the framework of anti-EGFR inhibitors as treatment for colorectal cancer patients, we will review the knowledge we have reached until now in improving the development of a personalized cancer therapy and we will try to indicate the future challenges this field will face in the future.

"Background: Preoperative chemoradiotherapy (CRT) improves the survival of patients with oesophageal cancer when compared with surgery alone.. . Methods: We conducted a phase II, multicenter trial of FOLFOX-4 and cetuximab in patients with locally advanced oesophageal cancer (LAEC) followed by daily radiotherapy (180 cGy fractions to 5040 cGy) with concurrent weekly cetuximab. Cytokines levels potentially related to cetuximab efficacy were assessed using multiplex-bead assays and enzyme-linked immunosorbent assay at baseline, at week 8 and at week 17. Primary end point was complete pathological response rate (pCR).. . Results: In all, 41 patients were enroled. Among 30 patients who underwent surgery, a pCR was observed in 8 patients corresponding to a rate of 27%. The most frequent grade 3\/4 toxicity was skin (30%) and neutropenia (30%). The 36-month survival rates were 85 and 52% in patients with pathological CR or PR vs 38 and 33% in patients with SD or PD.. . Conclusions: Incorporating cetuximab into a preoperative regimen for LAEC is feasible; no correlation between cytokines changes and patient outcome was observed. Positron emission tomography\/computed tomography study even if influenced by the small number of patients appears to be able to predict patients outcome both as early and late metabolic response.. . " Background: Preoperative chemoradiotherapy (CRT) improves the survival of patients with oesophageal cancer when compared with surgery alone. Methods: We conducted a phase II, multicenter trial of FOLFOX-4 and cetuximab in patients with locally advanced oesophageal cancer (LAEC) followed by daily radiotherapy (180 cGy fractions to 5040 cGy) with concurrent weekly cetuximab. Cytokines levels potentially related to cetuximab efficacy were assessed using multiplex-bead assays and enzyme-linked immunosorbent assay at baseline, at week 8 and at week 17. Primary end point was complete pathological response rate (pCR). Results: In all, 41 patients were enroled. Among 30 patients who underwent surgery, a pCR was observed in 8 patients corresponding to a rate of 27%. The most frequent grade 3/4 toxicity was skin (30%) and neutropenia (30%). The 36-month survival rates were 85 and 52% in patients with pathological CR or PR vs 38 and 33% in patients with SD or PD. Conclusions: Incorporating cetuximab into a preoperative regimen for LAEC is feasible; no correlation between cytokines changes and patient outcome was observed. Positron emission tomography/computed tomography study even if influenced by the small number of patients appears to be able to predict patients outcome both as early and late metabolic response. © 2011 Cancer Research UK All rights reserved.

Nature Reviews Clinical Oncology, (2017). doi:10.1038/nrclinonc.2017.43 Jason J. Luke 0 0 2017-03-27T13:39:00Z 2017-11-29T14:35:00Z 1 312 1781 14 4 2089 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} Regorafenib is a multikinase inhibitor currently approved for the treatment of chemorefractory mCRC patients. No predictive biomarkers of efficacy have been identified. We recently reported that amplification or mutations in HER-2/neu might predict resistance to regorafenib in a small cohort of patients treated with Regorafenib. We therefore sought to better investigate the role of HER-2/neu in response to Regorafenib in preclinical and clinical models. Short-term proliferation assay with Regorafenib was performed in a panel of CRC cell lines. Basal protein expression of total and phospho Her2 were analized by WB analysis. RPPA data from MD Anderson cell lines project were used for external validation of total and phospho HER-2/neu. Sperman correlation was applied to correlate the expression levels of total and phospo HER2/neu and IC50 to Regorafenib. HT29 CRC cell line (HT29) was made resistant to Regorafenib (HT29R). WB analysis of basal levels of proteins of the EGFR and Her2 axis were investigated in both HT29 and HT29R. Moreover, HT29 and HT29R were treated with EGFR inhibitors, Her2/neu inhibitors, MAPK and PIk3Ca inhibitors. Apoptosis was perfromed by FACs analysis by using Annexin-V staining. We found a negative correlation between pHer2 expression and response to Regorafenib in both our data set of CRC cell lines and in the MD Anderson panel. Overexpression of all the epitelial markers of the EGFR and HER2/neu axis was observed in HT29R as compared to HT29. This translated to an increased sensitivity and apoptosis to Trastuzumab in HT29R as compared to HT29 (IC50 with 50 times fold change) and PIk3Ca inhibitor (IC50 with 5 times fold change). No differences of IC50 were observed with other inhibitors. Moreover, combined treatment with Trastuzumab and PIk3Ca inhibitor induced significantly early and late apoptosis in HT29R as compared to HT29. Our preliminary data indicate pHer2 levels to be predictive of resistance to Regorafenib in CRC. Functional work and IHC analysis of CRC patients treated with Regorafenib is ongoing and will be presented. Citation Format: Loredana Vecchione, Stefania Napolitano, Valentina Belli, Erika Martinelli, Nunzia Matrone, Christophe Hapke, Ulrich Keilholz, Josep Tabernero, Fortunato Ciardiello, Teresa Troiani. Her2/neu expression as potential marker of regorafenib resistance in CRC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2841.

