bluuebunny/crossref_metadata_2025 huggingface dataset:
Circulating tumor DNA testing and research in patients with gastrointestinal malignancies.
Authors: Shahjehan Faisal , Kamatham Saivaishnavi , Kasi Pashtoon Murtaza
Published: January 2019

525

Background: The hallmark of circulating tumor DNA (ctDNA) is its rapid turnaround and non-invasive nature. According to American Society of Clinical Oncology (ASCO) and College of American Pathologists joint ctDNA review published in March 2018, there is no sufficient evidence to support the use of ctDNA in practice for GI cancers. However, there were numerous studies presented at ASCO Annual Meeting supporting its value. We aimed to summarizing on its role in the management of gastrointestinal cancers based on the studies presented recently. Methods: We limited our search to keywords ‘ctDNA’, ‘circulating tumor DNA’, ‘cell-free DNA (cfDNA)’ and/or ‘liquid biopsy’, at the 2018 ASCO Annual Meeting library abstracts and presentations. Results: There were 35 studies that revolved around ctDNA as a diagnostic tool, prognostic marker and a measure of tumor heterogeneity in gastrointestinal cancers. Depending on the assay used, the results of several studies showed that ctDNA was able to identify relevant mutations including RAS, HER2/Neu, BRAF, MET, BRCA2, APC, TP53, ROS1, PTEN and NF1. The prognosis in terms of tumor mutation burden, objective response rate, metastasis and survival was also estimated based on ctDNA. The findings showed that higher baseline ctDNA levels and/or increased number of mutations detected in ctDNA were associated with poor survival and multi-site metastasis. Right-sided colon cancer was associated with higher number of mutations in ctDNA than left-sided colon and rectal cancers. Similarly, tubular adenocarcinoma subtype of gastric cancer was more likely to have higher ctDNA levels than signet-ring cell subtype. The response to therapy and the residual metastatic disease which was otherwise not detected on imaging could be detected by ctDNA as well. Conclusions: The research at ASCO 2018 report an increasingly promising role of ctDNA in many forms in patients with gastrointestinal malignancies. Experts at the meeting argued that this may well indeed be ready for prime time for certain GI malignancies including colorectal cancers. Prospective studies and studies showing its feasibility into practice can potentially help revise the current guidelines.
Racial disparities and treatment outcomes among patients admitted with a diagnosis of colorectal cancer: Analysis of the 2014 national inpatient sample database.
Authors: Enofe Ikponmwosa , Rai Manoj P. , Osaghae Osamuyimen
Published: January 2019

529

Background: Colorectal cancer is the fourth most common cancer in the United states and the second most common cause of death. Despite universal advocacy for screening colonoscopies and early diagnosis, racial disparities in screening and diagnosis of colorectal cancer exist and affect patients outcomes. In this analysis we determine racial disparities and treatment outcomes for colorectal cancer treatment in the United States. Methods: We performed a retrospective analysis of the National Inpatient Sample 2014 Database (HCUP_NIS) which contains records of all hospital discharges in the United States Patients 18 years and older with a diagnosis of colorectal cancer were identified by their ICD 9 codes along with treatment they had for colorectal cancer. We then used multivariable regression to identify the effect of race on receiving a therapeutic procedure (open surgical, laparoscopic or robotic) during hospitalization and outcomes as it relates to inpatient mortality. We adjusted for patients age, sex, number of comorbidities (elixhauser comorbidity score), insurance type, and hospital level charactertistics (i.e. size, teaching status) and location (urban and rural location). Results: There were 25,749 discharge diagnosis of colorectal cancer in the United States in 2014 of which 19,300 were associated with undergoing a procedure for colorectal cancer treatment. Whites accounted for the majority of colorectal cancer admissions (65%) while blacks 11.4 %, Hispanics 8.0%, Asian/Pacific Islanders 3.2 %, and Native Americans 0.4%. Blacks had the lowest frequency of procedure related admissions and were less likely to undergo a therapeutic procedure relating to colorectal cancer treatment (67.5 vs. 76.6 OR 0.84 CI 0.75 - 0.93) compared to whites. For specific procedures, blacks (OR 0.81, CI 0.72-0.91) and Hispanics (OR 0.85, CI 0.74-0.98) had a significantly lesser odds of undergoing open surgical procedures when compared to whites but were similarly likely (Blacks OR 0.93, CI 0.81-1.05, Hispanics OR 0.84, CI 0.61-1.14) to undergo laparoscopic/robotic surgical procedure. On multivariable analysis, Asian/Pacific Islanders had a significantly higher mortality (OR 1.61 CI 1.01-2.60) for non-procedure related colorectal cancer admissions. However, this increase mortality was not seen in procedure related colorectal cancer admissions. Overall, after adjusting for potential confounders and treatment, there was no significant variation amongst different races for colorectal cancer mortality in patients admitted to the hospital. Conclusions: Among patients with colorectal cancer there was no procedure related mortality differences between various races. However, for some reason Asian/Pacific Islanders had a significantly higher mortality for non-procedure related colorectal cancer admissions. Further studies are warranted to understand the above findings.
Phase Ib study of andecaliximab (GS-5745, ADX) in combination with S-1+platinum chemotherapy in Japanese subjects with advanced gastric or GEJ adenocarcinoma.
Authors: Muro Kei , Satoh Taroh , Yamaguchi Kensei , Takashima Atsuo , Kadowaki Shigenori , Sakai Daisuke , Ichimura Takashi , Mitani Seiichiro , Kudo Toshihiro , Chin Keisho , Kitano Shigehisa , Bhargava Pankaj , Zavodovskaya Marianna , Liu JieJane , Fukui Masato , Boku Narikazu
Published: January 2019

