Phase II Trial of Postoperative Adjuvant Gemcitabine and Cisplatin Chemotherapy Followed by Chemoradiotherapy with Gemcitabine in Patients with Resected Pancreatic Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Despite curative resection, the 5-year survival for patients with resectable pancreatic cancer is less than 20%. Recurrence occurs both locally and at distant sites and effective multimodality adjuvant treatment is needed. @*Materials and Methods@#Patients with curatively resected stage IB-IIB pancreatic adenocarcinoma were eligible. Treatment consisted of chemotherapy with gemcitabine 1,000 mg/m2 on days 1 and 8 and cisplatin 60 mg/m2 on day 1 every 3 weeks for two cycles, followed by chemoradiotherapy (50.4 Gy/28 fx) with weekly gemcitabine (300 mg/m2/wk), and then gemcitabine 1,000 mg/m2 on days 1 and 8 every 3 weeks for four cycles. The primary endpoint was 1-year disease-free survival rate. The secondary endpoints were disease-free survival, overall survival, and safety. @*Results@#Seventy-four patients were enrolled. One-year disease-free survival rate was 57.9%. Median disease-free and overall survival were 15.0 months (95% confidence interval [CI], 11.6 to 18.4) and 33.0 months (95% CI, 21.8 to 44.2), respectively. At the median follow-up of 32 months, 57 patients (77.0%) had recurrence including 11 patients whose recurrence was during the adjuvant treatment. Most of the recurrences were systemic (52 patients). Stage at the time of diagnosis (70.0% in IIA, 51.2% in IIB, p=0.006) were significantly related with 1-year disease-free survival rate. Toxicities were generally tolerable, with 53 events of grade 3 or 4 hematologic toxicity and four patients with febrile neutropenia. @*Conclusion@#Adjuvant gemcitabine and cisplatin chemotherapy followed by chemoradiotherapy with gemcitabine and maintenance gemcitabine showed efficacy and good tolerability in curatively resected pancreatic cancer.

Adjuvant Chemotherapy in Microsatellite Instability–High Gastric Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Microsatellite instability (MSI) status may affect the efficacy of adjuvant chemotherapy in gastric cancer. In this study, the clinical characteristics of MSI-high (MSI-H) gastric cancer and the predictive value of MSI-H for adjuvant chemotherapy in large cohorts of gastric cancer patients were evaluated. Material and MethodsThis study consisted of two cohorts. Cohort 1 included gastric cancer patients who received curative resection with pathologic stage IB-IIIC. Cohort 2 included patients with MSI-H gastric cancer who received curative resection with pathologic stage II/III. MSI was examined using two mononucleotide markers and three dinucleotide markers. @*Results@#Of 359 patients (cohort 1), 41 patients (11.4%) had MSI-H. MSI-H tumors were more frequently identified in older patients (p < 0.001), other histology than poorly cohesive, signet ring cell type (p=0.005), intestinal type (p=0.028), lower third tumor location (p=0.005), and absent perineural invasion (p=0.027). MSI-H status has a tendency of better disease-free survival (DFS) and overall survival (OS) in multivariable analyses (hazard ratio [HR], 0.4; p=0.059 and HR, 0.4; p=0.063, respectively). In the analysis of 162 MSI-H patients (cohort 2), adjuvant chemotherapy showed a significant benefit with respect to longer DFS and OS (p=0.047 and p=0.043, respectively). In multivariable analysis, adjuvant chemotherapy improved DFS (HR, 0.4; p=0.040). @*Conclusion@#MSI-H gastric cancer had distinct clinicopathologic findings. Even in MSI-H gastric cancer of retrospective cohort, adjuvant chemotherapy could show a survival benefit, which was in contrast to previous prospective studies and should be investigated in a further prospective trial.