Background BRAF(V600E) colon cancers (CCs) are characterized by a distinct gene expression profile when compared to KRAS mutant and KRAS-BRAF double wild type (WT2) CCs. Most importantly, 20% of WT2 CCs are BRAF-like by gene expression profile (1,2). By using a loss of function genetic approach, we previously found that Vinorelbine (VBN) might represent a new therapeutic option for BRAF-like metastatic colorectal cancer (mCRC) patients (3). Recently, in a phase II study, Cremolini et al (4) reported no activity of VBN in BRAFV600E mutated chemorefractory mCRC patients. We hypothesize that the lack of response could be driven by the loss of the BRAF-like signature after several lines of treatment and/or the acquisition of a multidrug resistant, an EMT and/or a hypoxia phenotype. Material and methods We retrospectively collected formalin-fixed-paraffin-embedded (FFPE) tumor tissue of primary tumor or metastatic lesions of mCRC patients enrolled in the Cremolini et al study. In particular, both chemonaive tissue (before the start of any treatment) and chemorefractory tissue (before the start of VBN) were collected to perform gene expression analysis and whole genome sequencing (WGS). Agendia's full genome arrays were used for gene expression analysis and the TrueSeq Nano Dna protocol was used for WGS analysis. In parallel, two independent genome wide CRISPR screens for resistance to VBN were performed in VACO432 CRC cell line by using the Gecko half library A and the Brunello library. Results and conclusions Matched paired samples were available for six out of twenty patients from the Cremolini et al cohort (Female: 0%, Male: 100%, median age at the start of VBN: 53 (26-71), Stage IV: 100%, chemorefractory: 84%). Samples were available for both gene expression and WGS. For WGS, genomic DNA was extracted from peripheral blood mononuclear cell (pbmc) for four patients and from normal colon FFPE tissue for two patients. All samples passed the quality control steps for both gene expression analysis and WGS. Six hits were identified from the CRISPR screens. Comparative genomic and transcriptomic analysis of the patients´ data will be integrated with CRISPR screens results and presented at the meeting. References 1. Popovici V et al. Identification of a poor-prognosis BRAF-mutant-like population of patients with colon cancer. Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2012;30(12):1288-95 2. Tian S et al (2013). A combined oncogenic pathway signature of BRAF, KRAS and PI3KCA mutation improves colorectal cancer classification and cetuximab treatment prediction. Gut 62, 540-549 3. Vecchione L et al. A Vulnerability of a Subset of Colon Cancers with Potential Clinical Utility. Cell. 2016;165(2):317-30 4. Cremolini C et al: ESMO Open Aug 2017, 2 (3) e000241; DOI: 10.1136/esmoopen-2017-000241 Citation Format: Loredana Vecchione, Ines Beumer, Antonio Mulero-Sanchez, Mireille Snel, Filippo Pietrantonio, Chiara Cremolini, Fotios Loupakis, Antonia Martinetti, Giovanni Fuca', Roberto Moretto, Gabriella Fontanini, Matteo Fassan, Sara Lonardi, Marta Schirripa, Ulrich Keilholz, Rene' Bernards. Identification of molecular determinants of vinorelbine resistance in BRAF(V600E) mutated chemorefractory metastatic colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1823.

BACKGROUND: Gastric cancer still represents a leading cause of death worldwide. Several cytotoxic agents have demonstrated activity and combination regimens improve progression-free survival, overall survival and quality of life. Nevertheless, now there is no standard therapy for advanced gastric cancer patients. OBJECTIVE: To evaluate the role of new investigational agents. METHODS: We analysed Phase I, II and III studies that evaluated tailored drugs directed against the epidermal growth factor receptor (EGFR), the c-erbB2, the vascular endothelial growth factor (VEGF), the vascular endothelial growth factor receptor (VEGFR), the matrix metalloproteinases (MMP) and the mammalian target of rapamycin (mTOR). CONCLUSION: Data from Phase II trials indicate the potential of improved efficacy of chemotherapy when administered in combination with bevacizumab and cetuximab. Trastuzumab results are ongoing, while marimastat has not obtained clinical developments even if it has demonstrated to be an active drug in this setting of patients.