53

Background: Andecaliximab (ADX) is a monoclonal antibody that inhibits matrix metalloproteinase 9 (MMP9), an extracellular enzyme involved in matrix remodeling, tumor growth, and metastasis. In preclinical models, anti-MMP9 inhibited tumor growth, reduced metastases, and increased survival. In this study, safety, tolerability, PK, exploratory biomarkers, and preliminary efficacy of ADX in combination with anti-cancer agents were assessed. Methods: The safety and efficacy of ADX in combination with S-1+cisplatin (SP) or S-1+oxaliplatin (SOX) were evaluated in subjects with systemic chemotherapy naïve advanced gastric or GEJ adenocarcinoma. For SP cohort, six Japanese subjects received ADX 800 mg via IV infusion Q2W. For SOX cohort, 10 subjects received ADX 1200 mg IV Q3W. All subjects continued until PD or unacceptable toxicity. Results: As of August 2018, a total of 16 subjects received S-1+platinum with six subjects enrolled into the SP combination cohort and 10 subjects enrolled into the SOX combination cohort. ≥ Grade 3 AEs were mainly neutropenia (31%), amylase increased, CPK increased, hepatic function abnormal, anorexia, hyperglycaemia, hyponatraemia, anaemia, stomatitis, and peripheral sensory neuropathy (each 6%). The ORR in subjects with measurable target lesions was 73% (8/11) based on investigator evaluation. Median PFS and OS have not been reached. Exploratory biomarker analyses are ongoing. Conclusions: Preliminary safety data demonstrate a manageable safety profile for ADX in combination with S-1+platinum, and the combination appears to show promising response rates. Clinical trial information: NCT02862535.
KRAS mutation status to predict response in first-line capox and bevacizumab therapy for metastatic colorectal cancer.
Authors: Yone You , Abdallah Mohammad , Tahir Saad Sabih , Cellek Selim , Zhang Jufen , Lester Yvonne , Shillito Lauren , Child Jennifer , Dawson Lizzie , Singizi Bryan , Bustin Stephen
Published: January 2019

536

Background: Capecitabine and Oxaliplatin (CAPOX) combined with the humanised anti-vascular endothelial growth factor Bevacizumab represents a standard first-line treatment for metastatic colorectal cancer (mCRC). However, the response rate is only approximately 50% and currently there is no biomarker to predict treatment response. This study aims to correlate KRAS status with response to CAPOX and Bevacizumab (CAPOX-Bev). Methods: Forty-five patients with mCRC were retrospectively screened between January 2012 and December 2015 at Broomfield Hospital, UK. DNA was extracted from formalin-fixed paraffin-embedded (FFPE) tissue samples (Qiagen FFPE tissue kit). Twelve types of mutations in Exons 2, 3 and 4 of the KRAS gene were analysed using a real-time quantitative polymerase chain reaction (qPCR) assay (EntroGen). Treatment response was assessed according to RECIST criteria version 1.1 by comparing pre-treatment and post-treatment radiological CT scans. The KRAS status was correlated with CT tumour response (responders: partial response and complete response; non-responders: progressive disease and stable disease). A Chi-square test was used to determine the correlation between KRAS status and tumour response. Results: 19/45 patients were KRAS wild type (WT, 42%) and 26 were KRAS mutant (MT, 58%). 8/19 (42%) KRAS WT patients were responders, compared to 3/26 (12%) KRAS MT patients. Conversely 11/19 (58%) of WT patients were non-responders, compared to 23/26 (88%) MT patients. The correlation of treatment response and KRAS status was statistically significant (p = 0.018), with a 31% difference in response rate between KRAS WT (42%) and KRAS MT (12%) groups. Conclusions: Within this pilot retrospective analysis, KRAS mutations demonstrated clinical value in identifying patients who are more likely to respond to first-line CAPOX-Bev in advanced colorectal cancer. This finding requires prospective evaluation within a large patient cohort powered to further detect potential differences in overall and progression free survival. [Table: see text]
Expanded RAS and BRAF V600 testing as predictive biomarkers for single agent cetuximab in the randomized phase III CO.17 trial.
Authors: Loree Jonathan M. , Dowers Anthony , Tu Dongsheng , O'Callaghan Christopher J. , Edelstein Dan , Quinn Hannah , Jonker Derek J. , Karapetis Chris , Price Timothy Jay , Zalcberg John Raymond , Moore Malcolm J. , Waring Paul Michael , Kennecke Hagen F. , Hamilton Stanley R. , Kopetz Scott
Published: January 2019

537

Background: KRAS/NRAS ( RAS) testing of exons 2, 3 and 4 is standard prior to anti-EGFR treatment in metastatic colorectal cancer and many consider BRAFV600 ( BRAF) mutations predictive. CO.17 was a randomized phase III trial comparing cetuximab vs best supportive care (BSC) in unselected patients (pts). Re-analysis tested only KRAS exon 2, thus the benefit of cetuximab in RAS/BRAF wild type (WT) pts is unclear. Methods: We retrospectively performed expanded RAS/BRAF testing using a highly sensitive digital PCR method (BEAMing; 1% allele frequency detection limit) on micro-dissected archival tissue from 248 CO.17 pts. Additional pts without available archival tissue, with prior Sanger sequencing or therascreen results were included in analyses if mutations were previously detected (n = 77). Overall survival (OS), progression free survival (PFS), and response rates (RR) were compared by molecular profile. Results: Of 248 sequenced pts, 139 (56%) were RAS mutant, with 112 (45%) exon 2, 11 (4%) exon 3 and 6 (2%) exon 4 KRAS mutant, and 10 (4%) NRAS mutant pts. Seven (3%) BRAF mutant, and 97 (30%) confirmed RAS/BRAF WT pts were identified. Results are summarized below. A test of interaction indicated RAS status was predictive for PFS (p = 0.0001) and OS (p = 0.037) and BRAF status neared significance as a predictive marker for PFS (p = 0.089) but not OS (p = 0.24). Conclusions: These updated results demonstrate an improved PFS (HR 0.25 vs 0.40 previously) and OS (HR 0.51 vs 0.55 previously) for cetuximab in RAS/BRAF WT pts compared to prior analyses that included only KRAS exon 2 mutation status. We provide an estimate of single agent cetuximab efficacy for future anti-EGFR re-challenge studies and demonstrate further support that BRAF mutations may predict lack of benefit from anti-EGFR therapy. Clinical trial information: NCT00079066. [Table: see text]
Excision repair cross-complementing group-1 (ERCC1) gene induction in peripheral blood mononuclear cells as a marker of outcome in patients with colorectal cancer treated with oxaliplatin.
Authors: Rao Devika , Basu Mallick Atrayee , Merla Amartej , Jiffry Jeeshan , Chaudhary Imran , Augustine Titto A , Rajdev Lakshmi , Kaubisch Andreas , Maitra Radhashree , Goel Sanjay
Published: January 2019

