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Introduction: Preclinical data suggest that the single nucleotide polymorphism substituting a glycine for an arginine in codon 388 of the FGFR4 transmembrane domain may increase the proliferation of xenografted neuroendocrine cell lines and decrease their sensitivity to everolimus by modulating STAT3 signaling and the mTOR pathway. Aim: To evaluate the prognostic and predictive values of this polymorphism on everolimus efficacy in patients treated for digestive neuroendocrine tumor (NET). Patients and Methods: This monocentric retrospective cohort included patients with small bowel NET (SBNET) and pancreatic NET (PNET) treated with everolimus (2006-2013). The patients were genotyped by classical sequencing, and mTOR pathway activity was assessed by immunochemistry on formalin-fixed paraffin-embedded samples (PTEN/pPTEN/pAKT/pmTOR/pS6/p4EBP1). Results: Forty-one patients (21 males, median age 57 years) with PNET (n = 28), SBNET (n = 12) or NET of unknown origin (n = 1), grade 1 (n = 8), 2 (n = 27), 3 (n = 3) or unknown grade (n = 3), were studied. At least one 388Arg allele was found in 14/23 PNET and 10/11 SBNET. Progression-free survival in the whole population and the PNET subgroup was not influenced by the presence of one or two 388Arg alleles [HR = 1.31 (0.58-2.99), p = 0.52 and HR = 1.11 (0.45-2.73), p = 0.82, respectively]. Similarly, overall survival was not influenced. Finally, mTOR pathway molecule expression was not modified by the presence of at least one 388Arg allele. Conclusion: The Gly388Arg FGFR4 polymorphism does not seem to have a prognostic value in digestive NET. In addition, it neither predicts the response to everolimus nor modifies the activation of the mTOR pathway.

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in France. Recently, colorectal cancer subtyping consortium (CRCSC) identified 4 consensus molecular subtypes (CMS). CMS1 is enriched for CRC with deficient DNA mismatch repair system (dMMR) and tumors with mutated BRAF. Intriguingly, CMS1 is characterized by better relapse-free survival but worse survival after relapse, compared with the other subtypes. In this review, we provide a comprehensive overview of prognostic and predictive impacts of MMR and BRAF status. We highlight immune checkpoints inhibitors as potentially future therapeutics for CRC with deficient MMR. We also focus on the management of BRAF mutant metastatic CRC, with a particular interest on targeted therapies.

Mismatch-repair (MMR)-deficient cells show increased in vitro tolerance to thiopurines because they escape apoptosis resulting from MMR-dependent signaling of drug-induced DNA damage. Prolonged treatment with immunosuppressants including azathioprine (Aza), a thiopurine prodrug, has been suggested as a risk factor for the development of late onset leukemias/lymphomas displaying a microsatellite instability (MSI) phenotype, the hallmark of a defective MMR system. We performed a dose effect study in mice to investigate the development of MSI lymphomas associated with long term Aza treatment. Over two years, Aza was administered to mice that were wild type, null or heterozygous for the MMR gene Msh2. Ciclosporin A, an immunosuppressant with an MMR-independent signaling, was also administered to Msh2(wt) mice as controls. Survival, lymphoma incidence and MSI tumor phenotype were investigated. Msh2(+/-) mice were found more tolerant than Msh2(wt) mice to the cytotoxicity of Aza. In Msh2(+/-) mice, Aza induced a high incidence of MSI lymphomas in a dose-dependent manner. In Msh2(wt) mice, a substantial lifespan was only observed at the lowest Aza dose. It was associated with the development of lymphomas, one of which displayed the MSI phenotype, unlike the CsA-induced lymphomas. Our findings define Aza as a risk factor for an MSI-driven lymphomagenesis process.

Les malades atteints de rectocolite hemorragique et de maladie de Crohn presentent un risque accru de developper un cancer colorectal (CCR). Ces cancers compliquant une maladie inflammatoire chronique de l’intestin (MICI) sont precedes d’une lesion precancereuse, la dysplasie (ou neoplasie intra-epitheliale), qui offre la possibilite d’un traitement preventif. En depit des limites de la surveillance coloscopique, la dysplasie reste le meilleur marqueur de la prise en charge du risque de CCR dans le cadre des MICI. A la difference des adenomes qui precedent les CCR sporadiques, la dysplasie survenant dans un contexte de MICI a pour particularite d’etre tres heterogene d’un point de vue macroscopique et histologique. Or, la bonne connaissance de ces lesions est indispensable pour une prise en charge optimale de ces malades, le type de dysplasie diagnostiquee conditionnant une prise en charge differente.

Purpose: Aberrant activation of the hedgehog (Hh) pathway is implicated in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis. We investigated the prognostic and predictive value of four Hh signaling proteins and of the tumor stromal density. Experimental Design: Using tissue microarray and immunohistochemistry, the expression of Shh, Gli1, SMO, and PTCH1 was assessed in 567 patients from three independent cohorts who underwent surgical resection for PDAC. In 82 patients, the tumor stromal index (SI) was calculated, and its association with overall survival (OS) and disease-free survival (DFS) was investigated. Results: Shh and Gli1 protein abundance were independent prognostic factors in resected PDACs; low expressors for those proteins experiencing a better OS and DFS. The combination of Shh and Gli1 levels was the most significant predictor for OS and defined 3 clinically relevant subgroups of patients with different prognosis (Gli1 and Shh low; HR set at 1 vs. 3.08 for Shh or Gli1 high vs. 5.69 for Shh and Gli1 high; P < 0.001). The two validating cohorts recapitulated the findings of the training cohort. After further stratification by lymph node status, the prognostic significance of combined Shh and Gli1 was maintained. The tumor SI was correlated with Shh levels and was significantly associated with OS (P = 0.023). Conclusions: Shh and Gli1 are prognostic biomarkers for patients with resected PDAC. Clin Cancer Res; 21(5); 1215–24. ©2014 AACR.