Inhibition of ATR Increases the Sensitivity to WEE1 Inhibitor in Biliary Tract Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Currently, the DNA damage response (DDR) pathway represents a key target for new cancer drug development. Advanced biliary tract cancer (BTC) has a poor prognosis because of the lack of efficacious treatment options. Although DNA repair pathway alterations have been reported in many patients with BTC, little is known regarding the effects of DDR-targeted agents against BTC. @*Materials and Methods@#In this study, nine BTC cell lines were exposed to the WEE1 inhibitor (AZD1775). In vitro, MTT assay, colony-forming assay, cell cycle analysis, phospho-histone H3 staining assay, Transwell migration assay, and western blot were performed. Then, to enhance the antitumor effect of AZD1775, the combination treatment of WEE1 inhibitor and ataxia telangiectasia mutated and Rad3 related (ATR) inhibitor (AZD6738) was conducted using MTT assay and comet assay. Finally, HuCCT-1 and SNU2670 xenograft models were established to confirm the anti-tumor effect of AZD1775 alone. Furthermore, the combination treatment was also evaluated in SNU2670 xenograft models. @*Results@#AZD1775 blocked the phosphorylation of CDC2 and CDC25C in all cell lines, but significantly increased apoptosis and S phase arrest in sensitive cells. However, increased p-ATR and phosphorylated ataxia telangiectasia mutated levels were observed in less sensitive cells. In addition, in vitro and in vivo data illustrated that AZD1775 combined with AZD6738 exerted more potent anti-tumor effects than either drug alone. Although WEE1 inhibition has promising anti-tumor effects in some BTC cells, the addition of ATR inhibitors could enhance its efficacy. @*Conclusion@#Taken together, this study supports further clinical development of DDR-targeted strategies as monotherapy or combination regimens for BTC.

Therapeutic Co-targeting of WEE1 and ATM Downregulates PD-L1 Expression in Pancreatic Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Pancreatic cancer (PC) is one of the most lethal cancers worldwide, but there are currently no effective treatments. The DNA damage response (DDR) is under investigation for the development of novel anti-cancer drugs. Since DNA repair pathway alterations have been found frequently in PC, the purpose of this study was to test the DDR-targeting strategy in PC using WEE1 and ATM inhibitors. @*Materials and Methods@#We performed in vitro experiments using a total of ten human PC cell lines to evaluate antitumor effect of AZD1775 (WEE1 inhibitor) alone or combination with AZD0156 (ATM inhibitor). We established Capan-1–mouse model for in vivo experiments to confirm our findings. @*Results@#In our research, we found that WEE1 inhibitor (AZD1775) as single agent showed anti-tumor effects in PC cells, however, targeting WEE1 upregulated p-ATM level. Here, we observed that co-targeting of WEE1 and ATM acted synergistically to reduce cell proliferation and migration, and to induce DNA damage in vitro. Notably, inhibition of WEE1 or WEE1/ATM downregulated programmed cell death ligand 1 expression by blocking glycogen synthase kinase-3β serine 9 phosphorylation and decrease of CMTM6 expression. In Capan-1 mouse xenograft model, AZD1775 plus AZD0156 (ATM inhibitor) treatment reduced tumor growth and downregulated tumor expression of programmed cell death ligand 1, CMTM6, CD163, and CXCR2, all of which contribute to tumor immune evasion. @*Conclusion@#Dual blockade of WEE1 and ATM might be a potential therapeutic strategy for PC. Taken toget

Jab1 Silencing Inhibits Proliferation and Sensitizes to Cisplatin in Biliary Tract Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Jab1 is a coactivator of c-Jun that enhances the transcriptional function of c-Jun. Jab1 is frequently overexpressed in various cancers and is associatedwith poor prognosis of cancer patients. Thus, Jab1 could be a potential therapeutic target in cancer. However, the role of Jab1 in biliary tract cancer (BTC) has not been studied. MATERIALS AND METHODS: We performed in vitro and in vivo experiments to evaluate the therapeutic potential ofJab1 inhibition in BTC. RESULTS: Among 8 BTC cell lines, many showed higher Jab1 expression levels. In addition, Jab1 silencing by siRNA increased p27 expression levels. SNU478 and HuCCT-1 cells exhibited profound Jab1 knockdown and increased p27 expression by Jab1-specific siRNA transfection. Jab1 silencing induced anti-proliferative and anti-migratory effects and resulted in G1 cell cycle arrest in SNU478 and HuCCT-1 cells. In addition, Jab1 silencing potentiated the anti-proliferative and anti-migratory effects of cisplatin by increasing DNA damage. Interestingly,Jab1 knockdown increased PTEN protein half-life, resulting in increased PTEN expression. In the HuCCT-1 mouse xenograft model, stable knockdown of Jab1 by shRNA also showed anti-proliferative effects in vivo, with decreased Ki-67 expression and AKT phosphorylation and increased Terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling and p27 expression. CONCLUSION: Jab1 knockdown demonstrated anti-proliferative and anti-migratory effects in BTC cells by increasing DNA damage and stabilizing PTEN, resulting in G1 cell cycle arrest. In addition, Jab1 silencing potentiated the anti-proliferative effects of cisplatin. Our data suggest that Jab1 may be a potential therapeutic target in BTC that is worthy of further investigations.

