Inhibition of b16 melanoma metastasis by administration of g(m3)- or gg3- liposomes - blocking adhesion of melanoma-cells to endothelial-cells (antiadhesion therapy) via inhibition of g(m3)-gg3cer or g(m3)-laccer interaction

Tumor cell (TC) metastasis is initiated by selective adhesion of TCs to target structures such as basement membrane and endotheliaI cells (ECs), followed by transvascular migration of TCs. Variants of murine B16 melanoma having different metastatic potentials (in the order BL6 greater than or equal to F10>F1>WA4) have been characterized by the same decreasing order of cell surface G(M3) expression level, relative adhesiveness to nonactivated ECs, and relative degree of G(M3)-dependent adhesion to Gg3Cer- or LacCer-coated plates. Degree of integrin-dependent cell adhesion and adhesion to IL-1-activated ECs was similar for BL6, F10, and F1. These results suggest that metastatic potential of these B16 variants is closely dependent on relative adhesion to nonactivated ECs, which is based on G(M3)-Gg3Cer or G(M3)-LacCer interaction. This possibility has been supported by further studies showing that blocking of G(M3)-dependent melanoma adhesion by mu M-order concentrations of G(M3) or Gg3Cer in liposomes, or by sialidase treatment of melanoma cells, strongly inhibited BL6 metastasis to lung. Paragloboside or sialylparagloboside did not affect G(M3)-dependent BL6 cell adhesion and did not inhibit metastasis. Spontaneous metastasis from subcutaneously-grown tumors was significantly reduced if G(M3)- or Gg3Cer-liposomes were intravenously injected during tumor growth. Thus, blocking of TC adhesion to nonactivated ECs based on carbohydrate-carbohydrate interaction may provide effective anti-adhesion therapy against tumor progression, in analogy to the antimetastatic effect produced by blocking of integrin-dependent cell adhesion.

SU-E-J-68: An Optical Image Guidance System: To Detect Arbitrarily Attached Markers Behind a Full Facemask

PURPOSE

We developed an optical image guidance system to manage patient's inter-fractional set-up errors by tracking external markers at the specific positions (e.g., nose tip) behind a full facemask. However, a problem associated with the reproducibility of the marker positions during the entire course of treatments still remains. In order to remove this disadvantage, we applied the arbitrary-point-to-plane registration method to our existing system.

METHODS

Infra-red (IR) reflecting markers were attached on arbitrary positions of the head phantom's face and then the phantom was immobilized by a full face thermoplastic mask. 3D coordinates of the IR markers behind the full facemask were reconstructed by the calibrated stereo camera system using the direct linear transform (DLT) algorithm. In order to match arbitrarily attached markers with a planning CT image, rough positions of three markers were manually defined (rough registration) and then the coordinates of all markers were determined through the point-to-plane registration using the contractive projection point (CPP) algorithm (fine registration). In addition, the marker registration error in 6 DOF was calculated. In order to validate accuracy of the system, the phantom was intentionally moved according to 10 sets of known translation parameters.

RESULTS

A mean target registration error (TRE) determined by the experiments for arbitrarily attached markers was 1.24 ± 0.32 mm. The fine registration following the rough registration allowed fast and robust registrations.

CONCLUSIONS

The proposed solution for arbitrarily attached markers behind a full facemask enables us to avoid any daily errors in attaching the external markers at the specific positions. This work was supported in part by the SNU interdisciplinary project (2009-2010) and the SNU Brain Fusion project (2010-2011).

SU-E-T-21: Modeling a MLC Scatter Source for In-Air Output Factors

PURPOSE

Scattered radiation from multi-leaf collimators (MLCs) is no longer negligible for calculating in-air output ratio, Sc for small and irregular fields often used in intensity-modulated radiation therapy (IMRT). An extra-focal source model for scattered radiation from MLCs, namely MLC scatter source, has been developed to improve the accuracy of the Sc calculation.

METHODS

A conventional dual-source model was made by using Sc data that were measured for collimator-defined fields of Varian Clinac IX linear accelerator. Then, an MLC scatter source at the center of the MLC position of the linear accelerator was assumed in the model. The MLC scatter source model consisted of two Gaussian functions of which parameters were iteratively optimized against the Sc data measured for different MLC fields with fixed collimator sizes. To evaluate the effectiveness of the developed source model, measurements were made for various MLC-defined irregular or square fields. The calculated Sc data by using (1) the developed source model and (2) the conventional dual source model were compared with the measured data.