3563 Background: Prognosis of patients (pts) with metastatic colorectal cancer (mCRC) harboring microsatellite instability (MSI) is poorly characterized. We aimed to assess the clinical relevance of distinguishing sporadic (SP) from Lynch syndrome (LS)-related mismatch repair deficiency (dMMR). Methods: Pts with diagnostic of dMMR and/or MSI mCRC between 1998 and 2016 were retrospectively identified in 6 French hospitals. Tumor samples were systematically collected and screened for RAS/RAF mutations and MLH1 promotor methylation. dMMR and MSI statuses were confirmed using immunohistochemistry and Pentaplex© PCR assay. Sporadic cases were molecularly defined as those displaying MLH1 loss of expression with BRAFV600E mutation and/or MLH1 hypermethylation. Clinical data (demographic data, metastatic sites, therapeutic strategies) were recorded. Results: 129 pts, of which 48 SP and 81 LS, were included. Compared with LS, SP were associated with female (P < .001), older age at diagnostic (P < .001), proximal colon (P = 0.002), and less liver metastasis (25% vs 47%, P = .02). For initially localized CRC, median disease free survivals (DFS) were 9.1 months (m) for SP (n = 22) and 12.3 m for LS (n = 47) (hazard ratio (HR) = 0.5, 95%CI 0.28-0.90, P = .02). Median overall survivals (OS) from stage IV diagnosis were 43.9 m in the overall population, 23 m for SP and not reached for LS (HR = 0.23, 95%CI 0.10-0.52, P < .001). BRAF mutation was harbored by 29 SP tumors (60%) and did not impact OS among SP pts (P = .52). Metastatic disease was less frequently resectable for SP than LS (21% vs 56%, P < .001). Median DFS for pts with resected metastatic disease (n = 55) were respectively 6.7 and 10.5 m (HR = 0.28, 95%CI 0.10-0.73, P = .01). At the data cut-off date, 16 pts (15 LS and 1 SP) were still in complete remission. Median progression free survivals with first-line chemotherapy for pts with unresectable metastasis (n = 61) were 3.9 m for SP and 5.0 m for LS (P = .71). Conclusions: This retrospective study suggests a worse prognosis of pts with SP MSI mCRC compared to these with LS-related mCRC.

300 Background: Ampullary adenocarcinoma (AA) is a rare entity. AA can originate from either intestinal or pancreaticobiliary ductal epithelium, and patients are often managed as those with pancreaticobiliary carcinomas. The study objectives were the genetic profiling of AA and the identification of specific molecular profiles according to these 2 pathological types. Methods: AA patients included in the AGEO retrospective multicenter cohort who underwent surgical resection of their tumor between 1999 and 2010 were selected. Formalin-fixed, paraffin-embedded (FFPE) archival tissue blocks were collected. Next generation sequencing (NGS) using a 50 gene panel (Ion AmpliSeq Cancer panel) on tumor DNA, and immunohistochemistry (IHC) panel including CK7, CK20, MUC1, MUC2 and CDX2, on tumor sections, were performed. Results: NGS was performed on 101 tumors from 6 hospitals, with 1 technical failure. In total, the most frequent gene mutations were: KRAS (45%), TP53 (40%), APC (15%), PIK3CA (12%), SMAD4 (9%), BRAF (8%), CDKN2A (6%). No mutation was found in 21% of tumors. According to IHC, the most common histological type was intestinal (51%), followed by pancreaticobiliary type (42%) and undetermined (7%). BRAF mutation was significantly associated with intestinal type (8 vs 0, p = 0.017). According to Cosmic database, similarities of molecular profiles exist between AA with intestinal type and colorectal adenocarcinoma, and between AA with pancreaticobiliary type and pancreas adenocarcinoma, respectively. Conclusions: This study shows that AA is a heterogeneous entity and that a large proportion of AA presents a molecular profile that is more similar to that of colorectal adenocarcinoma, compared to pancreatic adenocarcinoma. This important information could be interesting to guide treatment decision in patients with this rare disease.

International audience; BACKGROUND:: Crohn's disease (CD) is associated with an increased risk of small bowel adenocarcinoma (SBA). However, there are no guidelines for the screening and early diagnosis of SBA. Colorectal cancer associated with chronic colitis arises from dysplasia. High-risk patients benefit from surveillance colonoscopies aimed to detect dysplasia. The dysplasia-carcinoma sequence remains poorly documented in CD-associated SBA. Moreover, molecular data about SBA complicating CD and associated dysplasia are very limited. We therefore assessed dysplasia and several key molecular markers of carcinogenesis in SBA and dysplasia developed in patients with CD. METHODS:: Forty-five SBA complicating CD and 4 specimens with dysplasia without SBA were screened. In SBA, we looked for dysplasia and determined their pathological characteristics (type, grade, distribution). We also stained for mismatch repair proteins (MLH1, MSH2, MSH6, PMS2), p53, β-catenin, and p16 and looked for KRAS, BRAF and PIK3CA mutations. RESULTS:: All neoplastic lesions, except 1 lesion, were found in inflamed mucosal areas. Dysplasia was found in 20 of 41 patients with SBA (49%). Dysplasia was flat or raised, low grade or high grade, and adjacent or distant to concomitant SBA. Molecular markers of SBA carcinogenesis complicating CD were similar to those observed in chronic colitis-related colorectal cancer (KRAS, BRAF, p53, MSI), although differences were observed for β-catenin and p16. No PIK3CA mutations were observed. CONCLUSIONS:: These results suggest that there is an inflammation-dysplasia-adenocarcinoma sequence in at least half of CD-related SBA, similar to what is observed in chronic colitis-related colorectal cancer and may have implications for the prevention and treatment of this cancer.