Therapeutic Targeting of the DNA Damage Response Using an ATR Inhibitor in Biliary Tract Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The DNA damage response (DDR) is a multi-complex network of signaling pathways involved in DNA damage repair, cell cycle checkpoints, and apoptosis. In the case of biliary tract cancer (BTC), the strategy of DDR targeting has not been evaluated, even though many patients have DNA repair pathway alterations. The purpose of this study was to test the DDR-targeting strategy in BTC using an ataxia-telangiectasia and Rad3-related (ATR) inhibitor. MATERIALS AND METHODS: A total of nine human BTC cell lines were used for evaluating anti-tumor effect of AZD6738 (ATR inhibitor) alone or combination with cytotoxic chemotherapeutic agents through MTT assay, colony-forming assays, cell cycle analyses, and comet assays. We established SNU478-mouse model for in vivo experiments to confirm our findings. RESULTS: Among nine human BTC cell lines, SNU478 and SNU869 were the most sensitive to AZD6738, and showed low expression of both ataxia-telangiectasia mutated (ATM) and p53. AZD6738 blocked p-Chk1 and p-glycoprotein and increased γH2AX, a marker of DNA damage, in sensitive cells. AZD6738 significantly increased apoptosis, G2/M arrest and p21, and decreased CDC2. Combinations of AZD6738 and cytotoxic chemotherapeutic agents exerted synergistic effects in colony-forming assays, cell cycle analyses, and comet assays. In our mouse models, AZD6738 monotherapy decreased tumor growth and the combination with cisplatin showed more potent effects on growth inhibition, decreased Ki-67, and increased terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling than monotherapy with each drug. CONCLUSION: In BTC, DDR targeting strategy using ATR inhibitor demonstrated promising antitumor activity alone or in combination with cytotoxic chemotherapeutic agents. This supports further clinical development of DDR targeting strategy in BTC.

Pan-Pim Kinase Inhibitor AZD1208 Suppresses Tumor Growth and Synergistically Interacts with Akt Inhibition in Gastric Cancer Cells / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Pim kinases are highly conserved serine/threonine kinases, and different expression patterns of each isoform (Pim-1, Pim-2, and Pim-3) have been observed in various types of human cancers, including gastric cancer. AZD1208 is a potent and selective inhibitor that affects all three isoforms of Pim. We investigated the effects of AZD1208 as a single agent and in combination with an Akt inhibitor in gastric cancer cells. MATERIALS AND METHODS: The antitumor activity of AZD1208 with/without an Akt inhibitor was evaluated in a large panel of gastric cancer cell lines through growth inhibition assays. The underlying mechanism was also examined by western blotting, immunofluorescence assay, and cell cycle analysis. RESULTS: AZD1208 treatment decreased gastric cancer cell proliferation rates and induced autophagy only in long-term culture systems. Light chain 3B (LC3B), a marker of autophagy, was increased in sensitive cells in a dose-dependent manner with AZD1208 treatment, which suggested that the growth inhibition effect of AZD1208 was achieved through autophagy, not apoptosis. Moreover, we found that cells damaged by Pim inhibition were repaired by activation of the DNA damage repair pathway, which promoted cell survival and led the cells to become resistant to AZD1208. We also confirmed that the combination of an Akt inhibitor with AZD1208 produced a highly synergistic effect in gastric cancer cell lines. CONCLUSION: Treatment with AZD1208 alone induced considerable cell death through autophagy in gastric cancer cells. Moreover, the combination of AZD1208 with an Akt inhibitor showed synergistic antitumor effects through regulation of the DNA damage repair pathway.