SummaryMost BRAF (V600E) mutant melanomas are sensitive to selective BRAF inhibitors, but BRAF mutant colon cancers are intrinsically resistant to these drugs because of feedback activation of EGFR. We performed an RNA-interference-based genetic screen in BRAF mutant colon cancer cells to search for phosphatases whose knockdown induces sensitivity to BRAF inhibition. We found that suppression of protein tyrosine phosphatase non-receptor type 11 (PTPN11) confers sensitivity to BRAF inhibitors in colon cancer. Mechanistically, we found that inhibition of PTPN11 blocks signaling from receptor tyrosine kinases (RTKs) to the RAS-MEK-ERK pathway. PTPN11 suppression is lethal to cells that are driven by activated RTKs and prevents acquired resistance to targeted cancer drugs that results from RTK activation. Our findings identify PTPN11 as a drug target to combat both intrinsic and acquired resistance to several targeted cancer drugs. Moreover, activated PTPN11 can serve as a biomarker of drug resistance resulting from RTK activation.

Differences exist between the proximal and distal colon in terms of developmental origin, exposure to patterning genes, environmental mutagens, and gut flora. Little is known on how these differences may affect mechanisms of tumorigenesis, side-specific therapy response or prognosis. We explored systematic differences in pathway activation and their clinical implications.Detailed clinicopathological data for 3045 colon carcinoma patients enrolled in the PETACC3 adjuvant chemotherapy trial were available for analysis. A subset of 1404 samples had molecular data, including gene expression and DNA copy number profiles for 589 and 199 samples, respectively. In addition, 413 colon adenocarcinoma from TCGA collection were also analyzed. Tumor side-effect on anti-epidermal growth factor receptor (EGFR) therapy was assessed in a cohort of 325 metastatic patients. Outcome variables considered were relapse-free survival and survival after relapse (SAR).Proximal carcinomas were more often mucinous, microsatellite instable (MSI)-high, mutated in key tumorigenic pathways, expressed a B-Raf proto-oncogene, serine/threonine kinase (BRAF)-like and a serrated pathway signature, regardless of histological type. Distal carcinomas were more often chromosome instable and EGFR or human epidermal growth factor receptor 2 (HER2) amplified, and more frequently overexpressed epiregulin. While risk of relapse was not different per side, SAR was much poorer for proximal than for distal stage III carcinomas in a multivariable model including BRAF mutation status [N = 285; HR 1.95, 95% CI (1.6-2.4), P0.001]. Only patients with metastases from a distal carcinoma responded to anti-EGFR therapy, in line with the predictions of our pathway enrichment analysis.Colorectal carcinoma side is associated with differences in key molecular features, some immediately druggable, with important prognostic effects which are maintained in metastatic lesions. Although within side significant molecular heterogeneity remains, our findings justify stratification of patients by side for retrospective and prospective analyses of drug efficacy and prognosis.

Ravit Geva,1,2 Loredana Vecchione,2 Sabine Tejpar,2 Hubert Piessevaux,3 Eric Van Cutsem,2 Hans Prenen21Gastrointestinal Malignancies Service, Oncology Division, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; 2Department of Gastroenterology, Digestive Oncology Unit, University Hospitals Leuven, Leuven, Belgium; 3Department of Gastroenterology, Cliniques Universitaires Saint-Luc, Brussels, BelgiumPurpose: The combination of chemotherapy and bevacizumab, a monoclonal antibody targeting the vascular endothelial growth factor, is consistently being used as first- and second-line treatment in patients with metastatic colorectal cancer (mCRC). There is little data of the activity of bevacizumab in chemorefractory mCRC patients. The aim of this retrospective single center study was to evaluate the activity of bevacizumab combined with chemotherapy in this study population.Methods: Forty-six consecutive mCRC patients treated in the University Hospital Gasthuisberg (Leuven, Belgium) receiving bevacizumab in advanced lines following failure of conventional chemotherapy were included in this study. Treatment regimen consisted of bevacizumab 5 mg/kg in combination with leucovorin, 5-fluorouracil, and oxaliplatin (FOLFOX) or leucovorin, 5-fluorouracil, and irinotecan (FOLFIRI).Results: Bevacizumab plus chemotherapy was used in third-line treatment in eight (17%) patients and in fourth-line treatment or more in 38 patients (83%). All patients previously failed irinotecan-based chemotherapy, 44 (96%) failed oxaliplatin-based regimens, and 40 (87%) failed treatment with cetuximab. Bevacizumab was given in combination with irinotecan-based chemotherapy in 36 patients, oxaliplatin-based chemotherapy in nine patients, and with single agent 5-fluorouracil in one patient. Objective response was demonstrated in ten patients (22%) and disease control in 38 (83%) with a median progression-free survival of 8.9 months and a median overall survival of 13.8 months. Only four patients experienced grade III and above bevacizumab-related toxicity.Conclusion: Taking into account the retrospective nature of the study which can influence the selection of patients, bevacizumab given in advanced lines after failure of conventional chemotherapy and antiepidermal growth factor receptor agents can result in high disease control rates in patients with mCRC.Keywords: colorectal cancer, bevacizumab, chemorefractory

