Molecular diagnosis for personalized target therapy in gastric cancer

Gastric cancer is the second leading cause of cancer-related deaths worldwide. In advanced and metastatic gastric cancer, the conventional chemotherapy with limited efficacy shows an overall survival period of about 10 months. Patient specific and effective treatments known as personalized cancer therapy is of significant importance. Advances in high-throughput technologies such as microarray and next generation sequencing for genes, protein expression profiles and oncogenic signaling pathways have reinforced the discovery of treatment targets and personalized treatments. However, there are numerous challenges from cancer target discoveries to practical clinical benefits. Although there is a flood of biomarkers and target agents, only a minority of patients are tested and treated accordingly. Numerous molecular target agents have been under investigation for gastric cancer. Currently, targets for gastric cancer include the epidermal growth factor receptor family, mesenchymal-epithelial transition factor axis, and the phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin pathways. Deeper insights of molecular characteristics for gastric cancer has enabled the molecular classification of gastric cancer, the diagnosis of gastric cancer, the prediction of prognosis, the recognition of gastric cancer driver genes, and the discovery of potential therapeutic targets. Not only have we deeper insights for the molecular diversity of gastric cancer, but we have also prospected both affirmative potentials and hurdles to molecular diagnostics. New paradigm of transdisciplinary team science, which is composed of innovative explorations and clinical investigations of oncologists, geneticists, pathologists, biologists, and bio-informaticians, is mandatory to recognize personalized target therapy.

Association of YAP1 activation with poor patient prognosis and effect on chemoresistance in gastric cancer

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Background: Clinical heterogeneity in gastric cancer is likely due to biological differences among patients. Molecular subtypes and their associated biomarkers need to be established to improve treatment of this disease. We aimed to uncover subgroups of gastric cancer that have distinct biological characteristics associated with clinical outcome and to identify potential best treatments or therapeutic targets for each subgroup. Methods: We analyzed gene expression profiling data from gastric cancer cell lines and 267 patients with gastric cancer to uncover tumor subtypes and identify a gene expression signature associated with prognosis and response to adjuvant chemotherapy. The association of the signature with prognosis was validated in an independent cohort of 200 patients, and its association with response to adjuvant therapy was validated by cell culture experiments. Results: We identified an expression signature of 88 genes that specifically reflected activation of the oncogene YAP1. Compared with patients without this signature, patients with the YAP1 signature had significantly poorer prognosis. In multivariate analysis, the signature was the strongest indicator of overall survival among all demographic and clinical variables examined together (hazard ratio, 2.1; 95% confidence interval, 1.3-3.3;P = .002). Activation of YAP1 was significantly associated with resistance to adjuvant chemotherapy. We also demonstrated that the Notch pathway is a potential therapeutic target for overcoming chemoresistance mediated by YAP1. Conclusions: Activation of the oncogene YAP1 is significantly associated with poorer survival of patients with gastric cancer and induces chemoresistance to this disease. Therefore, YAP1 may be highly attractive therapeutic target for patients with gastric cancer resistant to standard chemotherapy.

Olaparib plus paclitaxel in patients with recurrent or metastatic gastric cancer: A randomized, double-blind phase II study

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Background: Our multicenter study compared the efficacy of the oral PARP inhibitor olaparib plus paclitaxel (O/P) vs paclitaxel alone (P) as second-line therapy in pts with recurrent/metastatic gastric cancer (GC) (NCT01063517). As initial preclinical data suggested that responsiveness of GC cell lines to olaparib was associated with low ATM protein levels, our study was enriched for pts with low ATM tumors (ATM–) by IHC (50% randomized vs 14% screening prevalence). Methods: Eligible pts were randomized 1:1 (stratified by ATM status) to receiveolaparib 100 mg bid (tablet form) plus paclitaxel (80 mg/m2 iv on days 1, 8, 15 per 28-day cycle) or placebo plus paclitaxel until progression or investigator decision. After combination therapy, pts could take olaparib 200 mg bid monotherapy or placebo until progression. Co-primary endpoints: progression-free survival (PFS; RECIST v1.1) in all pts and ATM– pts. Secondary endpoints: overall survival (OS), objective response rate (ORR), safety. Results: 123/124 randomized pts were treated (O/P=61; P=62). Baseline characteristics were generally well balanced. Use of post-progression therapy was similar in both arms (O/P=48.4%; P=43.5%) as was median paclitaxel duration (O/P=17 wks; P=16 wks); 18 pts received monotherapy (O/P=11; P=7). More pts in the O/P than P arm had delays (79 vs 63%) and reductions (41 vs 27%) in paclitaxel dosing. The most common grade ≥3 AEs in the O/P and P arms were neutropenia (56 vs 39%) and anemia (11 vs 11%). Conclusions: Olaparib plus paclitaxel was well tolerated and led to a statistically significant improvement in OS, but not PFS, vs paclitaxel alone in both all pts and ATM– pts, with a larger benefit in ATM– pts. Clinical trial information: NCT01063517. [Table: see text]

Gemcitabine combined with capecitabine compared to gemcitabine with or without erlotinib as first-line chemotherapy in patients with advanced pancreatic cancer: Comparative effectiveness study

