Biomarker In Metastatic Colorectal Cancer Research Articles

Primary Tumor Sidedness as Prognostic and Predictive Biomarker in Metastatic Colorectal Cancer

Primary Tumor Sidedness as Prognostic and Predictive Biomarker in Metastatic Colorectal Cancer: Further Validation of a Potentially Practice-Changing Variable Kristen Ciombor;Richard Goldberg; JAMA Oncology

561P - CDX2 loss as a prognostic and predictive biomarker in metastatic colorectal cancer

561P - CDX2 loss as a prognostic and predictive biomarker in metastatic colorectal cancer

Lack of Caudal-Type Homeobox Transcription Factor 2 Expression as a Prognostic Biomarker in Metastatic Colorectal Cancer

BackgroundAlthough the lack of CDX2 expression has recently been proposed as a potential biomarker for a high risk of relapse in patients with stage II and III colon cancer after complete surgical resection, its prognostic role in metastatic colorectal cancer (CRC) remains unclear and warrants investigation. Materials and MethodsWe identified 145 patients treated at our institution from 2006 to 2016, including 66 patients with CDX2-negative metastatic CRC and a comparison cohort of 79 patients with CDX2-positive metastatic CRC. Overall survival (OS) and progression-free survival (PFS) for first-line systemic therapy were estimated using the Kaplan-Meier method. The associations of CDX2 expression with survival were evaluated using Cox proportional hazards regression models. ResultsThe prevalence of absent CDX2 expression in our cohort was 5.6%. Patients with CDX2-negative metastatic CRC were significantly more likely to be female, and to have right-sided primary tumors, poorly differentiated histologic features, and distant lymph node metastasis. The median OS for patients with CDX2-negative and -positive metastatic CRC was 8 and 39 months, respectively (hazard ratio [HR], 4.04; 95% confidence interval [CI], 2.49-6.54; P < .0001). After adjusting for covariates in a multivariate model, the association of a lack of CDX2 expression and OS remained statistically significant (HR, 4.52; 95% CI, 2.50-8.17; P < .0001). In addition, the median PFS (3 vs. 10 months; HR, 2.23; 95% CI, 1.52-3.27; P < .0001) for first-line chemotherapy was significantly decreased in patients with CDX2-negative metastatic CRC. ConclusionThe results of the present study show that a lack of CDX2 expression in metastatic CRC is an adverse prognostic feature and a potential negative predictor of the response to chemotherapy.

153P Novel, highly sensitive molecular biomarkers for metastatic colorectal cancer

153P Novel, highly sensitive molecular biomarkers for metastatic colorectal cancer

Identification of Novel Biomarkers for Metastatic Colorectal Cancer Using Angiogenesis-Antibody Array and Intracellular Signaling Array

Colorectal cancer (CRC) is one of the three leading causes for cancer mortality. CRC kills over 600,000 people annually worldwide. The most common cause of death from CRC is the metastasis to distant organs. However, biomarkers for CRC metastasis remain ill-defined. We compared primary and metastatic CRC cell lines for their angiogenesis-protein profiles and intracellular signaling profiles to identify novel biomarkers for CRC metastasis. To this end, we used primary and metastatic CRC cell lines as a model system and normal human colon cell line as a control. The angiogenesis profiles two isogenic CRC cell lines, SW480 and SW620, and HT-29 and T84 revealed that VEGF was upregulated in both SW620 and T84 whereas coagulation factor III, IGFBP-3, DPP IV, PDGF AA/AB, endothelin I and CXCL16 were downregulated specifically in metastatic cell lines. Furthermore, we found that TIMP-1, amphiregulin, endostatin, angiogenin were upregulated in SW620 whereas downregulated in T84. Angiogenin was downregulated in T84 and GM-CSF was also downregulated in SW620. To induce CRC cell metastasis, we treated cells with pro-inflammatory cytokine IL-6. Upon IL-6 treatment, epithelial-mesenchymal transition was induced in CRC cells. When DLD-1 and HT-29 cells were treated with IL-6; Akt, STAT3, AMPKα and Bad phosphorylation levels were increased. Interestingly, SW620 showed the same signal activation pattern with IL-6 treatment of HT-29 and DLD-1. Our data suggest that Akt, STAT3, AMPKα and Bad activation can be biomarkers for metastatic colorectal cancer. IL-6 treatment specifically reduced phosphorylation levels of EGFR, HER2 receptor, Insulin R and IGF-1R in receptor tyrosine kinase array study with HT-29. Taken together, we have identified novel biomarkers for metastatic CRC through the angiogenesis-antibody array and intracellular signaling array studies. Present study suggests that those novel biomarkers can be used as CRC prognosis biomarkers, and as potential targets for the metastatic CRC therapy.

