Search

e15607 Background: Colorectal cancer is one of the most common malignancies worldwide. Approximately 85% of colorectal cancers are thought to result from adenoma. However, the molecular mechanism of adenoma transformation into colorectal cancer is still unclear. Methods: Ninety-nine adenoma patients aged from 25 to 78 years old were enrolled in this study. We collected tissue sample from each patient and 77 matched blood samples. Pathological subtypes included tubular villous adenomas, villous adenomas, tubular adenomas, high-grade intraepithelial neoplasia, and polyps. Eighty-one stage I colorectal cancer patients (CRC I) were also enrolled in this study. All samples underwent Next-generation sequencing with a panel of 405 cancer related genes. Results: Mutational profiles of adenoma and CRC I patients were compared. The top 5 most frequently mutated genes in adenoma were APC (71%), KRAS (41%), ATM (33%), RIF1 (31%), SYNE1 (28%). While in CRC I patients, top 5 mutated genes were APC (78%), TP53 (57%), TTN (35%), KRAS (33%) and TCF7L2 (22%). There were significant differences between TP53 and TTN by chi-square test. The frequency, number and TMB of mutations in stage I colorectal cancer patients were significantly higher than those in various adenoma subtypes. Stage I colorectal cancer patients have more mutated genes enriched in the Wnt and Notch pathways than adenoma patients. We analyzed mutation signatures in CRC I and adenoma patients, and CRC I were more focused on mutation signatures of mismatch repair such as signature 1, signature 6, signature 10, and signature 15. A total of 391 mutations were identified in tissue samples, while 130 mutations were found in plasma cell-free DNA, with 116 mutations shared between them. The two genes with the highest consistency between tissue and blood were PAX7 and KMT2D. Conclusions: TP53 and TTN are associated with the transition from CRC I to adenoma, and Wnt and Notch pathways may also be involved. PAX7 and KMT2D mutations frequently found in adenoma tissue and blood cfDNA demonstrate the diagnostic potential of these two genes in clinic.

e15553 Background: PD-1 antibody monotherapy has shown durable response in colorectal cancer (CRC) patients (pts) with microsatellite instability (MSI) high status, who account for only 10–15% of all CRC pts. Preclinical studies revealed that inhibition of MAPK pathway with MEK inhibitors can increase T-cell infiltration into tumors and therefore might enhance the antitumor activity of immune checkpoint inhibitor. Thus, this study was conducted to evaluate the safety and antitumor activity of SHR7390, a MEK1/2 inhibitor, plus camrelizumab (anti-PD-1) in pts with CRC. Methods: In this single-arm, open-label, phase I study, pts with treatment-refractory advanced or metastatic CRC were enrolled to receive SHR7390 in an accelerated titration scheme at doses of 0.125, 0.25, and 0.5 mg orally qd, plus camrelizumab at a fixed dose of 200 mg IV q2w. Eligible pts were given a single dose of SHR7390, observed for 7–10 days, and then treated continuously with SHR7390 and camrelizumab in 28-day treatment cycles until disease progression, intolerable toxicities, or withdrawal of consent. A recommended dose for expansion was determined based on the safety and tolerability of the dose escalation stage. The primary endpoints were dose limiting toxicity (DLT) and maximum tolerated dose (MTD). This study is registered with ClinicalTrials.gov, number NCT03182673. Results: At data cutoff on May 30, 2020, 22 pts were enrolled. The median follow-up duration was 6 months. Seven pts had received ≥3 lines of prior treatment. MSI status were available in 21 pts (MSS/MSI-L, n = 18; MSI-H, n = 3). There were two pts each in the SHR7390 0.125 and 0.25 mg cohorts, and 0.5 mg cohort was expanded to 18 pts. One DLT (grade 3 rash) was reported in a pt in the 0.5 mg cohort and the MTD was not reached. Grade 3–4 treatment-related adverse events (TRAEs) were rash (n = 4), increased lipase, oedema peripheral, face oedema, and anemia (n = 1 each). One pt reported a grade 5 TRAE (increased intracranial pressure). Five pts (23%) achieved partial response (0.125 and 0.25 mg cohorts, n = 1 each; 0.5 mg cohort, n =3), including one out of three pts with MSS/MSI-L & BRAF mutant tumors (response lasting 13 months), one out of 15 pts with MSS/MSI-L & BRAF wild type tumors (response lasting 8 months), and all three pts with MSI-H tumors (responses lasting 31, 11, and 10 months, respectively). Three pts with MSS/MSI-L achieved stable disease, and the overall disease control rate reached 36%. Conclusions: SHR7390 plus camrelizumab showed a tolerable safety profile. Preliminary clinical activity was reported regardless of BRAF and MSI status, and future studies are warranted to further evaluate these results. Clinical trial information: NCT03182673.

