bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymorphisms of GSTP1, GSTT1, GSTM1, MTHFR, TS, ERCC1, and ERCC2 in metastatic colorectal cancer treated by first-line mFOLFOX6 chemotherapy
Authors: Ishibashi K. , Okada N. , Ishiguro T. , Yokoyama M. , Miyazaki T. , Sano M. , Yamada H. , Ishida H.
Published: August 2020

e14628

Background: It was reported that determining functional polymorphisms of genes involved in drug-metabolising pathways and DNA repair may be useful for predicting the response to 5-FU/oxaliplatin chemotherapy in Caucasian patients with metastatic colorectal cancer. This study was performed to examine whether determining these polymorphisms had any clinical value in Asian patients with colorectal cancer receiving 5-FU/oxaliplatin therapy. Methods: Genomic DNA was extracted from peripheral blood lymphocytes (n=25) or colonic mucosa (n=47) in Japanese patients with metastatic colorectal cancer who were receiving first-line therapy with the modified FOLFOX6 regimen followed by FOLFIRI (n=42). Polymorphisms of 5 genes involved in drug metabolism (glutathione S-transferase (GST) P1 (IIe 105 Val), GSTT1 deletion, and GSTM1 deletion, methylenetetrahydrofolate reductase (MTHFR) (Ala 677 Val), and a 6-base pair (bp) deletion in the 3’-untranslated region (UTR) of thymidylate synthase (TS)), and polymorphisms of two DNA repair genes (excision repair cross complementing group 1 (ERCC1): Asp 118 Asn and ERCC2: Lys 751 Gln) were assessed in these patients by PCR-RFLP or the invader technique. Correlations between polymorphisms of these genes and the response to therapy were evaluated. Results: The distribution of the genotypes of GSTP1, GSTT1, TS, ERCC1, and ERCC2 in the present Japanese patients (but not that of GSTM1 or MTHFR), differed significantly from the distribution of these genotypes in a Caucasian population. The response rate and progression-free survival were not correlated with any of the functional polymorphisms investigated. However, patients who had both alleles containing the 6-bp nucleotide fragment in the 3’UTR of TS showed significantly shorter overall survival than those who had at least one allele without the 6-bp nucleotide fragment (p=0.03). Conclusions: These results suggest that 3’UTR polymorphism of TS may be an important predictor of overall survival for Japanese patients with metastatic colorectal cancer receiving first-line 5-FU/oxaliplatin therapy.

No significant financial relationships to disclose.
Mouse prostate tumor inhibition via disruption of murine telomerase: In vivo and in vitro data for a new preclinical cancer model
Authors: Xu T. , Xu Y. , Lao R. , He K. , Xue L. , Goldkorn A.
Published: August 2020

e14631

Background: Telomerase-interference (TI), a novel therapeutic strategy, exploits the high telomerase activity in prostate cancer by introducing a mutated telomerase RNA (MT-Ter) that encodes toxic telomeres. Until now, TI has been tested by targeting human telomerase in tumor cells xenografted into immuno-deficient mice, an inadequate model for predicting efficacy and toxicity. We designed and validated 2 new TI gene constructs that specifically target murine telomerase RNA (mTER), enabling the study of TI in preclinical mouse models that are immuno-competent and that develop endogenous prostate tumors. Methods: We designed 2 constructs and cloned them into a lentiviral delivery system: MT-mTER and siRNA against wild type mTer (α-mTer-siRNA). Using a mouse prostate cancer cell line, E4, we tested the 2 constructs for expression (RT-PCR), telomerase activity (TRAP), and biologic activity (53bp1 DNA damage staining, MTS growth assay, TUNEL and caspase apoptosis assays), as well as in vivo efficacy (NOD-SCID allografts). Results: We confirmed MT-mTER expression (∼50-fold) and showed that α-mTer-siRNA specifically depleted WT-mTER (80% reduction) but not MT-mTER when the 2 constructs are co-expressed; thus, the 2 constructs in combination effectively substituted MT-mTer for WT-mTer in the mouse prostate cancer cells. MT-mTER caused mutant telomeric repeats (TTTGGG instead of TTAGGG) to be added to the ends of telomeres, resulting in rapid telomeric uncapping marked by 53bp1 DNA damage foci (an average 7.5 foci/cell vs. 1.4 foci/cell in vector control). This, in turn, led to rapid and significant apoptosis (>90% TUNEL and caspase +) and growth inhibition in vitro (90% reduction by MTS) and in vivo (75% reduction in tumor allograft size). Conclusions: We successfully designed and validated MT-mTer and α-mTer-siRNA, 2 novel gene constructs that specifically target and co-opt murine telomerase activity within mouse prostate cancer cells. These constructs offer a significant advantage, as they can be used to investigate TI in immuno-competent mice that develop prostate cancer, thereby modeling actual human disease and testing TI-based therapies in a much more informative and authentic manner.