Resume Les metastases de cancers colorectaux a developpement endobiliaire sont rares. Nous rapportons le cas d’un malade âge de 36 ans opere 5 ans auparavant d’un cancer du sigmoide par sigmoidectomie et ayant consulte pour la survenue depuis un mois de douleurs de l’hypochondre droit sans fievre ni ictere. L’echographie, l’imagerie abdominale par tomodensitometrie et par resonance magnetique ainsi que la tomographie par emission de positons ont permis de poser le diagnostic de metastase endobiliaire traitee par hepatectomie droite curative. Une revue de la litterature prolonge cette observation sur les metastases endobiliaires. Ces tumeurs peuvent mimer au plan clinique, radiologique et meme anatomopathologique le cholangiocarcinome des voies biliaires intrahepatiques. L’objectif principal du bilan d’imagerie est d’etablir la resecabilite de ces lesions. La survie rapportee des rares malades atteints de metastases endobiliaires resequees semble meilleure que celle des malades porteurs de metastases hepatiques parenchymateuses.

Background The significance of positive para-aortic nodes in patients with resectable pancreatic carcinoma is unclear. This study sought to evaluate the accuracy of intraoperative detection and prognostic significance of these lymph nodes in patients with resected adenocarcinoma of the pancreatic head. Methods From 2000 to 2010, para-aortic node sampling was performed prospectively in all patients before pancreatoduodenectomy. Frozen sections were created and nodes categorized as positive or negative for metastases. Surgeons were blinded to the frozen-section results. This was followed by standard histopathological assessment of corresponding paraffin-embedded, haematoxylin and eosin-stained material. Nodes considered uninvolved by this analysis were examined immunohistochemically for micrometastases. Results A total of 111 consecutive patients were included, with a median follow-up of 20·8 (range 1·5–126) months. The 1-, 2- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 73·6, 54·0 and 24·7 per cent, and 51·8, 28·1 and 18·8 per cent respectively. Para-aortic node involvement was always associated with peripancreatic lymph node metastasis, and was detected by frozen-section analysis in 12 patients and by haematoxylin and eosin staining in 17. Sensitivity and specificity of frozen-section examination for detecting para-aortic lymph node metastases were 71 and 100 per cent respectively. Median OS for patients with and without para-aortic node involvement on frozen-section analysis was 9·7 versus 28·5 months respectively (P = 0·012), and 15·7 versus 27·2 months (P = 0·050) when assessed by haematoxylin and eosin staining. Median DFS for patients with and without para-aortic node involvement on frozen-section examination was 5·6 versus 12·9 months respectively (P = 0·041), and 8·4 versus 12·9 months (P = 0·038) for haematoxylin and eosin analysis. The presence of micrometastases in para-aortic nodes was not significantly associated with altered OS or DFS. Conclusion Para-aortic node sampling with frozen-section examination detects distant lymphatic involvement reliably. It should be performed systematically. When metastases are found, they should be considered a contraindication to pancreatic resection.

International audience; : Cap polyposis and colitis cystica profunda (CCP) are two rare, benign and distinct colorectal conditions whose etiology remains unclear. A rare association between cap polyposis and CCP has already been described. In those cases, cystic glands were present in the submucosal layer of the cap polyps.(1,2) Interestingly, in the present case, lesions of CCP were not intermingled with cap polyps, but were distant from them. This article is protected by copyright. All rights reserved.

The French Research Group of Rectal Cancer Surgery (GRECCAR); International audience; Background: Neoadjuvant radiochemotherapy (RCT) is now part of the armamentarium of cancer of the lower and middle rectum. It is recommended in current clinical practice prior to surgical excision if the lesion is classified T3/T4 or N+. Histological complete response, defined by the absence of persistent tumor cell invasion and lymph node (ypT0N0) after pathological examination of surgical specimen has been shown to be an independent prognostic factor of overall survival and disease-free survival. Surgical excision is usually performed between 6 and 8 weeks after completion of CRT and pathological complete response rate ranges around 12%. In retrospective studies, a lengthening of the interval after RCT beyond 10 weeks was found as an independent factor increasing the rate of pathological complete response (between 26% and 31%), with a longer disease-free survival and without increasing the operative morbidity. The aim of the present study is to evaluate in 264 patients the rate of pathological complete response rate of rectal cancer after RCT by lengthening the time between RCT and surgery.Methods/design: The current study is a multicenter randomized trial in two parallel groups comparing 7 and 11 weeks of delay between the end of RCT and cancer surgery of rectal tumors.At the end of the RCT, surgery is planified and randomization is performed after patient’s written consent for participation. The histological complete response (ypT0N0) will be determined with analysis of the complete residual tumor and double reading by two pathologists blinded of the group of inclusion. Patients will be followed in clinics for 5 years after surgery. Participation in this trial does not change patient’s management in terms of treatment, investigations or visits. Secondary endpoints will include overall and disease free survival, rate of sphincter conservation and quality of mesorectal excision. The number of patients needed is 264.

The purpose of the present study was to assess the prognostic impact of positive surgical margins (R1) after liver resection (LR) of colorectal liver metastases (CRLM) in the era of modern chemotherapy regimens. R1 resection is a negative prognostic factor after LR of CRLM. The significance of R1 margins in the era of effective chemotherapy is unknown.From January 2000 to December 2009, 215 patients (177 men: 62 %; median age 60 years; range 30-84 years) underwent LR of CRLM. The LR was considered R1 (margin1 mm) in 49 patients (23 %) and R0 in 166 patients (77 %). Overall, 108 (50 %) patients received preoperative chemotherapy and 156 (72 %) patients received postoperative chemotherapy.With a median follow-up of 36 months (range 1-141 months), the 5-year overall survival (OS) rate (47 vs 40 %; p = 0.05) and the disease-free survival (DFS) rate (36 vs 23 %; p = 0.006) were significantly lower in the R1 group. Recurrence developed in 152 patients (71 %) and the rate of recurrence was significantly higher (84 vs 67 %; p = 0.02) in the R1 group. On multivariate analysis, N+ status of the colorectal primary tumor (p = 0.008), presence of radiologically occult disease (p = 0.04), and R1 resection (p = 0.03) were independent adverse predictors of OS. The N+ status of the primary tumor (p = 0.003) and R1 resection (p = 0.02) were independent adverse predictors of DFS. On multivariate analysis use of postoperative chemotherapy was the only independent predictor of improved DFS (p = 0.02) in the R1 group.A positive resection margin remains a significant poor prognostic factor after LR of CRLM in the era of modern chemotherapy. Postoperative chemotherapy reduces recurrence rates after R1 resection of CRLM.