Abstract 4842: Pharmacodynamic stratification of metastatic colorectal cancer patients using genomic datasets

Abstract Previously, the mutation status of KRAS was the only validated predictive biomarker for metastatic colorectal cancer (CRC). While KRAS mutated tumors demonstrated resistance to epidermal growth factor (EGFR) inhibitors like cetuximab, KRAS WT and EGFR-expressing tumors were predicted to be responsive. However, KRAS WT metastatic colorectal cancer (CRC) patients have a poor prognosis even with EGFR inhibitor therapy as not all KRAS WT CRCs are responsive to such targeted agents. A gene expression based RAS signature score was developed based on multiple tumor tissue samples to identify RAS activated tumors independent of mutations in the KRAS gene [1, 2]. To further refine this score and define technologies that can be used on FFPE samples isolated in a clinical setting, we analyzed DNA and RNA derived from fifty-five (55) FFPE preserved colorectal cancer tumor biopsies using multiple sequencing, digital and array-based technologies. These samples were selected from a CRC cohort in which the initial gene expression-based RAS signature score was calculated utilizing data compiled from fresh frozen (FF) tumor samples from the same 55 patients. The 55 samples were selected for this study as they had representative samples with high, medium and low RAS signature scores. Transcriptomic analyses (RNA-Seq, Affymetrix microarrays, Nanostring and Targeted RNA-Seq) were performed on all 55 FFPE samples and three new RAS scores were calculated from the gene expression datasets. These RAS scores were based on different gene signatures (1) an 18 gene signature (2) a 13 gene signature, and (3) a 147 gene signature. A significant correlation was identified between RAS scores calculated from the 18 and 13 gene signatures (Correlation coefficient ∼ 0.88 and ∼0.76 respectively, p-value &amp;lt; 0.0001). To further refine gene expression signatures, samples were grouped based upon their mutation status obtained by whole exome sequencing (WES) and targeted DNA sequencing data (Illumina TruSight and LifeTech Cancer Panels). In our sample set, the 18 gene RAS score was found to be dependent on the mutation status of KRAS. Further analysis is being carried out to better understand the relationship between the calculated RAS signature scores and the mutation status of other genes. This analysis will lead to the development of a novel genomic signature for better pharmacodynamic stratification of colorectal carcinoma patients. 1. Loboda A et al. A gene expression signature of RAS pathway dependence predicts response to PI3K and RAS pathway inhibitors and expands the population of RAS pathway activated tumors. 2. BMC Medical Genomics 2010, 3:26Dry JR et al. Transcriptional Pathway Signatures Predict MEK Addiction and Response to Selumetinib (AZD6244). Cancer Res. 2010 Mar 15;70(6):2264-73. Citation Format: Sharon Austin, Fang Yin Lo, Kellie Howard, Mollie McWhorter, Heather Collins, Amanda Leonti, Lindsey Maassel, Christopher Subia, Tuuli Saloranta, Nicole Heying, Leila Ritter, Kerry Deutsch, James Cox, Steven Anderson, Anup Madan, Timothy Yeatman. Pharmacodynamic stratification of metastatic colorectal cancer patients using genomic datasets. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4842. doi:10.1158/1538-7445.AM2015-4842

The prognostic significance of CXCL1 hypersecretion by human colorectal cancer epithelia and myofibroblasts.

