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Dosage effect is one of the common mechanisms of somatic copy number alteration in the development of colorectal cancer, yet the roles of dosage-sensitive genes (DSGs) in colorectal cancer (CRC) remain to be characterized more deeply. In this study, we developed a five-step pipeline to identify DSGs and analyzed their characterization in CRC. Results showed that our pipeline performed better than existing methods, and the result was significantly overlapped between solid tumor and cell line. We also found that the top five DSGs (PSMF1, RAF1, PTPRA, MKRN2, and ELP3) were associated with the progression of CRC. By analyzing the characterization, DSGs were enriched in driver genes and they drove sub-pathways of CRC. In addition, immune-related DSGs are associated with CRC progression. Our results also showed that the CRC samples affected by high microsatellites have fewer DSGs, but a higher overlap with DSGs in microsatellite low instability and microsatellite stable samples. In addition, we applied DSGs to identify potential drug targets, with the results showing that 22 amplified DSGs were more sensitive to four drugs. In conclusion, DSGs play an important role in CRC, and our pipeline is effective to identify them., Graphical Abstract, Xu and colleagues developed a five-step pipeline to identify dosage-sensitive genes and analyzed their characterization in colorectal cancer. The results proved that the pipeline was effective. Additionally the dosage-sensitive genes were proven to be associated with colorectal cancer progression, drove the cancer sub-pathway, and were sensitive to drugs.

Immune checkpoint blockade has emerged as an effective therapeutic strategy for patients with advanced cancer. Identification of biomarkers associated with treatment efficacy will help to select patients more likely to respond to this approach. High levels of microsatellite instability, tumor expression of PD-L1, high tumor mutation burden, and increased tumor-infiltrating lymphocytes have all been associated with response to checkpoint inhibitor blockade. The purpose of this study was to determine if a subset of microsatellite-stable endometrioid endometrial carcinomas have higher immune cell infiltrates and/or expression of PD-L1. PD-L1 expression and characterization of immune cell infiltrates were analyzed in 132 microsatellite stable, FIGO grade 2 endometrioid carcinomas. PD-L1 was positive in 48% (63/132) of the tumors. Tumor cell expression of PD-L1 was significantly associated with lymphatic/vascular invasion and deep myometrial invasion. PD-L1 expression was especially prominent at the invasive front and in foci of tumor-associated squamous metaplasia. Twenty-one cases (16% of the total) with more diffuse and/or especially strong PD-L1 expression were identified. This PD-L1 high subset was associated with significantly higher numbers of tumor-associated CD3+ and CD8+ lymphocytes. Only one tumor in the PD-L1 high subset harbored a POLE mutation. PTEN immunohistochemical loss, a common event in endometrioid-type endometrial carcinoma and associated with local immune suppression in melanoma, was not associated with PD-L1 expression or lymphocyte/macrophage infiltration of the tumor. These results suggest that a subset of microsatellite-stable endometrial cancers has higher expression of PD-L1 and increased tumor-associated CD3+ and CD8+ lymphocytes, characteristics more commonly associated with endometrial cancers with high levels of microsatellite instability. These results suggest that screening strategies to select only microsatellite instability-high advanced endometrial cancers for checkpoint inhibitor therapy might exclude patients who could potentially benefit from this therapeutic approach.

Approximately 20% early-stage (I/II) colorectal cancer (CRC) patients develop metastases despite curative surgery. We aim to develop a formalin-fixed and paraffin-embedded (FFPE)-based predictor of metastases in early-stage, clinically-defined low risk, microsatellite-stable (MSS) CRC patients. We considered genome-wide mRNA and miRNA expression and mutation status of 20 genes assayed in 150 fresh-frozen tumours with known metastasis status. We selected 193 genes for further analysis using NanoString nCounter arrays on corresponding FFPE tumours. Neither mutation status nor miRNA expression improved the estimated prediction. The final predictor, ColoMet19, based on the top 19 genes' mRNA levels trained by Random Forest machine-learning strategy, had an estimated positive-predictive-value (PPV) of 0.66. We tested ColoMet19 on an independent test-set of 131 tumours and obtained a population-adjusted PPV of 0.67 indicating that early-stage CRC patients who tested positive have a 67% risk of developing metastases, substantially higher than the metastasis risk of 40% for node-positive (Stage III) patients who are generally treated with chemotherapy. Predicted-positive patients also had poorer metastasis-free survival (hazard ratios [HR] = 1.92, design-set; HR = 2.05, test-set). Thus, early-stage CRC patients who test positive may be considered for adjuvant therapy after surgery.