RESULTS

The mean discrepancy between the measured Sc and calculated Sc from the developed source model was 0.08+-0.28%, while one from the conventional source model was 0.44+-0.39%.

CONCLUSIONS

The developed MLC scatter source model in conjunction with the dual source model could improve the accuracy of the Sc calculation in IMRT fields.

Demonstration of a stable ultrafast laser based on a nonlinear microcavity

Ultrashort pulsed lasers, operating through the phenomenon of mode-locking, have had a significant role in many facets of our society for 50 years, for example, in the way we exchange information, measure and diagnose diseases, process materials, and in many other applications. Recently, high-quality resonators have been exploited to demonstrate optical combs. The ability to phase-lock their modes would allow mode-locked lasers to benefit from their high optical spectral quality, helping to realize novel sources such as precision optical clocks for applications in metrology, telecommunication, microchip-computing, and many other areas. Here we demonstrate the first mode-locked laser based on a microcavity resonator. It operates via a new mode-locking method, which we term filter-driven four-wave mixing, and is based on a CMOS-compatible high quality factor microring resonator. It achieves stable self-starting oscillation with negligible amplitude noise at ultrahigh repetition rates, and spectral linewidths well below 130  kHz.

Three-dimensional multipotent progenitor cell aggregates for expansion, osteogenic differentiation and 'in vivo' tracing with AAV vector serotype 6

Multipotent adult progenitor cells (MAPC) are bone marrow-derived stem cells with a high growth rate suitable for therapeutical applications as three-dimensional (3D) aggregates. Combined applications of osteogenically differentiated MAPC (OD-MAPC) aggregates and adeno-associated viral vectors (AAV) in bone bioengineering are still deferred until information regarding expansion technologies, osteogenic potential, and AAV cytotoxicity and transduction efficiency is better understood. In this study, we tested whether self-complementary AAV (scAAV) can potentially be used as a gene delivery system in a OD-MAPC-based “in vivo” bone formation model in the craniofacial region. Both expansion of rat MAPC (rMAPC) and osteogenic differentiation with dexamethasone were also tested in 3D aggregate culture systems “in vitro” and “vivo”. Rat MAPCs (rMAPCs) grew as undifferentiated aggregates for 4 days with a population doubling time of 37h. After expansion, constant levels of Oct4 transcripts, and Oct4 and CD31 surface markers were observed, which constitute a hallmark of rMAPCs undifferentiated stage. Dexamethasone effectively mediated rMAPC osteogenic differentiation by inducing the formation of a mineralized collagen type I network, and facilitated the activation of the wnt/β-catenin, a crucial pathway in skeletal development. To investigate the genetic modification of rMAPCs grown as 3D aggregates prior to implantation, scAAV serotypes 2, 3, and 6 were evaluated. scAAV6 packaged with the enhanced green fluorescent protein expression cassette efficiently mediated long-term transduction (10 days) “in vitro” and “vivo”. The reporter transduction event allowed the tracing of OD-rMAPC (induced by dexamethasone) aggregates following OD-rMAPC transfer into a macro-porous hydroxyapatite scaffold implanted in a rat calvaria model. Furthermore, the scAAV6-transduced OD-rMAPC generated a bone-like matrix with a collagenous matrix rich in bone specific proteins (osteocalcin and osteopontin) in the scaffold macro-pores 10 days post-implantation. Newly formed bone was also observed in the interface between native bone and scaffold. The collective work supports future bone tissue engineering applications of 3D MAPC cultures for expansion, bone formation, and the ability to genetically alter these cells using scAAV vectors.

