Primary Colon Carcinoma Research Articles

Penile metastasis of sigmoid colon carcinoma: a rare case report

BackgroundMetastasis to penis usually arises from genitourinary organs, but in rare cases, metastasis comes from the sigmoid colon. Furthermore, very few cases of penile metastasis of primary sigmoid colon carcinoma have been reported.Case presentationWe described a case of a 53-year-old man with penile metastasis of sigmoid colon carcinoma along with a review of the literature. Physical examination revealed two subcutaneous nodules on the glans penis. Biopsy of the nodules showed that penile metastasis of sigmoid colon carcinoma.ConclusionMetastasis of sigmoid colon carcinoma to the penis is extremely rare, which presents an advanced form of sigmoid colon carcinoma, therefore survival is extremely shortened. Although treatment of penile metastasis is almost always palliative, it is important to recognize this unusual manifestation so that timely appropriate treatment can be initiated. Early recognition may enhance survival rate of these patients.

Inter- and intra-tumor profiling of multi-regional colon cancer and metastasis

Intra- and inter-tumor heterogeneity may hinder personalized molecular-target treatment that depends on the somatic mutation profiles. We performed mutation profiling of formalin-fixed paraffin embedded tumors of multi-regional colon cancer and characterized the consequences of intra- and inter-tumor heterogeneity and metastasis using targeted re-sequencing.We performed targeted re-sequencing on multiple spatially separated samples obtained from multi-regional primary colon carcinoma and associated metastatic sites in two patients using next-generation sequencing. In Patient 1 with four primary tumors (P1-1, P1-2, P1-3, and P1-4) and one liver metastasis (H1), mutually exclusive pattern of mutations was observed in four primary tumors. Mutations in primary tumors were identified in three regions; KARS (G13D) and APC (R876*) in P1-2, TP53 (A161S) in P1-3, and KRAS (G12D), PIK3CA (Q546R), and ERBB4 (T272A) in P1-4. Similar combinatorial mutations were observed between P1-4 and H1. The ERBB4 (T272A) mutation observed in P1-4, however, disappeared in H1. In Patient 2 with two primary tumors (P2-1 and P2-2) and one liver metastasis (H2), mutually exclusive pattern of mutations were observed in two primary tumors. We identified mutations; KRAS (G12V), SMAD4 (N129K, R445*, and G508D), TP53 (R175H), and FGFR3 (R805W) in P2-1, and NRAS (Q61K) and FBXW7 (R425C) in P2-2. Similar combinatorial mutations were observed between P2-1 and H2. The SMAD4 (N129K and G508D) mutations observed in P2-1, however, were nor detected in H2. These results suggested that different clones existed in primary tumors and metastatic tumor in Patient 1 and 2 likely originated from P1-4 and P2-1, respectively.In conclusion, we detected the muti-clonalities between intra- and inter-tumors based on mutational profiling in multi-regional colon cancer using next-generation sequencing. Primary region from which metastasis originated could be speculated by mutation profile. Characterization of inter- and inter-tumor heterogeneity can lead to underestimation of the tumor genomics landscape and treatment strategy of personal medicine.

Mechanisms of Immune Signaling in Colitis-Associated Cancer

The inflammatory bowel diseases ulcerative colitis and Crohn’s disease are associated with an increased risk for the development of colorectal cancer. During recent years, several immune signaling pathways have been linked to colitis-associated cancer (CAC), largely owing to the availability of suitable preclinical models. Among these, chronic intestinal inflammation has been shown to support tumor initiation through oxidative stress–induced mutations. A proinflammatory microenvironment that develops, possibly as a result of defective intestinal barrier function and host–microbial interactions, enables tumor promotion. Several molecular pathways such as tumor necrosis factor/nuclear factor-κB or interleukin 6/signal transducer and activator of transcription 3 signaling have been identified as important contributors to CAC development and could be promising therapeutic targets for the prevention and treatment of CAC.

Human breast cancer and lymph node metastases express Gb3 and can be targeted by STxB-vectorized chemotherapeutic compounds.

