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Background & aims It is important to identify individuals with Lynch syndrome because surveillance programs can reduce their morbidity and mortality from colorectal cancer (CRC). We assessed the diagnostic yield of immunohistochemistry to detect Lynch syndrome in patients with advanced and multiple adenomas within our national CRC screening program. Methods We performed a prospective study of all participants (n = 1101; 55% male; median age, 66 years; interquartile range, 61–70 years) referred to the Erasmus MC in The Netherlands after a positive result from a fecal immunohistochemical test, from December 2013 to December 2016. Colon tissues were collected from patients with advanced adenomas, ≥4 nonadvanced adenomas, or CRC, and analyzed by immunohistochemistry to identify patients with loss of mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, or PMS2): a marker of Lynch syndrome. Specimens from patients with loss of MLH1 were analyzed for MLH1 promoter hypermethylation. Patients with an MMR-deficient tumor or adenoma without MLH1 promoter hypermethylation were referred for genetic analysis. Results At colonoscopy, 456 patients (41%) (65% male; mean age, 67 years; interquartile range, 63–71 years) were found to have CRC and/or an adenoma eligible for analysis by immunohistochemistry. Of 56 CRCs, 7 (13%) had lost an MMR protein and 5 had hypermethylation of the MLH1 promoter. Analyses of tumor DNA revealed that 2 patients without MLH1 promoter hypermethylation had developed sporadic tumors. In total, 400 patients with adenomas were analyzed. Of the examined adenomas, 208 (52%) had a villous component and/or high-grade dysplasia: 186 (47%) had a villous component and 41 (10%) had high-grade dysplasia. Only 1 adenoma had lost an MMR protein. This adenoma was found to have 2 somatic mutations in MSH6. Conclusions In a CRC screening program in The Netherlands for individuals aged 55 to 75 years, routine screening for Lynch syndrome by immunohistochemistry analysis of colon tissues from patients with advanced and multiple adenomas identified no individuals with this genetic disorder.

Background #x0026; Aims: The role of the mismatch repair gene PMS2 in hereditary nonpolyposis colorectal carcinoma (HNPCC) is not fully clarified. To date, only 7 different heterozygous truncating PMS2 mutations have been reported in HNPCC-suspected families. Our aim was to further assess the role of PMS2 in HNPCC. Methods: We performed Southern blot analysis in 112 patients from MLH1-, MSH2-, and MSH6-negative HNPCC-like families. A subgroup (n = 38) of these patients was analyzed by denaturing gradient gel electrophoresis (DGGE). In a second study group consisting of 775 index patients with familial colorectal cancer, we performed immunohistochemistry using antibodies against MLH1, MSH2, MSH6, and PMS2 proteins. In 8 of 775 tumors, only loss of PMS2 expression was found. In these cases, we performed Southern blot analysis and DGGE. Segregation analysis was performed in the families with a (possibly) deleterious mutation. Results: Seven novel mutations were identified: 4 genomic rearrangements and 3 truncating point mutations. Three of these 7 families fulfill the Amsterdam II criteria. The pattern of inheritance is autosomal dominant with a milder phenotype compared with families with pathogenic MLH1 or MSH2 mutations. Microsatellite instability and immunohistochemical analysis performed in HNPCC-related tumors from proven carriers showed a microsatellite instability high phenotype and loss of PMS2 protein expression in all tumors. Conclusions: We show that heterozygous truncating mutations in PMS2 do play a role in a small subset of HNPCC-like families. PMS2 mutation analysis is indicated in patients diagnosed with a colorectal tumor with absent staining for the PMS2 protein.