No significant financial relationships to disclose.
Effect of lenalidomide on the antiproliferative effect of gemcitabine against pancreatic tumor cells and on immune-mediated pancreatic cancer cell death
Authors: Wu L. , Liu W. , Galustian C. , Schafer P. , Dalgleish A. G. , Bartlett J. B.
Published: August 2020

e14635

Background: Lenalidomide is an immunomodulatory and anti-angiogenic agent that has demonstrated activity against a range of hematological malignancies. Despite evidence of direct anti-proliferative activity against hematological cells in vitro, there is no evidence of single agent direct activity against solid tumor cells in vitro. To take advantage of its known immune-enhancing properties alongside direct anti-tumor agents, lenalidomide is being advanced in solid tumor indications in combination with other agents. There are few data regarding the combination of lenalidomide and standard of care chemotherapeutic agents, such as gemcitabine. Methods: Here, we assess the effects of lenalidomide alone, and in combination with gemcitabine, on pancreatic cancer cell growth and survival, and the ability of lenalidomide to enhance the ability of human PBMC to kill allogeneic pancreatic tumor cells (BxPC3, PANC-1 and MiaPaCa) in a PBMC:tumor cell co-culture model. Results: Lenalidomide alone had no effect on the proliferation of pancreatic cancer cells (BxPC-3 and Panc-1) whereas gemcitabine had moderate anti-proliferative activity. With combination therapy there was clear synergistic enhancement of anti-proliferative activity in both cell lines and additive effects were observed in a BxPC-3 xenograft mouse model of pancreatic cancer. About 20% of tumor cells were sensitive to immune-mediated cell death and, for BxPC3, this was increased significantly in the presence of lenalidomide. Lenalidomide significantly and dose-dependently enhanced immune-mediated killing (both T and NK cells are required for tumor cell killing in this model). For PANC-1 and MiaPaCa, immune-mediated killing was also increased by lenalidomide, albeit non-significantly. Conclusions: These results suggest that, in addition to anti-angiogenic and other effects within the tumor microenvironment, lenalidomide may act as an immune adjuvant to enhance the recognition and apoptosis of tumor cells by host T and NK cells. These studies support the potential utility of lenalidomide in combination with chemotherapeutic agents, gemcitabine in particular, in the treatment of patients with solid tumors including pancreatic cancer.

[Table: see text]
Methylnaltrexone potentiates the antiangiogenic effects of the mTOR inhibitor, temsirolimus
Authors: Singleton P. A. , Moss J. , Garcia J. G.
Published: August 2020

e14636

Background: Angiogenesis is important in cancer growth and metastasis. Recent therapeutic interventions cancer, include drugs such as temsirolimus that target both tumor growth and angiogenesis including the mammalian target of rapamycin (mTOR) inhibitor. Previously, we have demonstrated that the peripheral opioid antagonist methylnaltrexone (MNTX) potentiates the effects of bevacizumab and 5FU on endothelial cell (EC) migration and proliferation. Since mTOR inhibitor therapy is also associated with significant side effects, we examined potential adjunctive agents that could reduce the therapeutic dose and improve the therapeutic window for this approach. Methods: We determined the effect(s) of MNTX, naloxone and/or temsirolimus on VEGF-induced human pulmonary microvascular EC proliferation and migration assays. We used siRNA and specific inhibitors to analyze Src, Akt and mTOR regulation. Results: MNTX inhibited EC VEGF-induced proliferation and migration with an IC50 of ∼100 nM. Adding 10 nM MNTX to EC shifted the IC50 of temsirolimus inhibition of VEGF-induced proliferation from ∼10 nM to ∼1 nM. Further, adding 10 nM MNTX shifted the IC50 of temsirolimus on inhibition of EC migration from ∼50 nM to ∼10 nM. These synergistic effects were not observed with naltrexone, a tertiary mu opioid receptor antagonist. On a mechanistic level, we observed that treatment of human EC with MNTX, but not naltrexone, increased protein tyrosine phosphatase (PTP) activity which was independent of mu opioid receptor expression. Treatment of human EC with the PTP inhibitor, 3,4-Dephostatin, inhibited both the synergy between MNTX and temsirolimus and increased VEGF-induced tyrosine phosphorylation of Src with enhanced PI3 kinase and mTOR complex 2-dependent phosphorylation of Akt and subsequent activation of mTOR complex 1 (temsirolimus target), while silencing Src, Akt or mTOR complex 2 components blocked VEGF-induced angiogenic events. Conclusions: Synergy of MNTX with mTOR inhibitors may have therapeutic implications which await clinical proof-of-concept.

[Table: see text]
Investigation on the mechanism of dichloroacetate (DCA) induced apoptosis in breast cancer
Authors: Ko L. , Allalunis-Turner J.
Published: August 2020

e14637

Background: DCA is a generic, orally available, small molecule metabolic modulator that has an established history in the treatment of mitochondrial diseases and lactic acidosis. DCA inhibits pyruvate dehydrogenase kinase (PDK), an inhibitor of pyruvate dehydrogenase, a key enzyme in glucose metabolism. DCA preferentially shifts glucose metabolism in cancer cells from glycolysis to glucose oxidation, reversing the unique aerobic glycolysis found in solid tumors. DCA induced apoptosis in cancer cells as evidenced by the efflux of cytochrome c and apoptosis-inducing factor from the mitochondria. Recent studies suggested apoptosis induction by DCA in glioblastoma, endometrial, prostate, and non-small cell lung cancers. In this study we attempt to establish a link between DCA and apoptosis in breast cancer cell lines. Methods: Six breast cancer cell lines were investigated (BT474, MCF-7, MDA-MB231, MDA- MB468, SKBR3, T47D). Quantitative real-time polymerase chain reaction (RT-PCR) was performed using Taqman probes to identify increased DNA templates of PDK isoforms 1–4, using DCA concentrations from 0 to 20mM. Western blots were performed to identify increased expression of PDK isoforms and correlate findings with Taqman. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)- 2-(4-sulfophenyl)-2H-tetrazolium) assays were performed to measure decreased mitochondrial activity and cytotoxicity. Flow cytometry using annexin V and propidium iodide was performed to measure apoptosis and cell death. Results: RT-PCR showed increased DNA expression of all PDK isoforms in MDA-MB231 cells after DCA treatment. The effect was most pronounced at 10mM concentration. 10mM of DCA also increased DNA expression of all PDK isoforms in MCF-7 cells, and PDK1 in T47D cells. MTS assays showed increased cell kill and decreased mitochondrial activity in all six cell lines, with IC50 ranging between 20mM and 30 mM. Flow cytometry showed increased apoptosis induced by DCA at IC50 for BT474 and MCF-7 cell lines. Conclusions: Apoptosis appears to play a role in the mechanism of DCA in breast cancer, with increased PDK isoform expressions, cytotoxicity and decreased mitochondrial activity. Data from flow cytometry suggested DCA-induced apoptosis in two cell lines.

