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Cell-cell and cell-matrix adhesion proteins that have been implicated in colorectal epithelial integrity and epithelial-to-mesenchymal transition could be robust prognostic and potential predictive biomarkers for standard and novel therapies. We analyzed in situ protein expression of E-cadherin (ECAD), integrin beta 4 (ITGB4), zonula occludens 1 (ZO-1), and cytokeratins in a single-hospital series of Norwegian patients with colorectal cancer (CRC) stages I-IV (n = 922) using multiplex fluorescence-based immunohistochemistry (mfIHC) on tissue microarrays. Pharmacoproteomic associations were explored in 35 CRC cell lines annotated with drug sensitivity data on > 400 approved and investigational drugs. ECAD, ITGB4, and ZO-1 were positively associated with survival, while cytokeratins were negatively associated with survival. Only ECAD showed independent prognostic value in multivariable Cox models. Clinical and molecular associations for ECAD were technically validated on a different mfIHC platform, and the prognostic value was validated in another Norwegian series (n = 798). In preclinical models, low and high ECAD expression differentially associated with sensitivity to topoisomerase, aurora, and HSP90 inhibitors, and EGFR inhibitors. E-cadherin protein expression is a robust prognostic biomarker with potential clinical utility in CRC.

BACKGROUND: While large GWAS analyses have not found convincing associations between MDM2 promoter SNP55 and gynaecological cancers, SNP55 is in linkage disequilibrium with two other functional SNPs in the same promoter, likely to obscure associations between single SNPs and cancer risk. Here, we assessed the impact of SNP55 on risk of endometrial and ovarian cancer, including sub-analyses stratified for other functional SNPs in the region.MATERIAL AND METHODS: Using a custom LightSNiP assay, we genotyped SNP55 in two large hospital-based cohorts of patients with ovarian (n = 1,332) and endometrial (n = 1,363) cancer and compared genotypes to healthy female controls (n = 1,858).RESULTS: Among individuals harbouring the SNP309TT genotype, the minor SNP55T-allele was associated with a reduced risk of endometrial (dominant model: OR = 0.63; CI = 0.45-0.88; p = 0.01). Regardless of the genotype in neighbouring SNPs, the SNP55T-allele was also associated with a reduced risk of endometrial cancer before 50 years of age (dominant model: OR = 0.56; CI = 0.34-0.90; p = 0.02). No association between SNP55 status and ovarian cancer risk was observed.CONCLUSIONS: MDM2 SNP55T-allele may correlate with reduced risk for endometrial cancer in a SNP309T-, but not SNP309G, context.

Flourescence-based multiplex immunohistochemistry (mIHC) combined with multispectral imaging and digital image analysis (DIA) is a quantitative high-resolution method for determination of protein expression in tissue. We applied this method for five biomarkers (CDX2, SOX2, SOX9, E-cadherin, and β-catenin) using tissue microarrays of a Norwegian unselected series of primary colorectal cancer. The data were compared with previously obtained chromogenic IHC data of the same tissue cores, visually assessed by the Allred method. We found comparable results between the methods, although confirmed that DIA offered improved resolution to differentiate cases with high and low protein expression. However, we experienced inherent challenges with digital image analysis of membrane staining, which was better assessed visually. DIA and mIHC enabled quantitative analysis of biomarker coexpression on the same tissue section at the single-cell level, revealing a strong negative correlation between the differentiation markers CDX2 and SOX2. Both methods confirmed known prognostic associations for CDX2, but DIA improved data visualization and detection of clinicopathological and biological associations. In summary, mIHC combined with DIA is an efficient and reliable method to evaluate protein expression in tissue, here shown to recapitulate and improve detection of known clinicopathological and survival associations for the emerging biomarker CDX2, and is therefore a candidate approach to standardize CDX2 detection in pathology laboratories., Digital image analysis (DIA) of multiplex fluorescence-based immunohistochemistry and visual chromogenic evaluation of CDX2, SOX2, SOX9, E-cadherin, and β-catenin in colorectal cancer are comparable, recognizing prognostic value of CDX2 and negative correlation with SOX2. Membrane staining is best evaluated visually, while DIA enables single-cell coexpression analysis and improves visualization and detection of clinicopathological and biological associations.