e16022 Background: Individuals with gastric cancer who present with peritoneal metastasis (PM) have poor prognosis. VEGF and VEGFR-2-mediated angiogenesis can increase vascular permeability, mesothelial cell permeability and promote peritoneal metastasis and ascites formation. This study assessed whether apatinib, a small-molecule VEGFR-2 tyrosine kinase inhibitor, in combination with paclitaxel would improve survival in patients with gastric cancer with PM as second-line therapy. Methods: This was a randomized, placebo-controlled, double-blind phase 2 trial. Recruitment of the trial was stopped after 44 patients due to poor accrual. Patients aged 18 years or older with gastric adenocarcinoma with PM and disease progression after first-line chemotherapy (platinum plus fluoropyrimidine) were randomly assigned in a 1:1 ratio to receive apatinib or placebo 500 mg oral once daily plus paclitaxel 80 mg/m2 intravenously on days 1, 8, and 15 of a 28-day cycle. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), overall response rate (ORR), disease control rate (DCR) and safety profiles. Results: Between January 2017 and January 2019, 44 patients were randomly assigned to treatment (21 in Paclitaxel/apatinib group while 23 in Paclitaxel/placebo group). Median PFS was significantly longer in apatinib plus paclitaxel group than in placebo plus paclitaxel group (4.67 months [95% CI, 3.90 to 9.13 months] vs 4.07 months [95% CI, 1.93 to 5.00 months]; hazard ratio 0.46 [95% CI, 0.22 to 0.97]; P=0.037). There was no significant difference between the two groups in median OS (8.57 months vs. 9.03 months; P=0.85), ORR (19.0% vs. 4.3%; P=0.290) and DCR (76.2% vs. 52.2%, P=0.098). Apatinib group showed a higher incidence of proteinuria (38.1% vs. 4.3%; P=0.016), while no significant difference was found in the incidence of grade 3 or higher drug-related adverse events. Conclusions: Compared with placebo plus paclitaxel, the combination of apatinib with paclitaxel as second-line therapy significantly improved median PFS with an acceptable safety profile in patients with gastric cancer with peritoneal metastasis. Clinical trial information: NCT03144843. [Table: see text]

Key Points Question Is prophylactic aprepitant therapy combined with palonosetron and dexamethasone effective in preventing nausea and vomiting in women receiving moderately emetogenic chemotherapy? Findings In this randomized phase 3 clinical trial that included 248 women younger than 50 years with no or little alcohol use, the complete response rate in the overall phase for chemotherapy-induced nausea and vomiting was 87% in the aprepitant group vs 67% in the control group. The overall complete response rate was significantly higher in the aprepitant group vs the control group. Meaning Adding aprepitant to palonosetron and dexamethasone was effective in reducing nausea and vomiting for women who received moderately emetogenic chemotherapy., Importance The prevention of chemotherapy-induced nausea and vomiting has an important role in the overall management of cancer treatment. Objective To evaluate whether adding aprepitant to palonosetron and dexamethasone can further prevent the incidence and severity of nausea and vomiting caused by FOLFIRI (fluorouracil, leucovorin, and irinotecan) or FOLFOX (fluorouracil, leucovorin, and oxaliplatin) chemotherapy regimens among women with gastrointestinal cancer at higher risk. Design, Setting, and Participants This phase 3, double-blind, placebo-controlled randomized clinical trial recruited young women (age ≤50 years) who drank little or no alcohol and had gastrointestinal cancer for which they received FOLFOX or FOLFIRI chemotherapy. A total of 248 women were enrolled and assigned in the ratio 1:1 to intervention and control groups from August 4, 2015, to March 31, 2020. Intention-to-treat analysis was used to evaluate patient baseline characteristics and efficacy. The analysis was conducted on October 30, 2020. Interventions Patients were randomly assigned to the aprepitant group (aprepitant, 125 mg, orally 60 minutes before initiation of chemotherapy on day 1 and 80 mg orally each morning of days 2 and 3; palonosetron, 0.25 mg, intravenously; and dexamethasone, 6 mg, orally 30 minutes before chemotherapy initiation on day 1) or the placebo group (placebo, 125 mg, orally 60 minutes before initiation of chemotherapy on day 1 and 80 mg orally on each morning of days 2 and 3; palonosetron, 0.25 mg, intravenously; and dexamethasone, 12 mg, orally 30 minutes before chemotherapy initiation on day 1). Main Outcomes and Measures The primary end point was the complete response (CR) rate, defined as the proportion of patients without emesis episodes or rescue medication use during the overall phase of the first cycle. Other efficacy indicators, such as no vomiting and no nausea, were measured as the secondary and exploratory end points. Results A total of 248 women from 4 clinical centers in China entered this study, and 243 patients (aprepitant regimen, 125 patients [51.4%]; placebo regimen, 118 patients [48.5%]) were evaluable for efficacy and safety; mean (SD) age of the total population was 40.1 (7.3) years. The CR rate was significantly higher in the aprepitant group vs the control group overall (107 [87.0%] vs 80 [66.7%]; P, This randomized clinical trial examines the use of aprepitant combined with palonosetron and dexamethasone for prophylactic treatment in women with chemotherapy-associated nausea and vomiting.

Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor 2 (Her2) and cluster determinant 44 (CD44), is one of the most malignant human tumors which causes a high mortality rate due to rapid tumor growth and metastasis. To develop effective therapeutic treatments, a dual-targeting hybrid nanoparticle (NP) system was designed and constructed to deliver the SN38 agent specifically to human solid gastric tumors bearing excessive Her2 and CD44. The hybrid NPs consist of a particle core made of the biodegradable polymer PLGA and a lipoid shell prepared by conjugating the AHNP peptides and n-hexadecylamine (HDA) to the carboxyl groups of hyaluronic acid (HA). Upon encapsulation of the SN38 agent in the NPs, the AHNP peptides and HA on the NP surface allow preferential delivery of the drug to gastric cancer cells (e.g., HGC27 cells) by targeting Her2 and CD44. Cellular uptake and in vivo biodistribution experiments verified the active targeting and prolonged in vivo circulation properties of the dual-targeting hybrid NPs, leading to enhanced accumulation of the drug in tumors. Furthermore, the anti-proliferation mechanism studies revealed that the inhibition of the growth and invasive activity of HGC27 cells was not only attributed to the enhanced cellular uptake of dual-targeting NPs, but also benefited from the suppression of CD44 and Her2 expression by HA and AHNP moieties. Finally, intravenous administration of the SN38-loaded dual-targeting hybrid NPs induced significant growth inhibition of HGC27 tumor xenografted in nude mice compared with a clinical antitumor agent, Irinotecan (CPT-11), and the other NP formulations. These results demonstrate that the designed dual-targeting hybrid NPs are promising for targeted anti-cancer drug delivery to treat human gastric tumors over-expressing Her2 and CD44.

Significance Current therapy for advanced colorectal cancer (CRC) is unsatisfactory and CRC remains a major cause of cancer-related deaths. Thus, novel and ubiquitously acting oncogenic mediators that are amenable to pharmacological targeting need to be identified. We found that loss of adenomatous polyposis coli ( APC ), which is mutated in the majority of human CRC, results in up-regulation of the signaling protein IL-6ST/gp130. This results in activation of Src family kinases (SFKs), YAP, Notch, and STAT3, which are simultaneously activated in 64% of human CRC. In addition to better explaining how APC loss initiates colorectal tumorigenesis, we show that combined treatment with SFK and JAK inhibitors results in regression of established colorectal tumors in mice.