No significant financial relationships to disclose.
MicroRNAs 15a and 16–1 regulates tumor proliferation in multiple myeloma
Authors: Roccaro A. M. , Sacco A. , Leleu X. , Thompson B. , Azab A. , Runnels J. , Lin C. , Witzig T. , Anderson K. , Ghobrial I.
Published: August 2020

e14640

Background: MicroRNAs (miRNAs) are non-coding RNAs that act as negative regulators of gene expression. They have been described to play roles in solid tumors and hematologic malignancies. However the role of miRNAs in multiple myeloma (MM) has not been yet fully described. Methods: We performed miRNA-profiling of primary bone marrow-derived CD138+ MM cells, compared to their normal cellular counterparts and validated data by qRT-PCR. In vitro and in vivo functional studies were performed on miRNA-15a- and -16–1-precursors-transfected MM cells. Effect of miRNA-15a and -16–1 on signaling cascades have been evaluated by western blot and immunofluorescence. NF-kB activity has been studied using the Active Motif TransAM kit. In vivo MM cell growth has been evaluated by either using an in vivo imaging model or bioluminescence. Angiogenesis has been studied both in vitro and in vivo using the chorioallantoic membrane model. Results: We identified a MM-specific miRNA signature characterized by down-expression of miRNA-15a, -16–1 and over-expression of miRNA-222/-221/-382/-181a/-181b (P<0.01). Data were confirmed by qRT-PCR on matched samples. Predicted targets for the decreased miRNAs in MM patients included pro-angiogenic cytokines, oncogenes, cell cycle regulators, NFkB activators. Conversely, predicted targets for the increased miRNAs included cell cycle inhibitors, suppressors of cytokine signaling, and pro-apoptotic factors. We demonstrated that miRNA-15a and - 16–1 regulate proliferation and growth of MM cells. Indeed, transfected cells showed decreased DNA synthesis; decreased cyclinD1/cyclinD3/CDC25a/pRb protein expression; phase G1 cell cycle arrest. Moreover, transfected cells showed inhibition of NFkB pathway as shown by reduced p65-/p50-/p52-NFkB activities; downregulation of p-p65/p50/p52 nuclear protein level; upregulation of cttosolic phospho-IkB; and inhibited translocation of p-p65 from the cytolplasm to the nucleus. Similarly, inhibition of MM cell growth was confirmed in vivo; and anti-angiogenic properties of miRNA-15a and -16–1 were demonstrated both in vitro and in vivo. Conclusions: These data indicate that miRNAs play a pivotal role in the biology of MM; providing the basis for the development of new miRNA-based targeted therapies in this disease.

No significant financial relationships to disclose.
Preclinical study of lithium sensitivity in human breast PTEN knock out cell lines
Authors: Higgins M. J. , Abukhdeir A. M. , Gustin J. , Vitolo M. I. , Bachman K. E. , Park B. H.
Published: August 2020

e14641

Background: Mutations of PIK3CA, the catalytic subunit of phosphatidylinositol 3-kinase (PI3K), are found in ∼25% of breast cancers. The tumor suppressor PTEN reverses the effects of PI3K and genetic alterations leading to loss or reduced function of PTEN also occur at high frequency in breast cancers. We have used somatic cell gene targeting to create paired isogenic cell lines with critical genetic alterations as their only differentiating factor. Our lab has introduced two “hotspot” oncogenic PIK3CA mutations into the MCF-10A human breast epithelial cell line. This study led to the discovery that lithium, an FDA approved therapy for bipolar disorders, has selective anti-neoplastic properties against human breast cancer cell lines containing oncogenic PIK3CA mutations. Due to the opposing interactions between PI3K and PTEN, we are now studying whether loss of PTEN also confers sensitivity to lithium using human somatic cell knock outs. Methods: Targeting vectors were created and used to knock out the PTEN gene in MCF-10A. Biochemical and phenotypical characterizations were performed. Paired isogenic cell lines were exposed to lithium to evaluate heterozygous and homozygous loss of PTEN as a predictive biomarker of response. Proteomic and phenotypic changes were measured and assessed. Results: Homozygous loss of PTEN (PTEN-/-) resulted in a transformed phenotype enabling growth in the absence of exogenous growth factors, a hallmark of malignant potential. Preliminary results suggest that treatment of PTEN-/- cells with lithium leads to a decrease in cell proliferation with selectivity for mutant PTEN knock out cell lines, although the effects are not as pronounced as that seen with mutant PIK3CA knock in cells. Conclusions: Our preliminary results suggest that loss of PTEN predicts for sensitivity to lithium in breast cell lines in a manner similar to that seen with oncogenic PIK3CA. We hypothesize that differences in the magnitude of response to lithium may be the result of varied levels of non-PI3K-AKT-mTOR activation between the PIK3CA knock in cell lines and the PTEN knock out cells.