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Background: Gemcitabine is the standard treatment for advanced pancreatic cancer. Though capecitabine and erlotinib are accepted as combination agent with gemcitabine, those two combination regimens have not been compared directly in clinical trial. This study compared the efficacy and tolerability between gemcitabine plus capecitabine (GEM-X), gemcitabine plus erlotinib (GEM-T), and gemcitabine monotherapy (GEM) as first-line chemotherapy in patients with advanced pancreatic cancer. Methods: We collected data ofpatients if they met the following criteria: histologically or cytologically confirmed ductal adenocarcinoma of the pancreas; unresectable/metastatic disease; treated with one of GEM, GEM-X, and GEM-T as first-line treatment; measurable or evaluable lesion; age more than 18 years; Eastern Cooperative Oncology Group performance status 0, 1, or 2; and adequate hematologic, hepatic, and renal function before first-line chemotherapy. Response rate, progression-free survival (PFS), overall survival (OS), and toxicity were evaluated. Results: Between January 2007 and November 2011, a total of 127 patients received one of GEM (n=47), GEM-T (n=44), and GEM-X (n=36). GEM-X significantly improved the objective response rate (21.2% vs. 12.7% and 15.9%), progression-free survival (8.9 vs. 5.2 and 3.9 months; p < 0.001) and OS (12.1 vs. 10.4 and 9.9 months; p = 0.03) compared to GEM and GEM-T, respectively. The incidence of adverse events was not significantly different among groups. Conclusions: GEM-X presented better clinical efficacy and acceptable tolerability than GEM-T and GEM in locally advanced and metastatic pancreatic cancers. It is worthy to further investigate which agent has clinical advantage as combination drug with gemcitabine in pancreatic cancer and to explore predictive markers for each regimen leading to personalize anti-cancer treatment.

Abstract 1147: Expression of ERO1L gene is poor prognostic factor for gastric cancer

Gastric cancer is the second cause of cancer-related deaths worldwide. Even though within same stage, gastric cancer patients present diverse clinical manifestations and prognosis. Molecular markers will be important in predicting patients’ outcomes and tailoring personalized treatments according to individual biology. In this study, we analyzed the gene expression profile of human gastric cancer (published on CCR) to identify potential biomarkers. We found that TXN family genes and ERO1L were significantly overexpressed and related to prognosis. We evaluated ERO1L significantly overexpressed in gastric cancer and ERO1L was very highly expressed in hypoxic condition. The other study has identified ERO1L as included in the small group of eight genes predicting poor survival of patients with pulmonary adenocarcinoma. To investigate the function of ERO1L gene in gastric cancer cell line (AGS, MKN1 and NCI-N87), we tested the effect of shRNA inhibition of ERO1L on gastric cancer cells. To determine the biologic role of ERO1L in regulating cancer cell proliferation, stable transfection of shRNA for ERO1L in gastric cancer cells. Our results showed that shERO1L decrease cell proliferation. Furthermore, Knock down expression by shERO1L have effects on regulating gastric cancer cell apoptosis. Next, we tested whether or not the ERO1L gene is involved in progression to metastatic disease in gastric cancer,especially in late tumorigenesis, including migration and invasion. As a results, Knock down expression for ERO1L significantly decreased the migration and invasiveness of gastric cancer cells. In conclusion, our findings show that a prognostic molecular signature that can predict the poor progression of gastric cancer tumors. Furthermore, unequal distribution of expression patterns reflecting activation of ERO1L with different survival rates supports a personalized target therapy in gastric cancer with biomarker gene signature driven patient selection. While further work is needed to elucidate the biological contributions of these markers in. in vivo, the results presented here provide a basis for future investigations of the functional and clinical effect of new target genes in gastric cancer.

Citation Format: So-Young Seol, Jae Yun Lim, Sun Och Yoon, Soon Won Hong, Jong Won Kim, Seung Ho Choi, Jae Yong Cho. Expression of ERO1L gene is poor prognostic factor for gastric cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1147. doi:10.1158/1538-7445.AM2013-1147

Abstract 1954: Circulating microRNA-21 predicts the response to hypomethylating agents in patients with myelodysplastic syndromes

Background: Although hypomethylating agents therapy have considerably improved the outcomes of patients with myelodysplastic syndromes (MDS), the discovery of sensitive non-invasive biomarkers that can facilitate the prediction of response to hypomethylating agents (HMA) and therapeutic outcomes are highly desirable to determine optimized strategies of epigenetic therapy for MDS. Circulating microRNAs have been evaluated as potential biomarkers for cancer diagnosis and prognosis prediction.

Purpose: We evaluated the significance of miR-21 expression in serum as a biomarker for predicting response in MDS patients treated with HMA.

Patients and methods: Serum miR-21 level was measured by quantitative real-time PCR in 58 MDS patients at diagnosis and 14 healthy controls. We analyzed the correlation between serum miR-21 level and clinical characteristics and response to HMA and survival.

Results: We found that serum miR-21 level was significantly downregulated in patients with MDS than those in healthy controls (P&lt;0.001). Moreover, miR-21 level was significantly lower in patients with response (CR, mCR, PR and SD with HI) to HMA compared to those without response (median, 0.9414±0.6349 vs. 1.1443±0.7707; P=0.041). Receiver-operator characteristic curve analysis indicated that serum miR-21 was useful in differentiating responder from non-responder with AUC of 0.648. At a cut-off value of 1.2613 for serum miR-21 level, the optimal sensitivity and specificity were 83.3% (95% CI: 68.6-93.3%) and 45.8% (95%CI: 25.5-67.1%), respectively. Patients, whose miR-21 level at diagnosis was higher than cutoff level, were defined as high miR-21 group (n=17) and the low miR-21 group representing the remaining 41 patients. We found that patients in high miR-21 grooup, compared with those in low miR-21 group, had a shorter median PFS (P=0.001). On multivariate analysis, Serum miR-21 level remained as a significant prognostic factor for response to HMA and PFS.

Conclusion: In this study, we evaluated the levels of serum miR-21 in patients with MDS, and found that serum miR-21 level predicts response to HMA and PFS in MDS. Although this prognostic significance should be validated in an independent set of patients receiving HMA, serum miR-21 level is a promising biochemical marker for response prediction to HMT.