We have developed a new multifunctional, non-viral gene delivery platform consisting of cationic poly(amine-co-ester) (PPMS) for DNA condensation, PEG shell for nanoparticle stabilization, poly(γ-glutamic acid) (γ-PGA) and mTAT (a cell-penetrating peptide) for accelerated cellular uptake, and a nuclear localization signal peptide (NLS) for enhanced intracellular transport of DNA to the nucleus. In vitro study showed that coating of the binary PPMS/DNA polyplex with γ-PGA promotes cellular uptake of the polyplex particles, particularly by γ-glutamyl transpeptidase (GGT)-positive cells through the GGT-mediated endocytosis pathway. Conjugating PEG to the γ-PGA led to the formation of a ternary PPMS/DNA/PGA-g-PEG polyplex with decreased positive charges on the surface of the polyplex particles and substantially higher stability in serum-containing aqueous medium. The cellular uptake rate was further improved by incorporating mTAT into the ternary polyplex system. Addition of the NLS peptide was designed to facilitate intracellular delivery of the plasmid to the nucleus--a rate-limiting step in the gene transfection process. As a result, compared with the binary PPMS/LucDNA polyplex, the new mTAT-quaternary PPMS/LucDNA/NLS/PGA-g-PEG-mTAT system exhibited reduced cytotoxicity, remarkably faster cellular uptake rate, and enhanced transport of DNA to the nucleus. All these advantageous functionalities contribute to the remarkable gene transfection efficiency of the mTAT-quaternary polyplex both in vitro and in vivo, which exceeds that of the binary polyplex and commercial Lipofectamine™ 2000/DNA lipoplex. The multifunctional mTAT-quaternary polyplex system with improved efficiency and reduced cytotoxicity represents a new type of promising non-viral vectors for the delivery of therapeutic genes to treat tumors.

Background: Tumor mutational burden (TMB) has been widely studied as a predictive biomarker of response to immune checkpoint inhibitors (ICIs). Besides, evidence suggests frameshift indels are a highly immunogenic mutational class and thus a potentially superior biomarker. However, the general prognostic impact of TMB and indel burden in patients with solid tumors has not been systematically investigated. Methods: We analyzed 20 primary solid cancer types from The Cancer Genome Atlas (TCGA) database. Clinicopathologic factors, TMB and indel burden were collected or calculated. For each cancer type, the impact of TMB or indel burden on overall survival (OS) was evaluated using the Kaplan-Meier method and Cox regression with the method of inverse probability of treatment weighting. Results: Twenty cancer types from 6,035 patients were analyzed. Survival analysis showed that TMB had a significant impact on OS in 14 out of these 20 cancer types. According to the general survival impact of TMB, they could be classified into three groups, namely the TMB-Worse (eight cancer types), TMB-Better (six cancer types) and TMB-Similar (six cancer types) group, in which higher TMB was associated with inferior, superior, or similar OS, respectively. The survival impacts of TMB in the TMB-Worse and TMB-Better groups were generally consistent when limited to genes from two FDA-approved panels. Notably, in two out of the six cancer types in the TMB-Similar group, the indel burden significantly affected OS. Conclusions: TMB, as well as indel burden, has divergent prognostic impact in different cancer types, thus could be incorporated in prognostication and risk stratification. More importantly, the general prognostic impact should be taken into account when establishing the predictive function of TMB to ICI treatment.

An effective blood-based method for the diagnosis and prognosis of hepatocellular carcinoma (HCC) has not yet been developed. Circulating tumour DNA (ctDNA) carrying cancer-specific genetic and epigenetic aberrations may enable a noninvasive 'liquid biopsy' for diagnosis and monitoring of cancer. Here, we identified an HCC-specific methylation marker panel by comparing HCC tissue and normal blood leukocytes and showed that methylation profiles of HCC tumour DNA and matched plasma ctDNA are highly correlated. Using cfDNA samples from a large cohort of 1,098 HCC patients and 835 normal controls, we constructed a diagnostic prediction model that showed high diagnostic specificity and sensitivity (P < 0.001) and was highly correlated with tumour burden, treatment response, and stage. Additionally, we constructed a prognostic prediction model that effectively predicted prognosis and survival (P < 0.001). Together, these findings demonstrate in a large clinical cohort the utility of ctDNA methylation markers in the diagnosis, surveillance, and prognosis of HCC.