BackgroundClinical therapy for metastatic colorectal cancer (CRC) remains limited, especially when the tumor harbors a KRAS mutation. This study aimed to identify prognostic biomarkers in CRC that are accessible for therapeutic inhibition.MethodsConditioned media from human CRC epithelial cells and myofibroblasts were screened by cytokine arrays for tumorigenic factors. The protein and mRNA expressions of these factors were determined by immunohistochemistry and gene microarrays in human CRC tissues. Prognostic biomarkers were determined by correlation of mRNA expression to overall survival in stage IV CRC patients. Inhibition of CXCL1 was performed with specific neutralizing antibody and lentiviral shRNAs. Malignant growth was assessed by soft agar growth assays and xenograft tumor growth in immunocompromised mice.ResultsCXCL1 was highly secreted by KRAS mutant human CRC cells and myofibroblasts in a complementary adaptive response to serum deprivation. Elevated CXCL1 level promoted anchorage-independent growth of murine fibroblasts and human CRC cells. Inhibition of CXCL1 by neutralizing antibody and specific shRNAs decreased CRC tumor growth. Highly elevated CXCL1 expression significantly correlated with decreased overall survival in stage IV CRC patients (hazard ratio 0.28; 95% CI 0.11–0.72).ConclusionsHigh CXCL1 expression is a poor prognostic biomarker in metastatic CRC. CXCL1 inhibition suppressed tumorigenic growth of KRAS mutant CRC cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-015-0555-4) contains supplementary material, which is available to authorized users.

Predictive serum biomarkers in metastatic colorectal cancer (mCRC) patients treated in the BECOX trial with oxaliplatin-capecitabine (CAPOX) plus bevacizumab (BVZ) (GEMCAD 09-01).

e14647 Background: Despite initial responsiveness, acquired resistance to both BVZ and chemotherapy in mCRC is universal. We have recently published that, chronically oxaliplatin resistant LoVo cel...

Prognostic value of biomarkers in metastatic colorectal cancer patients

BackgroundsThe prognostic value of biomarkers in metastatic colorectal cancer (mCRC) patients with liver metastases remains unclear. We assessed the difference of expression of biomarkers between primary tumors and liver metastases treated with chemotherapy in mCRC patients, as well as the prognostic value of these markers. MethodsForty-three mCRC patients with liver-limited disease from January 2007–November 2011 were analyzed. They all received resection of primary tumors followed by oxaliplatin-based chemotherapy. After chemotherapy, they all received hepatic resection. Forty-three paired primary and metastatic tumor specimens were collected to measure the messenger RNA expression of six biomarkers by the Danenberg tumor profile method (thymidylate synthase, dihydropyrimidine dehydrogenase [DPD], excision repair cross-complementing gene1, thymidine phosphorylase [TP], folylpolyglutamate synthase, and regenerating islet-derived family, member 4). ResultsThirty-six patients' messenger RNA was used for analysis. All markers showed similar expression between primary and metastatic sites. The low-expression group of Danenberg tumor profile and TP in the primary tumor showed significantly higher overall survival than the high-expression group (P < 0.001 and P = 0.033), but for DPD and TP in liver metastases, there were no significant differences of overall survival between the two groups. The ratios of marker expression in liver metastatic site to that in primary site of DPD and TP were significantly higher in chemo-responders than in non-chemo-responders (P = 0.034 and P = 0.022). ConclusionsBiomarkers' expressions in liver metastases were similar to those in the primary tumor. DPD and TP in the primary lesion may be a prognostic factor in chemotherapy-naïve mCRC patients with liver-limited disease, but those in liver tumor were not. Further validated analysis to our results would be warranted.

Abstract 2853: Epidermal growth factor receptor (EGFR) and prostaglandin-endoperoxide synthase 2 (PTGS2) are prognostic biomarkers for metastatic colorectal cancer