BackgroundThe B-subunit of Shiga toxin (STxB) specifically binds to the glycosphingolipid Gb3 that is highly expressed on a number of human tumors and has been shown to target tumor cells in mouse models and ex vivo on primary colon carcinoma specimen.MethodsUsing a novel ex vivo STxB labeling (ESL) method we studied Gb3 expression in cytological specimens of primary human breast tumors from 107 patients, and in synchronous lymph node metastases from 20 patients. Fluorescent STxB was incubated with fine-needle aspiration (FNA) specimens, and Gb3 expression was evaluated by fluorescence microscopy. Furthermore, 11 patient-derived human breast cancer xenografts (HBCx) were evaluated for expression of Gb3 by ESL and FACS. In addition, the biodistribution of fluorescent STxB conjugate was studied after intravenous injection in a Gb3 positive HBCx model.ResultsGb3 expression was detected in 62 of 107 patients (57.9%), mainly in epithelial tumor cells. Gb3 positivity correlated with estrogen receptor expression (p ≤ 0.01), whereas absence of Gb3 expression in primary tumors was correlated with the presence of lymph node metastases (p ≤ 0.03). 65% of lymph node metastases were Gb3 positive and in 40% of tested patients, we observed a statistically significant increase of metastatic Gb3 expression (p ≤ 0.04). Using concordant ESL and flow cytometry analysis, 6 out of 11 HBCx samples were scored positive. Intravenous injections of fluorescent STxB into HBC xenografted mice showed preferential STxB accumulation in epithelial cells and cells with endothelial morphology of the tumor.ConclusionThe enhanced expression of Gb3 in primary breast carcinomas and its lymph node metastases indicate that the development of STxB-based therapeutic strategies is of interest in this pathology. Gb3 expressing HBCx can be used as a model for preclinical studies with STxB conjugates. Finally, the ESL technique on FNA represents a rapid and cost effective method for the stratification of patients in future clinical trials.

Synchronous primary colonic and early gallbladder carcinomas: report of a rare case

The incidence of multiple primary malignant tumors in the same individual is increasing worldwide. We report a case of a 30 years old female with an adenocarcinoma of the colon in whom a high grade dysplasia/carcinoma in situ of the gallbladder was incidentally discovered in the cholecystectomy specimen resected with the colon for multiple gall stones. Synchronous adenocarcinomas of the colon and the gallbladder are extremely rare with only seven cases reported so far. The link between the colonic and the gall bladder carcinoma may reside in the presence of gall stones rather than a hereditary predisposition to cancer development as may be suggested by a negative family history for colorectal and gallbladder cancers. Because the colon is the organ that is most frequently involved in the setting of multiple primary malignant tumors, thorough preoperative screening and follow up for other cancers, including gallbladder cancer, is recommended for patients presenting with colorectal carcinoma.

Extracellular matrix signatures of human primary metastatic colon cancers and their metastases to liver.

BackgroundColorectal cancer is the third most frequently diagnosed cancer and the third cause of cancer deaths in the United States. Despite the fact that tumor cell-intrinsic mechanisms controlling colorectal carcinogenesis have been identified, novel prognostic and diagnostic tools as well as novel therapeutic strategies are still needed to monitor and target colon cancer progression. We and others have previously shown, using mouse models, that the extracellular matrix (ECM), a major component of the tumor microenvironment, is an important contributor to tumor progression. In order to identify candidate biomarkers, we sought to define ECM signatures of metastatic colorectal cancers and their metastases to the liver.MethodsWe have used enrichment of extracellular matrix (ECM) from human patient samples and proteomics to define the ECM composition of primary colon carcinomas and their metastases to liver in comparison with normal colon and liver samples.ResultsWe show that robust signatures of ECM proteins characteristic of each tissue, normal and malignant, can be defined using relatively small samples from small numbers of patients. Comparisons with gene expression data from larger cohorts of patients confirm the association of subsets of the proteins identified by proteomic analysis with tumor progression and metastasis.ConclusionsThe ECM protein signatures of metastatic primary colon carcinomas and metastases to liver defined in this study, offer promise for development of diagnostic and prognostic signatures of metastatic potential of colon tumors. The ECM proteins defined here represent candidate serological or tissue biomarkers and potential targets for imaging of occult metastases and residual or recurrent tumors and conceivably for therapies. Furthermore, the methods described here can be applied to other tumor types and can be used to investigate other questions such as the role of ECM in resistance to therapy.