Dynamics of Soluble Programmed Death-Ligand 1 (sPDL1) during Chemotherapy and Its Prognostic Implications in Cancer Patients: Biomarker Development in Immuno-oncology / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The soluble programmed death-ligand 1 (sPDL1) has immunosuppressive activity and is a candidate biomarker for immuno-oncology drug development. In this study, we measured sPDL1 at pre- and post-chemotherapy and at disease progression to uncover the dynamics of sPDL1 during treatment in biliary tract cancer (BTC) patients. MATERIALS AND METHODS: From 90 BTC patients (training cohort, 53; validation cohort, 37) who were candidates for palliative first-line chemotherapy, blood was collected at pre- and post-chemotherapy (at the time of best response) and at disease progression. The sPDL1 levels were measured using an enzyme-linked immunosorbent assay. Responses to chemotherapy, overall survival (OS), and other prognostic factors including the neutrophil-lymphocyte ratio (NLR) were analyzed. RESULTS: The OS of all patients was 11.5 months (confidence interval [CI], 9.7 to 16.2). The best response was complete response in seven (7.8%), partial response in 20 (22.2%), stable disease in 52 (57.8%), and disease progression (PD) in 11 patients (12.2%). Patients with high pre-chemotherapy sPDL1 (≥ 1.30 ng/mL) showed worse OS than patients with low prechemotherapy sPDL1 (9.1 months vs. 12.5 months, p=0.003). In multivariate analyses, high pre-chemotherapy sPDL1 (hazard ratio [HR], 1.96; 95% CI, 1.2 to 3.9; p=0.011) and high pre-chemotherapy NLR (HR, 1.82; 95% CI, 1.1 to 3.0; p=0.020) were independent poor prognostic factors for OS. At the time of PD, sPDL1 was increased significantly compared with pre-chemotherapy sPDL1 (1.59 ng/mL vs. 0.72 ng/mL, p=0.003). CONCLUSION: The sPDL1 at pre-chemotherapy confers the prognostic value for OS in BTC patients under palliative chemotherapy. The dynamics of sPDL1 during chemotherapy correlate with disease burden and have prognostic value.

Phase 1 Studies of Poziotinib, an Irreversible Pan-HER Tyrosine Kinase Inhibitor in Patients with Advanced Solid Tumors / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Poziotinib, a pan-human epidermal growth factor receptor 2 (HER) tyrosine kinase inhibitor, has shown potent activity againstwild type of epidermal growth factorreceptor(EGFR) family kinases including EGFR, HER2, and HER4 and EGFR-mutant cells in vitro. Two phase I studies were conducted to determine the maximum tolerated dose (MTD), pharmacokinetics, safety, and antitumor activity against advanced solid tumors. MATERIALS AND METHODS: Standard 3+3 dose escalation scheme using two different dosing schedules were studied: once daily, 14-day on, and 7-day off (intermittent schedule); and once daily continuous dosing with food effect. Additional patients were enrolled in an expansion cohort. RESULTS: A total of 75 patients were enrolled in the two studies. The most common drug-related treatment-emergent adverse eventswere diarrhea,rash, stomatitis, pruritus, and anorexia. Dose-limiting toxicities were grade 3 diarrhea in the intermittent schedule and grade 3 anorexia and diarrhea in the continuous dosing schedule. The MTDs were determined as 24 mg/day in the intermittent dosing schedule and 18 mg/day in the continuous dosing schedule. Eight (16%) and 24 (47%) of 51 evaluable patients in the intermittent schedule achieved partial response (PR) and stable disease (SD), respectively. Four (21%) and six (32%) of 19 evaluable patients in continuous dosing schedule achieved PR and SD, respectively. Patients with PR (n=7) or SD ≥ 12 weeks (n=7) had HER2 amplification (n=7; breast cancer, 5; and stomach cancer, 2) and EGFR amplification (n=1, squamous cell lung cancer). CONCLUSION: Poziotinib was safe and well tolerated in patients with advanced solid tumors. It showed an encouraging activity against EGFR-mutant and HER2-amplified cancers.