542

Background: Oxaliplatin is a third generation platinum agent that confers tumoricidal effect by forming platinum-DNA adducts and is an integral part of the standard of care regimens for patients with colorectal cancer (CRC). Tissue resistance to oxaliplatin appears to be multifactorial, with the nucleotide excision repair (NER) pathway playing a major role. We have previously demonstrated that Excision Repair Cross-Complementing group-1 (ERCC1), can be induced in colorectal cell lines on exposure to Oxaliplatin and high levels confer resistance to apoptosis. We aim to further this knowledge by analyzing gene expression in vivo, using PBMC as a surrogate, to assess ERCC1 as a biomarker of sensitivity to Oxaliplatin therapy. Methods: Patients with CRC who received oxaliplatin were consented to blood (PBMC) sampling at 0, 2, 48 hours, and 14 days during any cycle of chemotherapy. ERCC1 gene expression was quantified by qPCR (quantitative real time polymerase chain reaction) and WB (western blotting). Clinical benefit from oxaliplatin was determined using the parameters of relapse free survival (RFS) for limited stage and progression free survival (PFS) for mCRC. Results: Fifty-four patients were enrolled on study, 25 (46.3%) had mCRC. Twenty-four patients were included in final analysis based on clinical data. Thirteen (52%) had an increase in ERCC expression from baseline, while 11 (48%) showed no change or decrease. Median PFS was 190 and 237 days respectively (log-rank test HR 2.35, CI 1.005-5.479; p = 0.0182). In the 29 patients with limited stage disease, 19 (65.5%) had an induction of ERCC. However, in these patients change in expression did not correlate with RFS. We did not find any significant correlation of PFS with baseline expression of ERCC1 in either group. Conclusions: We confirm our hypothesis that the ERCC1 gene is induced in vivo in a sub-population of patients on treatment with Oxaliplatin. This induction can serve as a potential marker of resistance to oxaliplatin based chemotherapy in mCRC as evidenced by the significant difference in PFS. Further analyses of the influence of ERCC1 polymorphisms on outcomes is underway.
CEA response at four weeks as an early predictor for outcomes in patients (pts) with metastatic colorectal cancer (mCRC) treated with first-line cetuximab-based chemotherapy: A STEP-analysis in the JACCRO CC-05/06 trials.
Authors: Sunakawa Yu , Fang Xuemin , Kotaka Masahito , Tanioka Hiroaki , Takagane Akinori , Tani Satoshi , Yamaguchi Tatsuro , Watanabe Takanori , Masuishi Toshiki , Tsuda Masahiro , Okuno Tatsuya , Tamura Takao , Furushima Kaoru , Kuramochi Hidekazu , Koike Junichi , Yonemura Yutaka , Yasui Hisateru , Takeuchi Masahiro , Fujii Masashi , Ichikawa Wataru
Published: January 2019

543

Background: We have reported that carcinoembryonic antigen (CEA) response correlated with clinical outcomes of 1st-line cet-based therapy (Target Oncol 2017). Early tumor shrinkage (ETS) is considered to be an on-treatment biomarker for outcomes of chemotherapy; however, clinical biomarkers to predict outcomes earlier are warranted. Methods: This study included 69 pts who were assessable for CEA at baseline and 4 wks, and with observed survival time from 2 phase II trials of 1st-line therapy for KRAS exon2 wild-type mCRC; JACCRO CC-05 of cet plus FOLFOX (UMIN000004197) and CC-06 of cet plus SOX (UMIN000007022). We investigated the influence of baseline age, gender, PS, primary tumor sidedness (PTS), number of tumor sites, as well as the CEA decrease at 4 wks to the patient’s OS and PFS. Results: PTS and the CEA decrease at 4 wks were found to be important predictors to OS and PFS. Baseline CEA and CEA decrease at 4 wks were median of 31.0 (range, 1.0-20920.0) and median of 35% (range, -259%-97%), respectively. The STEP-analysis indicated that CEA response was most significantly associated with OS when a cut-off value of 50% for CEA-responder (HR 0.49, log-rank test p = 0.03). Median OS in responders (n = 25) and non-responders (n = 44) were 36.2 m and 21.5 m, respectively. When the same cut-off value was used, median PFS in responders and non-responders were 11.6 m and 6.5 m, respectively (HR 0.64, log-rank test p = 0.08). In addition, a multivariate Cox Proportional-Hazards Model with both PTS and CEA response as risk factors showed that PTS correlated with both OS and PFS. In pts with left-sided tumors, non-responders (n = 33) had shorter OS and PFS compared to responders (n = 23). In the above 2-covariate Cox proportional hazard model, adjusted HR for CEA 50% decrease is 0.55, p = 0.1; adjusted HR for PTS is 2.66, p = 0.008. Conclusions: Our analysis suggests 50% CEA decrease at 4 wks as an early on-treatment biomarker for 1st-line cet-based therapy in mCRC. It may potentially predict outcomes earlier compared to ETS. Also, CEA response at 4 wks may differentiate pts who receive more benefit from cet treatment in left-sided tumors. Clinical trial information: UMIN000004197 and UMIN000007022.
The correlation between DPYD*9A (c.85T > C) genotype and dihydropyrimidine dehydrogenase deficiency phenotype in patients with gastrointestinal malignancies treated with fluoropyrimidines: Updated analysis.
Authors: Singh Maharjan Anu , McMillin Gwendolyn A. , Patel Girijesh K. , Awan Saad , Taylor William R. , Pai Sachin , Frankel Arthur E. , Nelson Cindy , Wang Bin , Hosein Peter Joel , Singh Ajay , Khushman Moh'd M.
Published: January 2019