Despite a decrease in incidence and mortality, colorectal cancer (CRC) still represents the second leading cause of cancer worldwide. Recurrence following surgery and adjuvant treatment and the metastatic disease are still a major problem with a median overall survival of approximately 24 months. Nevertheless, there has been an improvement in outcome due to the introduction into clinical practice of new cytotoxic and targeted agents. The targeted agents that have improved the efficacy of the available chemotherapeutic regimens in CRC are the ones that target the vascular endothelial growth factor (VEGF) and the epidermal growth factor receptor (EGFR). In particular, bevacizumab, a recombinant humanized monoclonal antibody against VEGF, cetuximab, and panitumumab, two monoclonal antibodies that target the EGFR, have been approved for the treatment of metastatic CRC (mCRC). While for anti-EGFR agents, predictive biomarkers have been found, no good biomarkers have been found yet for anti-VEGF agents. Aflibercept and regorafenib have recently also been approved in patients with mCRC. This article reviews in an extensive way the data of large randomized clinical trials for the use of anti-VEGF and anti-EGFR in CRC. Aim of this review is also to describe the current status of biomarkers discovery and highlight how to improve the therapeutic index of these targeted agents by selecting in advance the subgroup of patients who will benefit from these treatments.

The RAS/RAF/MEK/MAPK and the PTEN/PI3K/AKT/mTOR pathways are key regulators of proliferation and survival in human cancer cells. Selective inhibitors of different transducer molecules in these pathways have been developed as molecular targeted anti-cancer therapies. The in vitro and in vivo anti-tumor activity of pimasertib, a selective MEK 1/2 inhibitor, alone or in combination with a PI3K inhibitor (PI3Ki), a mTOR inhibitor (everolimus), or with multi-targeted kinase inhibitors (sorafenib and regorafenib), that block also BRAF and CRAF, were tested in a panel of eight human lung and colon cancer cell lines. Following pimasertib treatment, cancer cell lines were classified as pimasertib-sensitive (IC50 for cell growth inhibition of 0.001 µM) or pimasertib-resistant. Evaluation of basal gene expression profiles by microarrays identified several genes that were up-regulated in pimasertib-resistant cancer cells and that were involved in both RAS/RAF/MEK/MAPK and PTEN/PI3K/AKT/mTOR pathways. Therefore, a series of combination experiments with pimasertib and either PI3Ki, everolimus, sorafenib or regorafenib were conducted, demonstrating a synergistic effect in cell growth inhibition and induction of apoptosis with sustained blockade in MAPK- and AKT-dependent signaling pathways in pimasertib-resistant human colon carcinoma (HCT15) and lung adenocarcinoma (H1975) cells. Finally, in nude mice bearing established HCT15 and H1975 subcutaneous tumor xenografts, the combined treatment with pimasertib and BEZ235 (a dual PI3K/mTOR inhibitor) or with sorafenib caused significant tumor growth delays and increase in mice survival as compared to single agent treatment. These results suggest that dual blockade of MAPK and PI3K pathways could overcome intrinsic resistance to MEK inhibition.

Despite the development of drugs inhibiting the oncogenic proteins that cancer cells are dependent on, attempts to match targeted therapies to the genetic makeup of individual tumors is proving more difficult than expected. Until now, the paradigm has been a binary correlation between a mutated cancer gene and response to a given therapy. However, recent evidence indicates that different genetic alterations, such as mutations in different codons of a cancer gene, might be related to distinct sensitivity to targeted therapies. An example is the divergent effect that individual EGFR, PIK3CA and KRAS mutations might have on response or resistance to tailored drugs. Furthermore, the idea that the presence of a specific mutation translates into sensitivity or resistance to a particular drug is likely too simplistic, since it does not capture the complexity of the signaling pathways in an individual cancer. Only the overall genetic milieu (alterations in upstream and/or parallel pathways) ultimately determines the response of individual tumors to therapy. We have critically analyzed data supporting the genetic, biological and biochemical differences of individual mutations within a single cancer gene. The role of cancer mutations as predictors of sensitivity and resistance to targeted therapies is discussed, together with the implications for the 'personalized' treatment of cancer patients.