TAK-264 (MLN0264) in Previously Treated Asian Patients with Advanced Gastrointestinal Carcinoma Expressing Guanylyl Cyclase C: Results from an Open-Label, Non-randomized Phase 1 Study / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This phase 1 dose-escalation portion of the study evaluated the safety, pharmacokinetics (PK), and antitumor activity of TAK-264 in Asian patients with advanced gastrointestinal (GI) carcinoma or metastatic or recurrent gastric or gastroesophageal junction adenocarcinoma expressing guanylyl cyclase C (GCC). MATERIALS AND METHODS: Adult patients with advanced GI malignancies expressing GCC (H-score ≥ 10) received TAK-264 on day 1 of 3-week cycles as 30-minute intravenous infusions for up to 1 year or until disease progression or unacceptable toxicity. The primary objectives were to evaluate the safety profile including dose-limiting toxicities (DLTs) during cycle 1, determine the maximum tolerated dose (MTD), and characterize the PK profile of TAK-264. RESULTS: Twelve patients were enrolled and treated with 1.2 mg/kg (n=3), 1.5 mg/kg (n=3), or 1.8 mg/kg TAK-264 (n=6). Median number of treatment cycles received was two (range, 1 to 10). None of the patients experienced a DLT and the MTD was not determined. Ten patients (83%) experienced adverse events (AEs). The most common were neutropenia, anorexia, and nausea (each reported by four patients). Five patients (42%) experienced grade ≥ 3 AEs consisting of tumor hemorrhage and hypertension, ascites, adrenal insufficiency, neutropenia and asthenia. Serum exposure to TAK-264 increased proportionally with the dose and the median half-life was approximately 5.5-6.6 days. No patients experienced an objective response. CONCLUSION: TAK-264 demonstrated a manageable safety profile with limited antitumor activity consistent with studies conducted in Western patients with advanced GI malignancies. TAK-264 exposure increased proportionally with the dose.

Real-World Treatment Patterns among Patients with Advanced Gastric Cancer in South Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to understand patient treatment patterns, outcomes, and healthcare resource use in cases of metastatic and/or locally recurrent, unresectable gastric cancer (MGC) in South Korea. MATERIALS AND METHODS: Thirty physicians reviewed charts of eligible patients to collect de-identified data. Patients must have received platinum/fluoropyrimidine first-line therapy followed by second-line therapy or best supportive care, had no other primary cancer, and not participated in a clinical trial following MGC diagnosis. Data were summarized using descriptive statistics. Kaplan-Meier analysis was used to describe survival. RESULTS: Of 198 patients, 73.7% were male, 78.3% were diagnosed with MGC after age 55 (mean, 61.3 years), and 47.0% were current or former smokers. The majority of tumorswere located in the antrum/pylorus (51.5%). Metastatic sites most often occurred in the peritoneum (53.5%), lymph nodes (47.5%), and liver (38.9%). At diagnosis, the mean Charlson comorbidity indexwas 0.4 (standard deviation, 0.6). The most common comorbidities were chronic gastritis (22.7%) and cardiovascular disease (18.7%). Most patients (80.3%) received second-line treatment. Single-agent fluoropyrimidine was reported for 22.0% of patients, while 19.5% were treated with irinotecan and a fluoropyrimidine or platinum agent. The most common physician-reported symptoms during second-line treatment were nausea/vomiting (44.7%) and pain (11.3%), with antiemetics (44.7%), analgesics (36.5%), and nutritional support (11.3%) most often used as supportive care. Two-thirds of inpatient hospitalizations were for chemotherapy infusion. Outpatient hospitalization (31.6%) and visits to the oncologist (58.8%) were common among second-line patients. CONCLUSION: Most patients received second-line treatment, although regimens varied. Understanding MGC patient characteristics and treatment patterns in South Korea will help address unmet needs.