Background: Grade 3 (G3, poorly differentiated) is an important treatment-decision factor in stage II colon cancer, but no unified diagnostic criteria are established. According to previous studies, an intra-tumoural poorly differentiated area with no glandular formation (POR) that fills the microscopic field of a 40× objective lens was an essential factor that defined G3. We aimed to prospectively validate this in a randomised controlled study of adjuvant chemotherapy (SACURA trial). Methods: Between 2006 and 2010, we enrolled 991 patients with stage II colon cancer from 123 institutions. POR was quantitatively graded according to the 40× objective lens rule and the intensity of poorly differentiated clusters (GradePOR). The prognostic power of GradePOR was compared with that of the conventional tumour grade based on the predominant histology rule (Gradeconv). Findings: According to GradePOR, 313, 526 and 152 tumours were classified as G1POR, G2POR and G3POR, respectively, and the 5-year relapse-free survival (RFS) rates were 91·1%, 82·9%, and 74·7%, respectively (P < 0·0001). When G3POR and G3conv were alternatively added to the standard prognostic model consisting of eight conventional factors, only G3POR was a significant factor for RFS (P = 0·040, Wald test). The adverse impact of G3POR on RFS was greater in the microsatellite stable (MSS)/microsatellite instability (MSI)-low subset (hazard ratio [HR], 2·61; 95% confidence interval [CI], 1·81–3·77) compared with that in the full analysis set (HR, 1·93; 95% CI, 1·34–2·77). In the MSS/MSI-low subset, the 5-year RFS rate of patients with G3POR tumours in the adjuvant chemotherapy group achieved greater improvement (9·1%) than the surgery-alone group (HR, 0·65; 95% CI, 0·34–1·24). Interpretation: The validated prognostic value of the least differentiation policy with the 40× objective lens rule may be highlighted as the diagnostic criterion for G3 in the adjuvant treatment setting for stage II colon cancer, particularly for MSS/MSI-low tumours. Trial Registration: ClinicalTrials.gov NCT00392899 Funding: This study was supported by the Foundation for Biomedical Research and Innovation at Kobe, Translational Research Center for Medical Innovation (TRI), under the funding contract with Taiho Pharmaceutical Co. Ltd., Japan. Declaration of Interests: MI has received consulting fees from Taiho Pharmaceutical Co. Ltd., BristolMyers Squibb and Merck Serono Co. Ltd; honoraria from Taiho, Chugai Pharmaceutical Co. Ltd., and Yakult Honsha Co. Ltd. HM has received consulting fees from Otsuka Pharmaceutical Factory, Inc. and Sysmex Co.; honoraria from Taiho, Chugai, Yakult Honsha, Daiichi Sankyo Co. Ltd., Astellas Pharma Inc. NT has received research funding from Taiho, Chugai, and Yakult Honsha; honoraria from Taiho, Chugai, Takeda Pharmaceutical Co. Ltd., Merck Serono. YS has received honoraria from Taiho, Chugai and Yakult Honsha. KT has received honoraria from Taiho and Takeda. KK has received consulting fees from Taiho and Chugai; honoraria from Taiho, Chugai, Bristol-Myers, Merck Serono and Otsuka. MW has received research funding from Taiho, Chugai, Yakult Honsha, Johnson and Johnson K. K. and Covidien Japan Co. Ltd. YK has received honoraria from Taiho and Chugai. H. Ueno has received honoraria from Taiho, Chugai, Yakult Honsha, BristolMyers and Daiichi Sankyo. TI has received research funding from Taiho; honoraria from Chugai. H. Uetake has received consulting fees, research funding, and honoraria from Taiho, Chugai, Takeda, Bristol-Myers and Merck Serono. SM has no competing interest. ST has received consulting fees from Taiho, Daiichi Sankyo and Solasia Pharma K. K.; research funding from Daiichi Sankyo, Yakult Honsha and Kureha Co. Ltd.; honoraria from Daiichi Sankyo. KS has received consultant fees, research funding and honoraria from Taiho, Chugai, Takeda, Yakult Honsha, Daiichi Sankyo, Bristol-Myers, Merck Serono, and Pfizer Co. Ltd. Ethics Approval Statement: The study protocol was approved by the Institutional Review Boards of each participating institution and was conducted in accordance with the tenets of the Declaration of Helsinki and comparable Japanese ethical standards. Furthermore, written informed consent was obtained from all study participants.