Purpose: Cancer cell survival, invasion, and metastasis depend on cancer cell proliferation and on tumor-induced angiogenesis. We evaluated the efficacy of the combination of sorafenib and erlotinib or cetuximab. Experimental Design: Sorafenib, erlotinib, and cetuximab, alone or in combination, were tested in vitro in a panel of non–small cell lung cancer (NSCLC) and colorectal cancer cell lines and in vivo in H1299 tumor xenografts. Results: Epidermal growth factor receptor (EGFR) ligand mRNAs were expressed in all NSCLC and colorectal cancer cell lines with variable levels ranging from 0.4- to 8.1-fold as compared with GEO colorectal cancer cells. Lung cancer cells had the highest levels of vascular endothelial growth factors (VEGF) A, B, and C, and of VEGF receptors as compared with colorectal cancer cells. Combined treatments of sorafenib with erlotinib or cetuximab produced combination index values between 0.02 and 0.5, suggesting a significant synergistic activity to inhibit soft agar colony formation in all cancer cell lines, which was accompanied by a marked blockade in mitogen-activated protein kinase and AKT signals. The in vitro migration of H1299 cells, which expressed high levels of both VEGF ligands and receptors, was inhibited by treatment with sorafenib, and this effect was significantly increased by the combination with anti-EGFR drugs. In nude mice bearing established human H1299 xenografts, treatment with the combination of sorafenib and erlotinib or cetuximab caused a significant tumor growth delay resulting in 70 to 90 days increase in mice median overall survival as compared with single-agent sorafenib treatment. Conclusions: Combination treatment with sorafenib and erlotinib or cetuximab has synergistic antitumor effects in human colorectal and lung cancer cells. Clin Cancer Res; 16(20); 4990–5001. ©2010 AACR.

Although the incidence of gastric cancer has been declining in Western countries, it is still a major health problem and a leading cause of cancer mortality. Surgery is the mainstay of treatment for gastric adenocarcinoma. However, even among patients undergoing gastrectomy with curative intent, 5-year survival rates are disappointing due to locoregional relapse and distant metastases. This emphasizes the importance of multidisciplinary management of patients with gastric cancer. In contrast to the preoperative approach, several phase III trials have been carried out in the adjuvant setting, but postoperative chemotherapy has not proven to be superior to surgery alone. Therefore, at present the routine use of adjuvant therapy should be regarded as an investigational approach. Improved clinical trial designs with standardized surgical techniques and the incorporation of newer active drugs are needed.

We evaluated the association of a weekly cisplatin (35 mg/mq) and paclitaxel (45 mg/mq) regimen with radiotherapy (46 Gy) as primary treatment in locally advanced esophageal cancer (LAEC). The main end point was the activity in terms of pathologic complete response (pathCR) rate. Thirty-three LAEC patients received chemoradiation therapy during weeks 1-6 followed by esophagectomy. A pathCR was observed in 10/33 patients; 20/33 and 3/33 patients showed PR and SD, respectively. The EUS maximal transverse cross sectional area reduction >50 significantly correlated with pathCR. Three-year survival rate was 35%. These results support the activity and mild toxicity of this regimen. © 2010 Informa Healthcare USA, Inc.

Several trials show a relationship between skin toxicity, response rate, and overall survival in cetuximab-treated patients. We analyzed our database to evaluate the importance of skin rash as a surrogate marker of favorable outcome in cancer patients referred to our institution in the last three years. We retrospectively analyzed 90 cetuximab-treated patients: 57 colon cancer patients, 10 NSCLC patients, 14 locally advanced esophageal cancer patients, and 9 miscellaneous. A significant correlation was observed between skin rash and response to therapy. Skin rash was experienced by 93% of PR and 100% of CR patients. The mean TTP was 184 days in patients showing skin rash and 94 days in patients without skin rash, respectively. On multivariate analysis, skin rash was demonstrated to be the only independent prognostic variable with regard to TTP. Patients who did not develop skin rash had a 2-fold greater likelihood to manifest tumor progression significantly earlier than patients who developed skin rash. In our series, a statistically significant correlation between rash, response rate, and TTP was demonstrated in 90 cetuximab-treated patients. Skin toxicity was confirmed as the only clinical variable able to predict the response to cetuximab.

The recent introduction of new chemotherapeutic and radiotherapeutic schemes into clinical practice has led to the improvement in the overall survival of cancer patients. Hodgkin’s disease, testicular cancer, and pediatric malignancies are the pathologies with the highest survival rate; improved cure rates have also been achieved for breast cancer, ovarian cancer, and non-Hodgkin’s lymphoma. However, the long-term survival and/or recovery conferred by these treatments paradoxically expose cancer patients to a higher risk of important longterm complications, the most serious of which is the development of a second tumor.