Antitumor Effect of KX-01 through Inhibiting Src Family Kinases and Mitosis / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: KX-01 is a novel dual inhibitor of Src and tubulin. Unlike previous Src inhibitors that failed to show clinical benefit during treatment of breast cancer, KX-01 can potentially overcome the therapeutic limitations of current Src inhibitors through inhibition of both Src and tubulin. The present study further evaluates the activity and mechanism of KX-01 in vitro and in vivo. MATERIALS AND METHODS: The antitumor effect of KX-01 in triple negative breast cancer (TNBC) cell lines was determined by MTT assay. Wound healing and immunofluorescence assays were performed to evaluate the action mechanisms of KX-01. Changes in the cell cycle and molecular changes induced by KX-01 were also evaluated. A MDA-MB-231 mouse xenograft model was used to demonstrate the in vivo effects. RESULTS: KX-01 effectively inhibited the growth of breast cancer cell lines. The expression of phospho-Src and proliferative-signaling molecules were down-regulated in KX-01-sensitive TNBC cell lines. In addition, migration inhibition was observed by wound healing assay. KX-01-induced G2/M cell cycle arrest and increased the aneuploid cell population in KX-01-sensitive cell lines. Multi-nucleated cells were significantly increased after KX-01 treatment. Furthermore, KX-01 effectively delayed tumor growth in a MDA-MB-231 mouse xenograft model. CONCLUSION: KX-01 effectively inhibited cell growth and migration of TNBC cells. Moreover, this study demonstrated that KX-01 showed antitumor effects through the inhibition of Src signaling and the induction of mitotic catastrophe. The antitumor effects of KX-01 were also demonstrated in vivo using a mouse xenograft model.

Korean Cancer Patients' Awareness of Clinical Trials, Perceptions on the Benefit and Willingness to Participate / Journal of the Korean Cancer Association, 대한암학회지

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.

Findings of a 1303 Korean whole-exome sequencing study

Ethnically specific data on genetic variation are crucial for understanding human biology and for clinical interpretation of variant pathogenicity. We analyzed data obtained by deep sequencing 1303 Korean whole exomes; the data were generated by three independent whole exome sequencing projects (named the KOEX study). The primary focus of this study was to comprehensively analyze the variant statistics, investigate secondary findings that may have clinical actionability, and identify loci that should be cautiously interpreted for pathogenicity. A total of 495 729 unique variants were identified at exonic regions, including 169 380 nonsynonymous variants and 4356 frameshift insertion/deletions. Among these, 76 607 were novel coding variants. On average, each individual had 7136 nonsynonymous single-nucleotide variants and 74 frameshift insertion/deletions. We classified 13 pathogenic and 13 likely pathogenic variants in 56 genes that may have clinical actionability according to the guidelines of the American College of Medical Genetics and Genomics, and the Association for Molecular Pathology. The carrier frequency of these 26 variants was 2.46% (95% confidence interval 1.73–3.46). To identify loci that require cautious interpretation in clinical sequencing, we identified 18 genes that are prone to sequencing errors, and 671 genes that are highly polymorphic and carry excess nonsynonymous variants. The catalog of identified variants, its annotation and frequency information are publicly available (https://koex.snu.ac.kr). These findings should be useful resources for investigating ethnically specific characteristics in human health and disease.

CA19-9 or CEA Decline after the First Cycle of Treatment Predicts Survival in Advanced Biliary Tract Cancer Patients Treated with S-1 and Cisplatin Chemotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: While tumor markers (carbohydrate antigen 19-9 [CA 19-9] and carcinoembryonic antigen [CEA]) can aid in the diagnosis of biliary tract cancer, their prognostic role has not been clearly elucidated. Therefore, this study was conducted to evaluate the prognostic role of tumor markers and tumor marker change in patients with advanced biliary tract cancer. MATERIALS AND METHODS: Patients with pathologically proven metastatic or relapsed biliary tract cancer who were treated in a phase II trial of first-line S-1 and cisplatin chemotherapy were enrolled. Serum tumor markers were measured at baseline and after the first cycle of chemotherapy. RESULTS: Among a total of 104 patients, 80 (77%) had elevated baseline tumor markers (69 with CA 19-9 elevation and 40 with CEA). A decline ≥ 30% of the elevated tumor marker level after the first cycle of chemotherapy conferred an improved time to progression (TTP), overall survival (OS), and better chemotherapy response. Multivariate analysis revealed tumor marker decline as an independent positive prognostic factor of TTP (adjusted hazard ratio [HR], 0.44; p=0.003) and OS (adjusted HR, 0.37; p < 0.001). Subgroup analysis revealed similar results in each group of patients with CA 19-9 elevation and CEA elevation. In addition, elevated baseline CEA was associated with poor survival in both univariate and multivariate analysis. CONCLUSION: Tumor marker decline was associated with improved survival in biliary tract cancer. Measuring tumor marker after the first cycle of chemotherapy can be used as an early assessment of treatment outcome.