Abstract Background: Resection of colorectal cancer liver metastasis (CRCLM) with curative intent is beneficial in approximately 30% of cases, indicating the need for prognostic biomarkers to improve clinical management of CRCLM patients. Protein expression levels of epidermal growth factor receptor (EGFR) and prostaglandin-endoperoxide synthase 2 (PTGS2; also known as cyclooxygenase-2 or COX2) have been associated with carcinogenesis, metastases and survival. EGFR and PTGS2 are targets for molecular drugs and exhibit complex molecular interactions. Aim: We aimed to determine the prognostic value of EGFR and PTGS2 expression in CRCLM of patients who underwent liver resection. Patients and methods: Formalin-fixed paraffin-embedded CRCLM tissue and corresponding primary tumor specimens from a multi-institutional cohort of patients who underwent liver resection between 1990 and 2010 were incorporated into tissue microarrays (TMAs). TMAs were stained for EGFR and PTGS2 by immunohistochemistry and a hazard rate ratio (HRR) for the association between expression in CRCLM and overall survival (OS) was calculated. Results were validated by 500-fold cross-validation. Results: EGFR expression could be evaluated in 323 patients and PTGS2 expression in 351 patients. EGFR expression in CRCLM was associated with poor prognosis in both univariate analysis (average HRR 1.47; P=0.03) and multivariate analysis with standard clinicopathological prognostic variables (average HRR 1.54; P=0.02). PTGS2 expression was also associated with poor prognosis in both univariate (average HRR 1.63; P&amp;lt;0.01) and multivariate analysis (average HRR 1.59; P=0.01). Stratification for systemic therapy demonstrated prognostic value for EGFR and PTGS2 only in the subgroup of patients who were not treated (HRR 1.78; P&amp;lt;.01 and HRR 1.64; P=0.04, respectively), with worst prognosis when both EGFR and PTGS2 were highly expressed (HRR 3.08; P&amp;lt;.01). CRCLM expression of PTGS2 was concordant in 69.2% of matched primary tumors (P=0.02), while there was no such correlation for EGFR expression (P=0.51). Conclusion: EGFR and PTGS2 expression are prognostic molecular biomarkers with added value to standard clinicopathological variables for patients with CRCLM. Citation Format: Jeroen A.C.M. Goos, Annemieke C. Hiemstra, Veerle M.H. Coupé, Begoña Diosdado, Wendy Kooijman, Pien M. Delis-van Diemen, Cemile Karga, Jeroen A.M. Beliën, C. Willemien Menke-van der Houven van Oordt, Albert A. Geldof, Gerrit A. Meijer, Otto S. Hoekstra, Remond J.A. Fijneman. Epidermal growth factor receptor (EGFR) and prostaglandin-endoperoxide synthase 2 (PTGS2) are prognostic biomarkers for metastatic colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2853. doi:10.1158/1538-7445.AM2014-2853

Abstract 5507: Activation of a subset of growth factor-associated genes in cetuximab-sensitive colorectal cancer GEO cells with KRAS mutation

Abstract KRAS mutation has been widely used in the clinic as a predictive biomarker in metastatic colorectal cancer (mCRC) for insensitivity to the anti-EGFR antibody cetuximab (Erbitux). However recent clinical studies indicate that a subset of mCRC patients with mutated KRAS may still retain sensitive to the drug. Thus it is important to identify alternative signaling pathways that bypass the activated KRAS pathway and mediate cetuximab-induced tumor killing effects. The mCRC cell line GEO harbors mutated KRAS (G12A) but is one of the most sensitive cell lines to cetuximab. The underlying mechanisms by which KRAS-mutated cells remain responsive to EGFR inhibitors have not been explored. In the current study, we compared the expression of KRAS and EGFR in four CRC cells (GEO, LOVO, HT-29, Caco2) with varying KRAS status and evaluated the treatment effects of cetuximab in these models. Cell proliferation was detected by MTT assay. Drug effects in xenografts were assessed by monitoring tumor growth delay. At the molecular level, active K-Ras was detected by pull-down assay and EGFR-associated signaling pathways were determined by Western blotting. KRAS gene expression was tested by qPCR, and EGFR expression in tumor tissues was tested by immunohistochemical staining. Finally, GEO xenografted tumors with or without cetuximab treatment were processed for PCR array analysis to detect the gene expression of molecular components associated with growth factor (EGF, PDGF) signaling networks. In accordance with the sequencing information, we confirmed the constitutively active K-Ras in GEO cells compared to KRAS-wildtype counterparts. However, consistent with other studies, we found that of GEO cell proliferation and xenograft tumor growth were significantly inhibited by cetuximab, a phenotype similar to that in KRAS normal HT-29 but not observed in the KRAS mutated LOVO model. Further, cetuximab inhibited expression of p-Akt but not p-ERK, p-STAT3, p-Src and total EGFR. Interestingly, PCR arrays showed that a subset of genes was highly activated in cetuximab treated GEO tumors, including LTA, MAP2K7, MAPK10 and STAT1. These gene products have been previously implicated in growth arrest and apoptosis however their association with EGFR/K-Ras signaling remains unknown. Studies on examining the functional role of these candidate genes in mCRC cells in response to cetuximab are ongoing. These preliminary findings support further investigations to identify alternative molecular signatures as potential biomarkers that may predict cetuximab-mediated tumor response in a subset of mCRC cells that harbors KRAS mutation. Citation Format: Yao Dai, Dietmar Siemann, Wenyin Shi. Activation of a subset of growth factor-associated genes in cetuximab-sensitive colorectal cancer GEO cells with KRAS mutation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5507. doi:10.1158/1538-7445.AM2014-5507