Background: Small bowel adenocarcinoma (SBA) is a rare tumour with a poor prognosis. Molecular biology data on SBA carcinogenesis are lacking. Methods: Expression of HER2, β-catenin, p53 and mismatch repair (MMR) protein was assessed by immunohistochemistry. KRAS, V600E BRAF mutations and microsatellite instability were investigated. Results: We obtained samples from 63 SBA patients (tumour stages: I–II: 30% III: 35% IV: 32% locally advanced: 3%). HER2 overexpression (3+) was observed in 2 out of 62 patients, overexpression of p53 in 26 out of 62, abnormal expression of β-catenin in 12 out of 61, KRAS mutation in 21 out of 49, BRAF V600E mutation in 1 out of 40 patients, MMR deficiency (dMMR) in 14 out of 61 and was consistent with Lynch syndrome in 9 out of 14 patients. All of the dMMR tumours were in the duodenum or jejunum and only one was stage IV. Median overall survival (OS) was 36.6 months (95% CI, 26.9–72.2). For all patients, in univariate analysis, stages I–II (P

Background Standard operative management of colorectal cancer (CRC) with adherent adjacent organs is en bloc resection to obtain clear resection margins. We analyzed early and long-term outcomes after multivisceral resection for clinically suspected T4 CRC and identified factors predicting survival. Methods All patients operated on for clinically suspected T4 CRC between 2000 and 2010 were identified retrospectively. Data concerning demographics, surgery, pathologic examination and oncologic outcome were analyzed. Results One hundred fifty-two patients underwent partial or total en bloc resection of ≥1 adherent organ. An R0 resection was achieved in 136 patients (89.5%). Malignant invasion of the adherent organ was histologically confirmed in 98 patients (64.5%). Five-year overall survival and disease-free survival rates were 77.4% and 58.1%, respectively. On univariate analysis, margin positivity, pT4 stage, and lymph node invasion were predictors of a worse disease-free survival. The presence of liver metastases and concomitant hepatectomy were both factors of poor overall and disease-free survival. On multivariate analysis, resection of ≥2 adjacent organs was a predictor of better overall survival. This finding may be explained by the significantly higher rate of tumors with microsatellite instability (MSI) in the group with resection of multiple organs. Conclusion The oncologic outcome of multivisceral resection for clinically suspected colorectal T4 tumors was good, especially in MSI patients and patients without liver metastases. The number of organs requiring resection should not contraindicated radical surgery as in this study it was associated with a good prognosis.

Background & Aims Patients with colorectal tumors with microsatellite instability (MSI) have better prognoses than patients with tumors without MSI, but have a poor response to 5-fluorouracil–based chemotherapy. A dominant-negative form of heat shock protein (HSP)110 (HSP110DE9) expressed by cancer cells with MSI, via exon skipping caused by somatic deletions in the T 17 intron repeat, sensitizes the cells to 5-fluorouracil and oxaliplatin. We investigated whether HSP110 T 17 could be used to identify patients with colorectal cancer who would benefit from adjuvant chemotherapy with 5-fluorouracil and oxaliplatin. Methods We characterized the interaction between HSP110 and HSP110DE9 using surface plasmon resonance. By using polymerase chain reaction and fragment analysis, we examined how the size of somatic allelic deletions in HSP110 T 17 affected the HSP110 protein expressed by tumor cells. We screened 329 consecutive patients with stage II–III colorectal tumors with MSI who underwent surgical resection at tertiary medical centers for HSP110 T 17 . Results HSP110 and HSP110DE9 interacted in a 1:1 ratio. Tumor cells with large deletions in T 17 had increased ratios of HSP110DE9:HSP110, owing to the loss of expression of full-length HSP110. Deletions in HSP110 T 17 were mostly biallelic in primary tumor samples with MSI. Patients with stage II–III cancer who received chemotherapy and had large HSP110 T 17 deletions (≥5 bp; 18 of 77 patients, 23.4%) had longer times of relapse-free survival than patients with small or no deletions (≤4 bp; 59 of 77 patients, 76.6%) in multivariate analysis (hazard ratio, 0.16; 95% confidence interval, 0.012–0.8; P = .03). We found a significant interaction between chemotherapy and T 17 deletion ( P = .009). Conclusions About 25% of patients with stages II–III colorectal tumors with MSI have an excellent response to chemotherapy, due to large, biallelic deletions in the T 17 intron repeat of HSP110 in tumor DNA.

Small bowel adenocarcinomas are rare tumours, but their incidence is increasing. Their most common primary location is the duodenum. The few studies that have collected data regarding small bowel adenocarcinoma are not homogeneous and are widely spread over time. Even though these tumours are most often sporadic, some predisposing diseases have been identified, among which Crohn's disease and genetic syndromes. Early diagnosis of small bowel adenocarcinoma remains difficult despite significant radiological and endoscopic progress. After surgical resection the main prognostic factor is node invasion; in this case, adjuvant chemotherapy can be expected to be beneficial, although this has not been established by randomised trials. For metastatic disease, platinum-based chemotherapy seems to be the most effective treatment. Targeted therapies have not yet been evaluated in this type of cancer.