544

Background: The correlation between DPYD*9A (c.85T > C) genotype and dihydropyrimidine dehydrogenase (DPD) deficiency phenotype is controversial. In our cohort of 28 patients with gastrointestinal malignancies (GI) treated with fluoropyrimidines, DPYD*9A was the most commonly diagnosed variant (46%) and there was a noticeable genotype-phenotype correlation (Khushman et al). In this updated analysis, a larger cohort of a mixed racial background was genotyped for DPYD*9A variant to confirm the incidence and genotype-phenotype correlation. Methods: Between 2011 and 2018, in addition to genotyping for high risk DPYD variants (DPYD*2A, DPYD*13 and DPYD*9B), genotyping for DPYD*9A variant was performed on 113 patients. Fluoropyrimidines-associated toxicity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (v 5.0). Results: DPYD variants were identified in 61 patients. DPYD*2A was identified in 3 patients and DPYD*9B was identified in 2 patients (one patient had double heterozygous *9A and *9B). Heterozygous DPYD*9A was identified in 46 patients (41%) and homozygous DPYD*9A was identified in 11 patients (10%). Among patients with DPYD*9A variant, Caucasians represented 51% and African Americans represented 46%. 27 patients (47%) were females. Grade 3-4 toxicities were experienced in 26 patients with mutant DPYD*9A (3 patients had homozygous DPYD*9A) and in 20 patients with no identified DPYD mutation (P = 0.7035). In patients who received full dose fluoropyrimidines (N = 85), grade 3-4 toxicities were experienced in 22 patients with mutant DPYD*9A (2 patients had homozygous DPYD*9A) and in 17 patients with no identified DPYD mutation (P = 0.8275). Conclusions: In our updated analysis, DPYD*9A variant was the most commonly diagnosed variant. The correlation between DPYD*9A variant and DPD clinical phenotype was not reproduced. The noticeable correlation that we previously reported is likely due to small sample size and patients’ selection and testing bias.
Germline pharmacogenomics of thymidylate synthase gene in patients with gastrointestinal malignancies treated with fluoropyrimidines-based chemotherapy regimens.
Authors: Awan Saad , Patel Girijesh K. , Singh Maharjan Anu , McMillin Gwendolyn A. , Taylor William R. , Pai Sachin , Frankel Arthur E. , Smith Clayton , Grimm Leander , Rider Paul , Hunter John , Liles Spencer , Nelson Cindy , Wang Bin , Hosein Peter Joel , Singh Ajay , Khushman Moh'd M.
Published: January 2019

545

Background: Fluoropyrimidines are antimetabolites that target the S phase of the cell cycle. The active metabolite, 5-fluorodeoxyuridine monophosphate inhibits thymidylate synthase (TS) enzyme, thus preventing DNA synthesis and ultimately cell death. While controversy exists in the literature, polymorphism in the promoter region of thymidylate synthase gene (TYMS) that decrease TS expression has been associated with increased fluoropyrimidines-associated toxicities. This study explored the association between polymorphism in the promoter region of TYMS gene and fluoropyrimidines-associated toxicities in patients with gastrointestinal malignancies with mixed racial background. Methods: Between 2011 and 2018, 126 patients were genotyped for TYMS. Patients with known high-risk dihydropyrimidine dehydrogenase gene variants were excluded. Fluoropyrimidines-associated toxicity was graded according to the National Cancer Institiute Common Terminology Criteria for Adverse Events (v 5.0). Fisher’s exact test was used for statistical analysis. Results: TYMS genotypes that predict increased TS expression (3RG/3RG, 3RG/3RC, 2R/3RG, 2R/4R, 3R/4R, 4R/3RG) were identified in 55 patients (44%). TYMS genotypes that predict decreased TS expression (2R/2R, 2R/3RC, 3RC/3RC) were seen in 71 patients (56%). Among patients with genotypes that predict increased TS expression (N = 55), 12 patients had grade 3-4 toxicity (22%) while among patients with genotypes that predict decreased TS expression, 30 patients had grade 3-4 toxicities (42%) (P = 0.0219). Compared to patients with genotypes predicting increased TS expression, 17 out of 31 patients (55%) with 2R/2R TYMS genotype had grade 3-4 toxicity (P = 0.0039) and 15 out 40 patients (38%) with 2R/3RC and 3RC/3RC TYMS genotype had grade 3-4 toxicity (P = 0.1108). Among patients with 2R/2R TYMS, Caucasians represented 61% and African Americans represented 39%. Females represented 65% of the patients. Conclusions: Polymorphism in the promoter region of TYMS gene that predict decreased TS expression due to 2R/2R variant was associated with grade 3-4 fluoropyrimidines-associated toxicities.
RAS amplified colorectal cancers are enriched in RAS-WT, BRAF-WT, MSS tumors and may predict for anti-EGFR resistance.
Authors: Fakih Marwan , Sandhu Jaideep Singh , Wang Chongkai , Ali Siraj Mahamed , Schrock Alexa Betzig
Published: January 2019