No significant financial relationships to disclose.
A pilot study to compare FXR expression in normal and malignant tissue in receptor-positive early-stage breast cancer
Authors: Kounalakis N. , Lau S. , Darling D. , Palomares M. , Senthil M. , Lai L.
Published: August 2020

e14645

Background: Farnesoid X receptor (FXR), a nuclear receptor, is a ligand dependent transcriptional factor regulating cholesterol and carbohydrate metabolism. Recently, FXR was shown to have a contributing role in colorectal cancer. We hypothesize that FXR expression changes from normal to premalignant to malignant tissue in patients with breast cancer. Methods: We identified 16 paired formaldehyde fixed, paraffin embedded tissue (normal, premalignant, and malignant) from patients with receptor positive, early stage breast cancer. Clinical information was extracted from a prospective database initiated in 2006 under institutional approval. Immunohistochemical staining of FXR using a validated polyclonal antibody was completed with appropriate positive and negative controls. The slides were graded independently by two investigators using an agreed upon scale to detect the percentage of positively stained cells to the nearest 10th percentile. Statistical analysis was performed by ANOVA and Student's t-test. A p-value of 0.05 was considered significant in all analyses. Results: Normal tissue and invasive cancer was identified in all 16 patient specimens. Of the 16 invasive cancers, 12 were ductal and 4 were lobular. 8/16 (50%) of the specimens also contained non-invasive cancer. 5/16 patients (31%) had N1 disease. FXR expression did not correlate with grade, histology, stage, or lymph node status. However, FXR expression increases with malignant transformation of the breast cancer cell. The mean percentage of cells staining positive for FXR in normal breast tissue was 58%, non-invasive 72% and invasive 79%. FXR staining in normal breast tissue was significantly less when compared to both invasive and noninvasive cancer (p< 0.007). Conclusions: FXR expression is upregulated in breast cancer when compared with expression in normal tissue and appears to progressively increase along the continuum of malignancy. Our pilot study results warrant further evaluation into FXR as a predictive biomarker for breast cancer, given the ability to target FXR via development of non-toxic oral ligands.

No significant financial relationships to disclose.
An open-label phase II trial to assess to efficacy of sunitinib as an antieffusion agent in patients with malignant peritoneal and/or pleural effusions
Authors: Trinh X. , van Dam P. , Tjalma W. , Wojtasik A. , Lybaert W. , Rasschaert M. , Rutten A. , Prové A. , Vermeulen P. , Dirix L.
Published: August 2020

e14647

Background: Pleural and peritoneal effusions are common in advanced malignant disease and relative resistant to traditional treatments. VEGF-A is considered to be a crucial factor in the biology of accumulation of malignant effusions (ME). Sunitinib is a multi-targeted TKI with a high potency of inhibiting VEGFR2. A treatment that could symptomatically reduce ME would be useful, regardless of its anti-tumoural or anti-angiogenic effect. Methods: Refractory patients with symptomatic ME were enrolled to receive 2x6 weeks of daily 37.5mg sunitinib regardless of their primary histology or site. Outcome was measured by time to re-puncture or by measurement of volume ME by CT-scan every 6 weeks or at the end of treatment. Puncture fluids and blood samples were collected for extensive biomarker analysis (VEGFA&C, VEGFR1–3, b-FGF, PDGFA-B, PDGFRα-β, PlGF1–2) on consecutive samples. Results: At present 6 patients have been enrolled. Patients had ovarian cancer (N=3), breast cancer (N=2) and squamous cervical cancer (N=1) as primary tumours. All patients had been extensively pre-treated with 4 to 8 lines of systemic therapy. Efficacy: Three (3/6) patients showed regression of effusion fluid by consecutive CT-scans. Two (2/6) patients had unchanged volume and one (1/6) patient had an increase of fluid volume. Follow-up: Two (2/6) patients stopped the trial early due to toxicity. Two patients (2/6) died during treatment due to disease progression elsewhere. Two patients (2/6) completed the 2 cycles of 6 weeks treatment. Of which, one had sustained reduction in volume fluid accumulation, while the other one had initial stabilisation after one cycle but eventually had increasing volume of ascites. Conclusions: These findings support the hypothesis that sunitinib could be useful in the management of ME. Although the numbers are low, in a majority of patients (5/6) there was reduction or stabilisation of fluid accumulation. Toxicity led to study withdrawal in a third of our patients. An update of patient numbers as well as results of translational/biomarker analysis will be presented at the meeting.

No significant financial relationships to disclose.
A comparison of overall and disease-specific survivals following adjuvant radiotherapy with neo-adjuvant radiotherapy for rectal cancer
Authors: Ahmed I. , Howard M. , Rehman Z. , Ofar F. , Marley P. , O’Doherty E. , Martin M. J.
Published: August 2020

e15008

Background: Preoperative radiotherapy is the preferred treatment for stage II-III rectal cancer. This arose following publication of the results of the German Rectal Cancer Study Group. It demonstrated a statistically significantly reduced local recurrence rate, and reduced toxicity for preoperative treatment compared with postoperative treatment. However, it failed to demonstrate improved overall survival. This study used the Surveillance, Epidemiology, and End Results (SEER) Program to compare overall and disease specific survival in rectal cancer patients treated with preoperative versus those receiving postoperative radiotherapy. Methods: 14,553 patients were identified with stage II-III rectal cancer, treated with either preoperative (5,136 patients) or postoperative radiotherapy (9,417 patients). Kaplan-Meier survival analyses and Cox multivariate analyses were used to compare 5 and 10 year overall and disease specific survival rates. Cause of death (COD) recorded as ‘Rectum and Rectosigmoid Junction’ was used to calculate rectal-specific survival. CODs recorded as ‘Colon excluding Rectum’ and ‘Rectum and Rectosigmoid Junction’ were used for colorectal-specific survival. Results: Kaplan-Meier analysis failed to demonstrate any statistical significant differences in survival figures. Cox multivariate analysis returned hazard ratios for overall survival of 1.207 (95% CI 1.122 - 1.298) and 1.180 (95% CI 1.103 - 1.263) at 5 and 10 years respectively for preoperative radiotherapy when compared with postoperative radiotherapy. For rectal-specific survival, 5 and 10 year hazard ratios of 1.381 (95% CI 1.239 - 1.539) and 1.342 (95% CI 1.210 - 1.489) respectively were obtained. Colorectal-specific survival returned 5 and 10 year hazard ratios of 1.222 (95% CI 1.124 - 1.329) and 1.193 (95% CI 1.101–1.292) respectively. Conclusions: Preoperative radiotherapy is the preferred treatment for stages II-III rectal cancer. This is because of its decreased risk of local recurrence and more optimal toxicity profile. However, this study suggests that preoperative radiotherapy is associated with poorer survival when compared with postoperative radiotherapy in the treatment of stage II-III rectal cancer.