Relative bioavailability of two 5-mg montelukast sodium chewable tablets: a single dose, randomized, open-label, 2-period crossover comparison in healthy korean adult male volunteers

Montelukast sodium, cysteinyl leukotriene receptor 1 specific antagonist, has been marketed in Korea for the treatment of bronchial asthma and allergic rhinitis. The aim of this study was to compare the pharmacokinetics and relative bioavailability of a test and reference formulation of montelukast 5-mg chewable tablets in healthy Korean male volunteers to meet KFDA regulatory criteria for marketing of the new generic formulation. This study was designed as a single-dose, 2-treatment, and 2-period crossover trial with 32 healthy volunteers. Each subject was randomly assigned to receive the test (Dong-Kook Montelukast Sodium Chewable Tablet 5 mg®) or reference (Singulair Chewable Tablet 5 mg®) formulation. The tablet was chewed 20 times, and then swallowed with 240 mL of water. Plasma concentrations of montelukast up to 24 h after the dose were determined using a validated UPLC-MS/MS method, and the bioequivalence between the 2 formulations was assessed by statistical analysis of mean ratios of log-transformed AUC0-24 h and Cmax. No period or sequence effects were detected. The AUC0-24 h was 1 835 ng·h/mL for the test formulation, and 1 930 ng·h/mL for the reference formulation. The respective values of AUC0-∞ were 1 917 and 2 015 ng·h/mL. The Cmax of the test and reference products (247 and 283 ng/mL, respectively) reached at 2.25 and 2.72 h, respectively. Then, they gradually decreased with the mean terminal t1/2 of 5.25 and 5.30 h for the test and reference products, respectively. The 90% CIs for the ratio of log-transformed AUC0-24 h and Cmax for the test and reference formulations were 0.92-0.99 and 0.83-0.91, respectively. No adverse events were reported in this study. This single dose study found that the test and reference products met the regulatory criteria for bioequivalence in these fasting healthy Korean male volunteers.

Effect of omega-3 fatty acids on the modification of erythrocyte membrane fatty acid content including oleic acid in peritoneal dialysis patients

Erythrocyte membrane fatty acids (FA), such as oleic acid, are related to acute coronary syndrome. There is no report about the effect of omega-3 FA on oleic acid in peritoneal dialysis (PD) patients. We hypothesized that omega-3 FA can modify erythrocyte membrane FA, including oleic acid, in PD patients. In a double-blind, randomized, placebo-controlled study, 18 patients who were treated with PD for at least 6 months were randomized to treatment for 12 weeks with omega-3 FA or placebo. Erythrocyte membrane FA content was measured by gas chromatography at baseline and after 12 weeks. The erythrocyte membrane content of eicosapentaenoic acid and docosahexaenoic acid was significantly increased and saturated FA and oleic acid were significantly decreased in the omega-3 FA supplementation group after 12 weeks compared to baseline. In conclusion, erythrocyte membrane FA content, including oleic acid, was significantly modified by omega-3 FA supplementation for 12 weeks in PD patients.

P4-10-03: Association between BMI, Physical Activity and Breast Cancer Histologic Types

Background: Previous research indicates that certain breast cancer risk factor associations vary by histologic tumor type. However, most studies have been too small to examine risk factors for uncommon histologic types. We examined the association between body mass index (BMI), physical activity, and the relative risk of breast cancer histologic types in a large prospective cohort study to determine whether associations for these risk factors varied by histology.

Methods: This analysis included women in the NIH-AARP Diet and Health Cohort Study who were 50 to 71 years old, postmenopausal at baseline, and not previously diagnosed with cancer (N=190,348). The study cohort was established in 1995–1996 when participants completed a baseline questionnaire regarding health and nutritional information. BMI (kg/m2) was calculated from self-reported height and weight. Daily routine physical activity at work or home was derived from a question asking women what best described their daily routine at work, or throughout the day if they did not work at a job. Choices were mostly sitting with little walking, sitting with a fair amount of walking, mostly standing or walking, light lifting or climbing stairs/hills, or heavy work/carrying heavy loads. Cancer diagnosis and histology were obtained from state cancer registries. This analysis includes participant follow-up through December 31, 2006. After a median 11.2 years of follow-up, 7,631 invasive breast cancers were diagnosed: 5,278 ductal, 831 lobular, 640 mixed ductal-lobular, 214 mucinous, 132 tubular, and 536 other types. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression.