The epidermal growth factor receptor (EGFR) is a member of the erbB family overexpressed in most of the solid tumors. In cancer cells, the overexpression of EGFR correlates with the development and the progression of tumor. Panitumumab is a fully human monoclonal antibody that blocks the extracellular domain of the EGFR and has not been associated with the formation of any antibodies directed against it. This review summarizes on the preclinical and clinical development of panitumumab in human solid tumors. As bevacizumab and cetuximab have been approved for colorectal cancer because of their improvements in progression-free survival and overall survival when associated with chemotherapy, panitumumab represents an interesting molecule which needs more phase III studies to validate its efficacy.

Background: Capecitabine and docetaxel have demonstrated preclinical antitumor synergy and activity in advanced gastric cancer. We assessed the clinical activity and the toxicity of weekly docetaxel in combination with capecitabine in untreated patients with advanced gastric cancer. Patients and methods: A total of 38 patients were treated with docetaxel 36 mg/m2 on days 1, 8, and 15 i.v., plus capecitabine, 625 mg/m2 bid per os on days 5 to 18 repeated every 4 weeks. Results: All patients were assessable for response to treatment and for toxicity. Major responses were observed in eight patients (21%), with three patients achieving a CR (7.8%) and five showing a PR (13%). The median time to progression was 5.4 months and the overall survival was 7.7 months. The safety profile of this schedule was acceptable with a low rate of myelossuppression, diarrhoea and hand-foot syndrome. Conclusions: The combination of docetaxel and capecitabine at the doses and schedule investigated in this study is safe, but does not show significant activity in untreated patients with advanced gastric cancer. Background: Capecitabine and docetaxel have demonstrated preclinical antitumor synergy and activity in advanced gastric cancer. We assessed the clinical activity and the toxicity of weekly docetaxel in combination with capecitabine in untreated patients with advanced gastric cancer. Patients and methods: A total of 38 patients were treated with docetaxel 36 mg/m2 on days 1, 8, and 15 i.v., plus capecitabine, 625 mg/m2 bid per os on days 5 to 18 repeated every 4 weeks. Results: All patients were assessable for response to treatment and for toxicity. Major responses were observed in eight patients (21%), with three patients achieving a CR (7.8%) and five showing a PR (13%). The median time to progression was 5.4 months and the overall survival was 7.7 months. The safety profile of this schedule was acceptable with a low rate of myelossuppression, diarrhoea and hand-foot syndrome. Conclusions: The combination of docetaxel and capecitabine at the doses and schedule investigated in this study is safe, but does not show significant activity in untreated patients with advanced gastric cancer. © 2006 Oxford University Press.

3626 Background: Although cetuximab treatment has been successful for the treatment of KRAS wild-type colorectal cancers, complete remissions are rarely seen in patients, leading ultimately to resistance. We hypothesized that in cetuximab-sensitive patients, the ErbB network is insufficiently targeted since network plasticity may occur. Methods: We have used EGFR-sensitive colorectal cancer cells and investigated ErbB network activity and adaptations by RTK arrays, western blot, and Collaborative Enzyme Enhance Reactive immunoassay (CEER). These were complemented by ErbB heterodimerization (HER2:3, HER1:2, HER1:3, HER3:PI3K) assays using CEER. Effects on cell survival were measured using colony formation assay. In addition to the EGFR sensitive cell line, 200 clinical colorectal cancer (CRC) samples were profiled utilizing CEER for RTKs, downstream signaling, and heterodimerization. Results: EGFR and downstream signaling proteins AKT, ERK, and RSK were potently inhibited by cetuximab or gefitinib at 24h of treatment in EGFR sensitive colorectal cancer cell line. At 24h of treatment, we observed approximately 2 folds increase in total HER2 and HER3 protein levels, 2.7 folds in phosphorylated HER3, and 5.4 folds in HER2:HER3 heterodimer formation. Concurrently, increased in ErbB heterodimer formation was accompanied by 5 folds increase in PI3K binding to HER3, resulting in enhanced HER3 signaling, with increase in AKT, ERK, and RSK. Co-treatment of these cells with cetuximab and HER2 inhibitor Trastuzumab or by treatment with lapatinib blocked the induction of HER2:HER3 heterodimer, HER3 phosphorylation, and PI3K binding to HER3. In 30% of the 200 clinical colorectal cancer samples profiled, we observed an increased in phosphorylated HER3, formation of HER2:HER3 and HER3:PI3K heterodimers along with HER1 activation (KRAS WT). Conclusions: Combination of HER2 inhibitor with an EGFR inhibitor could potentially increase the therapeutic index in cetuximab sensitive patients, and suppress activation of feedback mechanisms upon EGFR inhibition. Current findings suggest that CRC patients with similar profile would benefit from these combination therapies.