Gastric cancer is the fifth most common cancer and the third cause of global cancer mortality. CDX2 is an intestinal differentiation marker with prognostic value in gastric cancer and transcriptionally regulates the expression of glycoprotein A33 (GPA33) and liver intestine cadherin (LI-cadherin). This study evaluated the clinical significance of the combined expression of CDX2 and its targets GPA33 and LI-cadherin in gastric cancer by fluorescence-based multiplex immunohistochemistry together with digital image analysis and chromogenic immunohistochemistry in 329 gastric cancer samples arranged in tissue microarrays. Additionally, publicly available RNA-seq expression data from 354 gastric cancer samples from the TCGA database were used to validate the immunohistochemistry results. Expression of the three markers (CDX2, GPA33, and LI-cadherin) was strongly correlated, defining an intestinal differentiation panel. Low or negative protein expression of the intestinal differentiation panel identified patients with particularly poor overall survival, irrespective of the methodology used, and was validated in the independent series at the RNA-seq level. Expression of the intestinal differentiation panel (CDX2, GPA33, and LI-cadherin) defines a set of biomarkers with a strong biological rationale and favourable impact for prognostication of gastric cancer patients.

Background: There is a need for improved selection of patients for adjuvant chemotherapy after resection of non-metastatic colorectal cancer (CRC). Regulator of chromosome condensation 2 (RCC2) is a potential prognostic biomarker. We report on the establishment of a robust protocol for RCC2 expression analysis and prognostic tumour biomarker evaluation in patients who did and did not receive adjuvant chemotherapy. Materials and Methods: RCC2 was analysed in 2916 primary CRCs from the QUASAR2 randomised trial and two single-hospital Norwegian series. A new protocol using fluorescent antibody staining and digital image analysis was optimised. Biomarker value for 5-year relapse-free survival was analysed in relation to tumour stage, adjuvant chemotherapy and the molecular markers microsatellite instability, KRAS/BRAFV600E/TP53 mutations and CDX2 expression. Results: Low RCC2 expression was scored in 41% of 2696 evaluable samples. Among patients with stage I–III CRC who had not received adjuvant chemotherapy, low RCC2 expression was an independent marker of inferior 5-year relapse-free survival in multivariable Cox models including clinicopathological factors and molecular markers (HR 1.45, 95% CI 1.09 to 1.94, p=0.012, N=521). RCC2 was not prognostic in patients who had received adjuvant chemotherapy, neither in QUASAR2 nor the pooled Norwegian series. The interaction between RCC2 and adjuvant chemotherapy for prediction of patient outcome was significant in stage III, and strongest among patients with microsatellite stable tumours (pinteraction=0.028). Conclusions: Low expression of RCC2 is a biomarker for poor prognosis in patients with stage I–III CRC and seems to be a predictive biomarker for effect of adjuvant chemotherapy.

Colorectal cancer commonly metastasizes into multiple liver foci, but intermetastatic heterogeneity remains poorly described. Here, we demonstrate that mutations of RAS/BRAF/TP53 are homogeneous within patients, while DNA copy number aberrations can vary greatly. RAS/BRAF/TP53 co‐mutations conferred a dismal prognosis, and co‐mutations combined with a high burden and heterogeneity of copy number aberrations identified patients with the poorest outcome., Hepatic resection is potentially curative for patients with colorectal liver metastases, but the treatment benefit varies. KRAS/NRAS (RAS)/TP53 co‐mutations are associated with a poor prognosis after resection, but there is large variation in patient outcome within the mutation groups, and genetic testing is currently not used to evaluate benefit from surgery. We have investigated the potential for improved prognostic stratification by combined biomarker analysis with DNA copy number aberrations (CNAs), and taking tumor heterogeneity into account. We determined the mutation status of RAS, BRAF V600, and TP53 in 441 liver lesions from 171 patients treated by partial hepatectomy for metastatic colorectal cancer. CNAs were profiled in 232 tumors from 67 of the patients. Mutations and high‐level amplifications of cancer‐critical genes, the latter including ERBB2 and EGFR, were predominantly homogeneous within patients. RAS/BRAF V600E and TP53 co‐mutations were associated with a poor patient outcome (hazard ratio, HR, 3.9, 95% confidence interval, CI, 1.3–11.1, P = 0.012) in multivariable analyses with clinicopathological variables. The genome‐wide CNA burden and intrapatient intermetastatic CNA heterogeneity varied within the mutation groups, and the CNA burden had prognostic associations in univariable analysis. Combined prognostic analyses of RAS/BRAF V600E/TP53 mutations and CNAs, either as a high CNA burden or high intermetastatic CNA heterogeneity, identified patients with a particularly poor outcome (co‐mutation/high CNA burden: HR 2.7, 95% CI 1.2–5.9, P = 0.013; co‐mutation/high CNA heterogeneity: HR 2.5, 95% CI 1.1–5.6, P = 0.022). In conclusion, DNA copy number profiling identified genomic and prognostic heterogeneity among patients with resectable colorectal liver metastases with co‐mutated RAS/BRAF V600E/TP53.