Introduction The surgical approach for the treatment of tumors of the upper third of the rectum remains controversial. Several publications have shown that partial excision of the mesorectum (PME) with division of the mesorectum and rectum 5 cm below the tumor could be a reasonable approach although total mesorectal excision (TME) is still considered the gold standard for all rectal cancers in many studies. We aimed to assess the specifics risks of anterior resection with PME and colorectal anastomosis (CRA) in rectal cancer. Patients and Methods Files of all of the patients who underwent a PME between 2000 and 2011 were reviewed in consecutive order. Complications that occurred within 3 months after surgery, oncological outcome, local and distant recurrences, and survival were assessed. Results One hundred seventy-two patients had a PME with CRA of whom 49 (28.5%) had a dysfunctional stoma. Grade III to IV complications occurred in 18 (10.5%) patients and 2 (1.2%) died. Thirteen (7.6%) developed an anastomotic leakage, and 5 (2.9%) resulted with a permanent stoma. Mean follow-up was 151 months (range, 0-151 months). The 5-year local recurrence rate was 5.3%. The 5-year overall and disease-free survival assessed in the 147 patients without synchronous metastasis were 93.2% and 79.7%, respectively. Conclusion Partial excision of the mesorectum can be performed safely, in 1 stage in many patients, with a low risk of definitive stoma. The local recurrence and the survival rates that we observed indicate that the prognosis is not altered compared with TME. Therefore, PME can be recommended in the treatment of upper and some mid rectal tumors.

Links between cancer and stem cells have been proposed for many years. As the cancer stem cell (CSC) theory became widely studied, new methods were developed to culture and expand cancer cells with conserved determinants of “stemness”. These cells show increased ability to grow in suspension as spheres in serum-free medium supplemented with growth factors and chemicals. The physiological relevance of this phenomenon in established cancer cell lines remains unclear. Cell lines have traditionally been used to explore tumor biology and serve as preclinical models for the screening of potential therapeutic agents. Here, we grew cell-forming spheres (CFS) from 25 established colorectal cancer cell lines. The molecular and cellular characteristics of CFS were compared to the bulk of tumor cells. CFS could be isolated from 72 % of the cell lines. Both CFS and their parental CRC cell lines were highly tumorigenic. Compared to their parental cells, they showed similar expression of putative CSC markers. The ability of CRC cells to grow as CFS was greatly enhanced by prior treatment with 5-fluorouracil. At the molecular level, CFS and parental CRC cells showed identical gene mutations and very similar genomic profiles, although microarray analysis revealed changes in CFS gene expression that were independent of DNA copy-number. We identified a CFS gene expression signature common to CFS from all CRC cell lines, which was predictive of disease relapse in CRC patients. In conclusion, CFS models derived from CRC cell lines possess interesting phenotypic features that may have clinical relevance for drug resistance and disease relapse.

The familial cancer syndrome referred to as Lynch I and II was renamed hereditary nonpolyposis colorectal cancer (HNPCC) only to revert later to Lynch syndrome (LS). LS is the most frequent human predisposition for the development of colorectal cancer (CRC), and probably also for endometrial and gastric cancers, although it has yet to acquire a consensus name. Its estimated prevalence ranges widely from 2% to 7% of all CRCs due to the fact that tumors from patients with LS are difficult to recognize at both the clinical and molecular level. This review is based on two assumptions. First, all LS patients inherit a predisposition to develop CRC (without polyposis) and/or other tumors from the Lynch spectrum. Second, all LS patients have a germline defect in one of the DNA mismatch repair (MMR) genes. When a somatic second hit inactivates the relevant MMR gene, the consequence is instability of DNA repeat sequences such as microsatellites and the tumors are referred to as having the microsatellite instability (MSI) phenotype. However, some of the inherited predisposition to develop CRC without concurrent polyposis, termed HNPCC, is found in non-LS patients, while not all MSI tumors are from LS cases. LS tumors are therefore at the junction of inherited and MSI cases. We describe here the defining characteristics of LS tumors that differentiate them from inherited non-MSI tumors and from non-inherited MSI tumors.

In locally advanced rectal cancer (LARC) patients, major response to neoadjuvant radiotherapy (NR) has been associated with favorable long-term outcomes. Positive pathologic nodal status was recently proven to be associated with poor prognosis even after total regression of primary tumor (ypT0). The aim of this study was to evaluate the rate of lymph node (LN) involvement in patients with complete (ypT0) or major (TRG1: very few viable tumor cells) response.Included were patients with complete or major response after radiotherapy followed by surgery and histological examination of the whole specimen.From 1996 to 2010, 245 patients with LARC were treated by NR. We collected clinical data for 53 patients (21.6 %) with ypT0 (n = 26, 49 %) or TRG1 (n = 27, 51 %) response. Sphincter-preserving surgery was performed in 40 patients (75 %). Overall, nine patients (16.9 %) presented LN involvement: 2 (7.7 %) in the ypT0 group and 7 (25.9 %) in the TRG1 group (NS). Patients with ypT3 tumors had significantly more invaded LN than patients with ypT1-T2 tumors (6 of 13 [46 %] vs 1 of 14 [7 %], p = .032). After median follow-up of 30 months (range, 1-160 months), 5-year disease-free and overall survivals were 88.2 and 89.0 %, respectively.There was a clear cutoff between patients with ypT0-T2 (3 of 40, 7.5 %) and ypT3 (6 of 13, 46 %) concerning the incidence of metastatic LN in patients achieving pathologic complete or major response after NR. In patients with good clinical response, local full-thickness resection of the residual tumor could be a first step, followed by standard rectal resection in cases of ypT3.

The familial cancer syndrome referred to as Lynch I and II was renamed hereditary nonpolyposis colorectal cancer (HNPCC) only to revert later to Lynch syndrome (LS). LS is the most frequent human predisposition for the development of colorectal cancer (CRC), and probably also for endometrial and gastric cancers, although it has yet to acquire a consensus name. Its estimated prevalence ranges widely from 2% to 7% of all CRCs due to the fact that tumors from patients with LS are difficult to recognize at both the clinical and molecular level. This review is based on two assumptions. First, all LS patients inherit a predisposition to develop CRC (without polyposis) and/or other tumors from the Lynch spectrum. Second, all LS patients have a germline defect in one of the DNA mismatch repair (MMR) genes. When a somatic second hit inactivates the relevant MMR gene, the consequence is instability of DNA repeat sequences such as microsatellites and the tumors are referred to as having the microsatellite instability (MSI) phenotype. However, some of the inherited predisposition to develop CRC without concurrent polyposis, termed HNPCC, is found in non-LS patients, while not all MSI tumors are from LS cases. LS tumors are therefore at the junction of inherited and MSI cases. We describe here the defining characteristics of LS tumors that differentiate them from inherited non-MSI tumors and from non-inherited MSI tumors.