Specificity of lectin-immobilized fluorescent nanospheres for colorectal tumors in a mouse model which better resembles the clinical disease.

We have been investigating an imaging agent that enables real-time and accurate diagnosis of early colorectal cancer at the intestinal mucosa by colonoscopy. The imaging agent is peanut agglutinin-immobilized polystyrene nanospheres with surface poly(N-vinylacetamide) chains encapsulating coumarin 6. Intracolonically-administered lectin-immobilized fluorescent nanospheres detect tumor-derived changes through molecular recognition of lectin for the terminal sugar of cancer-specific antigens on the mucosal surface. The focus of the present study was to evaluate imaging abilities of the nanospheres in animal models that reflect clinical environments. We previously developed an orthotopic mouse model with human colorectal tumors growing on the mucosa of the descending colon to better resemble the clinical disease. The entire colon of the mice in the exposed abdomen was monitored in real time with an in vivo imaging apparatus. Fluorescence from the nanospheres was observed along the entire descending colon after intracolonical administration from the anus. When the luminal side of the colon was washed with phosphate-buffered saline, most of the nanospheres were flushed. However, fluorescence persisted in areas where cancer cells were implanted. Histological evaluation demonstrated that tumors were present in the mucosal epithelia where the nanospheres fluoresced. In contrast, no fluorescence was observed when control mice, without tumors were tested. The lectin-immobilized fluorescent nanospheres were tumor-specific and remained bound to tumors even after vigorous washing. The nanospheres nonspecifically bound to normal mucosa were easily removed through mild washing. These results indicate that the nanospheres combined with colonoscopy, will be a clinically-valuable diagnostic tool for early-stage primary colon carcinoma.

Expression analysis of heat shock protein 90 (HSP90) and Her2 in colon carcinoma.

The molecular chaperone heat shock protein 90 (HSP90) plays an important role in several types of tumors also participating in the modulation of the activity of receptor tyrosine kinases activity such as members of the Her family. We evaluated the significance of HSP90 and Her2 expression in colon cancer. HSP90 and Her2 expression was determined by immunohistochemistry and by fluorescence in situ hybridization (FISH) on 355 primary resected colon carcinomas. Results were correlated with pathologic features (Union for International Cancer Control (UICC) pTNM category, tumor localisation, tumor differentiation), additional molecular genetic characteristics (BRAF, KRAS mutational status, mismatch repair genes (MMR)), and survival. HSP90 immunoreactivity was observed in various degrees. Fifty-one cases (14 %) were positive for Her2 (score 2+ and 3+) with 16/43 cases with Her2 2+ staining pattern showing amplification of Her2 determined by FISH. There was a significant correlation between high HSP90 expression and Her2 overexpression (p = 0.011). High HSP90 expression was associated with earlier tumor stages (p = 0.019), absence of lymph node (p = 0.006), and absence of distant metastases (p = 0.001). Patients with high tumoral HSP90 levels had a better survival (p = 0.032), but this was not independent from other prognostic relevant pathologic parameters. Her2 expression was not associated with any of the investigated histopathological, molecular, or clinical parameters. High HSP90 levels are reflecting lower malignant potential in colon cancer. Her2 positivity can be observed in a small number of cases. Targeting HSP90 and/or Her2 may be an alternative therapeutic approach in colon cancer in a subset of patients.