An increasing demand for genetic testing has moved the procedure from highly selected at-risk individuals, now also including cancer patients for treatment associated testing. The heritable fraction of ovarian cancer is more than 10%, and our department has offered BRCA testing to such patients irrespective of family history since 2002. This study examined potential psychosocial distress associated with this procedure using The Multidimensional Impact of Cancer Risk Assessment (MICRA) questionnaire and other patient-rated generic distress instruments. Patients were divided into four groups according to cancer risk: mutation carriers, own history of breast cancer and ovarian cancer, family history of breast cancer and/or ovarian cancer, and patients without family history. In a postal survey, 354 patients responded. Good acceptance of the MICRA was observed, and previously described good psychometric properties were confirmed. A significant association between MICRA total score and receiving a positive BRCA test result was found. No significant between-group differences were observed with generic distress instruments. Time since cancer diagnosis, test result, and survey showed no significant associations with MICRA scores. Internal consistencies of instruments were adequate. Exploratory and confirmatory factor analyses showed adequate fit indices for a three factor solution of the MICRA, but further refinement of the items should be considered. In conclusion, the specific types of worry and distress most relevant to receiving genetic testing irrespective of family history were not captured by the generic distress instruments. The MICRA was supported as a useful tool for detection of mental distress related to genetic testing and risk evaluation.

The pan lymphocyte marker CD45 exists in various isoforms arising from alternative splicing of the exons 4, 5 and 6. While naïve T cells express CD45RA translated from an mRNA containing exon 4, exons 4–6 are spliced out to encode the shorter CD45R0 in antigen-experienced effector/memory T cells. The SNP C77G (rs17612648) is located in exon 4 and blocks the exon’s differential splicing from the pre-mRNA, enforcing expression of CD45RA. Several studies have linked C77G to autoimmune diseases but lack of validation in other cohorts has left its role elusive. An incidental finding in an ovarian cancer patient cohort from West Norway (Bergen region, n = 312), suggested that the frequency of C77G was higher among ovarian cancer patients than in healthy Norwegians (n = 1,357) (3.0% vs. 1.8% allele frequency). However, this finding could not be validated in a larger patient cohort from South-East Norway (Oslo region, n = 1,198) with 1.2% allele frequency. Hence, C77G is not associated with ovarian cancer in the Norwegian population. However, its frequency was increased in patients with FIGO stage II, endometrioid histology or an age at diagnosis of 60 years or older indicating a possible association with a less aggressive cancer type. publishedVersion

The MDM4 protein (also known as MDMX or HDMX) is a negative regulator of p53, not only by direct interaction but also through its interaction with MDM2. Further, MDM4 overexpression and amplification have been observed in several cancer forms. Recently, a single nucleotide polymorphism (SNP) in the 3’ untranslated region of the MDM4 gene, SNP34091A > C (rs4245739) was reported to alter MDM4 messenger RNA (mRNA) stability by modulating a microRNA binding site, thereby leading to decreased MDM4 levels. In this case-control study, we aimed to evaluate the possible association between MDM4 SNP34091 status and cancer risk by comparing the genotype frequencies in large hospital-based cohorts of endometrial- (n = 1404) and ovarian (n = 1385) cancer patients with healthy female controls (n = 1870). Genotype frequencies were compared by odds ratio (OR) estimates and Fisher exact tests. We found that individuals harboring the MDM4 SNP34091AC/CC genotypes had a significantly elevated risk for serous ovarian cancer (SOC) in general and high-grade serous ovarian cancer (HGSOC) in particular (SOC: OR = 1.18., 95 % CI = 1.01–1.39; HGSOC: OR = 1.25, CI = 1.02–1.53). No association between SNP34091 genotypes and endometrial cancer risk was observed. Our data indicate the MDM4 SNP34091AC/CC genotypes to be associated with an elevated risk for SOC and in particular the HGSOC type. © The Author(s) 2016. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