Citation Format: Yoo Hong Min, Jae Yong Cho, Yundeok Kim, Yeo-Kyeoung Kim, Soo Jeong Kim, Jin Seok Kim, June-Won Cheong, Hyeuong Joon Kim. Circulating microRNA-21 predicts the response to hypomethylating agents in patients with myelodysplastic syndromes. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1954. doi:10.1158/1538-7445.AM2013-1954

Abstract 1961: Overexpression of miR-196b and HOXA10 characterize a poor-prognosis gastric cancer subtype

Background: Gastric cancer is composed of disease subgroups with heterogeneous clinical and biological behaviors. A previous study identified two subgroups with distinct gene-expression profiles strongly associated with prognosis. To identify molecular biologic differences between these two subgroups, we performed an integrative analysis of mRNA, microRNA, and protein expression.

Methods: Array technologies were used to generate microRNA and protein expression profiles of frozen tissue samples from 60 patients with gastric cancer. All patients underwent curative gastric resection in 2005 and distributed from stage I to IV and their clinical characteristics were collected. BRB-ArrayTools were used for microarray data analysis. Data was compared between gastric cancer tissue and normal gastric tissue and also between two different prognostic groups. Aberrantly expressed microRNA and associated mRNA in patients with poor-prognosis gastric cancer were validated by quantitative RT-PCR and tissue microarray, respectively.

Results: Four microRNAs were aberrantly expressed in gastric cancer tissue, especially poor prognostic group (P &lt; 0.05). In the poor-prognosis subgroup, miR-196b showed the most significantly high expression patterns and also miR-135b, miR-93. On the contrary, miR-29c* was down-regulated. MiR-196b expression was positively correlated with HOXA10 expression (r = 0.726; P &lt; 0.001), which was significantly increased in poor-prognosis patients (P &lt; 0.001). HOXA10 protein-positive expression was identified in 56 of 368 gastric cancer tissue microarray samples. In reverse-phase protein array, 46/124 proteins were expressed differently (P &lt; 0.05); COX2 (P &lt; 0.001) and cyclin B1 (P = 0.017) were clearly over-expressed in the poor-prognosis group.

Conclusion: Integrative analysis of RNA and protein expression profile facilitates interpretation of the molecular biologic heterogeneity of cancer. Co-activation of miR-196b and HOXA10 characterized a poor-prognosis subgroup of patients with gastric cancer. As HOXA10 is involved in the proliferation of hematopoietic stem cells and progenitor cells, the relevance of hematopoietic progenitor cell and gastric cancer development/progression should be further investigated.

Citation Format: Jae Yun Lim, Sun Och Yoon, So-Young Seol, Soon Won Hong, Jong Won Kim, Seung Ho Choi, Ju-Seog Lee, Jae Yong Cho. Overexpression of miR-196b and HOXA10 characterize a poor-prognosis gastric cancer subtype. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1961. doi:10.1158/1538-7445.AM2013-1961

REGARD: A phase III, randomized, double-blinded trial of ramucirumab and best supportive care (BSC) versus placebo and BSC in the treatment of metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma following disease progression on first-line platinum- and/or fluoropyrimidine-containing combination therapy

LBA5

Background: VEGF and VEGF receptor-2 mediated signaling and angiogenesis may contribute to gastric cancer pathogenesis. Ramucirumab (RAM; IMC-1121B) is a fully human IgG1 monoclonal antibody targeting VEGF-receptor 2. We conducted a placebo-controlled, double-blind, phase III international trial to evaluate the safety and efficacy of RAM in pts with metastatic gastric or GEJ adenocarcinoma progressing on first-line platinum- and/or fluoropyrimidine containing combination therapy. Methods: Pts were randomized 2:1 to receive RAM (8 mg/kg IV) plus BSC or placebo (PL) plus BSC every 2 weeks (wks) until disease progression, unacceptable toxicity, or death. Eligible patients had disease progression within 4 months (m) after 1st-line therapy for metastatic disease or within 6 m after adjuvant therapy. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), 12-wk PFS rate, overall response rate (ORR) and safety. Results: From 10/09 to 01/12, 355 pts were randomized (RAM: 238; PL: 117). Baseline characteristics were well balanced between arms. The Hazard Ratio (HR) for OS was 0.776 (95% CI, 0.603-0.998; p = 0.0473). Median OS was 5.2 m for RAM and 3.8 m for PL. The HR for PFS was 0.483 (95% CI, 0.376-0.620; p < 0.0001). Median PFS was 2.1 m for RAM and 1.3 m for PL. 12-wk PFS was 40% for RAM and 16% for PL. ORR was 3.4% for RAM and 2.6% for PL. Disease control rate was 49% for RAM and 23% for PL (p < 0.0001). Use of anti-cancer therapy post-study: 32% RAM; 39% PL. The most frequent of grade ≥ 3 adverse events (AEs) were: hypertension (7.2% RAM; 2.6% PL), anemia (6.4% RAM; 7.8% PL), abdominal pain (5.1% RAM; 2.6% PL), ascites (4.2% RAM; 4.3% PL), fatigue (4.2% RAM; 3.5% PL), decreased appetite (3.4% RAM; 3.5% PL) and hyponatremia (3.4% RAM; 0.9% PL). Conclusions: Ramucirumab conferred a statistically significant benefit in OS and PFS compared to PL in metastatic gastric or GEJ adenocarcinoma following progression on 1st-line therapy with an acceptable safety profile. Clinical trial information: NCT00917384.

Ginsenoside-Rp1 inhibits platelet activation and thrombus formation via impaired glycoprotein VI signalling pathway, tyrosine phosphorylation and MAPK activation

BACKGROUND AND PURPOSE

Ginsenosides are the main constituents for the pharmacological effects of Panax ginseng. Such effects of ginsenosides including cardioprotective and anti-platelet activities have shown stability and bioavailability limitations. However, information on the anti-platelet activity of ginsenoside-Rp1 (G-Rp1), a stable derivative of ginsenoside-Rg3, is scarce. We examined the ability of G-Rp1 to modulate agonist-induced platelet activation.