547

Background: Pre-clinical models implicate RAS amplifications ( RASa) as a mechanism of resistance to anti-Epidermal Growth Factor Receptor (EGFR) therapies. Yet, there is little guidance on the impact of RASa, as identified by next generation sequencing (NGS), on anti-EGFR response. Methods: We investigated the Foundation Medicine (FM) database for RASa in CRC and characterized this population based on patient (pt) characteristics and other concurrent genomic alterations. We subsequently investigated City of Hope (COH) mCRC molecular data set (using FoundationOne) and described the RASa population characteristics and response to anti-EGFR. Results: FM cohort included 21,315 CRC unique pt cases. 365 (1.5%) pts had RASa, of which 123 (0.6%) had ≥ 20 copy number (CN) ( RASa≥20). The incidence of MSI-H, RAS and BRAF short variant mutations in the overall, RASa, and RASa≥20 populations were (MSI-H: 5%, 0%, 0%), ( RAS: 54%, 32%, 2%), and ( BRAF: 6%, 1%, 0%), respectively. RASa≥20 tumors had higher level of genomic amplification than the overall population (29% vs. 5% had ≥ 5 genes amplified). COH cohort included 338 mCRC. 12 pts (3.6%) had RASa. The median RAS CN was 27 (7 - 72); 8/12 pts had RASa≥20. All but 2 COH pts with RASa had a RAS/BRAF-WT tumors. Both pts with concurrent RAS mutations had relatively low RAS CN (7&13). Tumors with RASa were predominantly left-sided (11/12). 7/12 pts were treated with anti-EGFR therapy. All 7 pts were RAS/BRAF wild-type: 6 left-sided; 3 pts 1st/2nd lines (1 pt oxaliplatin-based and 2 pts irinotecan-based) and 4 pts chemo-refractory (all irinotecan-based). All 4 chemo-refractory pts had RASa≥20 and progressed on anti-EGFR on 1st post-treatment CT (PFS in all pts ≤ 3 mo). One 1st line pt had SD (PFS = 4 mo). One 2nd line pt had SD (PFS = 7 mo) and one had PD as best response. Conclusions: NGS identifies RASa and RASa≥20in 1.5% and 0.6% of CRC, respectively. RASa≥20 tumors are MSS and, generally lack RAS/ BRAF mutations, and predict for resistance to anti-EGFR. This supports the potential relevance of 20-CN cut-point for the exclusion of pts from anti-EGFR. These findings would benefit from additional validation from retrospective analyses of completed prospective anti-EGFR clinical trials.
Gender and survival benefit from initial irinotecan in metastatic colorectal cancer: Analysis of the XELAVIRI (AIOKRK0110) study.
Authors: Modest Dominik Paul , Ricard Ingrid , Heinrich Kathrin , Fischer von Weikersthal Ludwig , Decker Thomas , Vehling-Kaiser Ursula , Graeven Ullrich , Stahler Arndt , Jung Andreas , Kirchner Thomas , Held Swantje , Stintzing Sebastian , Giessen-Jung Clemens , Heinemann Volker
Published: January 2019

549

Background: XELAVIRI compared initial versus sequential irinotecan (iri) in combination with fluoropyrimidine (FP) plus bevacizumab (bev) in patients (pts) with mCRC, trial identification: NCT01249638. In the full analysis set of the study, non inferiority of time to failure of strategy (TFS) of the sequential use could not be demonstrated (primary endpoint). Methods: The secondary endpoints overall response rate (ORR), progression-free survival (PFS) as well as overall survival (OS) were evaluated in female versus male pts as well as molecular subgroups (RAS mutational status). Interaction of treatment and gender was tested by likelihood ratio tests. Results: Of 421 patients, 281/140 were male/female. In female pts, ORR was 43% in both arms, PFS was 8.9 (95% CI 6.8-11.1) versus 10.1 (95% CI 8.5-11.8) months (HR: 1.09 (95% CI 0.76-1.55), P = 0.65) in pts with initial iri versus pts without initial iri, respectively. In females, a trend for inferior OS with initial iri was seen: 21.8 (95% CI 14.8-28.8) months with initial iri versus 28.4 (95% CI 21.9-34.9) months without initial iri (HR: 1.46 (95% CI 0.95-2.24), P = 0.08). This difference was significant in the multivariate analysis (HR: 1.73 (95% CI 1.04-2.86, P = 0.034). Male pts benefitted across all analysed endpoints from initial iri: ORR was 58.3% with initial iri and 33.6% without iri (P < 0.001), PFS was 10.1 (95% CI 9.2-11.0) versus 7.4 (95% CI 6.3-8.5) months (HR: 0.54 (95% CI 0.42-0.69) P < 0.001) and OS 23.9 (95% CI 19.1- 28.6) versus 20.5 (95% CI 18.1-22.9) months (HR: 0.63 (95% CI 0.47-0.85), P = 0.002), with initial iri versus without initial iri, respectively. Interaction of treatment and gender was seen for ORR (P = 0.018), PFS (P = 0.002) and OS (P = 0.001). Additional data including treatment and toxicities will be presented at the meeting. Conclusions: This unplanned exploratory analysis suggests that gender might interact with efficacy of initial iri when used in the context of FP and bev. While male patients derived a significant and clinically meaningful benefit from initial use of iri, this was not observed in female patients. Clinical trial information: NCT01249638.
Role of enterocyte-specific gene polymorphisms in adjuvant treatment for stage III colorectal cancer.
Authors: Suenaga Mitsukuni , Cao Shu , Zhang Wu , Matsusaka Satoshi , Okazaki Satoshi , Berger Martin D. , Miyamoto Yuji , Schirripa Marta , Barzi Afsaneh , Ueno Masashi , Lenz Heinz-Josef
Published: January 2019

550

Background: Enterocyte subtype of the Colorectal Cancer (CRC) Assigner classifier is known as favorable to oxaliplatin-based adjuvant treatment for stage III CRC. We previously reported potential predictive value of single nucleotide polymorphisms (SNPs) in enterocyte-related genes in metastatic CRC (Suenaga, ASCO2018). In this study, we examined clinical significance of MS4A12 and CDX2 SNPs in adjuvant treatment (AT) for Stage III CRC. Methods: 350 patients with Stage III CRC were included in this study: 274 received AT (discovery cohort: median age = 62, median follow-up = 59.9 months) and 76 received surgery alone (control: median age = 75, median follow-up = 58.0 months). 68 and 206 patients received FOLFOX and oral fluoriopyrimidine, respectively. SNPs were analyzed by PCR-based direct sequencing. Disease-free survival and overall survival (OS) were analyzed using Kaplan-Meier curves, log-rank test, and Cox proportional hazards regression. Results: In discovery cohort, the G/G variant in MS4A12 rs4939378 was associated with lower 5-y survival rate than any A allele in uni- and multi-variate analyses (70% vs 90%, univariate: HR 2.29, 95% CI: 1.03-5.06, P = 0.035; multivariable: HR 2.58, 95% CI: 1.15-5.76, P = 0.021). Patients with the G/G variant in CDX2 rs3812863 had better OS than those with any A, though not significant in multivariable analysis (5 y-survival rate: 95% vs 82%, univariate: HR 0.34, 95% CI: 0.12-0.97, P = 0.034; multivariable: HR 0.39, 95% CI: 0.13-1.11, P = 0.078). There was no significance in the control, and significant interaction was observed between MS4A12 genotypes and groups (interaction P = 0.007). In addition, there was no interaction between MS4A12 rs4939378 and FOLFOX vs oral fluoropyrimidine. Conclusions: Our findings suggest that MS4A12 and CDX2 gene polymorphisms may predict outcome in patients with Stage III CRC. However, clinical significance of the SNPs for oxaliplatin seems to differ depending on tumor stage. Further research and validation study are warranted to explore the association of the SNPs with carcinogenesis or cancer progression.
Anal melanoma: A comparative comprehensive genomic profiling study.
Authors: Ross Jeffrey S. , Gay Laurie M. , Elvin Julia Andrea , Vergilio Jo-Anne , Killian Jonathan Keith , Ngo Nhu , Ramkissoon Shakti , Severson Eric Allan , Hemmerich Amanda , Duncan Daniel , Ali Siraj Mahamed , Chung Jon , Reddy Prasanth , Miller Vincent A. , Madison Russell , Schrock Alexa Betzig , Corona Robert John
Published: January 2019