SummaryMDM2 plays a key role in modulating p53 function. The MDM2 SNP309T > G promoter polymorphism enhances Sp1 binding and has been linked to cancer risk and young age at diagnosis although with conflicting evidence. We report a second MDM2 promoter polymorphism, SNP285G > C, residing on the SNP309G allele. SNP285C occurs in Caucasians only, where 7.7% (95% CI 7.6%–7.8%) of healthy individuals carry the SNP285C/309G haplotype. In vitro analyses reveals that SNP309G enhances but SNP285C strongly reduces Sp1 promoter binding. Comparing MDM2 promoter status among different cohorts of ovarian (n = 1993) and breast (n = 1973) cancer patients versus healthy controls (n = 3646), SNP285C reduced the risk of both ovarian (OR 0.74; CI 0.58–0.94) and breast cancer (OR 0.79; CI 0.62–1.00) among SNP309G carriers.

Gastric cancer is one of the most common types of cancer and the third cause of cancer-related death worldwide. The aggressiveness of the disease is related to, among other factors, tumour differentiation. CDX2 is a known intestinal differentiation marker with prognostic value in gastric cancer and two of its targets are expressed at the cell surface: GPA33 (glycoprotein A33) and LI-cadherin (liver intestine cadherin). Whether these membrane proteins are good biomarkers in gastric cancer and could refine the significance of CDX2 expression remains unknown. In order to answer these questions, we evaluated the expression of CDX2, GPA33 and LI-cadherin using immunohistochemistry in 350 gastric cancer samples arranged in TMAs (tissue microarrays) and evaluated the co-localization of the biomarkers using fluorescent multiplex immunohistochemistry. CDX2 was expressed in 36% of the cases, while GPA33 and LI-cadherin were positive in 55% and 66%, respectively. All markers were significantly correlated with each other and are more often expressed in early stage (I and II) cancers (p < 0.05). Overall survival analysis showed that both GPA33 and LI-cadherin predict better outcome. When stratifying the series in early (I and II) and late (III and IV) stages, both proteins significantly associate with better outcome for late stages of disease progression. Overall, these data indicate that the presence of an intestinal differentiation program in gastric cancer is a marker of good prognosis. The concordance rate between CDX2 and GPA33 and CDX2 and LI-cadherin expression was 68% and 64%, respectively. Since CDX2 displays a heterogeneous pattern of expression and TMA sampling can, by chance, select a negative area in a positive tumour, we also compared CDX2 expression between whole-tissue sections and TMAs. In our series we obtained 68 discrepant cases (positive for CDX2 in whole-tissue sections and negative in the TMAs). For the majority of these cases (50, corresponding to 74%) the combined expression of CDX2 targets, GPA33 and LI-cadherin, can rescue the underrepresentation of CDX2 expression in the TMAs and identifies CDX2-dependent intestinal differentiation. We conclude that CDX2, GPA33 and LI-cadherin are significantly associated with each other and are commonly expressed in early stages of gastric cancer. The expression of GPA33 and LI-cadherin is associated with better overall survival, particularly in late-stage disease patients. Finally, GPA33 and LI-cadherin are good cell surface surrogate markers for CDX2 expression, not only because of the good concordance of expression, but also because the combined expression of GPA33 and LI-cadherin rescues false negative CDX2 cases in TMAs versus whole-tissue samples. Citation Format: Nair Lopes, Christian Bergsland, Merete Bjornslett, Jarle Bruun, Ragnhild Lothe, Raquel Almeida, Leonor David. CDX2 targets, GPA33 and LI-cadherin, are novel biomarkers with prognostic value in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 565.