EXPERIMENTAL APPROACH

G-Rp1 in vitro and ex vivo effects on agonist-induced platelet-aggregation, granule-secretion, [Ca(2+) ](i) mobilization, integrin-α(IIb) β(3) activation were examined. Vasodilator-stimulated phosphoprotein (VASP) and MAPK expressions and levels of tyrosine phosphorylation of the glycoprotein VI (GPVI) signalling pathway components were also studied. G-Rp1 effects on arteriovenous shunt thrombus formation in rats or tail bleeding time and ex vivo coagulation time in mice were determined. KEY RESULT: G-Rp1 markedly inhibited platelet aggregation induced by collagen, thrombin or ADP. While G-Rp1 elevated cAMP levels, it dose-dependently suppressed collagen-induced ATP-release, thromboxane secretion, p-selectin expression, [Ca(2+) ](i) mobilization and α(IIb) β(3) activation and attenuated p38(MAPK) and ERK2 activation. Furthermore, G-Rp1 inhibited tyrosine phosphorylation of multiple components (Fyn, Lyn, Syk, LAT, PI3K and PLCγ2) of the GPVI signalling pathway. G-Rp1 inhibited in vivo thrombus formation and ex vivo platelet aggregation and ATP secretion without affecting tail bleeding time and coagulation time, respectively.

CONCLUSION AND IMPLICATIONS

G-Rp1 inhibits collagen-induced platelet activation and thrombus formation through modulation of early GPVI signalling events, and this effect involves VASP stimulation, and ERK2 and p38(-MAPK) inhibition. These data suggest that G-Rp1 may have therapeutic potential for the treatment of cardiovascular diseases involving aberrant platelet activation.

Abstract P3-01-02: Correlation of Mammographic breast density and tumor characteristics in Korean breast cancer patients

Introduction: Western studies have demonstrated high breast density as a strong risk factor for breast cancer, it is poorly understood whether breast density affects the diverse phenotypes of breast cancer. We examined the association between various tumor characteristics and mammographic breast density in women with breast cancer.

Methods: We conducted a cross-sectional analysis in 910 Korean women diagnosed with breast cancer to evaluate the associations between breast density and tumor size, lymph node status, lymphovascular invasion, histologic grade, estrogen receptor, progesterone receptor, HER2. Breast density was classified as fatty (percent density less than 50% by a computer-assisted thresholding program, named “Cumulus™”; n = 470) or dense (percent density 50% or more; n = 440) for the cancer-free breast at the time of operation. Logistic regression was used to examine whether the relationships were modified by adjustment for body mass index, age at diagnosis, age at first birth, menopausal status, history of breast-feeding, and breast cancer staging.

Results: Total 910 patients were involved, the mean age and median age at the operation was 48 years old (range 20–82), and the mean percent density was 48.09 (SD = 9.62 %: normally distributed, Kolmogorov-Smirnov test p = 0.32). Crude analysis shows that tumor size over than 0.5cm were more likely to have dense breasts compared with women with a tumor size &lt;=0.5 cm (OR = 3.21, 95% CI = 1.59–6.45, p = 0.001 for tumor sizes 0.6–1.0cm; OR = 2.02, 95% CI = 1.09–3.74, p = 0.03 for tumor sizes 1.1–1.5cm; OR = 1.8, 95% CI = 0.97–3.33, p = 0.06 for tumor sizes 1.6–2.0cm; and OR = 1.64, 95% CI = 0.92–2.94, p = 0.1 for tumor sizes 2.1cm or more). PD and histologic grade shows reverse association between histologic grade 1 and grade 2,3. Progesteron receptor positive patients tend to have more dense(OR = 1.27, 95% CI=0.97–1.66, p = 0.07) breast than receptor negative patients, although after adjustment of age the statistical significant disappeared. Percent density was not significantly associated with, ER (p = 0.74), HER2 (p = 0.72).

Thioredoxin and thioredoxin-interacting protein as prognostic markers for gastric cancer recurrence

AIM: To evaluate the potential of thioredoxin (TXN) and thioredoxin-interacting protein (TXNIP) expression as biomarkers for predicting gastric cancer recurrence.

METHODS: TXN and TXNIP expression levels were acquired from gene expression microarray data for 65 human gastric cancer tissues. We determined whether each gene expression level was associated with cancer recurrence and investigated the relationship between the two genes. For validation, the expression levels of TXN and TXNIP were measured by quantitative real-time reverse transcription polymerase chain reaction in 68 independent stage III gastric cancer patients. The correlation between gene expression and cancer prognosis was evaluated. Immunohistochemical staining was performed to investigate the protein expression levels of TXN and TXNIP and to characterize the expression patterns of each protein.

RESULTS: TXN was a prognosis-related gene (P = 0.009), whereas TXNIP, a TXN inhibitor, demonstrated a negative correlation with TXN in the gene expression microarray data. In the 68 stage III patients, the expression levels of both TXN and TXNIP had a statistically significant effect on recurrence-free survival (RFS, P = 0.008 and P = 0.036, respectively). The low TXN and high TXNIP expression group exhibited a better prognosis than the other groups, and the high TXN and low TXNIP expression group exhibited a poorer prognosis (P < 0.001 for RFS and P = 0.001 for overall survival). More than half of the patients in the simultaneously high TXN and low TXNIP expression group experienced a recurrence within 1 year after curative surgery, and the 5-year survival rate of the patients in this group was 29%, compared with 89% in the low TXN and high TXNIP expression group. The TXN protein was overexpressed in 65% of the gastric cancer tissues, whereas the TXNIP protein was underexpressed in 85% of the cancer cells. In a correlation analysis, TXN and TXNIP were highly correlated with many oncogenes and tumor suppressors as well as with genes related to energy, protein synthesis and autophagy.