BACKGROUND The optimal strategy of maintenance therapy for patients with mCRC is controversial. This study was to evaluate the efficacy and safety of maintenance therapy with capecitabine versus observation following inductive chemotherapy in patients with metastatic colorectal cancer. PATIENTS AND METHODS In this randomized, open-label, multicenter, phase III trial, patients who received 18-24 weeks of induction chemotherapy with XELOX or FOLFOX and achieved disease control were randomly assigned centrally (1:1) to receive maintenance therapy of capecitabine or only observation until disease progression. The primary end point was progression-free survival (PFS) from randomization; the secondary end points included overall survival (OS), PFS from induction treatment (PFS2) and safety. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT02027363. RESULTS Between 30 July 2010 and 15 September 2013, 274 patients were enrolled in the study from 11 sites in China and randomly assigned to maintenance group (n = 136) or observation group (n = 138). Clinicopathological characteristics were balanced in two groups. The median follow-up time from randomization was 29.0 months [interquartile range (IQR) 21-36 months]. The primary end point of PFS was statistically significantly longer in capecitabine maintenance group than in observation group {6.43 [95% confidence interval (CI) 5.26-7.71] versus 3.43 (2.83-4.16) months, HR 0.54 (0.42-0.70), P < 0.001}. The median OS of capecitabine maintenance group was longer than that of observation group, but not statistically significant [25.63 (22.46-27.80) versus 23.30 (19.68-26.92) months; HR 0.85 (0.64-1.11), P = 0.2247]. Similar safety profiles were observed in both arms. The most common grade 3 or 4 toxicities in capecitabine maintenance group versus observation group were neutropenia, hand-foot syndrome, and mucositis. CONCLUSIONS Maintenance therapy with a single agent of capecitabine can be considered an appropriate option following the induction of XELOX or FOLFOX in mCRC patients with acceptable toxicities. CLINICAL TRIALS NUMBER NCT02027363.

2593Background: APG-1387 is a bivalent small molecule Smac mimetic that antagonizes the IAPs. Preclinical studies have shown its dose- and schedule-dependent, strong antitumor activities in multipl...

4045Background: Gastric cancer (GC) is one of the most common tumors in China. The ToGA study has shown trastuzumab in combination with fluoropyrimidine plus cisplatin prolonged overall survival (O...

OBJECTIVE To investigate the efficiency and safety of the oxaliplatin, fluorouracil (5-FU) and leucovorin regimen (FOLFOX) in previously untreated patients with metastatic or recurrent colorectal cancer. METHODS Previously untreated patients with metastatic or recurrent colorectal cancer received 100 mg/m2 of oxaliplatin intravenously (IV) over 2 h on day 1, and IV 400 mg/m2 of leucovorin over 2 h followed by a bolus of 400mg/m2 of 5-FU. Then 2,600~3,000 mg/m2 of 5-FU was administered by continuous infusion over 46 h. RESULTS An evaluated response rate was determined for 97 of 105 treated patients. The overall response rate was 35.1%, 9 patients (9.3%) had a complete response and 25 patients (25.8%) a partial response. Thirty-two patients 33.0%) developed stable disease and 32.0% of the patients progressed. The median time to progression (TTP) was 7.7months and the median overall survival 20.5 months. One and 2-year survival rates were 68% and 32%. Toxic effects based on the National Cancer Institute-Common Toxicity Criteria (NCI-CTC), reaching grade 3/4 were:neutropenia 12.3%, anemia 11.3%, vomiting 4.1% and diarrhea 7.2%. Grade 3 neuropathy was 5.1%. The overall survival rate of patients who had received a radical resection was superior to the patients who had not received a operation, or had received a palliative resection ( P =0.0658). The serum levels of CEA, ALP and LDH had no relationship with survival ( P >0.05). CONCLUSION The FOLFOX regimen containing oxaliplatin, 5-FU plus leucovorin was an efficacious regimen with good tolerability in previously un -treated metastatic or recurrent colorectal cancer patients.

