STING activation reprograms tumor vasculatures and synergizes with VEGFR2 blockade

The stimulator of interferon genes (STING) signaling pathway is a critical link between innate and adaptive immunity, and induces anti-tumor immune responses. STING is expressed in vasculatures, but its role in tumor angiogenesis has not been elucidated. Here we investigated STING-induced tumor vascular remodeling and the potential of STING-based combination immunotherapy. Endothelial STING expression was correlated with enhanced T-cell infiltration and prolonged survival in human colon and breast cancer. Intratumoral STING activation with STING agonists (cGAMP or RR-CDA) normalized tumor vasculatures in implanted and spontaneous cancers, but not in STING-deficient mice. These were mediated by upregulation of type I/II interferon genes and vascular stabilizing genes (e.g., Angpt1, Pdgfrb, and Col4a). STING in non-hematopoietic cells is as important as STING in hematopoietic cells to induce a maximal therapeutic efficacy of exogenous STING agonist. Vascular normalizing effects of STING agonists were dependent on type I interferon signaling and CD8+ T cells. Notably, STING-based immunotherapy was maximally effective when combined with VEGFR2 blockade and/or immune checkpoint blockade (αPD-1 or αCTLA-4), leading to complete regression of immunotherapy-resistant tumors. Our data show that intratumoral STING activation can normalize tumor vasculature and the tumor microenvironment, providing a rationale for combining STING-based immunotherapy and anti-angiogenic therapy.

Development and validation of a prognostic model for patients with hepatocellular carcinoma undergoing radiofrequency ablation

Background

There are large variations in prognosis among hepatocellular carcinoma (HCC) patients undergoing radiofrequency ablation (RFA). However, current staging or scoring systems hardly discriminate the outcome of HCC patients treated with RFA.

Methods

A total of 757 treatment‐naïve HCC patients undergoing RFA (derivation cohort) were analyzed to establish a nomogram for disease‐free survival (DFS) based on Cox proportional hazard regression model. Accuracy of the nomogram was assessed and compared with conventional staging or scoring systems. Furthermore, external validation was performed in an independent cohort including 208 patients (validation cohort).

Results

Tumor size, tumor number, alpha‐fetoprotein, prothrombin induced by vitamin K absence‐II, lymphocyte count, albumin, and presence of ascites were adopted to construct the prognostic nomogram from the derivation cohort. Calibration curves to predict probability of DFS at 3 and 5 years after RFA showed good agreements between the nomogram and actual observations. The concordance index of the present nomogram was 0.759 (95% confidence interval 0.728‐0.790), which was superior to those of conventional staging or scoring systems (range 0.505‐0.683, all P < .001). These results were also reproduced in the validation cohort.

Conclusion

Our simple‐to‐use nomogram optimized for treatment‐naïve HCC patients undergoing RFA provided better prognostic performance than conventional staging or scoring systems.

Hyperprogressive disease during PD-1/PD-L1 blockade in patients with non-small-cell lung cancer

BACKGROUND

Immune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade.

PATIENTS AND METHODS

We enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8+ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD.

RESULTS

A total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868-7.440] and overall survival (HR, 5.079; 95% CI, 3.136-8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8+ T lymphocytes, a lower frequency of effector/memory subsets (CCR7-CD45RA- T cells among the total CD8+ T cells) and a higher frequency of severely exhausted populations (TIGIT+ T cells among PD-1+CD8+ T cells) were associated with HPD and inferior survival rate.

CONCLUSION

HPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.