551

Background: Anal melanomas (AM) share histologic features with cutaneous melanomas (CM), are highly aggressive and behave in a distinct clinicopathologic pattern. We performed comprehensive genomic profiling (CGP) of AM to learn of potential matched targeted and immunotherapies that may improve clinical outcomes for the disease. Methods: FFPE tissues from late stage AM (81 cases) and CM (1804 cases) underwent hybrid-capture based CGP to evaluate all classes of genomic alterations (GA). Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. Results: AM and CM had a similar age, but AM females and CM males were significantly more common (P < 0.0001) (Table). Given the UV light exposure in the CM, the GA/tumor was significantly higher than AM as were the median TMB and frequency of TMB ≥ 10 and 20 mutations/Mb (P < 0.0001 for all comparisons). All AM and CM were MS-stable. The contrast in S FB1 mutations in AM and TERT GA in CM were significant (P < 0.0001). AM featured significantly more KIT GA than CM (P < 0.0001), whereas CM featured significantly more BRAF GA (P < 0.0001). Only 11% of AM BRAF GA were V600E whereas 74% of CM BRAF GA were V600E (P < 0.0001). MTOR pathway targets including NF1 and PTEN were commonly altered in both tumor types. Potentially targetable PDGFRA and ERBB2 GA were found in AM but not in CM. Conclusions: UV light exposure drives high GA/tumor and TMB in CM, both associated with immune checkpoint inhibitor (ICPI) responsiveness, whereas AM lacks the high TMB and therefore is far less likely to benefit from ICPI treatments. CM is classically associated with opportunities for anti-BRAF therapies and AM with an array of kinase targets including KIT, BRAF, PDGFRA and ERBB2. Finally, MTOR pathway targets are common to both tumor types. [Table: see text]
Classification of BRAF mutated colorectal cancer based on microsatellite stability.
Authors: Nakano Michitaka , Sagara Kosuke , Koreishi Sakuya , Aikawa Tomomi , Nishijima Tomohiro F. , Takayoshi Kotoe , Komoda Masato , Baba Eishi , Esaki Taito
Published: January 2019

553

Background: BRAF mutated metastastic colorectal cancer (CRC) shows poor outcome in spite of development of the treatment. Thus, classification of BRAF mutated CRC based on therapeutic target is warranted. Particularly, about half of the BRAF mutated CRC reveals high microsatellite instability (MSI-H) that is characterized by high mutation burden and frequent infiltration of lymphocytes. Hence, the patients with BRAF mutation carrying MSI-H would potentially benefit from immune-check point inhibitor. However, the precise evaluation of immune status of these patients has not been clarified. Furthermore, the character of BRAF mutation with microsatellite stability (MSS) is not fully investigated. Methods: Transcriptomic information of BRAF mutated CRC with MSS/MSI-H was downloaded from open database, Gene Expression Omnibus (GEO); GSE75316 (n = 59), GSE35896 (n = 62), GSE39582 (n = 585). Gene expression of BRAF mutation with MSI-H/MSS (GSE75316: n = 5/3, GSE35896: n = 1/5, GSE39582: n = 31/14) were normalized and differentially expressed genes were identified by using GeneSpring (Agilent technologies). Pathway analysis was performed by GSEA. Results: Pathway analysis revealed datasets regarding cytotoxic T cell (FDR q value: 0.09), helper T cell (FDR q value: 0.05), natural killer T cell (FDR q value: 0.11), and activated inflammatory response (FDR q value: 0.16) were significantly enriched in BRAF mutation with MSI-H. (FDR q value < 0.25 means significant). The differentially expressed genes were identified in both of 2 groups. Significantly high expression of Granzyme A, Granzyme B, and Perforin were observed in BRAF mutated MSI-H. At the same time, highly expressed genes including MLH1 were identified in BRAF mutated MSS. Conclusions: High infiltration of cytotoxic T cells was suggested by the pathway analysis and expression of Granzayme A, B, and Perforin among BRAF mutated MSI-H. The activated immune status within these patients suggested the potential response of immune-checkpoint inhibitors. Furthermore, our data would give us a clue in considering the therapeutic strategy against BRAF mutated MSS, that will be the remained population among BRAF mutated CRC to which effective treatment have not been established.
Prognostic value of genomic alterations (GA) on overall survival in appendiceal adenocarcinoma (AA).
Authors: Jacome Alexandre A , Raghav Kanwal Pratap Singh , Shaw Kenna Rael , Fournier Keith F. , Royal Richard Eldon , Taggart Melissa , Foo Wai Chin , Matamoros Aurelio Aurelio , Ahmed Shahab U. , Guerra Jennifer L. , Overman Michael J. , Eng Cathy
Published: January 2019