CA19-9 or CEA Decline after the First Cycle of Treatment Predicts Survival in Advanced Biliary Tract Cancer Patients Treated with S-1 and Cisplatin Chemotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: While tumor markers (carbohydrate antigen 19-9 [CA 19-9] and carcinoembryonic antigen [CEA]) can aid in the diagnosis of biliary tract cancer, their prognostic role has not been clearly elucidated. Therefore, this study was conducted to evaluate the prognostic role of tumor markers and tumor marker change in patients with advanced biliary tract cancer. MATERIALS AND METHODS: Patients with pathologically proven metastatic or relapsed biliary tract cancer who were treated in a phase II trial of first-line S-1 and cisplatin chemotherapy were enrolled. Serum tumor markers were measured at baseline and after the first cycle of chemotherapy. RESULTS: Among a total of 104 patients, 80 (77%) had elevated baseline tumor markers (69 with CA 19-9 elevation and 40 with CEA). A decline ≥ 30% of the elevated tumor marker level after the first cycle of chemotherapy conferred an improved time to progression (TTP), overall survival (OS), and better chemotherapy response. Multivariate analysis revealed tumor marker decline as an independent positive prognostic factor of TTP (adjusted hazard ratio [HR], 0.44; p=0.003) and OS (adjusted HR, 0.37; p < 0.001). Subgroup analysis revealed similar results in each group of patients with CA 19-9 elevation and CEA elevation. In addition, elevated baseline CEA was associated with poor survival in both univariate and multivariate analysis. CONCLUSION: Tumor marker decline was associated with improved survival in biliary tract cancer. Measuring tumor marker after the first cycle of chemotherapy can be used as an early assessment of treatment outcome.

Long-Term Outcome of Distal Cholangiocarcinoma after Pancreaticoduodenectomy Followed by Adjuvant Chemoradiotherapy: A 15-Year Experience in a Single Institution / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study was conducted to evaluate the long-term outcome in patients undergoing pancreaticoduodenectomy (PD) followed by adjuvant chemoradiotherapy for distal cholangiocarcinoma (DCC) in a high-volume center and to identify the prognostic impact of clinicopathologic factors. MATERIALS AND METHODS: A total of 132 consecutive patients who met the inclusion criteria were retrieved from the institutional database from January 1995 to September 2009. All patients received adjuvant treatments at a median of 45 days after the surgery. Median follow-up duration was 57 months (range, 6 to 225 months) for all patients and 105 months for survivors (range, 13 to 225 months). RESULTS: The 5-year locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) rates were 70.7%, 55.7%, 49.4%, and 48.1%, respectively. Univariate analysis revealed poorly differentiated (P/D) tumors and lymph node (LN) metastasis were significantly associated with DMFS and OS. Additionally, preoperative carbohydrate antigen 19-9 level was significantly correlated with DFS, LRRFS, and DMFS. Upon multivariate analysis for OS, P/D tumors (p=0.015) and LN metastasis (p=0.003) were significant prognosticators that predicted inferior OS. Grade 3 or higher late gastrointestinal toxicity occurred in only one patient (0.8%). CONCLUSION: Adjuvant chemoradiotherapy after PD for DCC is an effective and tolerable strategy without significant side effects. During long-term follow-up, we found that prognosis of DCC was mainly influenced by histologic differentiation and LN metastasis. For patients with these risk factors, further research should focus on improving adjuvant strategies as well as other treatment approaches.