Current information suggests that SRCAP, TPR and CEACAM5 genes have cancer-related activities, but their alteration status is not well identified in colon cancer (CC). In this study, we analyzed frameshift mutations of these genes in CCs according to the microsatellite instability (MSI) status (high MSI (MSI-H) and microsatellite stable (MSS) CCs). In addition, regional difference in frameshift mutations of SRCAP, TPR and CEACAM5 genes were studied in CCs. In this study, we detected frameshift mutations (deletion or duplication of one or two bases) of SRCAP in 12 (12 %), TPR in 3 (3%) and CEACAM5 in 2 (2%) CCs with MSI-H. However, there was no such mutations in MSS cancers (P 0.001). 18.8 % and 6.3 % of 16 CCs showed the regional difference in the SRCAP and TPR mutations, respectively. Approximately in 60 % of the CCs, SRCAP expression was increased compared to normal colon cells. Our study shows that SRCAP, TPR and CEACAM5 frameshift mutations and their regional difference as well as altered SRCAP expression are present in MSI-H CCs, which could contribute to CC development with MSI-H.

Background Immune checkpoint inhibitors have shown limited clinical benefits in MSS-CRC; dual targeting of non-redundant pathways may enhance antitumor immune response. In a phase I/II, multicenter, open-label study, the anti-PD-L1 antibody durvalumab (D) was combined with monalizumab (M), an IgG4 mAb that blocks NKG2A binding to HLA-E to reduce inhibition of NK and CD8+ T cells. The combination (D+M) was well tolerated and showed encouraging activity in heavily pretreated pts with advanced MSS-CRC. In a dose-exploration cohort, D+M was assessed in combination with standard of care (SOC) chemotherapy and bevacizumab, an anti-VEGF agent, as first-line therapy for advanced/metastatic MSS-CRC. Methods Eligible pts had histologically defined MSS-CRC, regardless of RAS/RAF mutational status, ECOG 0–1 and no prior systemic therapy. They received durvalumab 1500mg Q4W, monalizumab 750mg Q2W, modified FOLFOX6 (folinic acid, fluorouracil, and oxaliplatin) Q2W and bevacizumab 5mg/kg Q2W until end of treatment; dose modifications were allowed according to SOC practice except during the DLT evaluation period. The primary endpoint was safety and tolerability of D+M with FOLFOX6 and bevacizumab; secondary endpoints included antitumor activity. Results As of Mar 25, 2019, 18 pts were enrolled with median follow-up of 6.2 months. Monalizumab-related adverse events (AEs) occurred in 13 (72%), serious in 1 (6%; embolism). Durvalumab-related AEs occurred in 14 (78%; none serious). All pts had chemotherapy-related AEs, serious in 1 (6%; febrile neutropenia) and 10 (56%) had bevacizumab-related AEs, serious in 2 (11%; embolism and febrile neutropenia). There were no grade 5 or dose-limiting toxicities. At 16 weeks, 17 pts were evaluable for response; 9 (53%) had partial responses (7 confirmed, 2 unconfirmed), 6 (35%) had stable disease and 2 (12%) had progressive disease; there were no complete responses. Median time to response for the 7 confirmed responders was 15.4 weeks; median duration of response was not yet reached. Conclusions First-line D+M combined with SOC showed manageable safety and preliminary activity in pts with advanced/metastatic MSS-CRC. Accrual is complete. Clinical trial identification NCT02671435. Editorial acknowledgement Medical writing support was provided by Hashem Dbouk, PhD, of Cirrus Communications (Lyndhurst, NJ), an Ashfield company, and was funded by AstraZeneca. Legal entity responsible for the study AstraZeneca. Funding AstraZeneca. Disclosure J.C. Bendell: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Gilead; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Genentech/Roche; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Advisory / Consultancy, Research grant / Funding (institution): Five Prime; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Merck; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Celgene; Research grant / Funding (institution): EMD Serono; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Taiho; Advisory / Consultancy, Research grant / Funding (institution): MacroGenics; Advisory / Consultancy, Research grant / Funding (institution): GSK; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Novartis; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: OncoMed; Advisory / Consultancy, Research grant / Funding (institution): LEAP; Advisory / Consultancy, Research grant / Funding (institution): TG Therapeutics; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BI; Advisory / Consultancy, Research grant / Funding (institution): Daiichi Sankyo; Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Research grant / Funding (institution): Incyte; Advisory / Consultancy, Research grant / Funding (institution): Apexigen; Research grant / Funding (institution): Koltan; Research grant / Funding (institution): SynDevRex; Research grant / Funding (institution): Forty Seven; Research grant / Funding (institution): AbbVie; Advisory / Consultancy, Research grant / Funding (institution): Array; Research grant / Funding (institution): Onyx; Advisory / Consultancy, Research grant / Funding (institution): Sanofi; Research grant / Funding (institution): Takeda; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): Celldex; Advisory / Consultancy, Research grant / Funding (institution): Agios; Research grant / Funding (institution): Cytomx; Research grant / Funding (institution): Nektar; Research grant / Funding (institution), Travel / Accommodation / Expenses: ARMO; Research grant / Funding (institution): Boston Biomedical; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Ipsen; Advisory / Consultancy, Research grant / Funding (institution): Merrimack; Research grant / Funding (institution): Tarveda; Research grant / Funding (institution): Tyrogenex; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Oncogenex; Research grant / Funding (institution): Marshall Edwards; Research grant / Funding (institution): Pieris; Research grant / Funding (institution): Mersana; Research grant / Funding (institution): Calithera; Research grant / Funding (institution): Blueprint; Research grant / Funding (institution): Evelo; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Forma; Research grant / Funding (institution): Merus; Research grant / Funding (institution): Jacobio; Research grant / Funding (institution): Effector; Research grant / Funding (institution): Novocare; Research grant / Funding (institution): Arrys; Research grant / Funding (institution): Tracon; Research grant / Funding (institution): Sierra; Advisory / Consultancy, Research grant / Funding (institution): Innate; Advisory / Consultancy, Research grant / Funding (institution): Arch Oncology; Advisory / Consultancy, Research grant / Funding (institution): Prelude Oncology; Research grant / Funding (institution): Unum Therapeutics; Research grant / Funding (institution): Vyriad; Research grant / Funding (institution): Harpoon; Research grant / Funding (institution): ADC; Advisory / Consultancy, Research grant / Funding (institution): Amgen; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Millennium; Research grant / Funding (institution): Imclone; Research grant / Funding (institution): Acerta Pharma; Research grant / Funding (institution): Rgenix; Research grant / Funding (institution): Bellicum; Advisory / Consultancy: Phoenix Bio; Advisory / Consultancy: Cyteir; Advisory / Consultancy: Molecular Partners; Advisory / Consultancy: Innate; Advisory / Consultancy: Torque; Advisory / Consultancy: Tizona; Advisory / Consultancy: Janssen; Advisory / Consultancy: Tolero; Advisory / Consultancy: TD2 (Translational Drug Development); Advisory / Consultancy: Seattle Genetics; Advisory / Consultancy: Moderna Therapeutics; Advisory / Consultancy: Tanabe Research Laboratories; Advisory / Consultancy: Beigene; Advisory / Consultancy: Continuum Clinical; Advisory / Consultancy: Kyn. J. Naidoo: Research grant / Funding (institution): Merck; Advisory / Consultancy, Research grant / Funding (institution): AstraZeneca; Advisory / Consultancy: BMS. X. Li: Full / Part-time employment: AstraZeneca. P. Kourtesis: Shareholder / Stockholder / Stock options, Full / Part-time employment: AstraZeneca. S.E. Abdullah: Travel / Accommodation / Expenses, Shareholder / Stockholder / Stock options, Full / Part-time employment: AstraZeneca. S. Patel: Advisory / Consultancy, Research grant / Funding (institution): AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy: Illumina; Advisory / Consultancy: Nektar; Advisory / Consultancy: Tempus; Research grant / Funding (institution): Eli Lilly; Research grant / Funding (institution): Fate; Research grant / Funding (institution): Incyte; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Roche/Genentech; Research grant / Funding (institution): Xcovery; Research grant / Funding (institution): Fate Therapeutics; Research grant / Funding (institution): Genocea; Research grant / Funding (institution): Iovance. All other authors have declared no conflicts of interest.