Elective laparoscopic surgery for sigmoid colon carcinoma incarcerated within an inguinal hernia: report of a case

Primary colon carcinoma within an inguinal hernia sac is very rare and most reported cases were found at emergency open surgery for an incarcerated hernia. We report a case of incarcerated sigmoid colon carcinoma diagnosed preoperatively and treated with elective laparoscopic surgery. A 67-year-old man with a 2-year history of swelling of the scrotum and a breast lump was referred to us for surgical treatment of an irreducible left inguinal hernia and a right breast tumor. Blood examination results showed severe anemia. Computed tomography scan and endoscopic biopsy confirmed sigmoid colon carcinoma incarcerated in the left inguinal hernia. Thus, we performed definitive laparoscopic sigmoidectomy and conventional hernia repair for preoperatively diagnosed sigmoid colon carcinoma within an inguinal hernia.

Expression of aldehyde dehydrogenase 1 in colon cancer

ObjectiveTo study the expression of ALDH1 in colon cancer and its clinical significance. MethodsThe expression of ALDH1 was examined in 98 surgical specimens of primary colonic carcinoma and 15 normal colon tissues with immunohistochemistry method. The correlations of the expression with clinicopathological parameters and prognosis of colon cancer were analyzed. ResultsThe positive rate of expression of ALDH1 was 76.5% (75/98) in the cancer tissues and 13.3% (2/15) in normal colon tissues. There were an obvious statistical difference (P<0.05) between the two groups. The ALDH1 expression was significantly correlated with the histological grade, TNM stages and lymph node metastasis in colon cancer (P<0.05). It was also related with patients' survival time, those with positive expressions had a poor prognosis (P<0.05). ConclusionsThe results suggeste that the overexpression of ALDH1 plays important roles in proliferation and progression in colon cancer, the ALDH1 may be a valuable marker to predict the biological behavior and trend of metastasis of colon cancer.

Detection of the BRAFV600E protein in human colon carcinomas by a mutation-specific antibody.

3576 Background: BRAF encodes a serine-threonine kinase that is a downstream effector of activated RAS. A point mutation (V600E) in BRAF occurs in a subset of colorectal cancers (CRCs) and is associated with adverse outcome and may predict non response to anti-EGFR antibodies. Detection of a BRAFV600E mutation in a CRC with microsatellite instability indicates a sporadic origin and excludes Lynch Syndrome. While BRAFV600E mutation status is determined using a DNA-based assay, antibodies against the BRAFV600E protein have recently been developed. We examined mutant BRAFV600E protein expression and its concordance with mutation status. Methods: Primary stage III colon carcinomas (50 BRAFV600E mutation carriers and 25 wild-type cases) were studied from a completed phase III adjuvant trial comparing FOLFOX +/- cetuximab (NCCTG N0147). In archival resection specimens, immunohistochemistry (IHC) was performed using a pan-BRAF antibody and a V600E mutation-specific antibody raised against an immunogenic synthetic peptide derived from the internal region of the BRAFV600E protein. BRAFV600E mutations in codon 15 were analyzed in extracted DNA using a multiplex, allele specific PCR–based assay. BRAF staining was scored independently by two pathologists blinded to mutation status. Results: In primary colon carcinomas stained with a pan-BRAF antibody, diffuse cytoplasmic staining for BRAF proteins was detected in 74 of 75 carcinomas with one case deemed non-evaluable. Using the mutation-specific BRAFV600E antibody, diffuse cytoplasmic staining was detected in 49 of 74 tumors without appreciable heterogeneity of expression. Among these 49 tumors expressing mutant BRAFV600E proteins, all (100%) were found to carry a BRAFV600E mutation according to a DNA-based assay. In contrast, absent BRAFV600E staining was observed in all 25 tumors that were found to have wild-type copies of BRAFV600E detected using a PCR-based assay. Conclusions: For the detection of mutant BRAFV600E, complete concordance was found between IHC and a DNA-based method in colon carcinomas. This finding supports the use of IHC as a simplified strategy to screen CRCs for mutant BRAFV600E proteins in routine clinical practice to inform clinical decision-making.