G A A b st ra ct s disease, and current in vitro systems do not lend to studying metastasis either. Hence, in this abstract, we demonstrate the development of a new model, called "Tumor in a Dish" or TiD. Methods: Epithelial cells and fibroblasts from the colon and lung, as well as human vascular endothelial cells were used to develop a colon and lung organoid, respectively. For mismatch repair [MMR] proficient and defective cells, we used HCT-116 and DLD-1, and SW480 and LS174T cells, respectively. In addition, we used freshly resected colon cancer samples. For therapeutic interventions, we used 5-fluouracil (5FU), oxaloplatin (OX), irinotecan (IRI) and SN38, the active metabolite of irinotecan. Results: In the multi-cell type organoid system, cancer cells were grown in a 3-dimensional (3D) culture containing normal epithelial cells, fibroblasts and endothelial cells, which took approximately 10 days to form. The model resembles in vivo tumor microenvironments, including cell-cell contact, tumor architecture, and the influence of different cell types. To study colon cancer, we developed both primary TiD (priTiD) and metastatic TiD (metTiD). In the priTiD, we used normal colon epithelial cells and fibroblasts to develop a primary colon organoid and included colon cancer cells to develop a colon tumor. For metTiD, we similarly developed a lung organoid in which we added colon cancer cells and demonstrate colonization. We next determined the efficacy of standard colon cancer treatment agents. We observed differential activity of 5FU in cells with MMR defects in both priand metTiD system when compared to standard 2D cultures. Another surprising result we found was with freshly resected patient samples. Without knowing the genetic characteristics of the cancer tissue, the TiD method was able to identify cells that were resistant to oxaloplatin. Moreover, using this method, we have developed novel drugs that target cancer cells while not affecting the normal tissue. Conclusion: We have developed a novel method for identifying the appropriate therapeutic agent that specifically target tumor tissues, especially with mismatch repair defects. More importantly, the technique has significant utility in precision/personalized medicine, wherein this phenotypic screen can be coupled with current DNA pharmacogenetics to identify the ideal therapeutic agent, thereby increasing the probability of response to treatment while reducing unnecessary side effects.

Background: The success of pancreatic cancer (PC) surveillance depends to a large extent on the commitment of participants to adhere to the repeated follow-up investigations. Though the results of our recently conducted retrospective study showed that the burden of PC surveillance is acceptable, a prospective assessment was warranted to document the mental and psychological impact of PC screening. We aimed to investigate possible changes in cancer worries and levels of anxiety and depression in high-risk individuals participating in a PC surveillance program. Methods Eligible for this prospective questionnaire study were high-risk individuals participating in our multicenter nationwide endoscopic ultrasound (EUS)-MRI-based PC-surveillance study. High-risk individuals were those with a strong family history of PC or carriers of PC-prone gene mutations. Questionnaires, administered both before (pretest) and after (posttest) the baseline PC screening investigations, assessed concerns about developing cancer (CancerWorry Scale), and levels of anxiety and depression (Hospital Anxiety and Depression scale). Results Of the 54 high-risk individuals, 47 (87%) completed both the pretest and posttest questionnaires (38% male, mean age= 52 yr., range 20-74 yrs.). Of these, 44 participated in the PC screening and 3 declined. All participants underwent both EUS and MRI. Prior to undergoing PC screening, 36% of the participants reported being fearful about undergoing EUS, whereas 5% was fearful about the MRI. After screening, 2.3% of all participants feared the next EUS (p

Background: The success of pancreatic cancer (PC) surveillance depends to a large extent on the commitment of participants to adhere to the repeated follow-up investigations. Though the results of our recently conducted retrospective study showed that the burden of PC surveillance is acceptable, a prospective assessment was warranted to document the mental and psychological impact of PC screening. We aimed to investigate possible changes in cancer worries and levels of anxiety and depression in high-risk individuals participating in a PC surveillance program. Methods Eligible for this prospective questionnaire study were high-risk individuals participating in our multicenter nationwide endoscopic ultrasound (EUS)-MRI-based PC-surveillance study. High-risk individuals were those with a strong family history of PC or carriers of PC-prone gene mutations. Questionnaires, administered both before (pretest) and after (posttest) the baseline PC screening investigations, assessed concerns about developing cancer (CancerWorry Scale), and levels of anxiety and depression (Hospital Anxiety and Depression scale). Results Of the 54 high-risk individuals, 47 (87%) completed both the pretest and posttest questionnaires (38% male, mean age= 52 yr., range 20-74 yrs.). Of these, 44 participated in the PC screening and 3 declined. All participants underwent both EUS and MRI. Prior to undergoing PC screening, 36% of the participants reported being fearful about undergoing EUS, whereas 5% was fearful about the MRI. After screening, 2.3% of all participants feared the next EUS (p

