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Traditional tissue-based assessments of genomic alterations in castration-resistant prostate cancer (CRPC) can be challenging. To evaluate the real-world clinical utility of liquid biopsies for the evaluation of genomic alterations in CRPC, we preemptively collected available plasma samples and archival tissue samples from patients that were being treated for clinically confirmed CRPC. The cell-free DNA (cfDNA) and tumor tissue DNA were analyzed using the AlphaLiquid®100-HRR panel. Plasma samples from a total of 87 patients were included in this study. Somatic mutations from cfDNA were detected in 78 (89.7%) patients, regardless of the presence of overt metastasis or concomitant treatment given at the time of plasma sample collection. Twenty-three patients were found to have known deleterious somatic or germline mutations in HRR genes from their cfDNA. Archival tissue samples from 33 (37.9%) patients were available for comparative analysis. Tissue sequencing was able to yield an NGS result in only 51.5% of the tissue samples. The general sensitivity of cfDNA for detecting somatic mutations in tissues was 71.8%, but important somatic/germline mutations in HRR genes were found to have a higher concordance (100%). Liquid biopsies can be a reasonable substitute for tissue biopsies in CRPC patients when evaluating genomic alterations.

BACKGROUND: Circulating tumour DNA (ctDNA) has been spotlighted as an attractive biomarker because of its easy accessibility and real-time representation of tumour genetic profile. However, the clinical utility of longitudinal ctDNA monitoring has not been clearly defined. METHODS: Serial blood samples were obtained from metastatic colorectal cancer patients undergoing first-line chemotherapy. ctDNA was sequenced using a targeted next-generation sequencing platform which included 106 genes. Changes in ctDNA profile and treatment outcome were comprehensively analysed. RESULTS: A total of 272 samples from 62 patients were analysed. In all, 90.3% of patients had detectable ctDNA mutation before treatment. ctDNA clearance after chemotherapy was associated with longer progression-free survival which was independent of radiological response (adjusted hazard ratio 0.22, 95% confidence interval 0.10–0.46). Longitudinal monitoring was able to detect ctDNA progression which preceded radiological progressive disease (PD) in 58.1% (median 3.3 months). Diverse resistant mutations (34.9%) and gene amplification (7.0%) at the time of PD were discovered. For 16.3% of the PD patients, the newly identified mutations could be potential candidates of targeted therapy or clinical trial. CONCLUSION: ctDNA profile provided a more accurate landscape of tumour and dynamic changes compared to radiological evaluation. Longitudinal ctDNA monitoring may improve personalised treatment decision-making.

Background:Assessment of genomic alterations in castration-resistant prostate cancer (CRPC) patients has become an important process for treatment decisions, but traditional tissue-based evaluation can be challenging. Methods:To evaluate the clinical utility of liquid biopsy for the evaluation of genomic alterations in CRPC, we have prospectively collected plasma samples from patients being treated for clinically confirmed CRPC. The cell-free DNA (cfDNA) extracted from the plasma samples were analyzed using AlphaLiquid®100-HRR panel. Available archival tumor tissue samples were also collected and analyzed using the same panel. Results:Plasma samples from a total of 87 patients were included in this study. Somatic mutations from cfDNA were detected in 78 (89.7%) of all 87 CRPC patients. Somatic mutations were detectable regardless of the presence of overt metastasis, or concomitant treatment given at the time of plasma sample collection. 23 patients were found to have known deleterious mutations in HRR genes from their cfDNA. 11 patients were additionally found to have possibly pathogenic mutations calculated by pathogenicity prediction algorithm. Archival tissue samples were available in 33 (37.9%) of the patients, 31 from prostate and 2 from metastatic bone lesions, collected a median of 2 years before the blood sample collection. Tissue sequencing was able to yield an NGS result in only 51.5% of the tissue samples. The general sensitivity of cfDNA for detecting somatic mutations discovered from tissues was 71.8%, but important somatic/germline mutations in HRR genes were found in higher concordance (100%). Conclusions:Liquid biopsy can be a reasonable substitute for tissue biopsy in CRPC patients for evaluating genomic alterations.

Circulating tumor DNA (ctDNA) may reveal dynamic tumor status during therapy. We conducted serial ctDNA analysis to investigate potential association with clinical outcome in metastatic colorectal cancer (mCRC) patients receiving chemotherapy. Tissue KRAS/NRAS wild-type mCRC patients were enrolled and treated with first-line cetuximab-containing chemotherapy. ctDNA isolated from plasma were analyzed by next generation sequencing (NGS) with 16 targeted gene panel. Among 93 patients, 84 (90.3%) had at least 1 somatic mutation in baseline ctDNA samples (average 2.74). Five patients with KRAS or NRAS hotspot mutation in the ctDNA showed significantly worse progression-free survival (PFS) (p = 0.029). Changes in average variant allele frequency (VAF) in ctDNA showed significant correlation with tumor size change at the time of first response evaluation (p = 0.020) and progressive disease (PD) (p = 0.042). Patients whose average VAF decreased below cutoff (p p = 0.018). At the time of PD, 54 new mutations including KRAS and MAP2K1 emerged in ctDNA. ctDNA sequencing can provide mutation profile that could better reflect tumor mutation status and predict treatment outcome.