Expression of homeobox B7 gene in colon carcinoma and its clinicopathological significance

Objective To explore the expression of the homeobox B7 (HOXB7) protein in colon carcinoma and its clinicopathological significance.Methods HOXB7 protein expression was detected by using immunohistochemistry in 73 samples of primary colon carcinoma and adjacent normal mucosa.Results The expression of HOXB7 was higher in colon carcinoma than in the adjacent normal colonic mucosa,and upregulation of HOXB7 protein was significantly correlated with T stage (P ＜ 0.01),AJCC stage (P ＜0.01),distant metastasis (P ＜ 0.05) and proliferating cell nuclear antigen (Ki-67) index (P ＜ 0.01).Conclusion Overexpression of HOXB7 may be an important molecular event in the progression of colon tumorigenesis. Key words: Homeobox B7; Colon cancer; Immunohistochemistry

Differential Roles of Hath1, MUC2 and P27Kip1 in Relation with Gamma-Secretase Inhibition in Human Colonic Carcinomas: A Translational Study

Hath1, a bHLH transcription factor negatively regulated by the γ-secretase-dependent Notch pathway, is required for intestinal secretory cell differentiation. Our aim was fourfold: 1) determine whether Hath1 is able to alter the phenotype of colon cancer cells that are committed to a differentiated phenotype, 2) determine whether the Hath1-dependent alteration of differentiation is coupled to a restriction of anchorage-dependent growth, 3) decipher the respective roles of three putative tumor suppressor genes Hath1, MUC2 and P27kip1 in this coupling and, 4) examine how our findings translate to primary tumors. Human colon carcinoma cell lines that differentiate along a mucin secreting (MUC2/MUC5AC) and/or enterocytic (DPPIV) lineages were maintained on inserts with or without a γ-secretase inhibitor (DBZ). Then the cells were detached and their ability to survive/proliferate in the absence of substratum was assessed. γ-secretase inhibition led to a Hath1-mediated preferential induction of MUC2 over MUC5AC, without DPPIV modification, in association with a decrease in anchorage-independent growth. While P27kip1 silencing relieved the cells from the Hath1-induced decrease of anchorage-independent growth, MUC2 silencing did not modify this parameter. Hath1 ectopic expression in the Hath1 negative enterocytic Caco2 cells led to a decreased anchorage-independent growth in a P27kip1-independent manner. In cultured primary human colon carcinomas, Hath1 was up-regulated in 7 out of 10 tumors upon DBZ treatment. Parallel MUC2 up-regulation occurred in 4 (4/7) and P27kip1 in only 2 (2/7) tumors. Interestingly, the response patterns of primary tumors to DBZ fitted with the hierarchical model of divergent signalling derived from our findings on cell lines.

Heterogeneity between primary colon carcinoma and paired lymphatic and hepatic metastases

Heterogeneity is one of the recognized characteristics of human tumors, and occurs on multiple levels in a wide range of tumors. A number of studies have focused on the heterogeneity found in primary tumors and related metastases with the consideration that the evaluation of metastatic rather than primary sites could be of clinical relevance. Numerous studies have demonstrated particularly high rates of heterogeneity between primary colorectal tumors and their paired lymphatic and hepatic metastases. It has also been proposed that the heterogeneity between primary colon carcinomas and their paired lymphatic and hepatic metastases may result in different responses to anticancer therapies. The heterogeneity in primary colon carcinoma and corresponding metastases by genome‑wide gene expression analysis has not been extensively studied. In the present study, we investigated the differentially expressed genes between a primary colon carcinoma specimen (obtained from a 40-year-old female colon carcinoma patient with lymphatic and hepatic metastases) and its paired lymphatic and hepatic metastases by genome-wide gene expression analysis using GeneChip HGU133Plus2.0 expression arrays. Our results demonstrate that genome-wide gene expression varies between primary colon carcinoma and its paired lymphatic and hepatic metastases.