In 17 patients GC samples were reevaluated for histological characteristics, 14 were MSIH and 3 failed in MSI testing, however IHC stainings for the affected MMR protein were negative in all these patients. Six (35%), 4 (23%) and 7 (41%) GC samples showed intestinal type, diffuse type and mixed type characteristics respectively. In 13 GC samples, the tissue surrounding GC could be evaluated. Intestinal metaplasia was diagnosed in 5 (38%) samples and atrophic gastritis in 2 (15%) samples. Pre-malignant gastric lesions were evenly distributed throughout intestinal, diffuse and mixed type gastric cancer samples (p=0.40). Conclusions: This study demonstrates that GC develops along similar histopathologic pathways as sporadic gastric cancer in LS. Pre-malignant lesions in tissue surrounding GC were evident in >50% of samples. These data support upper GI surveillance endoscopy in LS subjects.

Colorectal cancer (CRC) is the second most frequent cause of cancer-related death in Western countries: one third of CRC is represented by rectal cancer (RC). Accurate staging is recommended to provide an optimal treatment strategy. Neoadjuvant chemoradiotherapy (NCRT) is increasingly used in the treatment of advanced RCwith the intention of downsizing and downstaging the tumour and to reduce tumour recurrence. Accuracy of EUS staging is reported to be 75-94% for tumour penetration and 7283% for nodal metastases. However after NCRT the EUS accuracy for T staging may decrease (50%) because marked fibrosis, peritumoral infiltration of inflammatory cell necrosis. AIMS: the aims of this study was to verify the accuracy of EUS in restaging RC after neoadjuvant CRT and the efficacy of the therapy in the downstaging and downsizing the tumour. METHODS: we prospectively enrolled consecutive patients affected by RC in stage II-b and III who underwent EUS and MRI or CT or PET before and after neoadjuvant CRT. EUS scanning was performed by one endosonographer using an electronic radial ecoendoscope (Olympus GF UE 160-AL5) with imaging at 7,5-10 MHz. Patients underwent surgical resection after reassessment staging. The reduction of diameter of RC was evaluated using RECIST criteria. Pathological staging was undertaken according to the TNM classification. RESULTS: 14 patients with locally advanced RC were assessed: 10 male, median age 64 yrs (range 56-73). The median distance from the anus was 5 cm. Seven patients were in in stage II-b and 7 in stage III. All patients underwent radiotherapy with no complication associated with chemotherapy (10 pts with CDDP, 2 pts with FOLFOX and 2 pts with FUFA). The downstaging after neadjuvant therapy was observed in 7/14 patients, and significant reduction of tumor diameter in 13/14 patients. There were 13 anterior resections and 1 abdominoperineal resections. EUS post-NCRT T stage was correct in 11/14 pts (3 T0, 5 T3, 3 T2), while 3 pts were over staged (2 T2 and 1 T1). Overall accuracy of EUS post-RCT for pathologic T stage was 93% for T0-T1 stage and 86% for T3 stage. EUS accuracy for N-stage was 79%. CONCLUSION: in our preliminary study neoadjuvant CRT was useful to downstage and downsize locally advanced RC. EUS seems to be an accurate tool to restage RC after neoadjuvant CRT. However our results needed to be confirmed in a large cohort of patients with locally advanced RC.