No significant financial relationships to disclose.
Evaluation of the potential association of preoperative chemotherapy with steatohepatitis in surgical patients with hepatic colorectal metastases
Authors: Artinyan A. , Castillo E. , Foster B. , Wagman L.
Published: August 2020

e15009

Background: The treatment of hepatic colorectal cancer metastases is increasingly multi-modal. Preoperative chemotherapy may be associated with steatohepatitis, which may increase morbidity in patients undergoing resection. Our objective was to determine if preoperative chemotherapy is associated with steatohepatitis and to determine which agents confer the greatest risk. Materials and Methods: 149 patients who had undergone liver resection or biopsy for hepatic colorectal cancer metastases were identified from an institutional database. Surgical specimens were assessed for percent steatosis and the presence of steatohepatitis as defined by the Kleiner score. The medical record was reviewed for details of preoperative chemotherapy and post-operative course. The association of preoperative chemotherapy with steatosis and steatohepatitis was assessed. Preoperative non-contrast CT scans were reviewed for evidence of steatosis as determined by the radiographic liver/spleen (L/S) ratio. The association of the L/S ratio with the presence of steatohepatitis was determined. Post-operative outcome was compared in patients with and without steatohepatitis. Results: The mean age of the population was 60.8 ±11.6 years, 56% of patients were male, and 37% of patients received preoperative chemotherapy. Steatohepatitis was identified in 45.7% of specimens. There was no statistically significant difference in the rate of steatohepatitis (59% vs. 50%, p=0.49) or percent steatosis (37% vs. 32%, p=0.29) with or without preoperative chemotherapy. No individual agent predicted a greater risk of steatohepatitis or a greater degree of steatosis. There was no significant difference in the L/S ratio in patients with or without steatohepatitis (p=NS). In patients undergoing liver resection, there was no difference in total ICU stay, blood loss, total surgery time or total length of stay between the steatohepatitis and non-steatohepatitis groups. Conclusions: Although steatohepatitis remains a potential complication of systemic chemotherapy in surgical patients with hepatic colorectal metastases, the risk and impact of chemotherapy associated steatohepatitis have not been significant in our patient population.

No significant financial relationships to disclose.
Efficacy and safety of cetuximab, oxaliplatin, and capecitabine as first-line therapy for metastatic colorectal cancer (mCRC): Results of a phase II study
Authors: Barroso S. A. , Sanches E. , Ferreira M. , Passos M. , Sá A. , Nabiço R. , Sotto-Mayor C. , Espírito Santo J. , San- Bento R.
Published: August 2020

e15013

Background: To date, few studies have investigated the use of cetuximab in combination with oxaliplatin and capecitabine in the first-line treatment of mCRC. We therefore conducted an uncontrolled, open-label, multicenter study to evaluate the efficacy and safety of this combination in this setting. Methods: Patients (pts) received intravenous (iv) oxaliplatin 130 mg/m2 (3h day 1) plus capecitabine 1,000 mg/m2 twice daily (days 1–14) every 3 weeks (XELOX) and cetuximab 400 mg/m2 iv week 1 then 250 mg/m2 weekly over 8 cycles. Treatment was continued until disease progression (PD), unacceptable toxicity or completion of therapy. Pts were followed until death. The primary endpoint was overall response rate (ORR). A sample size of 45 pts was necessary to obtain a 95% confidence interval (CI) for ORR with a maximum width of 15% assuming an ORR of 50–80%. Results: From Sept 2005-Jan 2007, 49 pts were enrolled (ITT population): 67% male, mean age 60 (range: 44–75) years, 56.3% ECOG PS 0. Of 42 pts evaluable for ORR, 4 (9.5%) achieved a complete response, 31 (73.8%) a partial response, 6 (14.3%) had stable disease and 1 (2.4%) had PD. The ORR was 83.3% (95% CI: 72.0–94.6%). Median time to progression was 9 months (95% CI: 7.1–10.9 months). Of the 49 pts evaluable for safety, 27 (55.1%) had at least one grade 3/4 toxicity, 42 (85.7%) had acne-like rash (8 pts [16.3%] grade 3). Most common grade 3/4 toxicities included diarrhea (n=9;18.4%) and changes in potassium (n=6;12.2%). 24 (3.4%) AEs led to dose reductions (12 unrelated, 10 unlikely and 2 definitely related to cetuximab), 56 (7.8%) led to a dose delay (12 unrelated, 28 unlikely, 8 possibly, 6 probably, 2 definitely related to cetuximab) and 2 (0.3%) led to infusion rate reduction (not treatment related). 27 (55.1%) pts discontinued therapy: 10 (20.4%) due to AEs, 7 (14.3%) PD, 10 (20.4%) other reasons. 33 (67.3%) pts died: 30 (61.2%) due to PD, 2 (4.1%) intercurrent event/disease, 1 (2.0%) acute pancreatitis. The results according with the HGFR evaluation by IHC will be presented. Conclusions: In this first-line mCRC study, 83.3% of pts treated with cetuximab, oxaliplatin and capecitabine achieved an overall response. This combination appears to be a highly active and well-tolerated regimen.