Background A novel approach to differentiate somatic vs. germline BRCA1/2 mutations in cfDNA using a beta binomial model (AACR 2018, abst #4272) may enable identification of pts with advanced GI tumors who are likely to benefit from a PARP inhibitor. The results from the GOZILA study, the Nationwide Cancer Genome Screening Project utilizing Guardant360, are presented here. Methods Pts with advanced GI tumors who were appropriate for any systemic therapy and had progressed following at least one prior treatment were eligible. We investigated the prevalence of somatic vs. germline BRCA1/2 mutations and the association between BRCA1/2 mutations, TMB and MSI. Results From Jan 2018 to Mar 2019, 850 pts were prospectively enrolled among 26 major cancer centers in Japan. Of 40 (4.7%) actionable BRCA1/2 mutations, 14 were germline: esophagus (squamous cell carcinoma only), 2 pts (N = 62, 3.2%); stomach, 2 pts (N = 131, 1.5%); colorectum, 3 pts (N = 377, 0.8%); pancreas, 3 pts (N = 157, 1.9%); biliary tract, 4 pts (N = 77, 5.2%); and others, none (N = 31, 0%). Notably, the majority of BRCA1/2 mutations (75%) in pts with esophageal, pancreas and biliary tract cancers were germline, while 81% of BRCA1/2 mutations in pts with stomach and colorectal cancers were somatic (p = 0.001). Median TMB of pts with germline BRCA1/2 mutations was significantly lower than those with somatic BRCA1/2 mutations (p = 0.042). In addition, all pts with germline BRCA1/2 mutations were microsatellite stable, while 19% of pts with somatic BRCA1/2 mutations were MSI-high. Conclusions Analysis of cfDNA identified a unique subset of pts with germline BRCA1/2 mutations in advanced GI cancers. Given the association of these findings with efficacy of PARP inhibitor and immune-based therapies, these findings suggest that the identification of BRCA1/2 mutations and their germline-somatic origin may have future implications for therapy selection. Clinical trial identification UMIN000029315. Legal entity responsible for the study SCRUM-Japan GI-SCREEN. Funding Guardant Health, Ono Pharmaceutical. Disclosure Y. Kawamoto: Honoraria (self): Taiho Pharmaceutical Co., Ltd.; Honoraria (self): Daiichi Sankyo Co., Ltd.; Honoraria (self): Takeda Pharmaceutical Co., Ltd.; Honoraria (self): Chugai Pharmaceutical Co., Ltd.; Honoraria (self): Merck Biopharma Co., Ltd.; Honoraria (self): Eli Lilly Japan K.K.. Y. Nakamura: Research grant / Funding (institution): Ono Pharmaceutical; Research grant / Funding (institution): Taiho Pharmaceutical. M. Ikeda: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Novartis Pharma; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Bayer Yakuhin; Research grant / Funding (institution): Bristol-Myers Squibb; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Eisai; Honoraria (self): Taiho Pharmaceutical; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Eli Lilly Japan; Research grant / Funding (institution): Yakult; Advisory / Consultancy: Otsuka Pharmaceutical; Advisory / Consultancy: Daiichi-Sankyo; Honoraria (self): Sumitomo Dainippon Pharma; Honoraria (self), Advisory / Consultancy: Teijin Pharma; Honoraria (self): EA Pharma; Honoraria (self): MSD; Advisory / Consultancy, Research grant / Funding (institution): ASLAN Pharmaceuticals; Advisory / Consultancy, Research grant / Funding (institution): Chugai Pharmaceutical; Research grant / Funding (institution): Ono Pharmaceutical; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Merck Serono; Research grant / Funding (institution): Nano Carrier; Honoraria (self): Gilead. H. Bando: Honoraria (self): Taiho Pharmaceutical company; Honoraria (self): Eli Lilly; Research grant / Funding (self): Sysmex; Research grant / Funding (self): AstraZeneca. T. Esaki: Honoraria (self), Research grant / Funding (institution): Taiho; Honoraria (self): Chugai; Honoraria (self), Research grant / Funding (institution): Ono; Honoraria (self): Takeda; Honoraria (self): Bayer; Honoraria (self): Eli Lilly; Research grant / Funding (institution): Astellas; Research grant / Funding (institution): MSD; Research grant / Funding (institution): Daiichi-Sankyo; Research grant / Funding (institution): Merck Serono; Research grant / Funding (institution): Dainippon Sumitomo; Research grant / Funding (institution): Novartis. M. Ueno: Honoraria (self), Research grant / Funding (institution): Taiho Pharmaceutical; Honoraria (self), Research grant / Funding (institution): Yakult Honsha; Honoraria (self), Research grant / Funding (institution): AstraZeneca; Honoraria (self): Novartis; Honoraria (self): Lilly; Honoraria (self): Teijin Pharma; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Shire; Honoraria (self), Research grant / Funding (institution): Ono Pharmaceutical; Honoraria (self), Research grant / Funding (institution): Merck Serono; Research grant / Funding (institution): Daiichi Sankyo; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): MSD; Research grant / Funding (institution): NanoCarrier; Research grant / Funding (institution): Dainippon Sumitomo Pharma; Research grant / Funding (institution): Incyte; Research grant / Funding (institution): ASLAN Pharmaceuticals. T. Nishina: Honoraria (self), Research grant / Funding (institution): Taiho pharmaceutinal; Honoraria (self), Research grant / Funding (institution): Chugai Pharma; Honoraria (self), Research grant / Funding (self): Merck Serono; Honoraria (self), Research grant / Funding (institution): Bristol-Myers Suibb; Honoraria (self): Nihonkayaku; Honoraria (self), Research grant / Funding (institution): Lilly Japan; Honoraria (self), Research grant / Funding (institution): Ono Pharmaceutical; Research grant / Funding (institution): Dainippon Sumitomo Pharma; Research grant / Funding (institution): MSD; Research grant / Funding (institution): Diichi Sankyo. E. Oki: Speaker Bureau / Expert testimony: Taiho Pham; Speaker Bureau / Expert testimony: Yakult Honsha; Speaker Bureau / Expert testimony: Merck; Speaker Bureau / Expert testimony: Chugai Pham; Speaker Bureau / Expert testimony: Takeda Pharm; Speaker Bureau / Expert testimony: Eli Lilly; Speaker Bureau / Expert testimony: Bayer. T. Denda: Speaker Bureau / Expert testimony: DAIICHI SANKYO COMPANY, LIMITED. T. Mizukami: Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Eli Lilly Japan; Advisory / Consultancy: Bristol-Myers Squibb Company; Speaker Bureau / Expert testimony: Takeda Pharmaceutical; Research grant / Funding (institution): TAIHO Pharmaceutical. N. Okano: Honoraria (self): Taiho Pharmaceutical; Honoraria (self): Merck Serono; Honoraria (self): Eisai; Honoraria (self): Ono Pharmaceutical; Honoraria (self): Yakult Honsha; Honoraria (self): Takeda; Honoraria (self): J-Pharma; Honoraria (self): Kyowa Hakko Kirin. M.I. Lefterova: Shareholder / Stockholder / Stock options, Full / Part-time employment: Guardant Health. J.I. Odegaard: Shareholder / Stockholder / Stock options, Full / Part-time employment: Guardant Health. H. Taniguchi: Honoraria (self): Chugai; Honoraria (self), Research grant / Funding (self): Takeda; Honoraria (self): Taiho; Honoraria (self): Eli Lilly; Research grant / Funding (self): Daiichi-Sankyo; Research grant / Funding (self): Sysmex. C. Morizane: Honoraria (self), Research grant / Funding (institution): Pfizer; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Yakult Honsha; Honoraria (self): Lilly; Honoraria (self), Research grant / Funding (institution): Nobelpharma; Honoraria (self): Fujifilm; Honoraria (self): Teijin Pharma; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Taiho Pharmaceutical; Honoraria (self), Research grant / Funding (institution): Eisai; Advisory / Consultancy: Abbvie; Research grant / Funding (institution): ONO PHARMACEUTICAL; Research grant / Funding (institution): J-Pharma. T. Yoshino: Research grant / Funding (self): Novartis Pharma K.K.; Research grant / Funding (self): MSD.K.K.; Research grant / Funding (self): Sumitomo Dainippon Pharma Co., Ltd.; Research grant / Funding (self): CHUGAI PHARMACEUTICAL Co., Ltd.; Research grant / Funding (self): Sanofi K.K.; Research grant / Funding (self): DAIICHI SANKYO Co., Ltd.; Research grant / Funding (self): PAREXEL International Inc.; Research grant / Funding (self): ONO PHARMACEUTICAL Co., Ltd. All other authors have declared no conflicts of interest.