Background: Recently, anti-PD-L1 in combination with cytotoxic chemotherapy has shown significant survival benefit in a randomized phase 3 trial for unresectable or metastatic biliary tract cancer (BTC). However, no biomarker including PD-L1 expression has been established to predict clinical outcomes, and there is an unmet need for a novel predictive biomarker for anti-PD-1 or PD-L1 therapy. Here, we assessed TILs using artificial intelligence (AI)-powered spatial analysis in advanced BTC treated with anti-PD-1 beyond 1st line treatment. Methods: An AI-powered whole-slide image (WSI) analyzer (Lunit SCOPE IO, Lunit, Seoul, Korea) was used to segment tumor epithelium and stroma, and identification of intratumor TIL (iTIL) and stromal TIL (sTIL). H&E stained WSI from pre-treatment samples was acquired from Asan Medical Center (n =166), and a total of 154 samples (92.8%) after quality control were used for the final analysis. Immune phenotypes (IP) were defined as follow: inflamed as high iTIL and sTIL; immune-excluded as low iTIL and high sTIL; immune-desert as low TIL overall. Among them, 20 patients were available for multi-color flow cytometry analysis (FACS) using peripheral blood mononuclear cells, collected at baseline, C1D8, and C2D1. Results: All patients (n=154) were treated with anti-PD-1 (pembrolizumab or nivolumab) monotherapy, and 72 of 154 patients (46.8%) were treated as 2nd line. Gemcitabine plus cisplatin (GemCis) was used prior to anti-PD-1 as first-line therapy in all patients. Overall, 15 (9.7%) patients showed inflamed IP. With median follow-up duration of 15.4 months, the inflamed IP group showed better overall survival (17.2 vs. 6.6 months, P=0.03), and progression-free survival (PFS; 4.5 vs. 2.6 months, P=0.09) along with higher PFS rate at 12 months (33.3% vs. 11.5%, P=0.035), and overall response rate (26. 7% vs. 8.6%, P=0.053) than other phenotype groups. There was no significant difference in median PFS with GemCis among IP groups (P=0.74). In the FACS available subgroup, inflamed IP showed higher baseline central memory T (Tcm)+effector memory T (Tem)/Tnaive ratio than other IPs. With the administration of anti-PD-1, Tcm+Tem/Tnaive ratio was increased, while the proportion of PD1+CD8+T, CD39+CD8+T, CD103+CD8+T and Treg were decreased in the inflamed IP group than other phenotype groups. Conclusions: Immune phenotypes classified by AI-powered spatial TIL analysis was effective to predict the clinical outcomes of patients with advanced BTC treated with anti-PD-1 therapy. Citation Format: Yeong Hak Bang, Kyunghye Bang, Jin Ho Shin, Hyunseok Yoon, Kyu-Pyo Kim, Inkeun Park, Jae Ho Jeong, Heung-Moon Chang, Baek-Yeol Ryoo, Chiyoon Oum, Seulki Kim, Yoojoo Lim, Gahee Park, Chan-Young Ock, Changhoon Yoo. Spatial analysis of tumor-infiltrating lymphocytes in tumor microenvironment as biomarker for immune checkpoint inhibition in biliary tract cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4333.

Among prospectively enrolled adult patients with cancer receiving immune checkpoint inhibitors (ICIs; n = 46) or cytotoxic agents (n = 90), seroprotection and seroconversion rates after seasonal quadrivalent influenza vaccinations were higher with ICI than with cytotoxic chemotherapy. These results support annual influenza vaccinations for cancer patients receiving ICIs. Clinical Trials Registration clinicaltrials.gov (NCT03590808).

Introduction: Regorafenib is a multikinase inhibitor which showed clinical benefit in patients with treatment refractory metastatic colorectal cancer. However, as only a subset of patients derives clinical benefit from regorafenib, it is essential to identify biomarker to predict therapeutic response. Circulating tumor DNA (ctDNA) is emerging as a valuable non-invasive tool to identify tumor heterogeneity and tumor burden. This study investigated ctDNA dynamics in patients with metastatic colorectal cancer treated with regorafenib. Methods: This is a prospective biomarker study including patients with refractory metastatic colorectal cancer treated with regorafenib (ClinicalTrial.gov Identifier: NCT01996969). Patients with metastatic colorectal cancer who were refractory to standard therapies (fluoropyrimidine, oxaliplatin, and irinotecan) were eligible for the current study. Patients received oral regorafenib 160 mg once daily for the first 3 weeks of each 4-week cycle and were treated until disease progression, death, unacceptable toxicity, or decision by the treating physicians. Blood samples were obtained prior to regorafenib treatment and after every two cycles of regorafenib treatment until disease progression. ctDNA was detected by AlphaLiquid® 100 target capture panel (IMBdx, Inc., Seoul, South Korea). Alphaliquid® 100 is a tumor agnostic panel consist of 106 genes, including 10 gene fusion and MSI. Variant allele frequency (VAF) amount was calculated by adding the VAF value of all altered genes. Results: A total of 110 patients were included in the present study. Baseline blood samples were successfully acquired in 107 patients (97.3%) with a total of 713 genetic alteration. Mutation was most frequently found in TP53 (76.6%) followed by APC (75.7%), KRAS (43.0%), PIK3CA (17.8%), and SMAD4 (17.8%). BRAF mutation was found in 8.4% of patients and NRAS was detected in 3.7% of patients. Blood samples after two cycle of regorafenib was acquired in 106 patients, and was acquired in 95 patients after disease progression. Among 104 patients with baseline and follow-up cfDNA, the mean VAF at baseline was 12.8% and 7.2% in follow-up. This resulted in a mean VAF change of -5.61% (absolute value) and -43.7% (relative change). VAF decreased markedly after 2 cycles of regorafenib in several genes, including CSF1R, JAK3, KIT, ROS1, and TERT. Although, VAF change of specific gene was not associated with regorafenib outcome, VAF change of whole gene was an early predictive marker for regorafenib. Reduction in VAF amount of ≥ 50% after two cycles of regorafenib were associated with a significantly improved PFS (6.1 vs. 2.7 months, p = 0.002), OS (11.3 vs. 5.9 months, p = 0.001), and higher disease control rate (86.3% vs. 51.1%, p < 0.001). Conclusions: Serial ctDNA could be used as an early predictive biomarker in metastatic colorectal cancer treated with regorafenib. Citation Format: Dae-Won Lee, Sae-Won Han, Yoojoo Lim, Hwang-Phill Kim, Hanseong Roh, Min Jung Kim, Seung-Bum Ryoo, Ji Won Park, Seung-Yong Jeong, Kyu Joo Park, Gyeong Hoon Kang, Tae-You Kim. ctDNA change predicts treatment outcome of regorafenib in metastatic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5157.