Abstract 683: A machine learning based clinical decision support system (CDSS) for anti-PD-1 therapy using non-invasive blood marker and clinical information for lung cancer patients

Cancer immunotherapy with anti-PD-1 therapy (αPD-1) has greatly improved the survival outcome of patients with non-small cell lung cancer (NSCLC). However, the response rates of αPD-1 are around 20-30% based on clinical trials. The presence of PD-L1, tumor infiltrating lymphocyte or tumor mutation burden may be used as indicators of response, but are still limited to predict αPD-1 response. In this study, we established the machine learning based clinical decision support system (CDSS) to predict the αPD-1 response by comprehensively combining clinical information and blood-based data which are easily assessable in routine practice.We enrolled 126 patients with NSCLC treated with the αPD-1 at Yonsei cancer center. Clinical data including patient characteristics, mutation, treatment outcomes, and adverse events were collected and analyzed. Forty patients additionally had blood-based immune data by flow cytometry. There were two data sets; clinical data set (n=126) with 15 variables, and immune data set (n=40) with 37 variables. We found that 27 variables out of 52 variables are selected by recursive feature elimination. The responders are defined as PR or SD ≥6 months and the non-responders are defined as the others. Supervised learning algorithms such as the LASSO, Ridge, Elastic Net, SVM, ANN, and RF were applied to each data set for predicting the αPD-1 response. The performances of each model were evaluated according to the ROC curve or cross-validation errors. Variable importance was measured by using the random forest and gradient boosting.Patient characteristics included male (69.8%), age ≥ 60 years (66.2%), ECOG 0/1 (77.7%), adenocarcinoma (69.8%), EGFR mutations (15.1%), and PD-L1 positive (61.2%). We classified the patients into responders (38%) and non-responders (62%) in total 126 patients. A result from the clinical data set of 126 patients demonstrated that the Ridge regression model (AUC: 0.78) can more accurately predict the αPD-1 response than others. Of 15 clinical variables, some are considered to be important in the following order; tumor burden,age, PD-L1, ECOG PS, and irAE based on the random forest. When we performed the machine learning process with clinical and immune data, The Ridge regression model (AUC:0.82) showed the good performance to predict αPD-1 response, compared to the single clinical model. The machine learning based CDSS for aPD-1 to NSCLC patients has benefit for predicting aPD-1 responses. Our prediction model could be easily accessible and fast processed in routine practice. The supervised machine learning based non-invasive predictive score (NIPS) demonstrates the rate of aPD-1 response on NSCLC patients. We will validate NIPS in independent patient cohort and currently are establishing the NIPS as web-based software.

Citation Format: Kyoung-Ho Pyo, Beung-Chul Ahn, Chun-Feng Xin, Dongmin Jung, Chang Gon Kim, Min Hee Hong, Byoung Chul Cho, Hye Ryun Kim. A machine learning based clinical decision support system (CDSS) for anti-PD-1 therapy using non-invasive blood marker and clinical information for lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 683.

A machine learning based prediction model of anti-PD-1 therapy response using noninvasive clinical information and blood markers of lung cancer patients

e14138

Background: Immune checkpoint inhibitors have become breakthrough therapy for various types of cancers. However, regarding their total response rate around 20% based on clinical trials, predicting accurate aPD-1 response for individual patient is unestablished. The presence of PD-L1 expression or tumor infiltrating lymphocyte may be used as indicators of response but are limited. We developed models using machine learning methods to predict the aPD-1 response. Methods: A total of 126 advanced NSCLC patients treated with the aPD-1 were enrolled. Their clinical characteristics, treatment outcomes, and adverse events were collected. Total clinical data (n = 126) consist of 15 variables were divided into two subsets, discovery set (n = 63) and test set (n = 63). Thirteen supervised learning algorithms including support vector machine and regularized regression (lasso, ridge, elastic net) were applied on discovery set for model development and on test set for validation. Each model were evaluated according to the ROC curve and cross-validation method. Same methods were used to the subset which had additional flow cytometry data (n = 40). Results: The median age was 64 and 69.8% were male. Adenocarcinoma was predominant (69.8%) and twenty patients (15.1%) were driver mutation positive. Clinical data set (n = 126) demonstrated that the Ridge regression (AUC: 0.79) was the best model for prediction. Of 15 clinical variables, tumor burden, age, ECOG PS and PD-L1, were most important based on the random forest algorithm. When we merged the clinical and flow cytometry data, the Ridge regression model (AUC:0.82) showed better performance compared to using clinical data only. Among 52 variables of merged set, the top most important immune markers were as follows: CD3+CD8+CD25+/Teff-CD28, CD3+CD8+CD25-/Teff-Ki-67, and CD3+CD8+CD25+/Teff-NY-ESO/Teff-PD-1, which indicate activated tumor specific T cell subset. Conclusions: Our machine learning based model has benefit for predicting aPD-1 responses. After further validation in independent patient cohort, the supervised learning based non-invasive predictive score can be established to predict aPD-1 response.