Results: Compared to women with a BMI of 18.5 to 24.9, obese women had increased risks of ductal (HR and 95% CI for BMI 30 to 34.9: 1.24, 1.14 — 1.36; BMI ≥ 35: 1.45, 1.30 — 1.62) and mucinous (HR and 95% CI for BMI 30 to 34.9: 1.58, 1.04 — 2.39; BMI ≥ 35: 1.93, 1.16 — 3.20) cancers. For both histologic types, the relative risk increased with increasing BMI (P-trend: ductal P<0.01; mucinous P<0.01). Women whose daily activity at work or home consisted of mostly standing or walking were at reduced risk of ductal and mixed ductal-lobular cancers compared with women who reported mostly sitting (HR and 95% CI for ductal: 0.86, 77 — 0.96; mixed-ductal lobular: 0.64, 0.48 — 0.86). Women who performed heavy work or carried heavy loads were also at a decreased risk of ductal and mixed ductal-lobular cancers compared with women reporting mostly sitting (HR and 95% CI for ductal: 0.68, 0.52−0.91; mixed ductal-lobular: 0.18, 0.04−0.72), though there were few mixed ductal-lobular cases who reported heavy activity.

Conclusions: High BMI was associated with increased risk of ductal and mucinous breast cancers. Women who spent their daily routine activity mostly standing or walking or doing heavy work had a reduced risk of ductal and mixed ductal-lobular cancers. These differences suggest that associations of BMI and physical activity vary by breast cancer histologic type in postmenopausal women and may have different roles in the etiology of these cancers.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-10-03.

Soluble human leukocyte antigen-G expression in hepatitis B virus infection and hepatocellular carcinoma

We investigated soluble human leukocyte antigen-G (sHLA-G) expression according to the phases of hepatitis B virus (HBV) infections and hepatocellular carcinoma (HCC). A total of 267 sera from anti-HBs positive healthy individuals (n = 50), chronic HBV carriers (n = 45), as well as patients with active hepatitis B (n = 46), liver cirrhosis (LC, n = 46) and early stage HCC (n = 80) were collected and assayed for sHLA-G. Relationships between sHLA-G levels and clinicopathologic parameters including HCC stages, differentiation grades, and levels of aminotransferases, HBV DNA and alpha-fetoprotein (AFP) were assessed. Concentrations of sHLA-G were higher in the active hepatitis B and HCC groups (median sHLA-G 53.7 and 178.8 U/ml, respectively) in comparison to other groups (P < 0.05), and there were no significant differences among sHLA-G levels of the anti-HBs positive, chronic HBV carrier and LC groups. Serum sHLA-G concentrations were not shown to be associated with clinicopathologic indices including the levels of aminotransferases, AFP, anti-HBs titer, HBV DNA, as well as HCC stages, numbers of tumor nodules, pathologic grades and presence of vessel invasion. The receiver-operating characteristic area under the curve (AUC) value of sHLA-G for differentiating HCC from LC was 0.98, which was greater than that of AFP (0.78) (P < 0.0001), and sensitivity and specificity of sHLA-G were, respectively, 90.0% and 95.7% for HCC when applying a cutoff level of 97.3 U/ml. Serum sHLA-G levels could be used as a diagnostic marker for HCC. Although sHLA-G levels did not reflect the severity of HBV infections and HCC, they were related with phases of the disease.

Allele frequencies of human leukocyte antigen-G in a Korean population

The human leukocyte antigen (HLA)-G is a nonclassical major histocompatibility complex class I molecule with relatively limited polymorphism. The differences in allele frequency according to ethnicity and country have not been studied enough, so far. Therefore, fundamental data including allele frequencies and polymorphism are needed for studies on immunological function of HLA-G in each population. We investigated allele frequencies and 14-bp polymorphism of the HLA-G in Koreans. HLA-G alleles and 14-bp polymorphisms were determined by sequence-based typing analysis of exons 2-4 and polymerase chain reaction of exon 8 in 200 unrelated individuals. Genotyping analysis identified eight different HLA-G alleles, which indicates that the Korean population presents limited HLA-G allelic polymorphism. HLA-G*01:01:01:01 and G*01:04:01 were frequent alleles (42.5% and 34.0%), and allelic frequencies were similar to those of other Asian populations. The 14-bp deletion alleles are higher (78%) in Koreans, although the frequencies of the 14-bp insertion/deletion polymorphism have been known to be nearly equal in many Caucasian populations. HLA-G*01:01:08 was reported strong linkage disequilibrium with the 14-bp deletion in a previous report; the same allele was accompanied with 14-bp insertion in our study. There are a few studies investigating allele frequencies, and most of them were studied before high-resolution method era. This is the first study regarding HLA-G genotypes in Korean, which were identified by high-resolution method. From this study, we identified HLA-G frequencies of a Korean population and expect this study could help further investigations for immunological and clinical implications of HLA-G.