Genetic variant in the down syndrome candidate region 1 (DSCR1) gene: A novel biomarker in metastatic colorectal cancer.

e14544 Background: Epidemiological studies have shown that Down’s syndrome individuals have a decreased risk of most solid tumors. The Down Syndrome Candidate Region 1 (DSCR1) gene is located in th...

Feasibility of proposed single-nucleotide polymorphisms as predictive markers for targeted regimens in metastatic colorectal cancer

Background:Surrogate biomarkers for metastatic colorectal cancer (mCRC) are urgently needed to achieve the best outcomes for targeted therapy.Methods:A clinical association analysis was performed to examine the three single-nucleotide polymorphisms (SNPs) that were previously proposed as markers of chemosensitivity to the cetuximab (124 patients) and bevacizumab regimens (100 patients) in mCRC patients. In addition, biological correlations were examined for the candidate SNPs in terms of their regulatory pathway.Results:For cetuximab regimens, patients homozygous for the wild-type alleles (GG) of LIFR rs3729740 exhibited a 1.9 times greater overall response rate (ORR) and 1.4 months longer progression-free survival (PFS) than those homozygous or heterozygous for the mutant allele (GA and AA; P=0.022 and 0.027, respectively). For bevacizumab regimens, patients homozygous for the minor alleles (TT) of ANXA11 rs1049550 exhibited an ORR twice as high as those homozygous or heterozygous for the ancestral allele (CC and CT; P=0.031). Overall response rate gain was achieved up to 10% in patients with wild-type LIFR rs3729740 patients either with wild-type KRAS or skin toxicity (P=0.001) respectively. Specifically in clones treated with cetuximab and bevacizumab regimens, active p-ERK and MMP-9 expressions were significantly reduced in clones expressing wild-type LIFR rs3729740 (P=0.044) and in those expressing minor-type ANXA11 rs1049550 (P=0.007), respectively.Conclusion:LIFR rs3729740 and possibly ANXA11 rs1049550 may be useful as biomarkers for predicting whether mCRC patients are sensitive to relevant target regimens, although further validation in large cohorts is needed.

Are Fragment C Gamma Receptor (FCGR) Germline Polymorphisms Predictive Biomarkers in Metastatic Colorectal Cancer?

The treatment of metastatic colorectal cancer has undergone significant improvements over the last decade with the introduction of molecularly targeted monoclonal antibodies (mAbs). Among these, cetuximab, a chimeric IgG1 antibody directed against the extracellular domain of EGFR, has demonstrated a survival benefit for KRAS wild type (WT) tumors. Even though KRAS genotyping has significantly refined patient selection allowing an increase in tumor radiological response from 25% of the whole metastatic colorectal cancer (MCRC) population to 45% of the KRAS-WT subset, still for a significant proportion of patients anti-EGFR mAbs will be ineffective, thus resulting in unnecessary toxicity and cost. Polymorphisms of Fragment C gamma receptor (FCGR) gene have the potential for being used as predictive biomarkers of cetuximab activity since part of this drug’s tumoricidal effect is immune-mediated via FcγR-triggered ADCC (antibody-dependent cellular cytotoxicity). The aim of the present review is to summarize available data on the predictive/prognostic value of FCGR polymorphisms for cetuximab-treated MCRC patients and to discuss possible future directions in this area of research.