Background Approximately 8-15% of colorectal (CRC) patients carry an activating mutation in BRAF. This CRC subtype is associated with poor outcome and with resistance, both to chemotherapeutic treatments and to tailored drugs. We recently showed that BRAF (V600E) colon cancers (CCs) have a characteristic gene expression signature (1, 2) which is found also in subsets of KRAS mutant and KRAS-BRAF wild type (WT2) tumors. Tumors having this gene signature, referred as “BRAF-like," have a similar poor prognosis irrespective of the presence of the BRAF (V600E) mutation. By using a shRNA-based genetic screen in BRAF mutant CC cell lines we aimed to identify genes and pathways necessary for survival and growth of BRAF mutant CC. Such studies may reveal additional targets for therapy and potentially provide new biomarkers for patient stratification. Method We identified 363 genes that are selectively overexpressed in BRAF mutant tumors as compared to WT2 type tumors, based on gene expression profiles of the PETACC3 (1) and Agendia (1) datasets. The TRC human genome-wide shRNA collection (TRC-Hs1.0) was used to generate a 1815 hairpins sub-library targeting those identified genes (BRAF library). BRAF(V600E) CC cell lines were infected with the BRAF library and screened for shRNAs that cause lethality. LIM1215 CC cell line (WT2) was used as a control. Cells stably expressing the shRNA library were cultured for 13 days, after which shRNAs were recovered by PCR. Deep sequencing was applied to determine the specific depletion of shRNA in BRAF(V600E) cells as compared to LIM1215 cells. Results Candidate genes were identified by using following filtering criteria: depletion in BRAF(V600E) cells by at least 50% and depletion in BRAF(V600E) cells 1,5-fold higher than in control cells with the corresponding p-value to be ≤ 0.1. A total of 34 genes met our criteria of which 6 genes were presented with more than one hairpin and were concordant across the cell lines selected for validation. Conclusion We identified candidate synthetic lethal genes in BRAF mutant CC cell lines. Functional analysis is ongoing. Data will be presented. Citation Format: Loredana Vecchione, Valentina Gambino, Giovanni D'Ario, Tian Sun, Iris Simon, Vlad Popovici, Mauro Delorenzi, Rene’ Bernards, Sabine Tejpar. Identification of synthetic lethal interactions with the BRAF oncogene in colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1219. doi:10.1158/1538-7445.AM2013-1219

Background Protein tyrosine phosphatases (PTPs) are known to be responsible for the negative regulation of many receptor tyrosine kinases by serving as antagonists to tyrosine kinase signaling. Several PTPs have been identified as candidate regulators of EGFR phosphorylation such as PTP1B, RPTP-sigma, RPTP-kappa, and PTPRJ (DEP-1). Here, we focused on PTPRO, a member of R3 family. The Drosophila ortholog of this family, Ptp4E/Ptp10D, negatively regulates EGFR signalling. Gene expression analysis of 688 primary tumours led us to identify PTPRO as a gene with strongly reduced expression in colorectal cancers with poor prognosis in particular the ones belonging to the Braf mutant subgroup. This suggests that PTPRO could act as a tumour suppressor by negative regulation of EGFR in colorectal cancer. Material and methods HEK293 cells were transiently transfected with wild-type (WT) PTPRO and with its catalytic mutant (C/S) and stimulated with EGF. After cell lysis, extracts were analyzed by SDS-PAGE and probed by western blotting with an anti-phosphotyrosine antibody (pY99, 4G10). The total level of EGFR is detected with anti-EGFR antibody. EGFR phosphorylation antibody arrays are used to identify the specific tyrosine phosphorylation sites. Results and discussion Upon expression of the PTPRO (C/S) mutant, we observe a delay in EGF induced EGFR degradation. Our preliminary data suggests that PTPRO might play a role in EGFR trafficking through the endocytic pathway and its catalytic activity is required for efficient endocytic progression of EGFR. Ongoing experiments will answer to this question. WT-PTPRO over-expression specifically decreases the Tyr 845 phosphorylation of EGFR, a known Src family tyrosine kinase (SFK) phosphorylation site. SFKs also regulate receptor turnover both at the level of endocytosis and cbl-mediated ubiquitination by phosphorylation. However, underlying mechanism how PTPRO can modulate EGFR signalling through the regulation of endocytic machinery is not known yet. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1218. doi:1538-7445.AM2012-1218