Hormonal and reproductive factors and risk of postmenopausal thyroid cancer in the NIH-AARP Diet and Health Study

BACKGROUND

Worldwide, thyroid cancer incidence rates are higher among women than men. While this suggests a possible etiologic role of female sex hormones, clear associations between hormonal and reproductive factors and thyroid cancer have not been observed. However, few large prospective studies have been conducted.

METHODS

Hazard ratios (HRs) and 95% confidence intervals (CIs) for hormonal and reproductive factors and incident thyroid cancer were estimated using Cox regression methods in the prospective US NIH-AARP Diet and Health Study. Between 1995 and 2006, 312 first primary incident thyroid cancers were diagnosed among 187,865 postmenopausal women ages 50-71 at baseline.

RESULTS

Thyroid cancer was not associated with ages at menarche or menopause, menopause type, or parity. Oral contraceptive use for ≥10 years (vs. never use) was inversely associated with thyroid cancer risk (HR, 0.48; 95%CI, 0.28-0.84; P(trend)=0.01). Women who reported current menopausal hormone therapy at baseline had an increased thyroid cancer risk vs. never users (HR 1.38; 95% CI: 1.07-1.79) but there was no trend with increasing duration of use. Women with benign breast disease (BBD) had a significantly higher thyroid cancer risk vs. women without BBD (HR, 1.47; 95% CI, 1.09-1.99).

CONCLUSIONS

Our results do not support a strong role for female hormonal and reproductive factors including ages at menarche and menopause, type of menopause or parity, in thyroid cancer etiology among postmenopausal women. Compared with previous studies, no clear patterns emerge for exogenous hormone use but further analysis in large, prospective populations may be informative. The HR for BBD is consistent with the one previous prospective analysis that examined this association.

Adjuvant capecitabine and oxaliplatin for gastric cancer: Results of the phase III CLASSIC trial

LBA4002

Background: Surgical resection is a recommended treatment for operable gastric cancer (GC) in general, despite high recurrence rates (40%–80%). Adjuvant chemotherapy aims to reduce recurrences; however, there is currently no universally accepted adjuvant regimen for GC. Methods: CLASSIC is a randomized, open-label, multicenter, international (South Korea, China, and Taiwan) study of XELOX (capecitabine 1000mg/m2 bid, d1–14, q3w and oxaliplatin 130mg/m2, d1, q3w x 8 cycles) vs observation, following D2 gastrectomy. Eligible patients were chemotherapy- and radiotherapy-naive, with stage II (T2N1, T1N2, T3N0), IIIa (T3N1, T2N2, T4N0), or IIIb (T3N2) GC resected within 6 weeks prior to randomization. The primary endpoint is 3-year disease-free survival (DFS). A sample size of 512 patients per arm was planned to observe the 385 DFS events required to provide 80% power at a 5% significance level for the hypothesized treatment effect (hazard ratio [HR] 0.75). The Independent Data Monitoring Committee recommended full evaluation and reporting of results following a positive pre-planned interim analysis at 266 events. Results: The XELOX and observation arms (ITT populations of 520 and 515 patients, respectively) were well balanced for baseline characteristics. The median duration of follow-up was 34.4 (16–51) months. XELOX-related grade 3/4 adverse events (AEs) occurred in 244/496 patients (49%) of the safety population. Neutropenia was the only AE observed in >10% of patients (21%, n=106/496). Serious XELOX-related grade 3/4 AEs occurred in 34/496 patients (7%). There were 62/496 (13%) and 80/476 (17%) deaths on study in the safety populations of XELOX and observation arms, respectively, mostly due to disease progression. Efficacy results in the ITT population are summarized below. Conclusions: This study demonstrates the superior efficacy of adjuvant XELOX vs observation alone following D2 gastrectomy. Although OS data are still immature, there is a trend towards superiority of XELOX. These data support the use of adjuvant XELOX for GC.