1173P - A Highly Sensitive Immunohistochemical Assay to Detect Braf V600E Mutations in Patients with Colorectal Cancer

ABSTRACT Background The BRAF V600E mutation is a well-validated negative prognostic biomarker in metastatic colorectal cancer (mCRC), and is a highly attractive drug target. Barriers to the development of agents targeting BRAF V600E in mCRC are the low rate of mutations (approximately 10%) and reliance on to sequencing-based technologies, which are not routinely available outside of large cancer centres. A simple immunohistochemistry (IHC) test, more suited to routine pathology practice, would provide much broader access to patient (pt) identification, and would also enable studies of tumor heterogeneity. Aims: To validate an IHC-based method of detecting the BRAF V600E mutation in a large cohort of community-based CRC patients. Methods Tissue microarrays, comprising matched normal and tumor paraffin embedded tissue samples obtained from colectomy specimens from a community cohort of 505 pts with stage I–IV CRC, were tested with 2 antibodies (Ab): pBR for total BRAF and VE1 for BRAF V600E, using the Ventana UltraView and OptiView kits, respectively. IHC was assessed independently by 2 blinded pathologists, and results compared to BRAF V600E status determined by Sanger sequencing (SS). pBR negative samples were considered non - evaluable. Nine discordant cases were re-tested with a BRAF V600E SNaPshot assay. Results Demographic features were evenly matched. SS was evaluable in 504/505; IHC in 477/505; with both evaluable in 476/505 pts. 56/476 (11.8%) pts had V600E mutations detected by SS, 65/476 (13.7%) by IHC. The positive predictive value was 84.6% (55/65). 1 pt was negative by IHC and positive on SS and SNaPshot; resulting in a negative predictive value of 99.8% (410/411 cases). There was 100% concordance between SS and SNaPshot. Further validation is ongoing, and outcome data will be available at the time of presentation. Conclusions We have conducted a comprehensive analytical and clinical validation and feasibility analysis of an IHC-based method to detect the BRAF V600E mutation in a large community-based population of pts with CRC. Shown to be highly sensitive, we are planning to adopt this approach as our initial screening step in an upcoming prospective combination trial targeting BRAF V600E in pts with mCRC. Disclosure J. Desai: Research Support: Roche, Ventana Medical Systems, A. Muranyi: Employee: Ventana Medical Systems, K. Shanmugam: Employee and Shareholder, Ventana Medical Systems, T. Grogan: Shareholder and Chief Scientific Officer, Ventana Medical Systems, P. Gibbs: Research Support, Ventana Medical Systems, P. Waring: Research Support: Ventana Medical Systems, All other authors have declared no conflicts of interest.

Finding a New Prognostic Biomarker for Metastatic Colorectal Cancer

See Article on Page 315-320 For detecting new biomarkers in colorectal cancer, whether they are prognostic or predictive, we should understand the mechanism of the metastatic process at the gene expression level. This article presents a new prognostic biomarker, 'placental growth factor (PlGF)' to the clinical field. PlGF, which is a member of the vascular endothelial growth factor (VEGF) family in conjunction with VEGF-A and VEGF-B, is a ligand for VEGF receptor-1, which is expressed on endothelial cells, monocytes/macrophages, and some tumor cells. PlGF was isolated in 1991 from the placenta and was found only in very low levels under physiological conditions, but it was up-regulated in pathological circumstances such as wound healing, ischemia and tumor growth [1]. PlGF up-regulation has been found in human meningiomas, hemangioblastomas, melanomas, and cervical squamous cell carcinomas and is associated with angiogenesis in renal cell carcinomas. On the contrary, PlGF is down-regulated in thyroid carcinomas, germ cell tumors and cervical adenocarcinomas. Chen et al. [2] reported that PlGF was significantly up-regulated in gastric cancer tissue and was significantly correlated with microvessel density-evaluated angiogenesis and tumor stage. In this research, the authors found that the PlGF protein expression level in colorectal cancer tissue was significantly correlated with microvessel density, overall patient survival, and clinicopathological factors such as lymph-node metastasis, tumor stage, and lymphovascular invasion. According to the authors, PlGF seems to be an independent surrogate prognostic factor for colorectal cancer progression. However, for these results to be adopted in the clinical filed, it is very important that a large-sample-size study be brought conducted in a validation setting. The findings of this research finding suggest that PlGF may constitute a novel approach to colorectal cancer treatment. Several agents against PlGF have already developed or are currently under development. Among these agents, two novel agents against PlGF will be briefly discussed. Firstly, aflibercept (ZALTRAP) is a recombinant fusion protein that acts as a soluble receptor that binds to VEGF-A, VEGF-B and PIGF. In April 2011, Van Cutsem et al. [3] reported that aflibercept improved the primary endpoint of overall survival in the Velour phase III clinical trial for second-line treatment for metastatic colorectal cancer. Secondly, the humanized anti-PlGF mAb (TB-403) is directed against PlGF. A trial with TB-403 has only completed its first phase. Antitumor activity has been demonstrated with TB-403 in human tumor xenograft models of renal cell carcinomas and hepatocellular carcinomas. The mechanism of action for TB-403 is currently under investigation; preclinical studies suggest its effects may include blocking tumor angiogenesis and primary tumor growth, as well as inhibition of metastasis. In addition, PIGF inhibition may complement and potentiate the antitumor effects of VEGF inhibition, in part by inhibiting macrophage recruitment [4].