The role of normal tissue gene promoter methylation in cancer risk is poorly understood.To assess associations between normal tissue BRCA1 methylation and ovarian cancer risk.2 case-control (initial and validation) studies.2 hospitals in Norway (patients) and a population-based study (control participants).934 patients and 1698 control participants in the initial study; 607 patients and 1984 control participants in the validation study.All patients had their blood sampled before chemotherapy. White blood cell (WBC) BRCA1 promoter methylation was determined by using methylation-specific quantitative polymerase chain reaction, and the percentage of methylation-positive samples was compared between population control participants and patients with ovarian cancer, including the subgroup with high-grade serous ovarian cancer (HGSOC).In the initial study, BRCA1 methylation was more frequent in patients with ovarian cancer than control participants (6.4% vs. 4.2%; age-adjusted odds ratio [OR], 1.83 [95% CI, 1.27 to 2.63]). Elevated methylation, however, was restricted to patients with HGSOC (9.6%; OR, 2.91 [CI, 1.85 to 4.56]), in contrast to 5.1% and 4.0% of patients with nonserous and low-grade serous ovarian cancer (LGSOC), respectively. These findings were replicated in the validation study (methylation-positive status in 9.1% of patients with HGSOC vs. 4.3% of control participants-OR, 2.22 [CI 1.40 to 3.52]-4.1% of patients with nonserous ovarian cancer, and 2.7% of those with LGSOC). The results were not influenced by tumor burden, storage time, or WBC subfractions. In separate analyses of young women and newborns, BRCA1 methylation was detected in 4.1% (CI, 1.8% to 6.4%) and 7.0% (CI, 5.0% to 9.1%), respectively.Patients with ovarian cancer were recruited at the time of diagnosis in a hospital setting.Constitutively normal tissue BRCA1 promoter methylation is positively associated with risk for HGSOC.Norwegian Cancer Society.

Two non-Hodgkin lymphomas (NHL), one chronic lymphocytic leukaemia/small lymphocytic lymphoma and one diffuse large B-cell lymphoma and three cases of myeloid leukaemia, two chronic (CML) and one acute (AML), showed, by G-banding analysis, apparently identical chromosomal translocations t(14;22)(q32;q11), in three of the cases as the sole abnormality. Fluorescence in situ hybridisation (FISH) analysis with locus-specific probes for ABL at 9q34 [bacterial artificial chromosomes (BACs) 835J22 and 1132H12], IGH at 14q32 [P1 artificial chromosome (PAC) 998D24] and IGL (PAC 1019H10) and BCR (BAC 74M14) at 22q11, as well as multicolour in situ hybridisation (M-FISH) analyses were performed. A three-way variant translocation of the classical t(9;22)(q34;q11), t(9;22;14)(q34;q11;q32), involving both BCR and ABL, was unravelled by the molecular cytogenetic investigations in the three myeloid leukaemia cases; a similar variant translocation has previously been reported in seven CML. The two cases of NHL (one NHL with a similar 14;22-translocation has been reported previously) had no involvement of BCR or ABL, but instead the IGH and IGL genes were shown to be juxtaposed by the t(14;22)(q32;q11). How such a rearrangement with recombination of IGH and IGL might elicit a pathogenetic effect is completely unknown.

A system for efficient heterologous expression of class II bacteriocins is described that is based on introducing two plasmids in a bacteriocin-negative Lactobacillus sake strain. The first plasmid (pSAK20) contains the genes necessary for transcriptional activation of the Sakacin A promoter as well as export and processing of bacteriocin precursors. The second plasmid (a pLPV111 derivative) contains the structural and immunity genes for the bacteriocin of interest fused to the sakacin A promoter. Using this system, various bacteriocins were produced at levels equal to or higher than those obtained with the corresponding wild-type producer strains.

Background While BRCA mutation carriers possess a 20-40% lifetime risk of developing ovarian cancer, knowledge about genetic modifying factors influencing the phenotypic expression remains obscure. We explored the distribution of the MDM2 polymorphisms SNP309T>G and the recently discovered SNP285G>C in Norwegian patients with BRCA related ovarian cancer. Methods 221 BRCA related ovarian cancer cases (BRCA1; n = 161 and BRCA2; n = 60) were tested for the MDM2 polymorphisms. Results were compared to healthy controls (n = 2,465). Results The SNP309G allele was associated with elevated OR for ovarian cancer in BRCA1 mutation carriers (SNP309TG: OR 1.53; CI 1.07-2.19; p = 0.020; SNP309GG: OR 1.92; CI 1.19-3.10; p = 0.009; SNP309TG+GG combined: OR 1.61; CI 1.15-2.27; p = 0.005). In contrast, the SNP285C allele reduced risk of BRCA1 related ovarian cancer in carriers of the SNP309G allele (OR 0.50; CI 0.24-1.04; p = 0.057). Censoring individuals carrying the SNP285C/309G haplotype from the analysis elevated the OR related to the SNP309G allele (OR 1.73; CI 1.23-2.45; p = 0.002). The mean age at disease onset was 3.1 years earlier in carriers of SNP309TG+GG as compared to carriers of SNP309TT (p = 0.068). No such associations were found in BRCA2 related ovarian cancer. Conclusions Our results indicate the SNP309G allele to increase and the SNP285C allele to reduce the risk of BRCA1 related ovarian cancer. If confirmed in independent studies, this finding may have implications to counseling and decision-making regarding risk reducing measures in BRCA1 mutation carriers.