[Table: see text]

Phase III study of gemcitabine/oxaliplatin (GEMOX) with or without erlotinib in unresectable, metastatic biliary tract carcinoma

LBA4032

Background: Currently, there is no standard regimen for palliative chemotherapy in metastatic, unresectable biliary tract cancer (BTC). A phase II trial of erlotinib monotherapy showed a promising anti-tumor activity in BTC with tolerable toxicity. Additionally, gemcitabine + erlotinib demonstrated superior efficacy when compared to gemcitabine alone in pancreatic cancer. Hence, we conducted a phase III trial to compare between GEMOX vs GEMOX+erlotinib (Tarceva [T]) (GEMOX/T) as first-line chemotherapy in unresectable, metastatic BTC. Methods: Eligible patients were as follows: histologically confirmed adenocarcinoma of biliary tract (CCC), ampulla of vater (AOV) or gall bladder (GB); unresectable or metastatic; ECOG performance status of 0~2; adequate marrow, hepatic, renal and cardiac functions; no prior chemotherapy. The primary endpoint was progression free survival (PFS). The study regimen was gemcitabine 1,000mg/m2, oxaliplatin 100mg/m2, erlotinib 100mg qd daily q 2 weeks. Results: From February 2009 to August 2010, 268 pts were randomized, 133 patients to GEMOX arm and 135 patients to GEMOX/T arm. Patient characteristics: median age 61 yrs (range 30-82); male (63.4%); CCC (n=180, 67.2%), GB (n=82, 30.6%), and AOV (n=6, 2.2%). With a median follow-up of 13.9 months (range, 6.7 – 25.0), median PFS was 5.8 months (95% CI, 4.6 - 7.0) in GEMOX/T arm and 4.2 months (95% CI, 2.7 - 5.7) in GEMOX arm (P=0.080). In subgroup analysis (CCC, n=180), however, median PFS was significantly longer in GEMOX/T arm (5.9 months) when compared with GEMOX arm (3.0 months, P=0.049). The overall response rate was significantly higher in the GEMOX/T arm when compared with GEMOX arm. There was no significant difference in overall survival between the two arms (GEMOX/T: 9.5 months, 95% CI, 7.6 – 11.4; GEMOX: 9.5 months, 95% CI, 7.5 – 11.5; P=0.611). The EGFR mutation testing results in correlation to responsiveness to erlotinib will be presented at the meeting. Conclusions: This phase III represents the first multicenter, randomized trial to compare GEMOX vs GEMOX/T in unresectable, metastatic BTC. Although PFS was not prolonged in GEMOX/T, there was a significant benefit in terms of PFS in GEMOX/T arm for CCC patients.

The natural history of acute hepatitis C: clinical presentation, laboratory findings and treatment outcomes

BACKGROUND

Acute hepatitis C has variable modes of presentation and frequently results in chronic infection. Its optimal management has yet to be defined.

AIM

To establish natural history and complications of treatment of acute hepatitis C.

METHODS

Data from all patients presenting with acute hepatitis C to the National Institutes of Health between 1994 and 2007 were reviewed.

RESULTS

Twenty-five patients were identified. Symptoms were reported by 80% and jaundice by 40%. Aminotransferase levels and hepatitis C virus (HCV) RNA levels fluctuated greatly; 18% of patients were intermittently negative for HCV RNA. Five patients recovered spontaneously whereas 20 developed chronicity or received interferon-based therapy during the acute phase. Among 15 patients treated during the acute phase with peginterferon with or without ribavirin for 24 weeks, all became HCV RNA negative within 4-8 weeks, and all except two (HIV-positive) achieved a sustained virological response. Side effects (particularly psychiatric) were common and limited treatment in 30%.

CONCLUSIONS

Among 25 patients with acute HCV infection, fluctuating illness was common and spontaneous recovery occurred in only 20%. Anti-viral treatment with a 24-week course of peginterferon and ribavirin was highly effective, but marked by frequent and severe side effects.

The natural history of acute hepatitis C: clinical presentation, laboratory findings and treatment outcomes

BACKGROUND

Acute hepatitis C has variable modes of presentation and frequently results in chronic infection. Its optimal management has yet to be defined.

AIM

To establish natural history and complications of treatment of acute hepatitis C.

METHODS

Data from all patients presenting with acute hepatitis C to the National Institutes of Health between 1994 and 2007 were reviewed.