Background Several studies in BRAFV600E colorectal cancers (CRC) have failed to replicate the efficacy of BRAF inhibitors in treatment of BRAFV600E melanomas (Mel), suggesting the existence of different resistance mechanisms as well as molecular and biological differences between the 2 tumor types. Herein, we examine these differences. Methods Tumor samples submitted to Caris Life Sciences for NGS DNA sequencing (592 gene panel) and RNA sequencing (54 gene panel) between the years 2015 and 2019 were retrospectively studied. Only microsatellite stable (MSS) tumors with either BRAFV600E mutation or wild type (WT) BRAF status were included in this initial analysis. Chi-square tests determined differences. Results A total of 8409 tumor samples were analyzed: CRC (N = 7453: BRAFV600E=373; WT = 7080) and Mel samples (N = 956: BRAFV600E=274; WT = 682). The most frequently mutated genes in BRAFV600E CRC were TP53 (81%), APC (26%), and SMAD4 (22.4%), compared to CDKN2A (22%), PTEN (13%), and TP53 (13%) in BRAFV600E Mel. Molecular alterations that are significantly more frequent in BRAFV600E CRC vs BRAFV600E Mel but not significantly different between BRAF WT CRC vs BRAF WT Mel included RSPO3 fusions (CRC=22.6% vs Mel=0%, P = 0.027); RNF43 deletions (2.0% vs 0%, p = 0.019); and mutations in RNF43 (18.8% vs 0%, P Conclusions BRAFV600E CRC carry molecular alterations that are distinct from BRAFV600E Mel. RSPO3 fusions and RNF43 alterations are prevalent in BRAFV600E CRC tumors in a mutually exclusive manner, suggesting that Wnt pathway activation via genetic alterations in upstream Wnt pathway regulators may play an important role in BRAFV600E CRC tumorigenesis and resistance to BRAF inhibitors. Drug combinations that target both the MAPK and Wnt pathways may warrant further investigation. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure M.E. Salem: Travel / Accommodation / Expenses: Caris Life Sciences. J. Xiu: Full / Part-time employment: Caris Life Sciences. A. Grothey: Travel / Accommodation / Expenses: Caris Life Sciences. R.M. Goldberg: Research grant / Funding (self), Travel / Accommodation / Expenses: Caris Life Sciences. Z. Gatalica: Full / Part-time employment: Caris Life Sciences. R. Feldman: Full / Part-time employment: Caris Life Sciences. M. Saul: Full / Part-time employment: Caris Life Sciences. W..M. Korn: Full / Part-time employment: Caris Life Sciences. A.F. Shields: Research grant / Funding (institution), Travel / Accommodation / Expenses: Caris Life Sciences. J.L. Marshall: Advisory / Consultancy: Caris Life Sciences. H.J. Lenz: Travel / Accommodation / Expenses: Caris Life Sciences. All other authors have declared no conflicts of interest.

e15679Background: The benefits of adjuvant chemotherapy remain controversial in microsatellite stable (MSS) stage II resected colorectal cancer (CRC) patients. In this study, we constructed an over...