Antitumor effects of FP3 in combination with capecitabine on PDTT xenograft models of primary colon carcinoma and related lymphatic and hepatic metastases

FP3 is an engineered protein which contains the extracellular domain 2 of VEGF receptor 1 (Flt-1) and extracellular domain 3 and 4 of VEGF receptor 2 (Flk-1, KDR) fused to the Fc portion of human immunoglobulin G1. Previous studies demonstrated its antiangiogenic effects in vitro and in vivo, and its antitumor activity in vivo. In this study, patient-derived tumor tissue (PDTT) xenograft models of primary colon carcinoma and lymphatic and hepatic metastases were established for assessment of the antitumor activity of FP3 in combination with capecitabine. Xenografts were treated with FP3, capecitabine, alone or in combination. After tumor growth was confirmed, volume and microvessel density in tumors were evaluated. Levels of VEGF, and PCNA in the tumor were examined by immunohistonchamical staining, level of thymidine phosphorylase (TP) was examined by ELISA, and levels of related cell signaling pathways proteins expression were examined by western blotting. FP3 in combination with capecitabine showed significant antitumor activity in three xenograft models (primary colon carcinoma, lymphatic metastasis, and hepatic metastasis). The microvessel density in tumor tissues treated with FP3 in combination with capecitabine was lower than that of the control. Antitumor activity of FP3 in combination with capecitabine was significantly higher than that of each agent alone in three xenograft models (primary colon carcinoma, lymphatic metastasis, and hepatic metastasis). This study indicated that addition of FP3 to capecitabine significantly improved tumor growth inhibition in the PDTT xenograft models of primary colon carcinoma and lymphatic and hepatic metastases.

339 Wnt/Beta Catenin Pathway Differences After Treatment of Primary and Metastatic Colon Carcinoma Cell Lines

339 Wnt/Beta Catenin Pathway Differences After Treatment of Primary and Metastatic Colon Carcinoma Cell Lines

Comparative label‐free LC‐MS/MS analysis of colorectal adenocarcinoma and metastatic cells treated with 5‐fluorouracil

A label-free mass spectrometric strategy was used to examine the effect of 5-fluorouracil (5-FU) on the primary and metastatic colon carcinoma cell lines, SW480 and SW620, with and without treatment. 5-FU is the most common chemotherapeutic treatment for colon cancer. Pooled biological replicates were analyzed by nanoLC-MS/MS and protein quantification was determined via spectral counting. Phenotypic and proteomic changes were evident and often similar in both cell lines. The SW620 cells were more resistant to 5-FU treatment, with an IC(50) 2.7-fold higher than that for SW480. In addition, both cell lines showed pronounced abundance changes in pathways relating to antioxidative stress response and cell adhesion remodeling due to 5-FU treatment. For example, the detoxification enzyme NQO1 was increased with treatment in both cell lines, while disparate members of the peroxiredoxin family, PRDX2 or PRDX5 and PRDX6, were elevated with 5-FU exposure in either SW480 or SW620, respectively. Cell adhesion-associated proteins CTNNB1 and RhoA showed decreased expression with 5-FU treatment in both cell lines. The differential quantitative response in the proteomes of these patient-matched cell lines to drug treatment underscores the subtle molecular differences separating primary and metastatic cancer cells.

Differential response to EGFR- and VEGF-targeted therapies in patient-derived tumor tissue xenograft models of colon carcinoma and related metastases

Heterogeneity in primary tumors and related metastases may result in failure of antitumor therapies, particularly in targeted therapies for the treatment of cancer. In this study, patient-derived tumor tissue (PDTT) xenograft models of colon carcinoma with lymphatic and hepatic metastases were used to evaluate the response to EGFR- and VEGF-targeted therapies. Our results showed that primary colon carcinoma and its corresponding lymphatic and hepatic metastases have a different response rate to anti-EGFR (cetuximab) and anti-VEGF (bevacizumab) therapies. However, the underlying mechanism of these types of phenomenon is still unclear. To investigate whether such phenomena may result from the heterogeneity in primary colon carcinoma and related metastases, we compared the expression levels of cell signaling pathway proteins using immunohistochemical staining and western blotting, and the gene status of KRAS using pyrosequencing in the same primary colon carcinoma and its corresponding lymphatic and hepatic metastatic tissues which were used for establishing the PDTT xenograft models. Our results showed that the expression levels of EGFR, VEGF, Akt/pAkt, ERK/pERK, MAPK/pMAPK, and mTOR/pmTOR were different in primary colon carcinoma and matched lymphatic and hepatic metastases although the KRAS gene status in all cases was wild-type. Our results indicate that the heterogeneity in primary colon carcinoma and its corresponding lymphatic and hepatic metastases may result in differences in the response to dual-inhibition of EGFR and VEGF.