Introduction: The fragment size of cfDNA derived from tumor cells are known to be shorter than that from normal cells for not yet precisely known mechanisms. We hypothesized that the fragment size of cfDNA can be utilized to reliably estimate tumor burden in patients with mCRC undergoing palliative chemotherapy. Methods: cfDNA sequencing data from mCRC patients receiving first-line palliative chemotherapy at Seoul National University Hospital (Seoul, Korea) were used for this analysis. The patients were enrolled in a main study evaluating the dynamic changes of circulating tumor DNA mutational profiles during chemotherapy. Blood samples were obtained prior to chemotherapy and after every four cycles of chemotherapy until disease progression. cfDNA sequencing data from normal individuals were used as control data. cfDNA sequencing for both cancer patients and normal individuals were performed using AlphaLiquid® 100 target capture panel (IMBdx, Inc., Seoul, South Korea). AlphaLiquid® 100 is a tumor agnostic panel consist of 106 genes, including 10 gene fusion and MSI. Based on the panel sequencing data, the genetic alterations and the fragment size of cfDNA were calculated. The fragmentation ratio was defined by the ratio of the read fragment proportion in size range P1 (100 - 155 bp) and P2 (160 - 180 bp). Results: cfDNA sequencing data from 280 plasma samples from 62 mCRC patients and 50 healthy controls were used for analysis. Compared to cfDNA from healthy controls, the cfDNA fragment sizes from mCRC patients were significantly shorter (169.585 bp vs. 173.964 bp; p < 0.001). Comparing the fragment sizes by the mutational status, the fragment sizes of alleles with detected somatic mutations were significantly shorter than those with reference alleles (mean fragment size 155.853 bp in alleles with somatic mutations vs. 160.613 bp in reference alleles; p < 0.001), but such difference was not observed with germline mutations (mean fragment size 160.911 bp in alleles with germline mutations vs. 159.889 bp in reference alleles; p = 0.992). Further, the clonality inferred from the variant allele frequency (VAF) of somatic mutation was negatively correlated with the size of the cfDNA fragment. The read fragment proportion in size range P1 was significantly associated with the clonality (r = 0.86, p Conclusions: The fragmentation ratio calculated from cfDNA in mCRC patients can represent tumor burden in dynamic samples and potentially can be used as a biomarker. Citation Format: Jun-Kyu Kang, Hwang-Phill Kim, Yoojoo Lim, Su Yeon Kim, Tae-You Kim. cell-free DNA (cfDNA) fragment size as a potential quantitative biomarker for metastatic colorectal cancer (mCRC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5164.

Although regorafenib has demonstrated survival benefits in patients with metastatic colorectal and gastrointestinal stromal tumors, no proven biomarker has been identified for predicting sensitivity to regorafenib. Here, we investigated preclinical activity of regorafenib in gastric and colorectal cancer cells to identify genetic alterations associated with sensitivity to regorafenib. Mutation profiles and copy number assays of regorafenib target molecules indicated that amplification of fibroblast growth factor receptor 2 (FGFR2) was the only genetic alteration associated with in vitro sensitivity to regorafenib. Regorafenib effectively inhibited phosphorylation of FGFR2 and its downstream signaling molecules in a dose-dependent manner and selectively in FGFR2-amplified cells. Regorafenib induced G1 arrest (SNU-16, KATO-III) and apoptosis (NCI-H716); however, no significant changes were seen in cell lines without FGFR2 amplification. In SNU-16 mice xenografts, regorafenib significantly inhibited tumor growth, proliferation, and FGFR signaling compared to treatment with control vehicle. Regorafenib effectively abrogates activated FGFR2 signaling in FGFR2-amplified gastric and colorectal cancer and, therefore, might be considered for integration into treatment in patients with FGFR2-amplified gastric and colorectal cancers.

BackgroundLittle is known about bridging clonal heterogeneity into the resistance of immune checkpoint inhibitors (ICI). Recent reports showed that excluded tumor-infiltrating lymphocytes (TIL) into stroma assessed by an artificial intelligence (AI)-powered spatial TIL analyzer, Lunit SCOPE IO, was related to loss-of-heterozygosity of HLA genes which would be one of crucial resistance pathways of ICI.1 In the current study, we hypothesized that Immune-excluded phenotype called by Lunit SCOPE IO would be related to clonal heterogeneity resulted from genome-wide accidents during early carcinogenesis which may cause an improper targeting of TIL for diverse clones with multiple genomic aberrations.MethodsFor spatial TIL analysis, we applied Lunit SCOPE IO1 which automatically detects TIL and segmentizes cancer area and stroma, then it classified Immune phenotype of 1 mm2-sized grid in H&E image. Inflamed score or Immune-excluded score were defined as the proportion of Inflamed phenotype, which is high intra-tumoral TIL density, or Immune-excluded phenotype, which is exclusively high TIL density only in stroma, within a whole-slide image, respectively. We evaluated the correlation of Immune phenotype with APOBEC mutational signature by single-base substitution (SBS) signature 2 and/or SBS13,2 whole-genome doubling, and subclonal genome fraction which reflects intra-tumoral heterogeneity,3 and clusters of T cell receptor (TCR) repertoire 4 derived from previous reports of The Cancer Genome Atlas (TCGA), consists of 7,467 tumor samples from 22 cancer types.Abstract 830 Table 1Correlation between immune phenotype and clonal evolution of cancer [* Median (95% confidence interval)]ResultsIn the TCGA pan-carcinoma database, APOBEC mutational signature was significantly correlated with increased ratio of cancer stroma to cancer epithelium (median 0.866 vs 1.19, fold change +37.4%), and increased TIL density in cancer stroma (median 558 vs 764 / mm2, fold change +36.9%), but it was not correlated with intra-tumoral TIL density (median 63 vs 59 / mm2, fold change -6.3%). Interestingly, Immune-excluded score (IES) called by Lunit SCOPE IO was positively correlated with APOBEC mutational signature as well as expression levels of APOBEC1, APOBEC3A, and APOBEC3B, whole-genome doubling, and subclonal genome fraction, respectively, while Inflamed score (IS) or immune cytolytic activity (GZMA and PRF1 expressions) was negatively or not significantly correlated to those variables (table 1). TCR repertoire was expanded in the tumor samples with high IS (spearman rho = 0.279), but it was not increased in those with high IES (spearman rho = -0.0595).ConclusionsThere is a significant correlation between distinct TIL deposition in stroma, or Immune-excluded phenotype, with APOBEC-attributed clonal expansion of cancer, without proper expansion of TCR repertoire.ReferencesOck CY, Park C, Paeng K, Yoo D, Kim S, Park S, Lee SH, Mok T, Bang YJ. Artificial intelligence-powered spatial analysis of tumor-infiltrating lymphocytes reveals distinct genomic profile of immune excluded phenotype in pan-carcinoma. Cancer Res 2021;81(Supp 13):1908.Alexandrov LB, Kim J, Haradhvala NJ, Huang MN, Tian Ng AW, Wu Y, Boot A, Covington KR, Gordenin DA, Bergstrom EN, Islam SMA, Lopez-Bigas N, Klimczak LJ, McPherson JR, Morganella S, Sabarinathan R, Wheeler DA, Mustonen V, PCAWG Mutational Signatures Working Group, Getz G, Rozen SG, Stratton MR, PCAWG Consortium. The repertoire of mutational signatures in human cancer. Nature 2020;578(7793):94–101.Taylor AM, Shih J, Ha G, Gao GF, Zhang X, Berger AC, Schumacher SE, Wang C, Hu H, Liu J, Lazar AJ, Cancer Genome Atlas Research Network, Cherniack AD, Beroukhim R, Meyerson M. Genomic and functional approaches to understanding cancer aneuploidy. Cancer Cell 2018;33(4):676–689.e3.Zhang H, Liu L, Zhang J, Chen J, Ye J, Shukla S, Qiao J, Zhan X, Chen H, Wu CJ, Fu YX, Li B. Investigation of antigen-specific T-Cell receptor clusters in human cancers. Clin Cancer Res 2020;26(6):1359–1371.