554

Background: AA are extremely rare tumors, with potentially aggressive clinical behavior. The characterization of the molecular alterations of the disease is poorly described, as well as its association with clinical outcomes. The present study aims to evaluate the prognostic influence of GA on overall survival (OS) of AA patients (pts). Methods: We performed a retrospective study involving AA pts at MD Anderson Cancer Center between October 2012 and April 2017 who underwent next-generation sequencing (NGS) (at least 45 genes), using either tumor tissue specimens or peripheral blood for cell-free DNA (cfDNA). GA identified by NGS and clinicopathological variables were correlated with OS. Survival curves were performed by the Kaplan-Meier method and compared with log-rank test. Multivariate analysis of prognostic factors was performed by the Cox model. Results: A total of 78 pts were identified, of which 35 had died (45%) in a median follow-up time of 4.8 y. The majority of pts presented with stage IV disease (72%); 46% underwent cytoreductive surgery (CRS) + HIPEC. Tissue-based and cfDNA-based sequencing were performed on 73% and 23% of the pts, respectively, and 4% had both. The most frequent GA were KRAS (62%), TP53 (36%), GNAS (28%), SMAD4 (18%), PIK3CA (16%), and APC (15%). By univariate analysis, stage, tumor grade, and CRS + HIPEC demonstrated prognostic value (p < 0.05). Multivariate subset analysis of stage IV pts adjusting for age, tumor grade (TG), CRS + HIPEC, KRAS, GNAS, and p53, demonstrated that poorly differentiated tumors and a KRAS mutated tumor resulted in worse OS (HR: 12.1 and HR: 3.9, respectively, both with p < 0.05) and CRS + HIPEC resulted in an improved OS (HR: 0.32, p < 0.05). Conclusions: Our analysis indicates that TG and the presence of the KRAS mutation are poor prognostic factors in the OS of pts with AA. CRS + HIPEC offers survival advantage . Molecular characterization and prognostication of these rare tumors may help guide therapy. These findings need validation, thereby continued evaluation in a larger population and utilizing a wider molecular platform is ongoing.
Nrf2 metagene as a prognostic biomarker across all stages of colorectal cancer (CRC).
Authors: O'Cathail Sean Micheal , Wu Chieh-Hsi , Lewis Annabelle , Maughan Tim , Hawkins Maria A
Published: January 2019

557

Background: Keap1/Nrf2 is an important intracellular canonical stress response pathway, with Nrf2 acting as a potent transcription factor. Lung cancer is known to acquire constitutive activation of the pathway thus promoting survival, resisting chemo-radiation and dysregulating metabolism. Mechanisms of pathway activation include methylation of KEAP1, somatic mutation and direct activation by KRAS, BRAF and MYC. Its role in CRC is unknown. Due to its role as a transcription factor, activated in many ways, we hypothesise a metagene of Nrf2 regulated genes would act as a prognostic biomarker in CRC. Methods: Using a candidate gene approach and publicly available data (GSE17536), we derived and trained a 36 gene metagene to aggregate Nrf2 pathway expression, using principal component analysis and cox proportional hazard models. GSE14333 was used for validation in stage I/II/III CRC. The first line metastatic FOCUS trial was used for validation in Stage IV disease. Results: 601 patients are included in the validation analysis. Nrf2 metagene expression is associated with worse DFS outcomes in stage I/II/III disease in Cox PH model comparisons (LRT, p = 0.00175) and worse OS in stage IV disease (LRT, p = 0.00574). On multivariate analysis, Nrf2 expression remained significant when adjusted for known prognostic factors of adjuvant chemotherapy and Duke’s stage in stage I/II/III disease (ANOVA, p = 0.03), BRAF V600E and sidedness in stage IV disease (ANOVA, p = 0.00255). Using the median cut point, high expression has a HR 2.36 (C.I 1.27-4.38) in stage I/II/III disease and HR 1.39 (C.I 1.12-1.72) in metastatic disease. Conclusions: Nrf2 expression is a novel, robust prognostic biomarker of poor prognosis across all stages of colorectal cancer. Greater understanding of its mechanistic role could lead to targeted strategies to improve outcomes in CRC. [Table: see text]
Somatic POLE proofreading domain mutations by next generation sequencing to predict outcomes in stage II colorectal cancer.
Authors: Mo Shaobo , Li Yaqi , Peng Junjie
Published: January 2019

559

Background: Stage II colorectal cancers (CRC) exhibit unique molecular heterogeneity and patients with somatic POLE mutations are defined as a distinct tumor subgroup. The aim of this study was to clarify the characteristics and prognostic effect of somatic POLE proofreading domain mutations by Next Generation Sequencing in stage II CRC. Methods: Recurrent patients were 1:1 matched to patient with no recurrence for stage II CRC patients diagnosed between 2008 and 2013 in Fudan University Shanghai Cancer Center (FUSCC). All patients were pathologically confirmed and received radical resection. Microsatellite instability status and POLE mutation status were determined by NGS using ColonCore panel (Burning Rock, Guangzhou, China). Groups based on NGS-POLE mutation status were compared in terms of patient demographics and pathologic features using chi-squared tests. Survival curves were plotted using the Kaplan-Meier method. Results: In total, 245 stage II CRC patients were enrolled. POLE mutations were detected in 25 (10.2%) of 245 stage II CRC, while only 9 (3.7%) was located in proofreading domain (NGS-POLE EDM-mutations) and other 16 were found in non-proofreading domain (non-NGS-POLE mutations). Compared to cases with wild-type POLE, cases with NGS-POLE EDM-mutations were more prone to be microsatellite instability-high (MSI-H) (3 of 9 [33.3%] vs. 23 of 236 [9.7%], p = 0.024), younger at diagnosis (median 46 years vs. 62 years, p < 0.001), and more frequently with right-sided tumor location (6 of 9 [66.7%] vs. 54 of 236 [22.9%]; p = 0.003). All tumors with NGS-POLE EDM-mutations presented with a surprisingly high tumor mutation burden (TMB) (median 145.2 per Mb). Patients with NGS-POLE EDM-mutations have favorable 5-year disease-free survival (DFS) compared with those with non-NGS-POLE EDM-mutations and wild-type POLE (100% vs. 62.5% vs. 52.5%, p = 0.037). Though there is DFS difference between patients with non-NGS-POLE EDM-mutations and wild-type POLE, the difference was not statistically significant (p = 0.412). Conclusions: Stage II CRC patients with NGS-POLE EDM-mutation identify a special cancer subset with better immune environment predicting excellent outcomes.
Development of a liquid-biopsy-based technique for the supplementary diagnosis of highly advanced lymph node metastasis in patients with locally advanced gastric cancer.
Authors: Oshima Takashi , Miyagi Yohei , Oue Naohide , Masuda Munetaka , Kimura Yayoi
Published: January 2019