No significant financial relationships to disclose.
Hepatic resection of initially unresectable liver metastases from colorectal cancer after hepatic arterial infusion of oxaliplatin and systemic 5-fluorouracil and leucovorin
Authors: Goere D. , Dsehais I. , de Baere T. , Boige V. , Malka D. , Bonnet S. , Dromain C. , Elias D. , Ducreux M.
Published: August 2020

e15015

Background: About 80% of patients (pts) presenting colorectal liver metastases (CRLM) are initially unresectable. A subgroup will become eligible for surgery after chemotherapy administration. Efficacy of hepatic arterial infusion (HAI) of oxaliplatin with systemic 5-Fluorouracil and leucovorin (LV5FU2) in with unresectable CRLM was previously demonstrated. This study was performed to evaluate the resection rate of pts with initially unresectable CRLM after oxaliplatin HAI and systemic LV5FU2. Methods: Patients treated in our hospital with oxaliplatin HAI and systemic LV5FU2 for unresectable CRLM from May 1999 to May 2007 were analyzed. Inclusion criteria were : unresectable CRLM, no extensive extrahepatic disease, HAI performed in our hospital, minimal follow up of 24 months. Eighty-seven pts were selected from a prospective database Results: Hepatic arterial infusion was delivered after previous systemic chemotherapy failure in 69 pts (80%). Main criterion for unresectability was massive liver involvement (80%). CRLM were synchronous and bilateral in respectively 85% and 90% of pts. The median number of oxaliplatin HAI cycles was 8 (0- 25). Thirty-one pts experienced technical problems with the arterial catheter, which was responsible for HAI withdrawal in seven. A total of 23 pts (26.4%) were operated, leading to resection and/or radiofrequency ablation of CRLM in 21 pts. No post-operative mortality was observed and the morbidity rate was 30%. The 3-year overall survival for patients operated was 72.5% versus 12% for non operated pts (p<0.0001). After a median follow-up of 75 months [24–118], intra-hepatic recurrence occurred in 10 pts. Conclusions: Hepatic artery infusion of oxaliplatin and systemic LV5FU2 increase the resectability rate in pts with advance CRLM even after previous systemic chemotherapy failure. Future studies combining oxaliplatin HAI and recent IV chemotherapy are needing to achieve an increase disease-free survival.

No significant financial relationships to disclose.
KRAS mutation profile in colorectal cancer patients in Brazil: A cohort of 989 individuals
Authors: Zalis M. G. , Vieira F. M. , Zalcberg-Renault I. , Bonamino M. H. , Ferreira C. G. , Oliveira S.
Published: August 2020

e15017

Background: KRAS mutation is common event in colorectal cancer occurring in around 40% of the patients. It is well- known that patients harboring the KRAS mutation do not derive benefit from cetuximab. However data available KRAS mutation profile is limited to Caucasian and Asian individuals and there is a lack of data in the population from Latin America. Brazilian population has a heterogeneous genetic background and this may have pharmacogenetic implications (Suarez-Kurtz, 2006). Methods: Between July and November 2008, we analyzed 989 consecutive patient samples sent to our laboratory for KRAS genotyping as a screening for cetuximab use. DNA was extracted from paraffin-embedded tissue, exons 1 were amplified by PCR and submitted to automatic sequencing. Codons 12 and 13 were analyzed. Results: The median age was 59 years and 53% of the patients were male and 47% female. The percentage of wild-type and mutated KRAS was 62 and 38%, respectively. Among the 375 mutated cases, 87% were in codon 12 versus 13% in codon 13. Mutation Gly12Asp was the most common being detected in 39% of the mutated cases. Due to the sample size a comparison among patients from different regions of Brazil was possible. However, no significant difference was observed in relation to the type or percentage of patients harboring the KRAS mutation. Interestingly, a significant difference in the percentage of mutated KRAS patients was observed between male and female (41 versus 35%, p= 0.05). Conclusions: The profile of KRAS mutation in the Brazilian population is similar to that reported for Caucasian and Asian populations. This is one of the largest cohorts of KRAS genotyping in colorectal cancer patients ever reported. To the best of our knowledge our data is the first to put forward the issue of a potential difference in the mutation rate according to gender. The observed higher incidence of KRAS-mutation in male than female deserves further investigation.

No significant financial relationships to disclose.
A phase II study of capecitabine, irinotecan, and bevacizumab (XELIRI-A) in patients (pts) with previously untreated metastatic colorectal cancer (mCRC)
Authors: Chen E. X. , Welch S. , Krzyzanowska M. , MacKay H. , Knox J. , Feld R. , Petronis J. , Blatter C. , Wang L. , Moore M. J.
Published: August 2020

e15019

Background: Capecitabine (XEL), irinotecan (IRI) and bevacizumab (A) are all active agents in the treatment of mCRC. However, combining these agents has proven to be problematic due to overlapping toxicities. Optimal dosing strategies for this combination remain unclear. This study prospectively evaluated toxicity and efficacy of the XELIRI-A combination with dose modification. Methods: This was a single-institution, open-label phase II clinical trial. Eligible pts include those with previously untreated metastatic CRC, adequate organ function and ECOG performance status 0–2. IRI (200 mg / m2) and A (7.5 mg / kg) were given on day 1, and XEL (1000 mg / m2 p.o. BID) was given on days 1–14 of every 21-day cycle. The dose of XEL was reduced to 750 mg / m2 BID for pts age ≥ 65. The primary endpoint was progression-free survival (PFS). Secondary endpoints included response rate, time to progression, overall survival and toxicity. Results: 50 pts (ECOG PS 0:1 = 27:23; male:female= 34:16) were enrolled over 19 months. Median age was 58 (range: 35–72). 7 pts had prior adjuvant chemotherapy. A total of 360 cycles were administered, with a median of 6 (range: 1–16). To date, 20 confirmed PR, 3 unconfirmed PR, and 20 SD by RECIST criteria were observed (ORR= 40%, disease control rate 86%). The median PFS was 11.1 months (95% CI: 9.2 months - not reached), and the 1-year progression-free rate was 49%. 7 pts have gone on to have metastatectomy. The most frequently reported related grade 3 or 4 adverse events were neutropenia (6), hand-foot syndrome (6), and diarrhea (5). One death was seen on study, and 1 pt had treatment-emergent grade 3 hypertension. Conclusions: XELIRI-A at doses studied appears to be well- tolerated. Results are favorable compared to those from previous studies. XELIRI-A at reduced doses is safe and effective as first-line treatment for mCRC.