CONCLUSION: TXN and TXNIP are promising prognostic markers for gastric cancer, and performing personalized adjuvant treatment based on TXN and TXNIP expression levels would be an effective practice in the treatment of gastric cancer.

Endoscopic submucosal dissection with sentinel node navigation surgery for early gastric cancer

We combined endoscopic submucosal dissection (ESD) and sentinel node navigation surgery with the purpose of achieving complete resection of early gastric cancer while preserving the organ and assessing pathological nodal status. A total of 13 patients with cT1( ≤ 3 cm)N0 early gastric cancer underwent combined ESD and sentinel node navigation surgery (ESN) at a single tertiary referral center. Sentinel node navigation surgery using indocyanine green was performed during ESD and all suspected sentinel nodes were removed laparoscopically and examined intraoperatively. ESN was converted to gastrectomy with D2 dissection if there was evidence of metastasis on frozen section. ESN was completed in 12 patients and in 1 patient was converted to gastrectomy after sentinel node navigation surgery. En bloc tumor resection was achieved in all cases. Two patients underwent additional gastrectomy because they had tumor-positive vertical margins. In all cases ESN was conducted without intraoperative or postoperative adverse events. ESN is a feasible minimally invasive procedure that allows en bloc tumor resection to be achieved while assessing the pathological status of the lymph nodes.

Comparison of two inflammation-based prognostic scores in patients with unresectable advanced gastric cancer

OBJECTIVES

The objective of this study was to compare the usefulness of two inflammation-based prognostic scores, neutrophil to lymphocyte ratio (NLR) and modified Glasgow Prognostic Score (mGPS), assessed at diagnosis in stage IV advanced gastric cancer (AGC).

METHODS

We retrospectively reviewed the medical records of 104 patients with newly diagnosed metastatic AGC treated with palliative chemotherapy.

RESULTS

In the univariate analysis, the following variables were associated with shorter overall survival (OS): poor or undifferentiated histology (p = 0.013), more than 1 metastasis (p = 0.004), the presence of lymph node metastasis (p = 0.003), the presence of bone metastasis (p = 0.019), a lower albumin level (p < 0.001), elevated C-reactive protein (p < 0.001), a high absolute neutrophil count (p = 0.016), NLR ≥3 (p < 0.001) and higher mGPS (p < 0.001 and p = 0.007, respectively). In the multivariate analysis, high NLR and mGPS were independent prognostic factors for shorter OS (p = 0.037, p < 0.001 and p = 0.010, respectively), along with lymph node metastasis (p = 0.005) and histological subtype (p = 0.048).

CONCLUSION

This study suggests that the inflammatory markers, NLR and mGPS, are independent prognostic factors for OS in patients with unresectable AGC treated with palliative chemotherapy.

Overexpression of the M2 isoform of pyruvate kinase is an adverse prognostic factor for signet ring cell gastric cancer

AIM: To investigate M2 isoform of pyruvate kinase (PKM2) expression in gastric cancers and evaluate its potential as a prognostic biomarker and an anticancer target.

METHODS: All tissue samples were derived from gastric cancer patients underwent curative gastrectomy as a primary treatment. Clinical and pathological information were obtained from the medical records. Gene expression microarray data from 60 cancer and 19 non-cancer gastric tissues were analyzed to evaluate the expression level of PKM2 mRNA. Tissue microarrays were constructed from 368 gastric cancer patients. Immunohistochemistry was used to measure PKM2 expression and PKM2 positivity of cancer was determined by proportion of PKM2-positive tumor cells and staining intensity. Association between PKM2 expression and the clinicopathological factors was evaluated and the correlation between PKM2 and cancer prognosis was evaluated.

RESULTS: PKM2 mRNA levels were increased more than 2-fold in primary gastric cancers compared to adjacent normal tissues from the same patients (log transformed expression level: 7.6 ± 0.65 vs 6.3 ± 0.51, P < 0.001). Moreover, differentiated type cancers had significantly higher PKM2 mRNA compared to undifferentiated type cancers (log transformed expression level: 7.8 ± 0.70 vs 6.7 ± 0.71, P < 0.001). PKM2 protein was mainly localized in the cytoplasm of primary cancer cells and detected in 144 of 368 (39.1%) human gastric cancer cases. PKM2 expression was not related with stage (P = 0.811), but strongly correlated with gastric cancer differentiation (P < 0.001). Differentiated type cancers expressed more PKM2 protein than did the undifferentiated ones. Well differentiated adenocarcinoma showed 63.6% PKM2-positive cells; in contrast, signet-ring cell cancers showed only 17.7% PKM2-positive cells. Importantly, PKM2 expression was correlated with shorter overall survival (P < 0.05) independent of stage only in signet-ring cell cancers.

CONCLUSION: PKM2 expression might be an adverse prognostic factor for signet-ring cell carcinomas. Its function and potential as a prognostic marker should be further verified in gastric cancer.