Background and aim Fistulae are one of the most frequent complications of Crohn's disease (CD) and occur in 30–40% of patients. Conversely, free perforation is a rare complication and is one of the indications for emergency surgery of CD because of secondary peritonitis. We report a case of a spontaneous fistula rupture secondary to a road traffic accident. Methods Case report. Results A 22 year-old man, with no personal significant medical history, was admitted in the emergency room after a road traffic accident. He underwent abdominal CT, which revealed pelvis fractures, abnormal bowel wall of the terminal ileum (wall thickening and mucosal enhancement), peritoneal effusion within the pelvis, mesenteric nodes and extra-luminal gas within an area of mesenteric inflammation: these features were suggestive of ileum perforation associated with inflammatory bowel disease, most likely CD. Laparoscopic assessment was decided and an ileocaecal resection with ileocolonic anastomosis was performed. Histological analysis revealed terminal ileitis with ulcers, non caseating granulomas and submucosal fibrosis, a transparietal fistula and a caecoappendicular inflammation, confirming CD. Post surgical outcome was uneventful and the patient was discharged at day 9. Conclusion Our patient presented this rare complication revealing CD. The involvement of the terminal ileum and fistulae were characteristics of CD. Rupture of the fistula was favored by the trauma and responsible for the peritonitis. A resection with primary anastomosis was possible. To our knowledge, it is the first case described for the rupture of an ileal fistula secondary to traumatism in a patient with CD.

International audience

Heat shock proteins (HSPs) are necessary for cancer cell survival. We identified a mutant of HSP110 (HSP110ΔE9) in colorectal cancer showing microsatellite instability (MSI CRC), generated from an aberrantly spliced mRNA and lacking the HSP110 substrate-binding domain. This mutant was expressed at variable levels in almost all MSI CRC cell lines and primary tumors tested. HSP110ΔE9 impaired both the normal cellular localization of HSP110 and its interaction with other HSPs, thus abrogating the chaperone activity and antiapoptotic function of HSP110 in a dominant-negative manner. HSP110ΔE9 overexpression caused the sensitization of cells to anticancer agents such as oxaliplatin and 5-fluorouracil, which are routinely prescribed in the adjuvant treatment of people with CRC. The survival and response to chemotherapy of subjects with MSI CRCs was associated with the tumor expression level of HSP110ΔE9. HSP110 may thus constitute a major determinant for both prognosis and treatment response in CRC.

Background & Aims Patients who undergo surgery for pancreatic ductal adenocarcinoma (PDAC) frequently receive adjuvant gemcitabine chemotherapy. Key determinants of gemcitabine cytotoxicity include the activities of the human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), and ribonucleotide reductase subunit 1 (RRM1). We investigated whether tumor levels of these proteins were associated with efficacy of gemcitabine therapy following surgery. Methods Sequential samples of resected PDACs were retrospectively collected from 434 patients at 5 centers; 142 patients did not receive adjuvant treatment (33%), 243 received adjuvant gemcitabine-based regimens (56%), and 49 received nongemcitabine regimens (11%). We measured protein levels of hENT1, dCK, and RRM1 by semiquantitative immunohistochemistry with tissue microarrays and investigated their relationship with patients' overall survival time. Results The median overall survival time of patients was 32.0 months. Among patients who did not receive adjuvant treatment, levels of hENT1, RRM1, and dCK were not associated with survival time. Among patients who received gemcitabine, high levels of hENT1 and dCK were significantly associated with longer survival time (hazard ratios of 0.34 [ P P = .012], respectively). Interaction tests for gemcitabine administration and hENT1 and dCK status were statistically significant ( P = .0007 and P = .016, respectively). On multivariate analysis of this population, hENT1 and dCK retained independent predictive values, and those patients with high levels of each protein had the longest survival times following adjuvant therapy with gemcitabine. Conclusions High levels of hENT1 and dCK in PDAC predict longer survival times in patients treated with adjuvant gemcitabine.

Adenocarcinoma of the stomach, oesophagogastric junction and lower oesophagus remains a major global public health issue. Recently, the introduction of neoadjuvant chemotherapy in the treatment of these cancers has changed the pathological processing of the surgical resection specimens of these patients. The neoadjuvant treatment induces histological changes of the tumour called "tumour response". This tumour response needs to be evaluated, even if at present, there is no adaptation of the adjuvant chemotherapy to the histological tumour response. Several grading systems have been proposed for the different tumour sites (lower oesophagus, oesophagogastric junction and stomach). We will discuss first the macroscopic processing of the surgical resection specimens and then the different ways of assessing the histological response to chemotherapy. A standardized assessment of the histological tumour response is a necessary prerequisite for future studies looking at the adaptation of chemotherapy depending on the histological tumour response.

Pancreaticoduodenectomy is an alternative to pancreas-sparing duodenectomy for radical treatment of duodenal lesions. The aims of this study were to assess the results of pylorus-preserving pancreaticoduodenectomy (PPPD) for severe duodenal polyposis in familial adenomatous polyposis in terms of morbidity, long-term influence on functional results, the recurrence rate of cancer or jejunal polyps, and survival.All patients operated on for a PPPD between 1992 and 2009 were included. Clinical data, endoscopic findings, and pathologic examinations were evaluated.A total of 19 patients underwent PPPD for severe duodenal polyposis (17 Spigelman IV, 1 Spigelman III, and 1 invasive carcinoma). Postoperative mortality was nil. The postoperative morbidity rate was 42%, including 4 pancreatic fistulae (21%) and 2 delayed gastric emptying (11%). Pathologic examination found 7 invasive carcinomas, of which only 1 was known before resection. One third of patients operated on without a preoperative diagnosis of malignancy already had an invasive duodenal carcinoma. After a mean follow-up of 58 months, 16 patients were alive. Thirteen patients underwent endoscopic follow-up, and new adenomas were found in 4 (31%). All were treated successfully during the same endoscopic procedure. PPPD did not modify the functional result after coloproctectomy.PPPD remains a safe and efficient therapeutic option for severe duodenal polyposis in familial adenomatous polyposis patients.