[Table: see text]
New CT treatment response score for predicting survival in patients with metastatic colorectal carcinoma: A pilot study
Authors: Fora A. , Fakih M. , Scheib S. , Hanna T. , Raczyk C. , Hutson A. , Gottlieb R.
Published: August 2020

e15026

Background: To develop a methodology that results in an optimized CT Treatment Response Score (CTRS) for prediction of survival using quantified changing lesion features. Methods: We evaluated the overall survival (OS) predictive value of a new methodology to assess CT scan-based responses versus RECIST guidelines in a homogenous metastatic colorectal cancer population. All patients (pts) with MCRC treated with cetuximab and irinotecan (cet & irino) between 2005 and 2008 in our Center after failure of prior oxaliplatin and fluoropyrimidine were included in this analysis. Other inclusion criteria included: at least 6 weeks of cet & irino and serial CT scans on cet & irino including baseline performed in our Center. 38 pts (22 men, 16 women, mean age = 62, range = 28–91 ) were included. CT scans were interpreted by 2 trained physician assistants initially independently with differences resolved by consensus. Parameters evaluated included change in tumor size using standard RECIST and visual based (VB) assessment, VB assessment of enhancement, and interval development of new lesions.VB scoring used Likert-type scales to code reader confidence as to change in an imaging characteristic (size, enhancement) and the presence/absence of a characteristic (new lesions). The most predictive parameters for OS were used to generate the CTRS with an overall range of -2 (definite tumor decrease) to +2 (definite tumor increase). Results: The optimal CTRS resulted from combining VB assessment of change in size of existing lesions and new lesion development. This resulted in prediction of survival with a Cox Hazard Ratio of 1.639 (p = 0.0008). Using a threshold value of 0 to generate good (scores ≤ 0) and poor (scores > 0) response groups resulted in probabilities of survival at 8 months (ms) of 75% (16 pts) and 32% (22 pts), median survival times of 13.3 ms (95% CI = 10.94 ms, 17.81 ms) and 5.06 ms (95% CI = 3.84 ms, 8.77 ms), respectively. CTRS was easier to perform and appeared to be more predictive of OS outcome than RECIST. Conclusions: The methodology results in a single CTRS with transparent for others to test and understandable in terms of predicting survival for pts and caretakers. This methodology needs validation in a larger patient data set and across various tumors and lines of treatment.

No significant financial relationships to disclose.
Histological hepatic changes in patients undergoing liver resection for colorectal metastasis: A retrospective cohort study
Authors: Allegro S. M. , Rowsell C. , Law C. , Ko Y.
Published: August 2020

e15034

Background: Patients with colorectal cancer (CRC) with liver metastases (LM) have a poor prognosis and the only potential cure is surgical resection. Neoadjuvant chemotherapy (NC) in this setting can increase the success of resection and can potentially improve survival. However, chemotherapy can be associated with hepatic toxicity which may influence postoperative morbidity. Methods: Consecutive patients who underwent hepatectomy for CRC with LM from 1999–2005 at a single institution (OCC) were retrospectively reviewed. Data on baseline characteristics, chemotherapy regimens, operative outcomes and pathology were collected. Results: 107 patients underwent hepatectomy for CRC LM. Median age was 62 years (range 24–84). 53 (53%) patients had positive lymph nodes (primary tumor) and 51 (48%) had with synchronous LM. 46 (43%) patients had a solitary LM and 90 (84%) underwent major resection (>4 segments). 63 (59%) patients received NC. 96% received a 5FU-based regimen. The majority of patients (55%) received 6–12 cycles of NC. The median time between NC and surgery was 6.5 weeks. Patients receiving NC before surgery were younger (mean 59.5 versus 65.5 years, p=0.0056). NC was more often administered in patients with positive primary lymph node status (72%,versus 40%, p=0.0014) and with multiple (versus solitary) LM (75% versus 37%, p=0.0001). Patients more often received NC with synchronous (versus metachronous) LM (90% versus 30%, p<0.0001). Operative and postoperative courses were not significantly different in patients with NC, including hemodynamic instability, postoperative complications, transfusion requirements (red blood cell and platelets) and mortality. Pathological analysis of the resected liver segments reviewed mild (<30%) steatosis in 58% of patients. Most specimens did not reveal lobular inflammation (56%) or ballooning (87%). Sinusoidal injury was most often graded as 1 (33%). There were no significant increased rates of liver toxicity in patients with NC. Conclusions: This study demonstrates that neoadjuvant chemotherapy, although associated with increased steatosis is not associated with increased perioperative morbidity and mortality with liver resection.