The efficacy and toxicity of 3-weekly TS-1 containing chemotherapy in patients with unresectable advanced gastric cancer

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Background: TS-1 has shown good efficacy against unresectable advanced gastric cancer (AGC). Conventionally TS-1 containing chemotherapy (CTx) is performed on 5-weekly or 6-weekly basis. We lack robust evidence for the efficacy and safety of 3-weekly TS-1 containing CTx. In Korea, 3-weekly TS-1 containing CTx can be used as off-label under permission of Health Insurance Review and Assessment service (HIRA). We and HIRA conducted this study to confirm the efficacy and tolerability of 3-weekly TS-1 containing CTx in unresectable AGC. Methods: We retrospectively analyzed patients with unresectable AGC who received 3-weekly TS-1 containing CTx between June 2007 and January 2011. In 3-weekly TS-1 monotherapy, TS-1 40-60mg depending on patient’s body surface area was administered orally twice a day for 14 days followed by a 1-week rest every 3 weeks. In 3-weekly TS-1/cisplatin combination CTx, TS-1 40mg/m2 was given orally twice a day for 14 days followed by 1-week rest and cisplatin 60 mg/m2 on day 1 was given by intravenous infusion every 3 weeks. Results: A total of 1372 patients (TS-1 monotherapy: 265 (19.3%), TS-1/cisplatin : 1107 (80.7%)) were enrolled from 31 institutions. Response rate of 3-weekly TS-1 monotherapy was 18.1%. Progression-free survival (PFS) and overall survival (OS) were 5.2 months (95% C.I., 4.5-5.9) and 14.3 months (95% C.I., 10.6-17.9), respectively. Response rate of 3-weekly TS-1/cisplatin was 29.4%. PFS and OS of 3-weekly TS-1/cisplatin were 6.8 months (95% C.I., 6.3-7.4) and 16.1 months (95% C.I., 14.4-17.9) respectively. Common toxicities of TS-1 monotherapy included nausea/vomiting (N/V) (13.6%), anemia (13.2%) and neutropenia (10.2%). However, the incidences of more grade 3/4 toxicities were less than 3.0%. All grades of neutropenia, N/V and anemia occurred in 35.4%, 21.1% and 13.3% of patients receiving 3-weekly TS-1/cisplatin. However, grade 3/4 toxicities including neutropenia, N/V and anemia occurred in only 17.8%, 3.0% and 2.9%. Conclusions: Three-weekly TS-1 monotherapy or TS-1/cisplatin CTx showed good efficacy and well tolerability. Our study suggests that 3-weekly scheduled regimens may be a good treatment option for unresectable AGC patients.

Abstract 970: Multi-layer and integrative analysis of the whole transcriptome in Asian gastric cancer: AMPKβ modulation in cancer progression

We performed whole-transcriptome profiling of gastric cancer_the most common cancer in developing countries and the second leading cause of cancer deaths in the world. Applying a innovative SOLiD RNA-Seq approach to 24 gastric tumor samples and 6 noncancerous samples, we generated 3.0 billion short reads to quantitatively measure the abundance of mRNAs and small non-coding RNAs. We then developed a multi-layer analysis to identify differentially expressed mRNAs and microRNAs, and novel single-nucleotide mutations candidates associated with gastric cancer. With the insights from the multi-layer analysis, we experimentally demonstrated a critical role for AMPKβ modulation in gastric cancer progression. This work provides a multi-faceted portrait of the Asian gastric cancer transcriptome, which facilitates the elucidation of molecular mechanisms of gastric carcinogenesis and the development of targeted therapies. By integrating data obtained on the expression of both mRNa and miRNa molecules, we were able to identify certain gene signatures uniquely expressed in gastric cancer. This gene signatures along with gastric cancer-related therapeutic target gene signature, showed molecular changes as robust biological markers. Integration of differentially expressed mRNAs and microRNA profiles allowed us to identify potential miRNA drivers of disease progression. We demonstrated the translational relevance of AMPKβ as a potential therapeutic target for treatment and for prediction of early stage gastric cancer. This work lays a critical foundation for the identification of molecular mechanisms of gastric carcinogenesis and the development of related targeted therapies.

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 970. doi:1538-7445.AM2012-970

Abstract 4536: Identification of new prognostic biomarker of gastric cancer by systems analysis

Gastric cancer is one of the most common and cancer-related deaths worldwide and accounts for an estimated 800,000 deaths annually. Prognosis depends on the stage of disease. Even though within same stage, gastric cancer patients present diverse clinical manifestations and prognosis. To differentiate the malignant potential appropriately, many efforts have been made to select prognostic markers. Molecular markers will be important in predicting patients’ outcomes and personalized treatments according to individual biology. In this study, we analyzed the gene expression profile of human gastric cancer (published on CCR) to identify potential biomarkers which could be used to classify patients according to prognosis and also become new therapeutic targets. We found that TXN family genes and ERO1L were significantly overexpressed and related to prognosis. qRT-PCR and tissue microarray validated TXN overexpression and ERO1L have poor prognosis in gastric cancer. Finally, systems analysis revealed TXN family genes are highly correlated with many oncogene and tumor suppressor functional genes and shown relationship on energy and protein synthesis. Survival analysis based on Hierarchical-clustering of TXN family correlated mRNA expression genes revealed that TXN and TXNIP are significantly influenced the patient survival. We evaluated ERO1L and find out also significantly overexpressed in gastric tumor and suggest TXN family members are actively involved in gastric cancer. In vitro hypoxic experiment ERO1L was very highly expressed in hypoxic condition and this also supports TXN high expressed cancer cells are in hypoxic condition. In conclusion, our findings show that a prognostic molecular signature that can predict the poor progression of gastric cancer tumors. Furthermore, unequal distribution of expression patterns reflecting activation of TXN family and ERO1L with different survival rates supports a personalized target therapy in gastric cancer with biomarker gene signature driven patient selection. While further work is needed to elucidate the biological contributions of these markers, the results presented here provide a basis for future investigations of the functional and clinical effect of new target genes in gastric cancer.