Background Mortality is high in patients with esophageal carcinoma as tumors are rarely detected before the disease has progressed to an advanced stage. Here, we sought to isolate cell-free DNA released into the plasma of patients with esophageal carcinoma, to analyze copy number variations of marker genes in the search for early detection of tumor progression. Methods Plasma of 41 patients with esophageal carcinoma was prospectively collected before tumor resection and chemotherapy. Our dataset resulted heterogeneous for clinical data, resembling the characteristics of the tumor. DNA from the plasma was extracted to analyze copy number variations of the erbB2 gene using real-time PCR assays. Results The real-time PCR assays for erbB2 gene showed significant (P = 0.001) copy number variations in the plasma of patients with esophageal carcinoma, as compared to healthy controls with high sensitivity (80%) and specificity (95%). These variations in erbB2 were negatively correlated to the progression free survival of these patients (P = 0.03), and revealed a further risk category stratification of patients with low VEGF expression levels. Conclusion The copy number variation of erbB2 gene from plasma can be used as prognostic marker for early detection of patients at risk of worse clinical outcome in esophageal cancer.

Background Adjuvant chemoradiotherapy does not represent the standard of care in patients with resected high-risk gastric cancer; however, results from phase 2 and randomized trials suggest improvement in overall survival. We assessed the feasibility and toxic effects of chemoradiotherapy as adjuvant treatment in locally advanced gastric cancer. Design Pilot study. Setting University hospital. Patients Twenty-nine patients with T4N+ or any TN23 gastric cancer previously treated with potentially curative surgery were enrolled. All of the patients received combined adjuvant chemotherapy with FOLFOX-4 (ie, a combination of folinic acid [leucovorin], fluorouracil, and oxaliplatin [Eloxatin]) for 8 cycles and concomitant radiotherapy (45 Gy in 25 daily fractions over 5 weeks). Radiotherapy was begun after the first 2 cycles of FOLFOX-4, which was reduced by 25% during the period of concomitant radiotherapy. Main Outcome Measures Treatment toxic effects according to the National Cancer Institute–Common Toxicity Criteria classification, overall and disease-free survival rates, and identification of prognostic indicators. Results All of the patients completed treatment. Severe hematologic and gastrointestinal toxic effects occurred in 10% and 33%, respectively. No acute hepatic or renal toxic effects were observed; 1 patient experienced severe neurotoxicity. Disease-free and overall survival rates at 1, 2, and 3 years were 79%, 35%, and 35% and 85%, 62.6%, and 50.1%, respectively, and were shown to be substantially better than those observed in untreated patients. Long-term outcome was related to TNM stage, basal serum tumor marker level, and, particularly, lymph node ratio. Conclusion A multimodal approach with FOLFOX-4 and radiotherapy is feasible and effective for the treatment of patients with resected high-risk gastric cancer.

4546 Background: Preoperative CRT improves the survival of pts with EC when compared with surgery alone. Epidermal growth factor receptor (EGFR) is overexpressed in 30–90% of EC and is associated with poor prognosis, providing the rationale for using the anti-EGFR monoclonal antibody cetuximab (C). The purpose of the study was to investigate the efficacy, toxicity and feasibility of C with FOLFOX- 4 regimen as induction CT followed by C and RT in pts with LAEC in a multicenter setting. Methods: Eligibility criteria: resectable, locally advanced (uT3 or uN1, T4 if deemed resectable) squamous cell carcinoma (SCC) or adenocarcinoma (AC) of the esophagus; staged by EUS, CT and PET scan; age 18–70y; PS 2 and further weekly infusion at a maintenance dose of 250 mg/m2 and 4 cycles of FOLFOX-4 every two weeks. Post-induction EUS and CT scans were performed, while a PET scan was repeated early before second cycle of CT: pts without PD were given daily RT (180cGy fractions to 5040cGy) with concurrent weekly C. Post RT, EUS plus biopsies, CT scan and PET were performed. At wk 18, pts without PD had esophagectomy. Simons two stage design was used. Primary endpoint was histopathological response rate. Results: Up to December 2008, 40 pts, 30 men, were enrolled from 4 institutions; median age 59 y (35–70y); AC 12; SCC 28; stage II 15, stage III 25 pts. At this time 32/40 pts were evaluable. The most frequent grade 3/4 toxicity of chemoradiotherapy were skin (32%),neutropenia (29%) and esophagitis (9%); 10 pts had no resection (9 progressive disease,1 patient's refusal). Of 22 operated pts, 17 pts (77%) had RO-resection, 5 pts had palliative surgery.2 pts died due to complications after surgery (1 after > 30 days). The pathological response rate was 68 %, with a complete histopathological remission recorded in 6 pts (27%);17 pts (53%) are still alive without residual or recurrent disease. Conclusions: The current findings suggest the feasibility of incorporating cetuximab into a preoperative regimen for LAEC pts and an encouraging antineoplastic activity with 68% histopathological responders. No significant financial relationships to disclose.