In this study, a dual-ligand polymer-lipid hybrid nanoparticle drug delivery vehicle comprised of an anti-HER2/neu peptide (AHNP) mimic with a modified HIV-1 Tat (mTAT) was established for the targeted treatment of Her2/neu-overexpressing cells. The resultant dual-ligand hybrid nanoparticles (NPs) consisted of a poly(lactide-co-glycolide) core, a near 90% surface coverage of the lipid monolayer, and a 5.7 nm hydrated polyethylene glycol shell. Ligand density optimization study revealed that cellular uptake efficiency of the hybrid NPs could be manipulated by controlling the surface-ligand densities. Furthermore, the cell uptake kinetics and mechanism studies showed that the dual-ligand modifications of hybrid NPs altered the cellular uptake pathway from caveolae-mediated endocytosis (CvME) to the multiple endocytic pathways, which would significantly enhance the NP internalization. Upon the systemic investigation of the cellular uptake behavior of dual-ligand hybrid NPs, docetaxel (DTX), a hydrophobic anticancer drug, was successfully encapsulated into dual-ligand hybrid NPs with high drug loading for Her2/neu-overexpressing SK-BR-3 breast cancer cell treatment. The DTX-loaded dual-ligand hybrid NPs showed a decreased burst release and a more gradual sustained drug release property. Because of the synergistic effect of dual-ligand modification, DTX-loaded dual-ligand hybrid NPs exerted substantially better therapeutic potency against SK-BR-3 cancer cells than other NP formulations and free DTX drugs. These results demonstrate that the dual-ligand hybrid NPs could be a promising vehicle for targeted drug delivery to treat breast cancer.

To determine the maximum tolerated dose (MTD) and preliminary efficacy of concurrent hepatic arterial infusion (HAI) of floxuridine (FUDR) and systemic modified oxaliplatin, 5-fluorouracil and leucovorin (m-FOLFOX6) in Chinese patients with unresectable hepatic metastases from colorectal cancer. Thirty-five patients with unresectable liver metastases with or without extrahepatic disease were treated with concurrent HAI and systemic m-FOLFOX6. HAI FUDR was delivered in a 14-day infusion with escalating dose levels, and each cycle was repeated every 4 weeks. The MTD for FUDR was 0.12 mg/kg/day when combined with systemic m-FOLFOX6. The dose-limited toxicities were neutropenia (8.6 %), alanine aminotransferase/aspartate aminotransferase elevation (5.7 %) and diarrhea (11.4 %). The overall response rate was 68.6 % for hepatic metastases and 14.3 % for extrahepatic metastases. The median progression-free survival and overall survival were 8.23 and 25 months, respectively. The recommended dose of FUDR was 0.12 mg/kg/day when combined with systemic m-FOLFOX6. This combination achieved a high response rate in hepatic disease and a high control rate in extrahepatic disease. Further study is needed to assess the potential additional value of HAI therapy in converting patients with hepatic metastases to candidates for resection.

Cathepsin L (CTSL) is a lysosomal cysteine protease that has been found to be overexpressed in ovarian cancer (OC). The aim of the present study was to investigate the possible involvement of CTSL in the development of OC. In this study, RNA interference with a CTSL small hairpin RNA (CTSL-shRNA), and a plasmid carrying CTSL were used to identify the effects of this enzyme on the regulation of the malignant behavior of OC cells. OV-90 and SKOV3 human ovarian cancer cell lines were selected as cell models in vitro and in vivo. The results showed that downregulation of CTSL significantly inhibits the proliferative and invasive capability of SKOV3 cells, and that upregulation of CTSL in OV-90 cells leads to opposite effects. Compared with parental OC cells, cells in which CTSL was silenced exhibited a reduced capacity to develop into tumors in nude mice, while the growth of tumor xenografts derived from these cells was markedly constrained. In conclusion, the results suggested that CTSL contributes to the proliferation and metastasis of OC, and that CTSL may be a novel molecular target for OC treatment.

A series of PEGylated poly(amine-co-ester) terpolymers were successfully synthesized in one step via lipase-catalyzed copolymerization of ω-pentadecalactone (PDL), diethyl sebacate (DES), and N-methyldiethanolamine (MDEA) comonomers in the presence of poly(ethylene glycol) methyl ether as a chain-terminating agent. The resultant amphiphilic poly(ethylene glycol)-poly(PDL-co-MDEA-co-sebacate) (PEG-PPMS) block copolymers consisted of hydrophilic PEG chain segments and hydrophobic random PPMS chain segments, which self-assembled in aqueous medium to form stable, nanosized micelles at physiological pH of 7.4. Upon decreasing the medium pH from 7.4 to 5.0, the copolymer micelles swell significantly due to protonation of the amino groups in the micelle PPMS cores. Correspondingly, docetaxel (DTX)-encapsulated PEG2K-PPMS copolymer micelles showed gradual sustained drug release at pH of 7.4, but remarkably accelerated DTX release at acidic pH of 5.0. The drug-loaded micelle particles were readily internalized by SK-BR-3 cancer cells and, compared to free DTX drug, DTX-loaded micelles of the copolymers with optimal compositions exhibited enhanced potency against the cells. Biodegradable PEG-PPMS copolymer micelles represent a new type of promising, pH-responsive nanocarriers for anticancer drug delivery, and the drug release rate from the micelles can be systematically controlled by both pH and the copolymer composition.