Purpose The purpose of this study was to assess current levels of awareness of clinical trials (CTs), perceptions regarding their benefits and willingness to participate to CTs among Korean cancer patients. Materials and Methods From December 2012 to August 2015, we distributed questionnaires to cancer patients receiving systemic anti-cancer therapy at Seoul National University Hospital, Seoul, Korea. Results A total of 397 out of 520 requested patients (76.3%) responded to the survey. Among the 397 patients, 62.5% were female and the median age was 52 years. Overall, 97.4% (387/397) answered that they have at least heard of CTs. When asked about their level of awareness, 23.8% (92/387) answered that they could more than roughly explain about CTs. The average visual analogue scale score of CT benefit in all patients was 6.43 (standard deviation, 2.20). Patients who were only familiar with the term without detailed knowledge of the contents had the least expectation of benefit from CTs (p=0.015). When asked about their willingness to participate in CTs, 56.7% (225/397) answered positively. Patients with higher levels of awareness of CTs showed higher willingness to participate (p < 0.001). Heavily treated patients and patients with previous experience regarding CTs also showed a higher willingness to participate (p < 0.001). The perceived benefit of CTs was higher in the group willing to participate (p=0.026). Conclusion The patient’s level of awareness regarding CTs was positively related to the positive perception and willingness to participate. Although the general awareness of CTs was high, a relatively large proportion of patients did not have accurate knowledge; therefore, proper and accurate patient education is necessary.

Although MEK blockade has been highlighted as a promising antitumor drug, it has poor clinical efficacy in KRAS mutant colorectal cancer (CRC). Several feedback systems have been described in which inhibition of one intracellular pathway leads to activation of a parallel signaling pathway, thereby decreasing the effectiveness of single-MEK targeted therapies. Here, we investigated a bypass mechanism of resistance to MEK inhibition in KRAS CRC. We found that KRAS mutant CRC cells with refametinib, MEK inhibitor, induced MIF secretion and resulted in activation of STAT3 and MAPK. MIF knockdown by siRNA restored sensitivity to refametinib in KRAS mutant cells. In addition, combination with refametinib and 4-IPP, a MIF inhibitor, effectively reduced the activity of STAT3 and MAPK, more than single-agent treatment. As a result, combined therapy was found to exhibit a synergistic growth inhibitory effect against refametinib-resistant cells by inhibition of MIF activation. These results reveal that MIF-induced STAT3 and MAPK activation evoked an intrinsic resistance to refametinib. Our results provide the basis for a rational combination strategy against KRAS mutant colorectal cancers, predicated on the understanding of cross talk between the MEK and MIF pathways.

Background Although induction chemotherapy can reduce distant metastases in locally advanced head and neck squamous cell carcinoma (HNSCC), overall survival (OS) improvement because of induction chemotherapy has not been confirmed. Methods We reviewed medical records of 224 patients diagnosed with locally advanced HNSCC who were treated with induction chemotherapy followed by concurrent chemoradiotherapy (CRT; induction chemotherapy/CRT; N = 144) and CRT alone (N = 80) from 2005 to 2013. We analyzed OS and progression-free survival (PFS). Results The 3-year OS rate was significantly higher in the induction chemotherapy/CRT group compared to the CRT group (74.0% vs 62.7%; p = .045). The 3-year PFS rate was 64.6% in the induction chemotherapy/CRT group and 54.1% in the CRT group (p = .060). Subgroup analysis showed patients with high N classification (N2 or N3) oropharyngeal cancer had greater benefits when treated with induction chemotherapy/CRT. Conclusion Induction chemotherapy plus CRT improved OS, compared to CRT alone in locally advanced HNSCC, especially with high N classification. © 2015 Wiley Periodicals, Inc. Head Neck 38: 277–284, 2016

Organoids are known to best in vitro model system which mostly mimic genetic, phenotypic feature of its origin. And it is expected and suitable to variable disease modeling and study. For cancer modeling using organoids as co-clinical model, our group derived organoids from 40 colorectal tumor including lymph node, terminal ileum metastatic tumor and ascites. Whole exome sequencing of matched tumor organoids and tissues was performed and their somatic mutation concordance was analyzed. As a results, Organoids reflect their genetic statues of the original tumor tissue and their phenotypic features are maintained. In order to prove the appliance of these organoids as a co-clinical model, clinical drugs on colorectal cancer such as 5-Fluorouracil, oxaliplatin, SN38 and cetuximab were tested. The drug results reflected the actual clinical outcome of the corresponding patients. To find the precise drug treatment option for conventional chemo-refractory patients, we performed 134 anti-cancer drug library screening. Organoids with specific mutations were sensitive to drugs which target these corresponding mutations. For instance, organoid with RNF43 mutation was sensitive to porcupine inhibitor which suppresses auto- and paracrine WNT- driven growth. In conclusion, we suggest that patient derived organoids can be applied in cancer treatment as a co-clinical model, due to their highly correlated genetic information and drug sensitivity with those of the patients themselves. Citation Format: Young-Won Cho, Hwang-Phill Kim, Dong Wook Min, Yoojoo Lim, Sang-Hyun Song, Sae-Won Han, Tae-You Kim. Application of patients derived organoids as co-clinical model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 36.