Concurrent Chemoradiotherapy Versus Chemotherapy Alone for Unresectable Locally Advanced Pancreatic Cancer: A Retrospective Cohort Study / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The optimal treatment strategy for locally advanced pancreatic cancer (LAPC), particularly the role of concurrent chemoradiotherapy (CCRT), remains debatable. We compared the clinical outcomes of CCRT and palliative chemotherapy alone (CA) in patients with unresectable LAPC. MATERIALS AND METHODS: Patients with LAPC who were consecutively treated between 2003 and 2010 were included. Resectability was evaluated according to National Comprehensive Cancer Network ver. 1.2012. The clinical outcomes for each treatment group (CCRT vs. CA) were evaluated retrospectively. RESULTS: Sixty-three patients (58.9%) and 44 patients (41.1%) were treated with CCRT and CA, respectively. The CCRT cohort included patients who were treated with CCRT with or without chemotherapy backbone (CCRT alone, induction chemotherapy-CCRT, CCRT-maintenance chemotherapy, and induction-CCRT-maintenance chemotherapy). Median progression-free survival (PFS) and overall survival (OS) of all patients were 7.2 months and 13.1 months. PFS of the CCRT and CA groups was 9.0 months and 4.4 months, respectively (p=0.020). OS of the CCRT and CA groups was 15.4 months and 9.3 months, respectively (p=0.011). In multivariate analysis, the adjusted hazard ratio of CCRT was 0.536 (p=0.003) for OS and 0.667 (p=0.078) for PFS. Although the pattern of failure was similar in the CCRT and CA groups, the times to both local and distant failure were significantly longer in the CCRT group. CONCLUSION: In patients with unresectable LAPC, those who underwent CCRT during their entire treatment courses had longer OS than patients treated with chemotherapy alone.

VEGF and Ki-67 Overexpression in Predicting Poor Overall Survival in Adenoid Cystic Carcinoma / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to evaluate potential prognostic factors in patients with adenoid cystic carcinoma (ACC). MATERIALS AND METHODS: A total of 68 patients who underwent curative surgery and had available tissue were enrolled in this study. Their medical records and pathologic slides were reviewed and immunohistochemistry for basic fibroblast growth factor, fibroblast growth factor receptor (FGFR) 2, FGFR3, c-kit, Myb proto-oncogene protein, platelet-derived growth factor receptor beta, vascular endothelial growth factor (VEGF), and Ki-67 was performed. Univariate and multivariate analysis was performed for determination of disease-free survival (DFS) and overall survival (OS). RESULTS: In univariate analyses, primary site of nasal cavity and paranasal sinus (p=0.022) and Ki-67 expression of more than 7% (p=0.001) were statistically significant factors for poor DFS. Regarding OS, perineural invasion (p=0.032), high expression of VEGF (p=0.033), and high expression of Ki-67 (p=0.007) were poor prognostic factors. In multivariate analyses, primary site of nasal cavity and paranasal sinus (p=0.028) and high expression of Ki-67 (p=0.004) were independent risk factors for poor DFS, and high expression of VEGF (p=0.011) and Ki-67 (p=0.011) showed independent association with poor OS. CONCLUSION: High expression of VEGF and Ki-67 were independent poor prognostic factors for OS in ACC.

The Impact of Diabetes Mellitus and Metformin Treatment on Survival of Patients with Advanced Pancreatic Cancer Undergoing Chemotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: A causal relationship between diabetes mellitus (DM) and pancreatic cancer is well established. However, in patients with advanced pancreatic cancer (APC) who receive palliative chemotherapy, the impact of DM on the prognosis of APC is unclear. MATERIALS AND METHODS: We retrospectively enrolled APC patients who received palliative chemotherapy between 2003 and 2010. The patients were stratified according to the status of DM, in accordance with 2010 DM criteria (American Heart Association/American Diabetes Association). DM at least 2 years' duration prior to diagnosis of APC was defined as remote-onset DM (vs. recent-onset). RESULTS: Of the 349 APC patients, 183 (52.4%) had DM. Among the patients with DM, 160 patients had DM at the time of diagnosis of APC (remote-onset, 87; recent-onset, 73) and the remaining 23 patients developed DM during treatment of APC. Ultimately, 73.2% of patients (134/183) with DM received antidiabetic medication, including metformin (56 patients, 41.8%), sulfonylurea (62, 45.5%), and insulin (43, 32.1%). In multivariate analysis, cancer extent (hazard ratio [HR], 1.792; 95% confidence interval [CI], 1.313 to 2.445; p < 0.001) showed association with decreased overall survival (OS), whereas a diagnosis of DM (HR, 0.788; 95% CI, 0.615 to 1.009; p=0.059) conferred positive tendency on the OS. Metformin treatment itself conferred better OS in comparison within DM patients (HR 0.693; 95% CI, 0.492 to 0.977; p=0.036) and even in all APC patients (adjusted HR, 0.697; 95% CI, 0.491 to 1.990; p=0.044). CONCLUSION: For APC patients receiving palliative chemotherapy, metformin treatment is associated with longer OS. Patients with DM tend to survive longer than those without DM.