We evaluated whether DNA repair gene polymorphisms had an effect on clinical outcomes in metastatic/recurrent nasopharyngeal carcinoma (NPC) patients treated with cisplatin-based chemotherapy.Clinical data of 101 patients with metastatic/recurrent NPC between 2004 and 2011 were reviewed. Five potentially functional polymorphisms (ERCC1 Asn118Asn, ERCC1 C8092A, XPD Lys751Gln, XRCC1 Arg399Gln and XRCC1 Arg280His) were genotyped using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.The ERCC1 C8092A polymorphism was an independent predictor of PFS in Chinese NPC patients treated with cisplatin-based chemotherapy. Compared to the patients carrying the C/C genotype, the patients with the C/A or A/A genotype had an increased risk of disease progression on cisplatin-based chemotherapy (7.9 vs. 9.3 months; HR 1.61; 95 % CI 1.08-2.61; p = 0.047). However, no association between the other polymorphisms, response rate, disease progression and survival was detected in metastatic/recurrent NPC patients.The ERCC1 C8092A polymorphism might be a useful predictive marker in metastatic/recurrent NPC patients treated with cisplatin-based chemotherapy. However, a large-scale prospective study is warranted to validate our findings.

3580 Background: Colorectal cancer (CRC) is one of the most common malignant tumors. All advanced CRC will progress after first-line treatment. Therefore, it is emergent to seek an efficient and lo...

Sir, We read with great interests the retrospective case–control study by Wei et al (2015). As the authors Wei et al introduced that epidemiological study is the first one, which found a potential association between hepatitis B virus (HBV) serology and gastric cancer risk. This main finding is indeed surprising to readers. On the basis of the literature from Chinese CNKI journal database, the prevalence of HBV DNA in gastric cancer tissues is only 0–3% by PCR test. Therefore, to evidence the causality between HBV infection and gastric cancer risk, a qualified study with adequate statistical power requires a dramatically larger scale of sample size than that of the study by Wei et al (2015). In particular, direct detection of HBV DNA in gastric cancer cells by in situ hybridisation is the most convincing evidence to confirm that association. As known, WHO has defined Helicobacter pylori as a class I human carcinogen for gastric cancer development (Fock et al, 2013). Besides, Epstein–Barr virus infection is also found to be associated with around 10% of gastric cancer (Murphy et al, 2009). However, in the study by Wei et al (2015), these two critical confounders were not considered in the logistic regression models. The investigated population in the study by Wei et al (2015) is also collected from an endemic region (Guangzhou Province) of both Helicobacter pylori and Epstein–Barr virus infections in mainland China (Wang and Chen, 2014). Therefore, the results are unable to rule out the confounding effects from these two kinds of infections. Probably, the association between HBV infection and gastric cancer risk might be biased by chance, imbalance of prevalence of H. pylori and/or Epstein–Barr virus infection in stomach, or potentially indirect linkage between HBV and those two pathogens. Without the adjustment for those two co-infections, the results may have a risk of misleading readers. Thus, we would like to underline these pitfalls behind interpreting the results to readers and practitioners. Critically, the epidemiological study Wei et al provides some information about the potential association between HBV infection and gastric cancer risk, but the obvious defect in covariate modelling makes the results still far from public health policy and clinical practice. Despite of that, the interesting findings also suggest further investigations with large scale and well-adjusted model to rule out potential biases.