FDG PET is effective in treatment response evaluation of cancer. However, there is no standard method for quantitative evaluation of FDG PET, particularly regarding cytostatic drugs. We compared various FDG PET quantitative methods in terms of response determination. A total of 39 refractory metastatic colorectal cancer patients who received a multikinase inhibitor treatment were included. Baseline and posttreatment FDG PET/CT scans were performed before and two cycles after treatment. Standardized uptake value (SUV) and total lesion glycolysis (TLG) values using various margin thresholds (30–70 % of maximum SUV with increment 10 %, twice mean SUV of blood pool, SUV 3.0, and SUV 4.0) were measured, with measurement target of the hottest lesion or a maximum of five hottest lesions. Treatment response by the PERCIST criteria was also determined. Predictive values of the PET indexes were evaluated in terms of the treatment response determined by the RECIST 1.1 criteria. The agreement rate was 38 % between response determined by the PERCIST and the RECIST criteria (κ = 0.381). When patients were classified into disease control group (PR, SD) and non-control group (PD) by the RECIST criteria, percent changes of TLG with various margin thresholds (particularly, 30–50 % of maximum SUV) exhibited significant differences between the two groups, and high diagnostic power for the response by the RECIST criteria. TLG-based criteria, which used a margin threshold of 50 % of maximum SUV, exhibited a high agreement with the RECIST criteria compared with the PERCIST criteria (κ = 0.606). In metastatic colorectal cancer, FDG PET/CT could be effective for treatment response evaluation by using TLG measured by margin thresholds of 30–50 % of maximum SUV. Further studies are warranted regarding the optimal cutoff values for this method.

BACKGROUND/AIMS We investigated the clinical characteristics and prognosis of elderly patients with acute lymphoblastic leukemia (ALL). METHODS We reviewed the clinical data, laboratory findings, bone marrow findings, and cytogenetic analysis of elderly patients (≥ 60 years) with ALL, and data of an additional 101 younger adult patients (< 60 years) with ALL were reviewed for comparison. RESULTS Twenty-six elderly patients (≥ 60 years) and 101 younger adult patients (< 60 years) with ALL were retrospectively enrolled. The median follow-up duration was 6.0 months (range, 0.4 to 113.2) in the elderly patients and 21.7 months (range, 1.0 to 122.7) in the adult patients. In total, 34.6% (9 patients) of the elderly patients and 24.8% (25 patients) of the adult patients had Philadelphia chromosome positive ALL. The overall complete remission (CR) rate was much higher in the younger than in the elderly patients (94.1% vs. 57.7%, p < 0.001). The median overall survival (OS) of the younger patients (< 60 years) was 26.3 months, whereas that of the elderly patients (≥ 60 years) was 10.3 months (p = 0.003). In the elderly patients with ALL, T cell lineage and the presence of lymphadenopathy were significant prognostic factors for OS in a univariate analysis (p = 0.033 and 0.041, respectively). CONCLUSIONS The outcomes of Korean elderly patients with ALL were poor, and the shorter OS was mainly due to the low CR rate. T-cell lineage and the presence of lymphadenopathy were significant prognostic factors in Korean elderly patients with ALL.

Background Regorafenib induces distinct radiological changes that represent its anti-angiogenic effect. However, clinical implication of the changes is unclear. Methods Tumor attenuation as measured by Hounsfield units (HU) in contrast-enhanced computed tomography (CT) and cavitary changes of lung metastases were analyzed in association with treatment outcome of metastatic colorectal cancer patients (N = 80) treated with regorafenib in a prospective study. Results 141 lesions in 72 patients were analyzed with HU. After 2 cycles of regorafenib, 87.5% of patients showed decrease of HU (Median change -23.9%, range -61.5%–20.7%). Lesional attenuation change was modestly associated with metabolic changes of 18-fluoro-deoxyglucose positron emission tomography-CT (Pearson’s r = 0.37, p = 0.002). Among 53 patients with lung metastases, 17 (32.1%) developed cavitary changes. There were no differences in disease control rate, progression-free survival, or overall survival according to the radiological changes. At the time of progressive disease (PD) according to RECIST 1.1, HU was lower than baseline in 86.0% (43/50) and cavitary change of lung metastasis persisted without refilling in 84.6% (11/13). Conclusion Regorafenib showed prominent anti-angiogenic effect in colorectal cancer, but the changes were not associated with treatment outcome. However, the anti-angiogenic effects persisted at the time of PD, which suggests that we may need to develop new treatment strategies.

The cell-free DNA (cfDNA) represents a minimally invasive and alternative source of tumor DNA for molecular profiling. Despite next-generation sequencing (NGS) technique is qualified for genotyping cancer using cfDNA as a noninvasive method, it has caused problems as sequencing error and reproducibility. cfDNA in plasma and gDNA of Peripheral Blood Mononuclear Cells (PBMC) were isolated from each 54 advanced colorectal cancer patients. 39 available tumor tissues were isolated from same patients. Deep target-sequencing was performed with paired-end library enriched exons of 10 genes which are recurrently mutated in colorectal cancer. To reduce sequencing error, we devised ‘Denoising’ and calculated concordance of somatic variants between cfDNA and tumor tissue sequencing data. In addition, correlation of concordance data was analyzed with the clinical information. As a result, we selectively could detect clinically important somatic alteration among low/high variant allele frequency (0.31%~79.42%). For somatic alteration of 10 genes, sensitivity, specificity and accuracy were increased from 84.5%, 74.6% and 76.9% to 87.6%, 92.0% and 91.1% respectively after ‘Denoising’. On the other hand, patients with high cfDNA concentration(>50ng/ml) had higher somatic mutant fragments and larger metastatic lesion in liver than patients who have low cfDNA concentration. Our study showed that denoised deep target-sequencing is a suitable method for cfDNA genotyping and provides insights into strategies for monitoring metastatic lesion of advanced colorectal cancer. Citation Format: Jun-Kyu Kang, Hwang-Phill Kim, Seul-Ki Cheon, Ye-Lim Park, Yoojoo Lim, Sae-Won Han, Tae-You Kim. Noninvasive approach to assess metastatic lesion of advanced colorectal cancer by denoised deep target sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1800. doi:10.1158/1538-7445.AM2017-1800