Immune Checkpoint Inhibitor-induced Reinvigoration of Tumor-infiltrating CD8+ T Cells is Determined by Their Differentiation Status in Glioblastoma

PURPOSE

Immune checkpoint inhibitors (ICI) are used for the treatment of various cancers, but clinical trials of anti-programmed cell death protein 1 (PD-1) with patients with recurrent glioblastoma (GBM) have failed to show clinical benefits. In this study, we examined the differentiation status of CD8⁺ tumor-infiltrating lymphocytes (TIL) from patients with primary GBM and their reinvigoration by ICIs to understand the nature of T-cell exhaustion in GBM.

EXPERIMENTAL DESIGN

We isolated TILs from 98 patients with newly diagnosed GBM and examined the expression of immune checkpoint receptors and T-cell transcription factors using flow cytometry. TILs were ex vivo stimulated with anti-CD3 in the presence of anti-PD-1 and/or anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) and their proliferation assessed.

RESULTS

CD8⁺ TILs had significantly increased expression of immune checkpoint receptors, including PD-1 and CTLA-4, compared with peripheral blood CD8⁺ T cells. Among CD8⁺ TILs, PD-1⁺ cells exhibited more terminally differentiated phenotypes (i.e., Eomes^hiT-bet^lo) than PD-1^- cells. These data were confirmed by analyzing NY-ESO-1₁₅₇-specific CD8⁺ TILs. Evaluating the proliferation of CD8⁺ TILs after ex vivo stimulation with anti-CD3 and anti-PD-1, we found that proliferation inversely correlated with the percentage of Eomes^hiT-bet^lo cells among PD-1⁺CD8⁺ TILs. When anti-CTLA-4 was used in combination with anti-PD-1, an additional increase in CD8⁺ TIL proliferation was observed in patients with low percentages of Eomes^hiT-bet^lo CD8⁺ TILs, who responded well to anti-PD-1 in ex vivo assays, but not in patients with high percentages of Eomes^hiT-bet^lo CD8⁺ TILs, who did not respond to anti-PD-1.

CONCLUSIONS

In primary GBM, the differentiation status of CD8⁺ TILs determines their reinvigoration ability upon ICI treatment.

Effect of combined anti-PD-1 and temozolomide therapy in glioblastoma

Background: Although programmed death-1 (PD-1) blockade is effective in treating several types of cancer, the efficacy of this agent in glioblastoma (GBM) is largely unknown. Methods: We evaluated therapeutic effects of anti-PD-1, temozolomide (TMZ), and their combination in an orthotopic murine GBM model. The phenotype, number, and composition of lymphocytes were evaluated using flow cytometry. Transcriptional profiles of tumor tissues were analyzed using microarrays. Generation of antitumor immunological memory was investigated upon rechallenge. Results: Combined treatment with anti-PD-1 and TMZ yielded synergistic antitumor efficacy in the presence of donor-originated PD-1⁺CD8⁺ T cells in vitro, necessitating in vivo validation. Whereas TMZ did not rescue GBM-implanted mice, anti-PD-1 completely eradicated GBM in 44.4% of mice, and combination of anti-PD-1 and TMZ in all mice. Anti-PD-1 significantly increased the number of tumor-infiltrating lymhpocytes (TILs), and reduced frequencies of exhausted T cells and regulatory T cells. However, combining TMZ with anti-PD-1 significantly decreased the number of TILs, which was also observed with TMZ treatment alone. A transcriptome analysis of tumor tissues revealed that anti-PD-1 monotherapy perturbed immune-related genes, distinctly with combined therapy. Upon rechallenge, tumor growth was not observed in mice cured by anti-PD-1 monotherapy, whereas tumors regrew in the combination group. Furthermore, an analysis of peripheral blood revealed that antitumor memory T cells were generated in mice cured by anti-PD-1 monotherapy, not in the combination group. Conclusion: PD-1 blockade induces long-term therapeutic response, and combination with TMZ further enhances antitumor efficacy. However, immunological memory is provoked by anti-PD-1 monotherapy, not by combined therapy.