High HSP27 and HSP70 expression levels are independent adverse prognostic factors in primary resected colon cancer

The expression of Heat Shock Proteins (HSPs) is increased in various cancers and has been shown to correlate with biological tumor behaviour. This study aimed to investigate the impact of HSP70, HSP60 and HSP27 expression in colon cancer. HSP expression was determined by immunohistochemistry on a tissue microarray with 355 primary resected colon carcinomas of all stages. Expression patterns were correlated with pathologic features (UICC pTNM category, tumor grading) and survival. Expression of HSP27, HSP60 and HSP70 ranged from negative to high. There was no correlation between HSP27, HSP60 and HSP70 expression among each other and with UICC pT category, presence of lymph node or distant metastases or tumor grading. High HSP70 expression was associated with worse overall survival (p < 0.001) and was an independent prognostic factor (p = 0.004) in multivariate analysis including the pathological parameters mentioned above. For patients without lymph node or distant metastases (UICC stages I/II) and with complete tumor excision, HSP70 expression was the only independent prognostic factor for survival (p = 0.001) and superior to UICC pT category. In left sided UICC stage I/II carcinomas, high HSP27 expression also had adverse prognostic impact and was an independent prognostic factor (p = 0.016) besides HSP70 (p = 0.002). High HSP70 and HSP27 expression is associated with worse clinical outcome in colon cancer. Determination of tumoral HSP70 and HSP27 may be used as additional biomarker for risk stratification especially for UICC stage I/II patients.

Abstract 4524: Characterization of 28 patient derived colorectal cancer xenografts and analysis for response markers to an antiangiogenic treatment

Abstract We have recently described an extended panel of new primary human CRC xenografts and their preclinical chemo-sensitivity to anti-cancer drugs (Poster 1584/3 AACR Annual Meeting 2010). These models consider more thoroughly the heterogeneity and genetic instability of tumors in a way ultimately enabling treatment decisions on an individualized basis. The approach is based on large scale screening for activity in new in vivo models combined with extensive characterization of these models (gene expression and mutations). Bioinformatic methods are used to further evaluate the mechanism of action of new drugs in colorectal cancer, to investigate possible resistance mechanisms and provide a rationale for combination therapies. Here we describe the evaluation of an antiangiogenic treatment in this panel of primary patient derived colorectal cancer models. Primary colon carcinoma tissue samples were collected using a standardized procedure. Tumor pieces were transplanted into immunodeficient mice immediately after surgery. A panel of 28 stably passagable colon cancer xenografts could be established as permanent tumor models. The results obtained so far, show that these patient-derived colon cancer models feature a high coincidence with the original tumor regarding histology and gene expression profiling. Response analysis in a subset of 19 xenografts evaluating the treated-to-control (T/C) ratios of tumor volumes revealed that the human specific VEGF antibody bevacizumab induces a meaningful biological effect (T/C below 50%) in 13 of 19 models. A first comparative genome-wide gene expression analyses of this subset revealed reasonable genes and pathways possibly involved in bevacizumab sensitivity. We will extend this investigation to all 28 tumor models in order to enhance the statistical robustness of the preliminary data. Our approach demonstrates that analysis of drug sensitivity together with bioinformatics correlations can provide candidate markers for further studies. An early implementation of such an approach in the drug development process could be helpful for the identification of predictive markers helping to select tumors likely to benefit from the drug as well as provide a rationale for combinations to be tested in clinical trials. These new strategies may help to better integrate research results in clinical development and may increase the success of new anti-cancer drugs in clinical studies. 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 4524. doi:1538-7445.AM2012-4524