KRAS is a frequently mutated gene in colorectal cancer. In addition, PIK3CA mutations commonly co-exist with KRAS mutations and lead to additive activation of the PI3K/mTOR signaling pathway. Here, we investigated preclinical activity of gedatolisib, a PI3K/mTOR dual inhibitor, to identify mechanism of inhibition of PI3K/mTOR in 28 colorectal cancer (CRC) cells. Cells specifically with PIK3CA mutation were sensitive while those with KRAS mutation were resistant to gedatolisib. 9 out of 28 CRC cells harbor PIK3CA & KRAS co-mutation and 7 out them were shown to be sensitive to gedatolisib. However, HCT15 and LS174T cells were resistant. We identified that resistant cell lines have high activity of GSK3B and TCF7 frameshift mutation (465insertC466;H155fs*), which functions as positive regulator of WNT/b-catenin pathway. The effects of GSK3B-knockdown showed decreased activity of mTOR downstream molecules in gedatolisib-treated resistant cells. Interestingly, these effects also caused a decrease in activity of WNT/b-catenin pathway. In addition, combination treatment of gedatolisib and CHIR-99021, GSK3B inhibitor, resulted in significantly enhanced cytotoxicity against gedatolisib-resistant TCF7 frameshift mutant cells. Taken together, these show that aberrant regulation of WNT/b-catenin pathway and high activity of GSK3B by TCF7 frameshift mutation cause resistance to PI3K/mTOR dual inhibitor. Inhibition of GSK3B activity in colorectal cancer cells with KRAS and PIK3CA co-mutations increases sensitivity to PI3K/mTOR dual inhibitor. Citation Format: Ye-Lim Park, Hwang-Phill Kim, Seul-Ki Cheon, Jun-Kyu Kang, Yoojoo Lim, Sang-Hyun Song, Sae-Won Han, Tae-you Kim. Activation of WNT/b-catenin signaling results in resistance to PI3K/mTOR dual inhibitor in co-existing KRAS and PIK3CA mutant colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5214. doi:10.1158/1538-7445.AM2017-5214

Although MEK blockade has been highlighted as a promising anti-tumor drug, it has poor clinical efficacy in KRAS mutant colorectal cancer. Several feedback systems have been described in which inhibition of one intracellular pathway leads to activation of a parallel signaling pathway, thereby decreasing the effectiveness of single-MEK targeted therapies. In this study, we describe a feedback mechanism in which MEK inhibition leads to activation of macrophage migration inhibitory factor (MIF)-induced stat3 signaling pathway in KRAS mutant colorectal cancer (CRC) cells. We found that KRAS mutant CRC cells with refametinib, MEK inhibitor, induced MIF secretion and resulted in activation of Stat3. MIF knockdown by siRNA partially restored sensitivity to refametinib in KRAS mutant cells. In addition, combination with refametinib and 4IPP, a MIF inhibitor, effectively reduced the activity of stat3 and MAPK, more than single agent treatment. As a result, combined therapy was found to exhibit a synergistic growth inhibitory effect against refametinib-resistant cells by downregulating MIF expression. These results reveal that MIF-induced stat3 activation evoked an intrinsic resistance to refametinib. Our results provide the basis for a rational combination strategy against KRAS mutant colorectal cancers, predicated on the understanding of cross-talk between the MEK and MIF pathways. Citation Format: Seul-Ki Cheon, Hwang-Phill Kim, Ye-Lim Park, Si Hyun Lee, Jun-Kyu Kang, Yoojoo Lim, Sang-Hyun Song, Sae-Won Han, Tae-You Kim. MIF-induced stat3 activation promotes resistance to MEK blockade in KRAS mutant colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3167. doi:10.1158/1538-7445.AM2017-3167

Introduction: Regorafenib is an oral multikinase inhibitor with anti-angiogenic activity. Decrease in tumor density without significant decrease in tumor volume is often observed after treatment with the drug, suggesting the necessity of further means of response evaluation in addition to size criteria. This study was planned to evaluate whether metabolic imaging with 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) could predict outcome in mCRC patient treated with regorafenib. Methods: Patients were enrolled into a main study entitled Identification of Predictive Biomarker of Regorafenib in Refractory Colorectal Cancer: A Prospective Explorative Study (NCT01996969). mCRC patients (N = 117) were treated with regorafenib, 160mg orally once daily, on days 1-21 of a 28-day cycle, and treatment outcome was evaluated according to the Response Evaluation Criteria in Solid Tumors 1.1. For this imaging sub-study, the results of 18-FDG PET scans obtained at baseline and after 2 cycles of treatment were analyzed. Total lesion glycolysis (TLG) of each patient was calculated by multiplying the volume exceeding the threshold of 40% of maximum standardized uptake value (SUV) by the mean SUV of the lesion, and the percentage changes of TLG after treatment were calculated. The association between the changes of the metabolic imaging and treatment outcome was analyzed. Results: A total of 44 patients were evaluable for 18-FDG PET scan results. The best overall response in the 44 patients were, partial response in 3 (6.8%), stable disease in 23 (52.3%) and progressive disease in 18 (40.9%). The median progression-free survival (PFS) and the median overall survival (OS) were 5.4 and 14.1 months, respectively. The median of TLG at baseline was 187.4 (range 18.3 to 8893.2). After 2 cycles of regorafenib, 50.0% of patients had a decrease in TLG. Median change in TLG was 1.7% (range, -75.7 to 251.6%). Changes in TLG were modestly associated with size changes (Pearson's r = 0.51, p = 0.001). Patients with lower baseline TLG (< 324.49) showed significantly longer OS (1 year survival rate 75.6 vs. 33.5%, p = 0.008). Moreover, patients showing higher decrease in TLG (change < 1.7%) showed significantly longer PFS (median 8.4 vs. 1.9 months, p Conclusions: Lower baseline TLG is associated with better OS and higher decrease in TLG after treatment predicted better PFS in mCRC patients treated with regorafenib. Citation Format: Yoojoo Lim, Ji-In Bang, Sae-Won Han, Jin Chul Paeng, Jeong Hee Yoon, Jeong Min Lee, Jae-Kyung Won, Gyeong Hoon Kang, Seung-Yong Jeong, Kyu Joo Park, Kyung-Hun Lee, Jee Hyun Kim, Tae-You Kim. Total lesion glycolysis (TLG) as an imaging biomarker of regorafenib treatment in metastatic colorectal cancer (mCRC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3972.

10067Background: Patients’ proper understanding and consent to participate are crucial for successful conduction of clinical trials (CT). We have conducted a survey, to assess the current patients’...