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 4536. doi:1538-7445.AM2012-4536

Abstract 4540: Pyruvate kinase M2 (PKM2) associated with poor prognosis in gastric signet ring cell carcinoma

Background: PKM2 (M2 isoform of pyruvate kinase) was identified as a driver of aerobic glycolysis, leading to cell growth and tumor development. PKM2 is usually known to overexpress in cancer, however, there are still remaining questions about the function and the potential as anti-cancer treatment target. We investigated the expression status of PKM2 in gastric cancer tissues and evaluated the possibility of biomarker and anticancer target. Methods: Paraffin-embedded tissue microarray blocks of gastric adenocarcinoma tissue specimens were obtained from 363 gastric cancer patients. All patients underwent curative gastric resection from 1999 to 2007 and distributed from stage I to IV and their clinical characteristics were collected. IHC (Immunohistochemical) assay was performed to evaluate PKM2 expression levels. The correlation of PKM2 expression level with gastric cancer prognosis / stage / histology was evaluated. Results: In our previous microarray study using 60 gastric cancer tissues, we identified PKM2 mRNA overexpressed in cancer tissue than non-cancer tissue (P&lt;0.01). In IHC assays, PKM2 expression level was classified to score 0 (negative, n=185), 1 (weak positive, n=136), and 2 (strong positive, n=42). 49% of gastric cancer tissues presented PKM2 expression (weak or strong positive). PKM2 expression had no relation with prognosis (p=0.913, recurrence free survival) and TNM stage (p=0.825). Intestinal and diffuse type cancer manifested different PKM2 expression pattern and signet ring cell carcinoma manifested 26.6% PKM2 expression. Within same Lauren classification, there was no significant difference of prognosis according to PKM2 expression except signet ring cell carcinoma. In signet ring cell cancer (n=78), PKM2 expression was related to poor overall survival (p=0.029) Conclusion: PKM2 protein expression was not correlated with gastric cancer prognosis. Only in signet ring cell gastric cancer, overexpressed PKM2 was associated with poor overall survival. The role of PKM2 should be further verified in signet ring cell gastric cancer model to find clinical significance in this subtype of gastric cancer.

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 4540. doi:1538-7445.AM2012-4540

AMPKα modulation in cancer progression: multilayer integrative analysis of the whole transcriptome in Asian gastric cancer

Gastric cancer is the most common cancer in Asia and most developing countries. Despite the use of multimodality therapeutics, it remains the second leading cause of cancer death in the world. To identify the molecular underpinnings of gastric cancer in the Asian population, we applied an RNA-sequencing approach to gastric tumor and noncancerous specimens, generating 680 million informative short reads to quantitatively characterize the entire transcriptome of gastric cancer (including mRNAs and miRNAs). A multilayer analysis was then developed to identify multiple types of transcriptional aberrations associated with different stages of gastric cancer, including differentially expressed mRNAs, recurrent somatic mutations, and key differentially expressed miRNAs. Through this approach, we identified the central metabolic regulator AMP-activated protein kinase (AMPK)α as a potential functional target in Asian gastric cancer. Furthermore, we experimentally showed the translational relevance of this gene as a potential therapeutic target for early-stage gastric cancer in Asian patients. Together, our findings not only provide a valuable information resource for identifying and elucidating the molecular mechanisms of Asian gastric cancer, but also represent a general integrative framework to develop more effective therapeutic targets.

Treatment outcome of patients with anaplastic thyroid cancer: a single center experience

PURPOSE

Anaplastic thyroid cancer is known to have a poor prognosis due to its aggressive and rapid metastasis with median survival of less than 6 months. Multimodal treatment involving surgery and chemoradiotherapy has been used to improve the survival of patients. Here, we retrospectively review of treatment outcome of 13 consecutive patients who were treated at a single center.

MATERIALS AND METHODS

We retrospectively reviewed medical records of 13 anaplastic thyroid cancer patients who received multidisciplinary treatment between 2006 and 2010. Kaplan-Meier survival curve was used to analyze progression-free survival and overall survival of patients.

RESULTS

The median patient age at diagnosis was 69 years, and six patients had stage IVc diseases. Eight patients received primary surgery followed by radiotherapy or concurrent chemoradiotherapy (CCRT). Five patients received weekly doxorubicin-based definitive CCRT, but only one patient's condition remained stable, while the rest experienced rapid disease progression. The median progression-free survival was 2.8 months (95% CI, 1.2-4.4 months), and the median overall survival was 3.8 months (95% CI, 3.0-4.6 months).

CONCLUSION

Patients with anaplastic thyroid cancer showed poor prognosis despite multimodality treatment. Therefore, identification of novel therapeutic targets is warranted to take an effective mode of treatment.

A phase II open-label trial of dacomitinib monotherapy in patients with HER2-positive advanced gastric cancer after failure of at least one prior chemotherapy regimen

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Background: HER2 is a clinically relevant therapeutic target in gastric cancer. Trastuzumab plus chemotherapy has improved patients’ survival in HER2 (+) advanced gastric cancer (AGC). Pan-HER inhibitor shows significant antitumor effects in in vitro and xenograft model of HER2 (+) gastric cancer. The aim of this study was to find the efficacy/safety of dacomitinib, a irreversible pan-HER tyrosine kinase inhibitor by Pfizer, in HER2 (+) AGC patients.

Methods: We enrolled AGC patients with HER2 FISH (+) or HER2 IHC 3+ who were treated with at least one prior palliative chemotherapy regimen and with ECOG PS 0-2, normal cardiac ejection fraction. Patients were treated with dacomitinib 45 mg once daily continuously every 4 weeks. Response was evaluated every 8 weeks using RECIST v1.1 and safety was assessed with CTCAE v4.0. The primary endpoint was 4 month-progression free survival rate (4m-PFS). PK and PD study were also conducted.