Cell adhesion is one function regulated by cellular prion protein (PrP(c)), a ubiquitous, glycosylphosphatidylinositol-anchored glycoprotein. PrP(c) is located in cell-cell junctions and interacts with desmosome proteins in the intestinal epithelium. We investigated its role in intestinal barrier function.We analyzed permeability and structure of cell-cell junctions in intestine tissues from PrP(c) knockout (PrP(c-/-)) and wild-type mice. PrP(c) expression was knocked down in cultured human Caco-2/TC7 enterocytes using small hairpin RNAs. We analyzed colon samples from 24 patients with inflammatory bowel disease (IBD).Intestine tissues from PrP(c-/-) mice had greater paracellular permeability than from wild-type mice (105.9 ± 13.4 vs 59.6 ± 10.1 mg/mL fluorescein isothiocyanate-dextran flux; P.05) and impaired intercellular junctions. PrP(c-/-) mice did not develop spontaneous disease but were more sensitive than wild-type mice to induction of colitis with dextran sulfate (32% mortality vs 4%, respectively; P = .0033). Such barrier defects were observed also in Caco-2/TC7 enterocytes following PrP(c) knockdown; the cells had increased paracellular permeability (1.5-fold over 48 hours; P.001) and reduced transepithelial electrical resistance (281.1 ± 4.9 vs 370.6 ± 5.7 Ω.cm(2); P.001). Monolayer shape and cell-cell junctions were altered in cultures of PrP(c) knockdown cells; levels of E-cadherin, desmoplakin, plakoglobin, claudin-4, occludin, zonula occludens 1, and tricellulin were decreased at cell contacts. Cell shape and junctions were restored on PrP(c) re-expression. Levels of PrP(c) were decreased at cell-cell junctions in colonic epithelia from patients with Crohn's disease or ulcerative colitis.PrP(c) regulates intestinal epithelial cell-cell junctions and barrier function. Its localization is altered in colonic epithelia from patients with IBD, supporting the concept that disrupted barrier function contributes to this disorder.

International audience; OBJECTIVES: Colorectal cancer (CRC), developing from dysplastic lesions, is the main long-term complication of pancolitis. The aims of the present study were to assess the risks for neoplasia and advanced neoplasia (AN), respectively, in ulcerative colitis (UC) and Crohn's disease (CD) patients with pancolitis, and to search for protective and risk factors for colorectal neoplasia. METHODS: A total of 855 inflammatory bowel disease (IBD) patients with longstanding pancolitis (276 UC, 56 IBD unclassified (IBDu), and 523 CD) had pathological examination of a proctocolectomy specimen (n=255) or multiple biopsy samples from a surveillance colonoscopy (n=600) after median disease duration of 115 months. Risk factors for low-grade dysplasia (LGD) and AN, respectively, were searched for in the whole group of patients and in a case-control comparison after matching for IBD phenotype. RESULTS: A total of 75 patients eventually developed colorectal neoplasia: 14 adenomas, 28 nonadenomatous LGD, and 33 ANs. The 25-year cumulative risks for neoplasia and AN, respectively, were 32.8±5.7% and 25.9±5.7% in UC and IBDu vs. 12.1±2.7% and 3.9±2.0% in CD (P

International audience; BACKGROUND AND AIMS: O(6)-Methylguanine-DNA methyltransferase (MGMT) removes methyl adducts from O(6)-guanine. Known as methylation tolerance, selection for mismatch repair (MMR)-deficient cells that are unable to initiate lethal processing of O(6)-methylguanine-induced mismatches in DNA is observed in vitro as a consequence of MGMT deficiency. It was therefore hypothesised that an MGMT field defect may constitute a preneoplastic event for the development of MMR-deficient tumours displaying microsatellite instability (MSI). METHODS: MGMT expression was investigated by immunohistochemistry and the methylation status of the gene promoter by PCR in neoplastic, adjacent and distant mucosal tissues of patients with MSI or non-MSI (MSS) colorectal cancer (CRC). The cancers were familial (42 MSI, 13 MSS) or sporadic (40 MSI, 49 MSS) in origin, or arose in the context of inflammatory bowel disease (IBD; 13 MSI, 36 MSS). Colonic mucosa from patients with diverticulitis (n=20) or IBD (n=39 in 27 patients) without cancer served as controls. RESULTS: Loss of MGMT expression was more frequent in MSI than MSS CRC (p=0.047). In comparison with MSS tumours, MSI CRC occurred more frequently adjacent to patches of mucosa that lacked MGMT expression (p=0.002). Overall, loss of MGMT expression was associated with MGMT gene promoter methylation (p=0.03). CONCLUSION: MGMT field defects are more frequently associated with MSI than MSS CRC. These findings indicate that methylation tolerance may be a crucial initiating step prior to MMR deficiency in the development of MSI CRC in familial, sporadic and IBD settings.