The nationwide statistical analysis of each disease of classical myeloproliferative neoplasm (MPN) in Korea has not been reported yet. To this end, we have analyzed incidence rates, survival rates and treatment pattern of polycythemia vera (PV), primary myelofibrosis (MF) and essential thrombocythemia (ET) using Korea National Cancer Incidence Database (KNCIDB) and Health Insurance Review and Assessment Service (HIRA) database. Between 2003 and 2011, a total of 4,342 new cases of MPN were reported to the KNCIDB. ET was the most common, followed by MF and PV. The crude incidence rates for PV, MF, and ET have increased during the period, reaching 0.40, 0.15, and 0.84 per 100,000, respectively. Five-year relative survival rate of all MPN patients was 89.3%, with lowest relative survival rate with MF (53.1%). The prevalence of each disease estimated from HIRA data also increased during the study period. Notably, ET was found to be most prevalent. The prescription rate of hydroxyurea and phlebotomy to PV, MF and ET patients remained constant over the period, and the prescription rate of hydroxyurea was higher in patients with age over 60 years. This is the first Korean nationwide statistics of MPN, using central registry data. This set of data can be utilized to compare the Korean MPN status to international data and guidelines., Graphical Abstract

In order to identify novel fusion transcripts in colorectal cancer, we carried out paired-end RNA sequencing in 28 human colorectal cancer cell lines. Fusion transcript candidates were identified using ChimeraScan and FusionMap tools. We obtained 1380 candidates having 4 or more read counts and spanning reads. Among the candidates, we selected 27 candidates for validation which harbors genes related to the Wnt signaling pathway or kinases according to KEGG or DAVID. After the targeted gene filtering step, validation using RT-PCR with fusion specific primers finally resulted in 2 intra- and 1 inter-fusion transcripts. Intra-fusion transcripts were NFATC3-PLA2G15 and AKAP13-PDE8A and inter-fusion transcript was KRT8-PKM2 each identified in colo-320, SW-480 and SNU-1235, respectively. The fusion junctions were confirmed by Sanger sequencing. NFATC3-PLA2G15 fusion transcripts consisted of exon 1-9 of NFATC3 (nuclear factor of activated T-cells, cytoplasmic 3) gene and exon 2-6 of the PLA2G15 (Phospholipase A2, Group 5) gene and both located on the same chromosome 16q. NFATC3 is known as transcription factor in the Wnt signaling pathway and regulates function of the target genes like cell proliferation, invasion and epithelial-to-mesenchymal transition (EMT). Under the experiments using siRNA in the colo-320 cell carrying fusion transcript, knockdown of the NFATC3-PLA2G15 fusion transcript decreased mRNA and protein expression of mesenchymal markers, namely vimentin (VIM), Twist-related protein 1 (TWIST1) and fibronectin (FN), and increased epithelial markers, E-cadherin (CDH1) and claudin-1 (CLDN1). Fusion transcripts knockdown also led to decrease of the invasion ability regulated by above markers. Moreover, soft agar assay showed inhibition of colony formation after fusion transcript knockdown. Fusion transcript downregulation also resulted in decrease of cell proliferation and mRNA and protein expression of cyclin D but increase in p27 level. The knockdown did not have influence in the fusion negative cell line. Collectively, these results suggest that the NFATC3-PLA2G15 fusion transcript is involved in invasion and proliferation of colorectal cancer cells. Citation Format: JE Jang, HP Kim, SH Lee, DW Lee, YJ Lim, SW Han, TY Kim. NFATC3-PLA2G15 fusion transcript identified by RNA-sequencing promotes tumor progression in colorectal cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A28.

Introduction: Regorafenib is an oral multikinase inhibitor, which has anti-angiogenic and anti-tumor activity by inhibition of a number of angiogenic and oncogenic kinases. It induces distinct radiological changes in metastatic colorectal cancer (mCRC), which are decrease in tumor attenuation and cavitation of lung metastasis. These changes may be a result of anti-angiogenic activity, but the clinical implications of the changes are unclear. This study was designed to analyze the radiological changes in association with treatment outcome in mCRC patients treated with regorafenib. Methods: All patients were a part of a main study entitled Identification of Predictive Biomarker of Regorafenib in Refractory Colorectal Cancer: A Prospective Explorative Study (NCT01996969). Tumor attenuation measured by Hounsfield units (HU) of contrast-enhanced computed tomography (CT) scan and cavitary changes of lung metastases were evaluated in mCRC patients (N = 80) treated with regorafenib (160mg orally once daily, on days 1-21 of a 28-day cycle). Maximum standardized uptake values (mSUV) of tumor lesions at baseline and after 2 cycles of treatment were analyzed in patients whose 18-fluoro-deoxyglucose positron emission tomography (PET)-CT images were available for analysis. Treatment outcome was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The association between radiological changes and treatment outcome was analyzed. Results: A total of 141 lesions in 72 patients were analyzed with HU measurement. After 2 cycles of regorafenib treatment, 87.5% of patients had a decrease in tumor attenuation. Median change in tumor attenuation was -23.9% (range -61.5% to 20.7%). Lesional attenuation changes were modestly associated with changes in mSUV in PET-CT scans (Pearson's r = 0.38, p Conclusions: Regorafenib showed prominent anti-angiogenic activity in mCRC represented by the radiological changes. Although the changes were not associated with treatment outcome, it was persistently observed at the time of PD by RECIST 1.1. The results suggest the possibility of inadequacy of current conventional response evaluation paradigm in treating mCRC patients with regorafenib. We may need to develop alternative evaluation and treatment strategies considering the anti-angiogenic activity. Citation Format: Yoojoo Lim, Sae-Won Han, Jeong Hee Yoon, Jeong Min Lee, Jung Min Lee, Jin Chul Paeng, Jae-Kyung Won, Gyeong Hoon Kang, Seung-Yong Jeong, Kyu Joo Park, Kyung-Hun Lee, Jee Hyun Kim, Tae-You Kim. Clinical implications of anti-angiogenic effect of regorafenib in metastatic colorectal cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A2.

Sarcomatoid carcinoma of the lung is defined as a group of poorly differentiated non-small cell carcinomas that contain a component of sarcoma or a sarcoma-like element. Most sarcomatoid carcinomas are known to have a poor prognosis. We describe a 45-year-old female never smoker and 49-year-old female never smoker with sarcomatoid carcinomas of the lung that expressed a specific EGFR mutation: microdeletion of exon 19. Their cancers progressed rapidly, despite appropriate conventional chemotherapy. After they took the EGFR-targeted agent gefitinib, there was a dramatic reduction in tumor size. Sarcomatoid carcinoma of the lung is a rare cancer whose pathogenesis is not well understood. According to these cases, the EGFR mutation could be a driver mutation and the potential therapeutic target of EGFR-targeted agents for sarcomatoid carcinoma in lung cancer patients, especially never smokers. (Korean J Med 2013;84:446-451)