YAP-Induced PD-L1 Expression Drives Immune Evasion in BRAFi-Resistant Melanoma

Activation of YAP, a Hippo pathway effector, is an important resistance mechanism to BRAF inhibitor (BRAFi) in melanoma. Emerging evidence also suggests that YAP is involved in suppression of the antitumor immune response. However, the potential direct impact of YAP activity on cytotoxic T-cell immune responses has not been explored yet. Here, we show that BRAFi-resistant melanoma cells evade CD8⁺ T-cell immune responses in a PD-L1-dependent manner by activating YAP, which synchronously supports melanoma cell survival upon BRAF inhibition. PD-L1 expression is elevated in BRAFi-resistant melanoma cells, in which YAP is robustly activated, and YAP knockdown decreases PD-L1 expression. In addition, constitutively active YAP (YAP-5SA) increases PD-L1 expression by binding to an upstream enhancer of the PD-L1 gene and potentiating its transcription. Both BRAFi-resistant and YAP-5SA-expressing melanoma cells suppress the cytotoxic function and cytokine production of Melan-A-specific CD8⁺ T cells, whereas anti-PD-1 antibody reverses the YAP-mediated T-cell suppression. Moreover, nuclear enrichment of YAP in clinical melanoma samples correlates with increased PD-L1 expression. Our findings show that YAP directly mediates evasion of cytotoxic T-cell immune responses in BRAFi-resistant melanoma cells by upregulating PD-L1, and targeting of YAP-mediated immune evasion may improve prognosis of melanoma patients. Cancer Immunol Res; 6(3); 255-66. ©2018 AACR.

Prognoses and Clinical Outcomes of Primary and Recurrent Uveal Melanoma

Purpose

Uveal melanoma has a very poor prognosis despite successful local primary tumor treatment. In this study, we investigated prognostic factors that more accurately reflected the likelihood of recurrence and survival and delineated a prognostic model that could effectively identify different risk groups based on initial clinical parameters.

Materials and Methods

Prognostic factors associated with distant recurrence, recurrence-free survival (RFS), progression-free survival, and overall survival from distant recurrence to death (OS2) were analyzed in 226 patients with stage I-III uveal melanoma who underwent primary local therapy.

Results

Forty-nine patients (21.7%) had distant recurrences, which occurred most frequently in the liver (87.7%). In a multivariate analysis, local radiotherapy improved RFS among patients with multiple recurrence risk factors relative to excision (not reached vs. 19.0 months, p=0.004). Patients with BRCA1-associated protein-1 (BAP1)‒negative primary tumors showed a longer RFS duration after primary treatments, while those with BAP1-negative metastatic tissues had a shorter OS2 compared to those with BAP1-positive tumors, both not statistically insignificance (RFS: not reached vs. 82.0 months, p=0.258; OS2: 15.7 vs. 24.4 months, p=0.216). Male sex (hazard ratio [HR], 3.79; p=0.012), a short RFS (HR, 4.89; p=0.014), and a largest metastatic tumor linear diameter ≥ 45 mm (HR, 5.48; p=0.017) were found to correlate with worse post-recurrence survival.