Background MDM4 enhances MDM2's E3 ligase activity causing ubiquitin-proteasome-dependent degradation of p53. Thus, elevated levels of both MDM4 and MDM2 may result in p53 inactivation and elevated cancer risk. A single nucleotide polymorphism in the MDM4 3′ UTR (SNP34091A>C; rs4245739) has been found to exert biological function as the SNP34091C allele creates a putative target site for hsa-miR-191 leading to specific hsa-miR-191 down-regulation of MDM4. Further, the SNP34091AA genotype is associated with increased risk for both recurrence and tumor related death in estrogen negative ovarian cancer patients. In the present study we assessed the potential effect of MDM4 SNP34091A>C on cancer risk in six major cancer forms. Materials and methods We analyzed 1717 breast-, 1331 lung-, 1531 colon-, 2501 prostate cancer cases and 3747 healthy controls form the same population based study (CONOR) as well as 1404 endometrial- and 1699 ovarian cancer cases from hospital based studies. All samples were genotyped for MDM4 SNP34091A>C using custom Light-SNiP assay on a LightCycler 480 II instrument. Potential associations between MDM4 SNP34091 and cancer risk were estimated by calculating Odds Ratio (OR) with 95% confidence intervals (CI). All statistical analyses were performed using the IBM SPSS 19 software. Results We observed no significant association between MDM4 SNP34091A>C status and cancer risk in any of the analyzed cancer forms. Interestingly, stratifying the ovarian cancer samples according to grade and histology, we observed a reduced risk of high grade serous ovarian cancer in patients harboring the MDM4 SNP34091AA genotype (OR = 0.80; 95% CI = 0.65 - 0.98). Stratifying according to MDM2 SNP309 status we found the MDM4 SNP34091A allele to be associated with increased risk for breast cancer (OR = 2.10; 95% CI = 1.08 - 4.10) in patients carrying the SNP309 GG genotype. Conclusions The data presented here indicate that the effect of MDM4 SNP34091 on cancer risk may be tissue specific and that there may be cooperative effects with MDM2 SNP309. Citation Format: Liv B. Gansmo, Merete Bjørnslett, Anne Dørum, Helga Salvesen, Pål Romundstad, Kristian Hveem, Lars Vatten, Per Eystein Lønning, Stian Knappskog. MDM4 SNP 34091 (rs4245739) effect on risk of breast, colon, lung, prostate, endometrial and ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4613. doi:10.1158/1538-7445.AM2015-4613

Background: The mechanisms underlying resistance to chemotherapy in ovarian cancer are incompletely understood. Identifying genetic alterations associated with treatment response is decisive in the determination of which patients may benefit from adjuvant chemotherapy. Methods: Biopsies were collected from twenty patients diagnosed with ovarian cancer who were subjected to post-operative taxane- and platinum-containing chemotherapy. Patients were selected for genetic analyses based on response to chemotherapy, determined as time to relapse (10 sensitive and 10 resistant patients). A panel of 620 genes, including known cancer driver genes, as well as genes involved in DNA repair were analysed by massively parallel sequencing. Alignment and mutation calling was performed using MiSeq Reporter, with further manual filtering of variants to exclude common SNPs. Validation of low quality mutation calls was done by Sanger sequencing. Results: A median of 6 genes (range: 3 - 45) per patient was found to harbour non-synonymous mutations. Among previously identified driver genes in ovarian cancer, we found mutations in TP53, BRCA1, CDK12, NF1 and CSMD3. These mutations were more common among patients with more advanced disease and higher grade. For example, TP53 mutations were found in 10 out of 12 patients with high grade, stage 3c or 4 disease, and in 2 out of 5 with lower stage and/or grade. One patient was found to have a tumor potentially of a hyper-mutator phenotype with 49 mutations in 45 genes identified within our gene panel. With respect to treatment efficacy, 73 and 40 genes were found to be mutated exclusively in patients with a good and poor response to treatment, respectively. Conclusion: We describe the profile of mutations in cancer driver genes and DNA repair genes among patients suffering from ovarian cancer according to treatment response. Citation Format: Einar Birkeland, Rakel Blaalid, Merete Bjørnslett, Anne Dørum, Per Eystein Lønning, Stian Knappskog. Mutation analysis of cancer drivers and DNA repair genes in chemosensitive versus resistant ovarian cancers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2833. doi:10.1158/1538-7445.AM2014-2833