No significant financial relationships to disclose.
Use of genotype subset selections of multi-UGT1As polymorphisms to predict severe neutropenia and tumor responses of metastatic CRC patients received FOLFIRI regimen
Authors: Hazama S. , Okuyama Y. , Kato T. , Okayama N. , Hinoda Y. , Sakamoto J. , Mishima H. , Fujita Y. , Hamamoto Y. , Oka M.
Published: August 2020

e15038

Introduction: The pharmacogenetics of irinotecan indicate that a common polymorphism in the uridine diphosphate glucuronosyltransferase 1As (UGT1As) gene predict severe toxicity. However the tumor response to irinotecan is variable and unpredictable. Methods: Two multi-center phase II studies of FOLFIRI (FLIGHT-1 and FLIGHT-2 study) were conducted for patients with metastatic colorectal cancer (CRC) in Japan. FLIGHT-1 study was first-line chemotherapy, and FLIGHT-2 study was FOLFOX-refractory second-line chemotherapy. 103 patients have been enrolled in these studies (53 patients in FLIGHT-1 and 50 patients in FLIGHT-2) from 20 institutions by April 2007 from November 2005. Seventy one patients were analyzed UGT1As polymorphisms, UGT1A1*28 (TA6>TA7), UGT1A1*6 (G>A), UGT1A1*60 (T>C), UGT1A7 (N129K; T>G), UGT1A7 (-57 T>G), UGT1A9*22 (T10>T9). Results: Out of 71 patients, 34 had G3/4 neutropenia or leukopenia, and 23 had tumor responses (CR +PR). G3/4 neutropenia was more frequent in patients with *6, N129K(G), -57(G), *22 allele than patients without these allele (p<0.05). Other polymorphism was not the predictive factor for toxicity and tumor response, independently. On the other hand, genotype subset selection of multi-UGT1As polymorphisms was useful to predict severe toxicities and tumor responses. Only 7 patients of 22 patients with TA6/TA6 and T10/T10, or TA6/TA7 and -57(T/T), or *6(G/G) and *60(T/T) had grade3/4 toxicity. Similarly, high risk group of toxicity or high and low tumor responses groups was also predicted by genotype subset selections. Conclusions: Genotype subset selections of multi-UGT1As polymorphisms were the excellent predictor for severe toxicities and tumor responses of metastatic CRC patients received FOLFIRI regimen.

No significant financial relationships to disclose.
Circulating microRNAs as potential blood-based biomarkers for detection of colorectal cancer
Authors: Chajut A. , Benjamin S. , Gilad S. , Goren Y. , Dan H. , Zion O. , Kushnir M. , Kundel Y. , Niv Y. , Brenner B.
Published: August 2020

e15040

Background: Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide. While there is a strong correlation between stage and prognosis in this disease, current screening methods for CRC have significant limitations, and newer technological approaches are desired. Circulating nucleic acids in body fluids have been studied as a source for diagnostic information and for cancer screening, yet the potential of microRNAs, a family of small non-coding regulatory RNAs, has not yet been thoroughly explored. Here we investigated the utility of microRNAs as potential serum biomarkers for early detection of CRC. Methods: We developed protocols for extracting and quantifying microRNA levels in serum. Serum levels of more than 350 microRNAs were measured using qRT-PCR on samples from 10 healthy controls and 10 CRC patients. Most microRNAs showed consistent levels across different individuals. A subset of microRNAs had significant differences in abundance between the two groups and was studied on a larger cohort of 118 patients and controls. Results: We initially identified a subset of microRNAs that showed significant differential abundance between sera of CRC patients and controls. Measuring the serum levels of 22 microRNAs on a cohort of 118 patients and controls, we showed that levels of circulating microRNAs can be very informative in the identification of CRC. Conclusions: The results demonstrate the potential of the microRNA processing and analysis methods that we developed. Certain microRNAs were found in different amounts in sera of CRC patients compared to healthy controls. Thus, circulating microRNAs represent promising candidates for diagnostic biomarkers in CRC.

[Table: see text]
Correlation of expression of pro-apoptotic proteins bax and bak with lymph node metastasis in colonic adenocarcinoma
Authors: Tracy R. A. , Chuang S. T. , Kim J. , Coppola D.
Published: August 2020

e15042

Background: Colon cancer has been associated with disturbances in the regulation of apoptosis. Down regulation of Bax and Bak, members of the Bcl-2 family, are associated with tumor metastasis. Here we investigate how these two pro-apoptotic markers correlate with lymph node (LN) metastasis in colonic adenocarcinoma (CA). Methods: Paraffin-embedded sections from 100 cases of CA were constructed in tissue microarrays and subjected to immunohistochemistry (IHC) using the ABC method and antibodies for Bax and Bak. The IHC score is the product of intensity and percentage of positively stained cells, and ranged between 0 and 9. The total scores were divided into categories of “2 or less” and “3 or more.” These were than correlated with LN metastasis. Results: For Bax, 88 tumors were available while Bak was present in 100 tumors. In scoring Bax, 67 tumors had a score of ≤2 and 21 had a score of ≥3. Within the ≤2 category, 23 of 67 (34%) tumors had no LN metastases while 15 of 21 (71%) in the ≥3 category had no metastasis (p= 0.0029). For Bak staining, 23 had a score of ≤2 and 77 had a score of ≥3. Five of 23 (22%) tumors with a score ≤2 had no metastases and 35 of 77 (46%) with score ≥3 had no metastases (p= 0.0427). The LOGISTIC Procedure was used to show that a patient with a ≥3 Bax score has a 4.78 times odds ratio (95% C.I.: 1.64- 13.98) of having no metastases while a patient with a ≥3 Bak score has a 3 times odds ratio (95% C.I.: 1.01- 8.90) of having no metastases. Conclusions: We show correlation of the pro-apoptotic proteins Bax and Bak with decreased lymph node metastasis in CA. The findings suggest a role for these markers in predicting stage and patient survival in colonic adenocarcinoma.

No significant financial relationships to disclose.