Correlation of Circulating Angiogenic Factors with Circulating Tumor Cells and Disease Recurrence in Patients Undergoing Curative Resection for Colorectal Liver Metastases

Circulating angiogenic factors (CAF) have been shown as therapeutic targets and prognostic biomarkers in metastatic colorectal cancer. However, their correlation with circulating tumor cells (CTC) is unknown, as is their role as prognostic biomarkers in patients amenable for curative resection. Preoperative blood samples were collected in patients undergoing potentially curative resection of colorectal liver metastases. Serum levels of eight CAF and CTC were analyzed by using ELISA and CK20 RT-PCR, respectively. Prognostic factors were identified by a Cox proportional hazards model. A total of 107 patients were eligible for final analyses. Circulating levels of PlGF, EGF, and bFGF were increased, whereas PDGF-A and Ang-1 levels were decreased in patients compared with healthy control subjects. CTC were detected in 36 of 63 patients (57%) and were associated with significantly lower levels of EGF and bFGF. On univariate analyses, multiple metastases (p = 0.04), a MSKCC risk score >2 (p = 0.004), and detection of CTC (p = 0.05) were associated with disease recurrence. Multivariate analysis, including the panel of eight CAF, revealed a MSKCC score >2 [hazard ratio (HR), 2.01; 95% confidence interval (CI), 1.11-3.82; p = 0.02] and low levels of circulating PlGF (HR, 0.26; 95% CI, 0.08-0.81; p = 0.02) as independent predictors of poor recurrence-free survival. CAF may indicate patients who are at high risk for disease recurrence. The notion that CAF may identify patients who benefit from adjuvant therapy or antiangiogenic agents warrants further investigation.

Abstract 5217: MMP9 is a prognostic biomarker for metastatic colorectal cancer

Abstract Background: Worldwide almost 700000 patients are diagnosed with colorectal cancer (CRC) each year. Of these patients more than 45% die as a consequence of metastases, of which the majority is located in the liver. Although patient selection for hepatectomy by 18FDG PET has significantly reduced futile surgery (Ruers, J Nucl Med 2009), 70% of all operated patients still die of metastases within 5 years after hepatic resection. To improve prediction of patient outcome, novel PET tracers with better prognostic value are needed. Matrix metalloproteinases, frequently associated with reduced survival in several types of cancer, might serve as prognostic biomarkers that can be used in PET imaging. Aim: To investigate the prognostic value of MMP9 expression in colon cancer liver metastases. Methods: Formalin-fixed paraffin-embedded colon cancer liver metastases, collected from 85 patients having had curative hepatectomy between 1990 and 2009, were incorporated into tissue microarrays (TMAs). MMP9 expression in both epithelial and stromal cells was assessed by immunohistochemistry and expression was correlated to patient survival data. Survival analysis was performed using a log rank test. Results: Mean age of the colon cancer patients (62.1% males, 37.9% females) was 62.0 (standard deviation 10.5). Chemotherapy was received by 45.9% (15.3% neoadjuvant, 14.1% adjuvant, 16.5% palliative) and radiofrequency ablation (RFA) was performed in 10.8%. Median overall survival was 35.0 months (standard deviation 5.7). High expression of MMP9 by epithelial colon cancer cells within the liver metastases was associated with increased survival rates (p=0.007 for disease-free survival and p=0.056 for overall survival). MMP9 expression in stromal cells was not associated with patient survival. Discussion and conclusion: Our results suggest that elevated levels of MMP9 in metastatic epithelial colon cancer cells are indicative of a good prognosis. Whether MMP9 qualifies as a target with prognostic relevance for imaging of lesions in patients with metastatic colorectal cancer remains to be determined. This research was supported by the Center for Translational Molecular Medicine (DeCoDe project). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5217. doi:10.1158/1538-7445.AM2011-5217