56

Background: The outcomes of patients with locally advanced gastric cancer who have highly advanced lymph node metastasis such as N3 remain poor despite radical resection. If the preoperative diagnoses of such patients improve, further improvement in treatment outcomes is expected to be obtained by means of personalized therapies such as preoperative chemotherapy; however, the accuracy of diagnosis remains unsatisfactory. Therefore, exploratory proteome analysis using sera was performed with the aim of developing a supplementary liquid-biopsy-based technique to diagnose highly advanced lymph node metastasis in patients with locally advanced gastric cancer. We report the results obtained thus far. Methods: The subjects were 24 patients with pT4a gastric cancer (12 with pN0 disease and 12 with pN3 disease). Proteins that had significantly different (P<0.001) expression levels in the preoperative serum on exploratory proteome analysis by liquid chromatography and mass spectrometry were identified. These proteins were verified by Enzyme-Linked ImmunoSorbent Assay (ELISA) using a different cohort (20 patients with pN0 disease and 13 with pN3 disease) from that described above. Results: In the exploratory proteome analysis, 2,357 kinds of proteins were identified and examined. Six these proteins were identified as candidate predictive markers of highly advanced lymph node metastasis. These proteins were verified using existing and newly developed ELISA kits, and reproducibility was verified for one protein (Protein V) (P = 0.003). Conclusions: The possibility of the supplementary diagnosis of highly advanced lymph node metastasis by liquid biopsy was suggested in patients with locally advanced gastric cancer. Further evaluations by prospective studies are now in progress, with the ultimate goal of clinical application.
Impact of genomic alterations (GAs) on outcomes and their distribution by age groups in metastatic colorectal cancer (mCRC) patients (pts).
Authors: Sahin Ibrahim Halil , Chen Wanqi H , Chen Zhengjia , Akce Mehmet , Alese Olatunji B. , Shaib Walid Labib , El-Rayes Bassel F. , Wu Christina
Published: January 2019

560

Background: Although clinical outcomes has substantially improved over the last decade, long term survival in mCRC remains rare. Molecular profiling (MP) of CRC is routinely conducted to identify potential therapeutic targets. The aim of this project is to evaluate the impact of uncommon GAs on outcomes and characterize their distribution by age. Methods: Pts were eligible if they had mCRC (synchronous or metachronous) and underwent MP between 01/2013 and 05/2018. GAs were obtained from Foundation Medicine reports. Clinical data were collected by trained personnel by detailed chart review. Multivariable survival analyses (MA) with Cox model were conducted for survival outcomes and Fisher’s exact test was used to assess the differences among age groups (< 45, 45-60, > 60). The study was reviewed by Institutional IRB ( IRB00097021 ). Results: 161 patients with mCRC had MP, and 159 of those patients had survival data. The most commonly detected GAs were APC (133/161, 82.6%) TP53 (128/161, 79.5%). In univariate analyses mutations in BRCA 1/2, RB1, SOX9, CDK8, FLT3, and IRS2 amplification were associated with worse survival outcomes. In MA, including initial stage of disease, GAs in BRCA1/2, RB1, FLT3, SOX9, and IRS2 remained statistically significant (Table). When we performed MA by age groups, mutations SOX9 in age group < 45 and BRCA1/2 in age group 45-60 were significant predictors of worse outcomes. We also compared the frequency of mutations among age groups and FAM123B was significantly more common in age group 45-60 (P = 0.038). Conclusions: Our data suggests that GAs in BRCA1/2, RB1, FLT3, SOX9, and IRS2 may predict worse outcomes in mCRC. Therapeutic approaches targeting these pathways should be investigated. Differences in distribution and prognostic significance of mutations were observed based on age. [Table: see text]
Effects of CDX2 on proliferation and glucose metabolism reprogram by targeting PGAM1 in colorectal cancer.
Authors: Li Qingguo , Mo Shaobo , Li Xinxiang , Cai SanJun
Published: January 2019

561

Background: The CDX2 expression is significantly decreased in colorectal cancer (CRC) tissues and lost its expression is associated with poor survival. However, the underline of this activity of CDX2 is not well understood. In the present study, we sought to determine the role of CDX2 in tumorigenesis, and elucidate the possible mechanism. Methods: The effect of CDX2 expression on proliferation of and glycolysis in CRC cells was assessed by altering its expression in vitro and in vivo. Mechanistic investigation was carried out using cell and molecular biological approaches. Human CRC tissues were also used to verify the relationship between CDX2 expression and glycolysis. Results: Forced CDX2 expression in CRC cells inhibited their proliferation and colony formation. In contrast, silencing CDX2 expression had the opposite effect, suggesting that CDX2 is a negative regulator of oncogenesis in CRC. Mechanistically, CDX2 negatively regulated the aerobic glycolysis, a process that contributed to tumor progression by providing energy source and building blocks for macromolecule synthesis. Consistent with this observation, an in vivo subcutaneous xenograft mouse model and in a series of patients (n=71) received PET/CT initial after diagnosed also confirmed the hypothesis that CDX2 is a negative regulator of glycolysis as reflected by the decreased 18FDG uptake in PET/CT system. Furthermore, increased expression of CDX2 downregulated that of a glycolytic enzyme, phosphoglycerate mutase 1(PGAM1) in vitro. Moreover, there was a negative relationship between CDX2 and PGAM1 expression in human CRC tissues as determined by both RT-PCR and Immunohistochemistry. Luciferase analysis further indicated that CDX2 could inhibited PGAM1 promoter activity at dose dependent. Conclusions: The CDX2 inhibits cell proliferation, reprograms glucose metabolism by targeting PGAM1 expression in CRC, and the CDX2/PGAM1 axis constitutes potential prognostic predictors and therapeutic targets for CRC.