The thiopurine prodrug azathioprine is used extensively in cancer therapy. Exposure to this drug results in the selection of DNA mismatch repair-deficient cell clones in vitro. It has also been suggested that thiopurine drugs might constitute a risk factor for the emergence of human neoplasms displaying microsatellite instability (MSI) because of deficient DNA mismatch repair.Azathioprine was administered via drinking water (6-20 mg/kg body weight per day) to mice that were null (Msh2⁻(/)⁻; n = 27), heterozygous (Msh2(+/)⁻; n = 22), or wild type (Msh2(WT); n = 18) for the DNA mismatch repair gene Msh2. Control mice (45 Msh2⁻(/)⁻, 38 Msh2(+/)⁻, and 12 Msh2(WT)) received drinking water lacking azathioprine. The effect of azathioprine on tumorigenesis and survival of the mice was evaluated by Kaplan-Meier curves using log-rank and Gehan-Breslow-Wilcoxon tests. Mouse tumor samples were characterized by histology and immunophenotyping, and their MSI status was determined by polymerase chain reaction analysis of three noncoding microsatellite markers and by immunohistochemistry. Msh2 status of tumor samples was assessed by loss of heterozygosity analyses and sequencing after reverse transcription-polymerase chain reaction of the entire Msh2 coding sequence. All statistical tests were two-sided.Most untreated Msh2(WT) and Msh2(+/)⁻ mice remained asymptomatic and alive at 250 days of age, whereas azathioprine-treated Msh2(WT) and Msh2(+/)⁻ mice developed lymphomas and died prematurely (median survival of 71 and 165 days of age, respectively). Azathioprine-treated Msh2(+/)⁻ mice developed diffuse lymphomas lacking Msh2 expression and displaying MSI due to somatic inactivation of the functional Msh2 allele by loss of heterozygosity or mutation. By contrast, azathioprine-treated Msh2(WT) mice displayed no obvious tumor phenotype, but histological examination showed microscopic splenic foci of neoplastic lymphoid cells that retained Msh2 expression and did not display MSI. Both untreated and azathioprine-treated Msh2⁻(/)⁻ mice had a reduced lifespan compared with untreated Msh2(WT) mice (median survival of 127 and 107 days of age, respectively) and developed lymphomas with MSI.Azathioprine-induced carcinogenesis in mice depends on the number of functional copies of the Msh2 gene.

Acinar cell carcinoma (ACC) of the pancreas accounts for approximately 1% of all exocrine pancreatic tumours. We report a rare form of ACC in a 66-year-old man. This tumour was revealed by epigastric pain and weight loss. Abdominal computed tomography showed a hypodense, well-demarcated, heterogeneous lesion, in the head of the pancreas, measuring 4.2 cm in diameter. There was a marked dilatation of the main pancreatic duct upstream, with tumour spreading within this duct. The diagnosis of ACC was made on the fine needle aspiration cytology performed during endoscopic ultrasound examination. On the pancreaticoduodenectomy specimen, the dilated main pancreatic duct (2.5 cm in diameter) was filled by an exophytic tumour. Histological examination showed an ACC, with predominant intraductal growth (main and accessory pancreatic ducts), with pancreatic parenchymal and duodenal invasion. Neuroendocrine markers were negative. To our knowledge, this is the second report of an ACC with predominant intraductal spread. These rare forms of ACC can be confused with intraductal papillary-mucinous neoplasms. In our report, fine needle aspiration cytology performed during endoscopic ultrasound examination was a valuable tool in the diagnostic assessment.

Objective: The relationship between sex hormones and hepatocellular adenoma development is well established. On the contrary, their contribution to liver adenomatosis (LA) development is still a debatable issue. Recently, inactivating mutations of hepatocyte nuclear factor-1α (HNF-1α) transcription factor gene or activating mutations of β-catenin have been demonstrated in some liver adenomas, and a possible link between HNF-1α gene mutations and oral contraceptives has been suggested. Only two cases of regressive LA after hormone withdrawal therapy have been described so far but without any information concerning the molecular characteristics of the tumours. Case: We report the case of a 48-year-old woman with LA, who had been taking an androgenic progestin therapy (lynestrenol) for 10 years. A major regression in the number and size of the lesions was observed 6 months after complete withdrawal of this therapy. Methods: Hepatocellular adenomas were studied by immunohistochemistry for oestrogen, progesterone and androgen receptors (ER, PR and AR respectively), and for β-catenin. Direct sequencing of the HNF-1α gene was also performed. Results: For the first time, we demonstrate significant immunostaining of AR in the hepatocellular adenomas. This staining was negative in the partially regressive adenoma. Immunostainings for ER and PR were negative. HNF-1α and the β-catenin pathways were not involved in tumour pathogenesis. Conclusions: Our case suggests a role of androgenic progestin therapy in some cases of LA. Hormone therapy withdrawal may induce a significant regression in lesions.

International audience; AIMS: To determine the clinicopathological features of colorectal cancer (CRC) in Crohn's disease (CD). METHODS AND RESULTS: All histological slides from surgical specimens with inflammatory bowel disease-related colorectal neoplasia examined in our hospital between 1990 and 2005 were reviewed. We identified 18 CRCs in 16 patients with CD and compared them with 57 CRCs in 41 patients with ulcerative colitis (UC). We also studied 25 patients with dysplasia without cancer (CD 2, UC 23). When CD and UC were compared, the median age at diagnosis of cancer (CD 52 years, UC 51 years), the frequency of mucinous adenocarcinoma (CD 16.7%, UC 17.5%) and the frequency of dysplasia adjacent to and distal from cancer (CD 56.3 and 37.5%, UC 65.8 and 39%, respectively) were similar. All neoplastic lesions occurred in areas affected by inflammatory bowel disease. CONCLUSIONS: CRC complicating CD and UC shares many clinicopathological features, in particular similar frequencies of dysplasia, both adjacent and distal, with cancer. Thus, surveillance for patients with Crohn's colitis should be similar to that for patients with UC. Consideration should be given to a more extensive UC-like surgical approach instead of segmental resection of the involved area.

Endobiliary metastasis of colorectal cancers are rare. We report a 36 years-old patient, operated on 5 years ago for a left colon cancer with a left colectomy. He consulted for pain in the upper right quadrant without fever nor jaundice. Ultra-sound, CTscan, RMI and PET led to the diagnosis of endobiliary metastasis and the patient underwent a right hepatectomy. A review of the literature of the endobiliary metastasis follows this case-report. These tumours can mimic intrahepatic cholangiocarcinoma in clinical presentation, imaging or even histological examinations. The main goal of the imaging explorations is to establish the resecability of such tumours. Patients with endobiliary metastasis seem to have better survival than patients with intrahepatic metastasis.