Results: A total of 27 patients were enrolled. The median age was 61 (range: 43-80). Twenty two patients were male. The ECOG PS was 0 in 9 patients, 1 in 16, and 2 in 2. The number of prior palliative chemotherapy regimen was 1 in 7 patients (25.9%), 2 in 9 (33.3%), more than 3 in 11 (40.7%). Six patients received prior anti-HER2 therapy (trastuzumab 2, lapatinib 2, lapatinib or placebo in clinical trial 2) A total of 80 cycles were delivered (median 2 cycles per patient, range: 1-6). The 4m-PFS was 22.2 % and median progression-free survival was 2.1 months (95% CI: 2.3-3.4) There was 2 PR, 9 SD and 16 PD, resulting in 7.4 % response rate (95% CI: 0-17.5%) and 40.7 % disease control rate (95% CI: 21.9-59.6%). Median overall survival was 7.1 months (95% CI: 4.4-9.8). The most common toxicities were skin rash, diarrhea, and fatigue, but most of them were grade ½. Grade 3 skin rash was observed in 3 patients. There was no treatment-related death.

Conclusions: Considering the heavily pretreated nature of enrolled patients, the dacomitinib is active and safe treatment option in HER2 (+) AGC patients. The results of PK and PD studies will be also presented at the meeting. (ClinicalTrials.gov: NCT01152853 )

Adjuvant capecitabine and oxaliplatin for gastric cancer after D2 gastrectomy (CLASSIC): a phase 3 open-label, randomised controlled trial

BACKGROUND

D2 gastrectomy is recommended in US and European guidelines, and is preferred in east Asia, for patients with resectable gastric cancer. Adjuvant chemotherapy improves patient outcomes after surgery, but the benefits after a D2 resection have not been extensively investigated in large-scale trials. We investigated the effect on disease-free survival of adjuvant chemotherapy with capecitabine plus oxaliplatin after D2 gastrectomy compared with D2 gastrectomy only in patients with stage II-IIIB gastric cancer.

METHODS

The capecitabine and oxaliplatin adjuvant study in stomach cancer (CLASSIC) study was an open-label, parallel-group, phase 3, randomised controlled trial undertaken in 37 centres in South Korea, China, and Taiwan. Patients with stage II-IIIB gastric cancer who had had curative D2 gastrectomy were randomly assigned to receive adjuvant chemotherapy of eight 3-week cycles of oral capecitabine (1000 mg/m(2) twice daily on days 1 to 14 of each cycle) plus intravenous oxaliplatin (130 mg/m(2) on day 1 of each cycle) for 6 months or surgery only. Block randomisation was done by a central interactive computerised system, stratified by country and disease stage. Patients, and investigators giving interventions, assessing outcomes, and analysing data were not masked. The primary endpoint was 3 year disease-free survival, analysed by intention to treat. This study reports a prespecified interim efficacy analysis, after which the trial was stopped after a recommendation by the data monitoring committee. The trial is registered at ClinicalTrials.gov (NCT00411229).

FINDINGS

1035 patients were randomised (520 to receive chemotherapy and surgery, 515 surgery only). Median follow-up was 34·2 months (25·4-41·7) in the chemotherapy and surgery group and 34·3 months (25·6-41·9) in the surgery only group. 3 year disease-free survival was 74% (95% CI 69-79) in the chemotherapy and surgery group and 59% (53-64) in the surgery only group (hazard ratio 0·56, 95% CI 0·44-0·72; p<0·0001). Grade 3 or 4 adverse events were reported in 279 of 496 patients (56%) in the chemotherapy and surgery group and in 30 of 478 patients (6%) in the surgery only group. The most common adverse events in the intervention group were nausea (n=326), neutropenia (n=300), and decreased appetite (n=294).

INTERPRETATION

Adjuvant capecitabine plus oxaliplatin treatment after curative D2 gastrectomy should be considered as a treatment option for patients with operable gastric cancer.

FUNDING

F Hoffmann-La Roche and Sanofi-Aventis.

Prevention of development of postoperative dysesthesia in transforaminal percutaneous endoscopic lumbar discectomy for intracanalicular lumbar disc herniation: floating retraction technique

BACKGROUND

Transforaminal percutaneous endoscopic lumbar discectomy (PELD) has become a routine surgical procedure because it is minimally invasive. Perioperative complications such as dural injury, infection, nerve root irritation and recurrence can occur not only with PELD, but also with conventional open microsurgery. In contrast, post-operative dysesthesia (POD) due to existing dorsal root ganglion (DRG) injury is a unique complication of PELD. When POD occurs, even if the traversing root has been successfully decompressed, it hinders swift recovery and delays the return to daily routines. Thus, prevention of POD is the key to successful and widespread use of PELD.

MATERIAL AND METHODS

From January 2006 to December 2008, 154 patients underwent percutaneous endoscopic discectomy by floating retraction technique at 160 disc levels under local anesthesia. This approach towards the superomedial border of the lower pedicle and the cannula can be placed by gentle retraction of the root with perineural fat instead of direct compression of dorsal root ganglion. The clinical outcomes were assessed using the Visual Analogue Scale (VAS, 0-10 point) for radicular pain and low back pain, and using the Oswestry Disability Index (ODI) for functional status. Perioperative complications and recurrence were reviewed.

RESULTS

The mean age was 45 years, the mean operative time was 36 min and the mean follow-up period was 3.4 years. The mean hospital stay for endoscopic discectomy was 1.8 days. No patient underwent repeated PELD or convert microsurgery by incomplete removal of the ruptured particle. All patients experienced early relief of symptoms, as determined by VAS and ODI. No patient developed POD. 1 patient experienced dural injury. There was 1 case of discitis. The recurrence rate was 1.95% (3 patients).

CONCLUSION

Transforaminal percutaneous endoscopic lumbar discectomy for intracanalicular lumbar disc herniation is a safe and effective procedure. The floating retraction technique is recommended to avoid development of POD.