RESULTS

Twenty-five patients were identified. Symptoms were reported by 80% and jaundice by 40%. Aminotransferase levels and hepatitis C virus (HCV) RNA levels fluctuated greatly; 18% of patients were intermittently negative for HCV RNA. Five patients recovered spontaneously whereas 20 developed chronicity or received interferon-based therapy during the acute phase. Among 15 patients treated during the acute phase with peginterferon with or without ribavirin for 24 weeks, all became HCV RNA negative within 4-8 weeks, and all except two (HIV-positive) achieved a sustained virological response. Side effects (particularly psychiatric) were common and limited treatment in 30%.

CONCLUSIONS

Among 25 patients with acute HCV infection, fluctuating illness was common and spontaneous recovery occurred in only 20%. Anti-viral treatment with a 24-week course of peginterferon and ribavirin was highly effective, but marked by frequent and severe side effects.

Updated survival results of the randomized phase II study comparing cisplatin/capecitabine (CX) with epirubicin plus CX (ECX) in advanced gastric cancer (AGC)

46

Background: We previously reported results of a randomized study showing that CX is equally active to ECX in terms of progression-free survival (PFS) (Yun et al. Eur J Cancer. 2010). Here we report updated overall survival (OS) results with an additional 12 months' follow-up.

Methods: Ninety-one chemotherapy-naïve patients with histologically-confirmed, measurable AGC were randomized to receive CX (cisplatin 75 mg/m2 iv on day 1 and capecitabine 1,000 mg/m2 bid po on days 1-14, n=45) or ECX (epirubicin 50 mg/m2 plus CX, n=44) every 3 weeks. After CX or ECX had failed, second-line chemotherapy (SLC) was recommended for all patients if their performance status was preserved.

Results: Treatment duration was similar for both arms (4.4 for CX v 4.2 months for ECX). There was no relevant difference in the occurrence of overall grade 3 or 4 toxicities between the CX and ECX arms (80% v 78%, respectively; p=0.516). However, none in the CX and 12% in the ECX arm discontinued treatment because of toxicity. There were no significant differences in therapeutic efficacy between CX and ECX with respect to the response rate (38% v 37%, respectively), PFS (6.4 v 6.5 months), as well as OS (12.7 v 13.8 months; p=0.51). After failure, 60% of patients (26 CX and 28 ECX patients) received SLC. However, OS was not differed whether a patient was treated with SLC or not (13.1 v 11.2 months; p=0.94).

Conclusions: The present analysis confirms previous findings that both CX and ECX appear to be comparatively active as first-line chemotherapy for AGC. Furthermore, the role of SLC in AGC warrants further evaluation.

No significant financial relationships to disclose.

Phase I dose-finding study of epirubicin, oxaliplatin, and S-1 (EOS) in patients with previously untreated advanced gastric cancer (AGC)

123

Background: To determine the recommended dose (RD) and dose-limiting toxicity (DLT) of EOS combination in patients with previously untreated AGC.

Methods: Previously untreated patients with histologically proven metastatic or recurrent AGC and ECOG performance status 0-2 were enrolled. Fixed dose of epirubicin (50 mg/m2) and oxaliplatin (130 mg/m2) was administered i.v. on day 1. The dose of S-1 was escalated as following schedule: Level I: 30 mg/m2, Level II: 40 mg/m2, Level III: 45 mg/m2, Level IV: 50 mg/m2. S-1 was administered orally twice a day on days 1-14. Each cycle was repeated every 21 days. DLTs were evaluated during the first two cycles of treatment.

Results: Nineteen patients were enrolled: 13 patients in dose-escalation phase and 6 patients in the extension at the RD. Median age was 53 years (range, 40-71 years). At dose level II, 1 DLT (grade 4 neutropenia lasting more than 5 days) was found among 6 patients while at dose level III, 2 DLTs (grade 3 diarrhea and nausea) were observed among 4 patients. Therefore, the dose level II was determined as RD. Cumulative (all cycles) grade 3/4 toxicity included neuropenia (58%), leucopenia (32%), thrombocytopenia (11%), diarrhea (11%), and nausea (5%). Of 13 patients with measurable lesions, 8 achieved partial response and 3 showed stable diseases, and the objective response rate was 62% (95% CI, 36-88%). The median progression-free survival was 6.5 months (95% CI, 4.7-8.2 months).