9569 Background: Ten to 15% of ovarian cancer patients are BRCA mutation carriers. By offering genetic testing, families at risk and healthy female mutation carriers will be identified and offered clinical follow-up. The MICRA questionnaire was developed as a brief, practical, and targeted assessment of concerns and psychosocial issues associated with genetic testing. This study evaluates the practical and psychometric properties of the MICRA (Norwegian translation) in tested ovarian cancer patient. Methods: Since 2002, ovarian cancer patients at Oslo University Hospital, Norwegian Radium Hospital are offered genetic counseling and testing. By the end of 2009, 1,032 were included. The 530 (51%) patients still alive, were mailed the MICRA and three other instruments relevant for mental distress. 354 (67%) patients responded. Among them 9% were BRCA mutation carriers, 7% had a personal history of breast cancer, 29% had a family history of breast and/or ovarian cancer, and 55% had no such family history. Results: In the BRCA mutation carrier group, the total MICRA score and its subscale scores of distress, uncertainty, and positive experiences were all significantly higher than in the other groups. Confirmatory factor analyses of the three subscales of MICRA showed inadequate fit indices, while a four factors solution including the new factor of Support from family (items #18 and #19), showed adequate fit. The Positive Experiences subscale showed a maximum of 4% explained variance in relation to the Hospital Anxiety and Depression Scale total score, the Impact of Event Avoidance and Intrusion scores, and the Eysenck’s Neuroticism score. The subscales of Distress and Uncertainty showed maximum 12% and 41% explained variance, respectively, while the total MICRA score showed 22% explained variance. Conclusions: Our study supports the feasibility of the MICRA in ovarian cancer patients. Frail women may be identified for closer follow-up by using MICRA. Discrimant, content and construct validities of the MICRA were supported, while the factor structure still is open to further investigation.

5030 Background: While BRCA mutation carriers possess a 20-40% lifetime risk of ovarian cancer (OC), genetic modifying factors that influence the individual phenotypic expression, remains obscure. ...

PTEN regulates cell homeostasis by inhibiting growth signals transduced through PI3-kinases. The gene is mutated in several cancer types, but so far, only a limited number of mutations have been reported in colorectal cancer. In the present study, direct sequencing was used to analyze the whole coding region and exon-intron boundaries of PTEN in a series of microsatellite stable (n=34) and microsatellite unstable (n=30) colorectal carcinomas with known TP53 mutation status. We detected 21 PTEN mutations in altogether 13 tumors (20%), including 19 mutations in the coding sequence and two in the exon-intron boundaries. Sixteen of these alterations have not been previously reported in colorectal cancer. Furthermore, seven out of the 13 altered tumors harbored more than one mutation, potentially leading to loss of gene function. Finally, all PTEN mutations found were in tumors harboring wild-type TP53. In conclusion, PTEN is mutated in a significant subgroup of colorectal carcinomas, and our findings further extend the previously small spectrum of reported PTEN changes. Additionally, it seems that mutations in PTEN and TP53 are mutually exclusive for this cancer type.

Cowden syndrome (multiple hamartoma syndrome, MIM 158350) is an early onset syndrome characterized by multiple hamartomas in the skin, mucous membranes, breast, thyroid and endometrium. Patients with Cowden syndrome have increased risk of breast cancer, thyroid cancer and endometrial cancer. In 1997 germline mutations in PTEN were demonstrated to cause Cowden syndrome. We report the results of diagnostic and predictive testing in all families with Cowden syndrome or suspected Cowden syndrome registered at the Norwegian cancer family clinics. PTEN mutations were found in all six families meeting the clinical criteria for Cowden syndrome, in none of the two families assumed to have Cowden syndrome but not fulfilling the criteria, and in none of the eight families selected in our computerized medical files to have a combination of breast and thyroid cancers. Age-related penetrances for the various neoplasms are given. All families but one were small and de novo mutations were found.