Introduction Colorectal cancer (CRC) is a molecularly diverse disease with few targeted treatment options. Focal and high-amplitude DNA copy number aberrations are potential tumour drivers, and their identification may contribute to improved therapeutic outcomes in small patient subgroups, as recently illustrated by targeting the over-expression of HER2 protein resulting from high-level ERBB2 amplification in KRAS wild-type metastatic CRC. However, few recurrent amplifications have been detected in CRC. Material and methods We analysed focal high-level amplifications in 203 microsatellite stable (MSS) primary colorectal tumours using genome-wide high-resolution Affymetrix SNP6.0 arrays. The ASCAT algorithm was used to derive discrete allele specific copy number estimates. Results and discussions The overall copy number profiles confirmed the frequent gains and losses previously described in MSS CRC studies. Extreme focal amplifications (defined as >15 copies and ERBB2 , which was amplified to 97, 27 and 22 additional copies in tumours from three individual patients (amplification frequency 1.5%). The transcription factor TOX3 (16q) was also recurrently amplified in 1.5% of the patients, while MYC (8q), CCND2 (12 p) and a region on 10q22.3-q23.1, where ANXA11 was nominated as a likely target by GISTIC analysis, were recurrent in 1% of the patients. Regions with extreme and focal amplifications were also investigated for lower-amplitude aberrations (5–15 additional DNA copies), revealing a 3% amplification frequency of TOX3 in our cohort. Conclusion We have identified several recurrent amplifications in cancer-critical genes in CRC MSS tumours, including the transcription factor TOX3 , suggesting novel drug targets for preclinical studies.

The genetic alterations of appendiceal carcinomas have not been reported in detail. We studied the clinicopathological factors and genetic alterations including microsatellite instability, p53 overexpression, and mutations of the K-ras proto-oncogene of 30 appendiceal adenocarcinomas, consisting of 23 mucinous and 7 nonmucinous carcinomas. Sixteen (70%) mucinous carcinomas presented with pseudomyxoma peritonei, but 6 of 7 (86%) nonmucinous carcinomas presented with appendicitis (P =.002). All carcinomas were microsatellite stable, and p53 overexpression was present in only 1 of 30 (3%) carcinomas. K-ras mutation was present in 11 of 20 (55%) carcinomas, including 8 of 16 (50%) mucinous and 3 of 4 (75%) nonmucinous carcinomas. The mean survival of patients with mucinous carcinomas was 26 +/- 19 months compared with 13 +/- 9 months for patients with nonmucinous carcinomas (P =.0002). Our findings suggest that mucinous and nonmucinous carcinomas of appendix have similar genetic alterations, but different clinical presentation and prognosis.

follow-up period (82,7 months). The study of methylator phenotype was possible in 543 patients (77,5%), with 146 CIMP+ (26,9%) and 397 CIMP(73,1%) patients. Some features between CIMP+ and CIMPCRCs were compared. CIMP+ showed a higher age at diagnosis (CIMP+ 72,8 [39-93]; CIMP70,8 [34-93]; p

It has been documented that Active Specific Immunotherapy (ASI), given as adjuvant treatment, improves survival of patients with stage II and III colorectal cancer. Here we report on the effects of adjuvant ASI in patients with Micro Satellite Stable (MSS) versus Micro Satellite Instable (MSI) tumors. From 196 patients with stage II or stage III colorectal cancer who previously participated in the ASI trial published by Vermorken et al. in the Lancet (1999;353:345e50), we collected frozen tumor samples and/or paraffin-embedded tumor material. From this material DNA was extracted and microsatellite status was assessed. KaplaneMeier curves were plotted to determine survival associations with microsatellite status and treatment group (placebo versus adjuvant ASI treatment). From 196 of the original 256 patients participating in the trial we retrieved good quality archival tumor DNA for further analysis of microsatellite status. We subsequently identified 162 (83%) Micro Satellite Stable tumors and 34 (17%) Micro Satellite Instable tumors. Irrespective of microsatellite status, the current study showed a significant survival benefit for those patients receiving ASI treatment (P 5 0.012), as expected based on the results of Vermorken et al. New to this is that irrespective of treatment, patients with MSI tumors showed significantly fewer recurrences than patients with MSS tumors (P 5 0.03). Taking both MS status and treatment into account, we found no significant difference in survival between ASI versus placebo treated patients bearing MSI tumors. In contrast to this, we found that patients with MSS tumors benefited from ASI treatment in that ASI treated patients showed significantly improved survival (P ! 0.05). It can be concluded that ASI will benefit only patients with MSS tumors, since only they showed significant improved survival upon ASI therapy. For the MSI group there is most likely no benefit of ASI therapy. CONSTITUTIONAL SUBMICROSCOPIC GENOME IMBALANCES IN CHILDREN WITH BOTH CANCER AND A CONGENITAL ANOMALY