Background Currently, many studies suggest that cancer stem cells (CSCs) are responsible for tumor initiation, tumorigenesis, metastasis and recurrence. CSCs have been identified from various human and murine tumors. The identification of CSCs allows us to develop strategies to target the CSCs. Methods and Results In this study, we used ALDEFLUOR as a single marker to isolate the CSCs from the human lung cancer cell line H460. We then characterized the CSCs by testing their sphere formation ability and tumorigenicity. Furthermore, we used CSC lysate-pulsed dendritic cells to stimulate CD8+T cells as a treatment strategy. Our study demonstrated that ALDEFLUOR could be used as a single marker to identify CSCs from the human lung cancer cell line H460. The ALDHhigh cells could form more spheres and were more tumorigenic than the ALDHlow cells. Further study demonstrated that ALDHhigh-CD8+T cells conferred more significant antitumor effects, resulting in the inhibition of tumor growth and prolonged survival. And the ALDHhigh-CD8+T cells-mediated anti-tumor immunity might be due to the directly targeting against ALDHhigh cancer stem cells (CSCs). Conclusions This study shows that ALDHhigh-CD8+T cells mediate anti-tumor immunity by selectively targeting cancer stem cells, which result in inhibiting tumor growth and prolonging the survival of tumor-bearing mice, which provides a new strategy using ALDHhigh-CD8+T cells to treat tumors.

e15047 Background: Several large studies have reported an extremely low incidence of MET gene amplification (GA) in patients with radically resected gastric cancer. The aim of our study was to evaluate the prevalence and prognostic role of MET GA and protein expression in recurrent/metastatic gastric cancer patients who received chemotherapy. Methods: This retrospective study included 232 recurrent/metastatic gastric cancer patients. MET GA and protein expression were evaluated by fluorescent in-situ hybridization (FISH) and immunohistochemistry (IHC), respectively.Results: MET GA and strong protein expression were observed in 8.3% and 9.6% of patients, respectively. MET IHC 3+ was significantly correlated with GA. Patients with MET GA more frequently had a poor performance status (P < 0.001) and poorly differentiate tumors (P = 0.015) than those without MET GA. Both MET GA and IHC 3+ expression were associated with substantially shorter median progression free survival (PFS) and overall survival (OS). The median OS and PFS for patients with MET GA positive vs. MET GA negative were 5.7 vs. 15.5 months (P < 0.001) and 3.6 vs. 6.9 months (P < 0.001), respectively.The median OS and PFS for patients with MET IHC 3+ vs. IHC (0 to 2+) were 6.3 vs. 15.1 months (P < 0.001) and 3.6 vs. 7.0 months (P < 0.001), respectively. Conclusions: In recurrent/metastatic gastric cancer, MET amplification and strong protein expression are not rare and significantly associated with unfavorable clinical outcomes.

4107 Background: To explore the association between serum human epidermal growth factor receptor-2 (HER2) extracellular domain (ECD) and tissue HER2 status, their relationship with clinicopathological parameters and impact on overall survival (OS) in metastatic gastric or gastro-oesophageal junction (GEJ) adenocarcinoma. Methods: A total of 219 histologically confirmed inoperable locally advanced, recurrent, or metastatic gastric or GEJ adenocarcinoma were included. Serum HER2 ECD was measured by chemiluminescent assay. Tissue HER2 status was accessed by fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) assay. Results: The median serum ECD level was 9.3 ng/ml (range 3.0 to >350). Tissue HER2 status was positive (IHC3+ or 2+ with FISH amplification) in 37 patients (16.9%) and negative in 182 patients (83.1%). Statistically significant associations were found between serum HER2 ECD level and HER2 status assessed by IHC and FISH. The ROC-analysis suggested the cutoff of 16.35 ng/ml (24 of 219 patients had HER2 ECD >16.35 ng/ml ) could produce a sensitivity of 51.4% and a specificity of 97.3% to predict tissue HER2 status. If the cutoff value was increaseed to 22 ng/ml, then all 12 patients with serum HER2 ECD >22 ng/ml were HER 2 positive in primary tumor, corresponding to a specificity of 100% and a sensitivity of 32.4%. High serum HER2 ECD levels were strongly associated with liver metastasis (P < 0.001), the intestinal histologic type (Lauren's classification) (P =0.003), large number of metastais (>2) (P=0.012) and increased LDH level (P < 0.001) . High serum HER2 ECD levels were more common in GEJ adenocarcinoma although the difference had no stastical significance. HER2 ECD levels did not show a significant impact on OS. Conclusions: A significant association was observed between serum HER2 ECD levels and tissue HER2 status in metastasis gastric or GEJ adenocarcinoma. The high specificity of serum HER2 ECD assay to predict tissue HER2 status suggests its potential use as a surrogate marker of the HER2 status in gastric cancer.