Hypertension and overall survival in metastatic colorectal cancer patients treated with bevacizumab-containing chemotherapy

Background:Hypertension (HTN) is a common toxicity of anti-VEGF (vascular endothelial growth factor) antibody treatment. It may be a marker of VEGF signalling pathway inhibition and therefore represent a cancer biomarker in metastatic colorectal cancer (mCRC) patients treated with chemotherapy and bevacizumab.Methods:A total of 101 consecutive patients with mCRC were treated with standard chemotherapy combined with bevacizumab at dose of 2.5 mg kg−1 per week in a single centre. The median follow-up time of the patients alive was 64 months. Blood pressure was measured before each bevacizumab infusion, and HTN was graded according to common toxicity criteria for adverse events version 3.0.Results:Overall, 57 patients (56%) developed ⩾grade 1 HTN (median blood pressure 168/97 mm Hg), whereas 44 (44%) remained normotensive when treated with bevacizumab-containing chemotherapy regimen. Overall response rate was higher among patients with HTN (30 vs 20% P=0.025). Hypertension was associated with improved progression-free survival (10.5 vs 5.3 months; P=0.008) and overall survival (25.8 vs 11.7 months; P<0.001), and development of HTN within 3 months had an independent, prognostic influence in a multivariate landmark survival analysis together with other known mCRC prognostic factors (P=0.007). There was no association between HTN and development of thromboembolic complications.Conclusion:Hypertension may predict outcome of bevacizumab-containing chemotherapy in mCRC. These data require confirmation in prospective studies including pharmacodynamic and pharmacokinetic analyses.

18f-fluorodeoxyglucose-positron emission tomography (FDG-PET) as a predictive biomarker in metastatic colorectal cancer (mCRC).

e14120 Background:Information on the prognostic and predictive role of FDG-PET in the management of patients (pts) with mCRC is limited. The growing complexity of current therapies and the increasing number of agents to be tested in this disease warrants better understanding of the role of FDG-PET in earlier treatment decisions. Methods: Consecutive pts with 2 or more serial FDG-PET scans at baseline and during the treatment course were studied. Tumor standardized uptake value (SUV) and its percentage change (%DSUV) were each studied for their potential association with time to progression (TTP) via univariate Cox models to estimate the hazard ratio (HR) for progression. Results: 31 pts (median age 58.4 yrs) with mCRC were studied. 87% of pts were treated in the first line setting. 48% had received prior adjuvant therapy. 61%, 22% and 13% received oxaliplatin based, irinotecan based, and fluropyrimidine only regimens, respectively. 84% received concurrent bevacizumab. Median pretreatment SUV was 9.0 (range 1.7-46.0); median post treatment SUV was 4.0 (range 0 - 13.5); median %DSUV was -70.7 (range -10% to -100%). Median interval between scans was 3.0 months. 9 (29%) patients had no tumor uptake on post treatment scans. 55% and 39% of pts had partial response and stable disease (RECIST criteria), respectively. Median TTP was 11.9 months (90% CI: 9.9–13.7 mos), with a median follow-up time for progression of 15.4 months. The HRs for baseline SUV and %DSUV were 1.009 (90% CI: 0.978–1.040, p = 0.635) and 1.014 (90% CI: 1.002–1.026, p = 0.049), respectively. Among the 20 pts with inter-scan interval < 4 months, the median TTP of pts with posttreatment SUV = 0 was 9.7 months vs. 6.6 months for pts with post-treatment SUV > 0. TTP duration did not differ significantly (p = 0.085). Conclusions: Systemic therapy substantially decreased the SUV on follow up PET scans in pts treated for mCRC. However, no significant association was seen between either baseline SUV or %DSUV and TTP. Further work is needed to optimize and standardize evaluation of tumor response in mCRC patients with FDG- PET. No significant financial relationships to disclose.