Purpose Exemestane has shown good efficacy and tolerability in postmenopausal women with hormone receptor-positive metastatic breast cancer. However, clinical outcomes in Korean patients have not yet been reported. Methods Data on 112 postmenopausal women with metastatic breast cancer were obtained retrospectively. Clinicopathological characteristics and treatment history were extracted from medical records. All patients received 25 mg exemestane daily until objective disease progression. Progression-free survival (PFS) was the primary endpoint, and secondary endpoints were overall survival (OS), objective response rate (ORR), and clinical benefit rate (CBR=complete response+partial response+stable disease for 6 months). Results The median age of the subjects was 55 years (range, 28-76 years). Exemestane treatment resulted in a median PFS of 5.7 months (95% confidence interval [CI], 4.4-7.0 months) and median OS of 21.9 months (95% CI, 13.6-30.3 months). ORR was 6.4% and CBR was 46.4% for the 110 patients with evaluable lesions. Symptomatic visceral disease was independently associated with shorter PFS (hazard ratio, 3.611; 95% CI, 1.904-6.848; p

TO THE EDITOR: Heparin-induced thrombocytopenia (HIT) is a significant complication of heparin therapy. Risk factors for HIT include the type of heparin used, duration of heparin exposure, and clinical setting. Here, we report a 76-year-old man who presented with life-threatening pulmonary thromboembolism and deep-vein thrombosis, preceded by a dramatic decrease in platelet count 1 week after radical cystectomy for transitional cell bladder carcinoma. He was diagnosed with type II HIT caused by a small amount of unfractionated heparin mixed into his total parenteral nutrition (TPN) solution. One thousand units heparin per day were added to his TPN for 1 week. A heparin-platelet factor-4 antibody enzyme-linked immunosorbent assay of his serum was strongly positive. After cessation of TPN infusion, argatroban was started for thrombosis. His platelet count gradually increased to a normal level, and the thrombosis was treated successfully. This case suggests HIT should be suspected in patients with typical clinical manifestations and risk factors, even if the infused heparin dose is small. Heparin is widely used in a variety of medical therapies from the treatment of life-threatening acute thromboembolisms to the maintenance of indwelling vascular catheter patency. However, heparin therapy is often complicated by thrombocytopenia. The incidence of heparin-induced thrombocytopenia (HIT) in patients who receive heparin including unfractionated heparin and low-molecular-weight heparin is 0.1-5% [1]. There are 2 types of HIT. Type I HIT is a relatively common non-immune reaction that causes an asymptomatic, transient, and mild decrease in platelet count. In contrast, type II HIT is an immune complex disorder involving heparin bound to the platelet-specific chemokine, platelet factor-4 (PF4). These heparin-PF4 complexes activate both platelets and endothelial cells, resulting in platelet consumption and endothelial injury with thrombosis and disseminated intravascular coagulation [2]. Heparin use could go unnoticed if it is not applied as a conventional anticoagulant but rather as a supportive agent to maintain vasc,ular patency. However, unrecognized HIT can lead to life-threatening complications. Therefore, it is important to suspect HIT in patients who develop acute thrombosis or thrombotic tendency preceded by a decrease in platelet count during or soon after heparin therapy, even if the infused amount is small. Immediate discontinuation of heparin administration and initiating alternative anticoagulant therapy are critical for avoiding further thrombosis, even before laboratory results are available [3]. To the best of our knowledge, this is the first report on a patient who experienced type II HIT after low-dose heparin added to his total parenteral nutrition (TPN) for 1 week.

Arsenic trioxide (As2O3) has shown substantial efficacy in the treatment of patients with acute promyelocytic leukemia (APL). However, since not all patients could achieve complete remission after As2O3 treatment, it is necessary to investigate a novel treatment method overcoming the resistance of current treatment. However, the therapeutic role of calcitriol against APL has not yet been fully elucidated. In our study, we investigated the anti-leukemic effect of calcitriol in combination with As2O3 on the human APL cell line HL-60. Inhibition of proliferation rate of HL-60 cells was measured by the trypan blue exclusion test was resulted in dose, time- dependent expressions. To evaluate the effects of combination treatment of As2O3 and calcitriol on the cell proliferation, we analyzed the combined effects of As2O3 and calcitriol using CalcuSyn software (BioSoft, Ferguson, MO, USA), which is based on the multiple drug-effect equation of Chou and Talalay (Chou TC, et al. Adv Enzyme Regul 1984): a combination index (CI) of 1 is defined as synergistic, additive, or antagonistic, respectively. In all combinations, the CI values calculated were less than 1. To investigate the effects of these treatments on the apoptosis pathway, we analyzed the expression of Bax, Caspase-3, Bcl-2 with the Western blot and the RT-PCR. In the Western blot analysis, lower Bcl-2 and higher Bax and Caspase-3 expressions were observed in the As2O3 or calcitriol-treated groups compared to the control group. The combination treatment decreased Bcl-2 expression and increased Bax and Caspase-3 expressions more prominently than the single treatment using either As2O3 or calcitriol. In the RT-PCR analysis, these trends were validated again with the same results. These cells were then labeled with fluorescein-conjugated Annexin V-FITC and propidium iodide (PI), and analyzed with flow cytometry to differentiate whether the main cause of cell death was apoptosis or necrosis. To resultsze, calcitriol in combination with As2O3 synergistically inhibited proliferation of the human APL cell line HL-60. In addition, calcitriol combined with As2O3 more prominently activated the apoptosis pathway than single treatment using either calcitriol or As2O3. The main cause of cell death was also apoptosis. Our results suggest that these novel findings could be applied to improve the therapeutic outcomes of patients with APL. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4909. doi:1538-7445.AM2012-4909

Abstract 5279 Background: There is a lack of clinical research regarding the effect of iron deficiency anemia on white blood cells (WBC).This study presents the incidence of leukopenia in patients with iron deficiency anemia and the relationship between the white blood cell count and the level of hemoglobin(Hb). Patients and Method: Medical records of patients over 12 years of age with iron deficiency anemia were reviewed. Patients with concomitant disease that may alter the WBC count such as hematologic malignancy, solid tumor, history of gastrectomy, vitamin B12 or folate deficiencies and active inflammation were excluded. Results: From January 2006 to December 2010, a total of 516 eligible patients were included. Median age was 47 years with female predominance (80.6%). Leukopenia was found in 91 patients (17.6%). The incidence of leukopenia was significantly higher in patients with hemoglobin level of less than 8 g/dL than those with higher level of hemoglobin (44/183, 24.0% vs. 47/333, 14.1%, P=0.005, Table 1). The levels of WBC count were found to decrease in accordance with the decrease in hemoglobin level (Pearson's coefficient: 0.178, P Conclusion: This study shows the high incidence of leukopenia in patients with iron deficiency anemia. The severity of leukopenia correlates with the decrease of hemoglobin in dose-dependent manner. Among the WBC subsets, lymphocyte count was significantly affected. Disclosures: No relevant conflicts of interest to declare.