Conclusions: The RD of the EOS regimen in patients with previously untreated AGC was epirubicin 50 mg/m2 and oxaliplatin 130 mg/m2 on day 1 and S-1 40 mg/m2 twice a day on days 1-14 of every 21-day cycle. This regimen seems to have promising preliminary activity.

No significant financial relationships to disclose.

A retrospective study of first-line combination chemotherapy in advanced colorectal cancer: A Korean single-center experience

623

Background: Fluoropyrimidine-based combination chemotherapy, in combination with either oxaliplatin or irinotecan, have demonstrated efficacy and tolerability against advanced colorectal cancer (ACC).

Methods: Between Jan 2006 and Dec 2007, 478 ACC patients were treated with combination chemotherapy in first-line setting: 5-fluorouracil, folinic acid plus oxaliplatin (FOLFOX, n=172), 5-fluorouracil, folinic acid plus irinotecan (FOLFIRI, n=95), capecitabine plus oxaliplatin (XELOX, n=155), and capecitabine plus irinotecan (XELIRI, n=56). FOLFOX and FOLFIRI were repeated every 2 weeks, whereas XELOX and XELIRI were repeated every 3 weeks until disease progression or unacceptable toxicity occurred or until a patient chose to discontinue treatment.

Results: The median age was 58 years (range, 19-84 years) and the median chemotherapy duration for FOLFOX, FOLFIRI, XELOX and XELIRI were 4.9, 4.5, 5.7 and 5.4 months, respectively. Combination chemotherapy regimens were generally well tolerated. The estimated median PFS for all patients was 6.8 months (95% confidence interval, 6.3-7.3 months). No statistically significant difference in PFS was found each regimen used as first-line chemotherapy. Sixty-percent (n=290) of patients received second or further lines of therapy after failure.

Conclusions: Fluoropyrimidine-based combination chemotherapy regimens appear to be equally active and tolerable as first-line therapy for ACC.

No significant financial relationships to disclose.

A single-arm, phase II feasibility study of neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy in potentially resectable gastric or gastroesophageal junction adenocarcinoma

96

Background: The aim of this study was to evaluate feasibility and safety of neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy in patients with potentially resectable adenocarcinoma of stomach or gastroesophageal junction.

Methods: Forty-one patients with clinical stage T3-4N0M0 or T2-4N+M0 determined by CT, endoscopic ultrasonography, and laparoscopy were enrolled between DEC 2008 and MAR 2010. Gastrectomy with D2 lymph node dissection was conducted after 3 cycles of DOS chemotherapy. DOS chemotherapy consists of docetaxel 50 mg/m2 iv (day1), oxaliplatin 100 mg/m2 iv (day1), and S-1 40 mg/m2 po bid (days1-14) at 3 weeks interval. After curative gastrectomy, the patients were given 1 year of adjuvant chemotherapy with S-1 (40 mg/m2 D1-28, every 6 weeks).

Results: All patients finished the planned neoadjuvant chemotherapy. Twenty-three (56%) patients achieved a partial response, and the remaining 18 patients had stable disease by CT scan after 3 cycles of DOS chemotherapy. No disease progression was observed during the neoadjuvant chemotherapy. A median 4.7 weeks (range, 4.0-7.6) after the start of the 3rd cycle of DOS chemotherapy, 39 (95%) patients underwent R0 resection with no pathologic residual disease in 4 (10%) patients. Hematologic toxicities were common including grade 4 neutropenia (32%), grade 3 thrombocytopenia (17%), and febrile neutropenia (10%). However, hematologic toxicities were generally transient and manageable. There were no grade 3 or 4 non-hematologic toxicities with frequency > 5% of patients. With all toxicities taken together, 21 (51%) patients experienced grade 3 or 4 toxicities (except grade 3 neutropenia). There was no treatment-related death, and surgical complications included only mild wound problem in 4 (10%) patients.

Conclusions: In this study, neoadjuvant DOS chemotherapy could induce a sufficient down-staging and R0 resection of locally advanced gastric cancer with mild and manageable toxicities. A phase III randomized trial is planned for evaluating the benefit of neoadjuvant DOS chemotherapy in patients with locally advanced gastric cancer.

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