Conclusion

Risk factors could be used to classify uveal melanoma cases and subsequently direct individual treatment strategies. Furthermore, metastasectomy appears to contribute to improved survival outcomes.

Role of adjuvant chemotherapy in locally advanced rectal cancer with ypT0-3N0 after preoperative chemoradiation therapy and surgery

Background

We aimed to explore the clinical benefit of adjuvant chemotherapy (AC) with fluoropyrimidine in patients with ypT0-3N0 rectal cancer after preoperative chemoradiation therapy (CRT) followed by total mesorectal excision (TME).

Methods

Patients with ypT0-3N0 rectal cancer after preoperative CRT and TME were included using prospectively collected tumor registry cohort between January 2001 and December 2013. Patients were categorized into two groups according to the receipt of AC. Disease-free survival (DFS) and overall survival (OS) were compared between the adjuvant and observation groups. To control for potential confounding factors, we also calculated propensity scores and performed propensity score-matched analysis for DFS and OS.

Results

Of the 339 evaluated patients, 87 patients (25.7%) did not receive AC. There were no differences in DFS (hazard ratio [HR], 0.921; 95% confidence interval [CI], 0.562–1.507; P = 0.742) and OS (HR, 0.835; 95% CI, 0.423–1.648; P = 0.603) between the adjuvant and observation groups. After propensity score matching, DFS (HR, 1.129; 95% CI, 0.626–2.035; P = 0.688) and OS (HR, 1.200; 95% CI, 0.539–2.669; P = 0.655) did not differ between the adjuvant and observation groups. Advanced T stage and positive resection margin were independently associated with inferior DFS and OS on multivariate analysis.

Conclusions

AC did not improve DFS and OS for patients with ypT0-3N0 rectal cancer after preoperative CRT followed by TME in this cohort study. The confirmative role of AC in locally advanced rectal cancer should be evaluated in prospective randomized trials with a larger sample size.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3624-7) contains supplementary material, which is available to authorized users.

Acute endophthalmitis after cataract surgery: 164 consecutive cases treated at a referral center in South Korea

PurposeTo identify prognostic factors in patients referred with endophthalmitis after cataract surgery, and to evaluate the efficacy of primary vitrectomy as an initial management.MethodsOver an eight-year study period, we retrospectively reviewed the medical records of 164 patients who were referred with endophthalmitis following cataract surgery. Treatment generally conformed to standard guidelines, although primary vitrectomy was performed in several eyes with a visual acuity of hand motion or better, depending on the patient's status. Using multivariate analysis, we analyzed outcomes to determine the effect on final visual outcome.ResultsA final visual acuity of ≥20/40 was achieved in 92/164 (56.1%) cases after treatment. Bacterial cultures showed bacterial growth in 89/164 cases (54.3%). Among the various baseline characteristics, old age (P=0.028), poor visual acuity at presentation (P=0.004), gram-negative bacterial infection (P=0.030), and short time between cataract surgery and signs of endophthalmitis (P=0.021) were associated with poor visual outcome. The visual outcome showed no significant difference, in terms of initial treatment feature, between the primary vitrectomy with intraocular antibiotics injection (IOAI) and IOAI-only groups. However, reintervention was significantly less frequent in the primary vitrectomy group than in the IOAI group (12.5 and 32.7%, respectively; P=0.002).ConclusionOld age, poor visual acuity at presentation, type of cultured organism (gram-negative bacteria), and early onset of endophthalmitis after cataract surgery were significantly related to poor visual outcome after endophthalmitis treatment. Primary vitrectomy may decrease the need for reintervention to control infection, although the treatment showed no benefits with regard to visual outcome.

Detection of activating and acquired resistant mutation in plasma from EGFR-mutated NSCLC patients by peptide nucleic acid (PNA) clamping-assisted fluorescence melting curve analysis

This study was designed to prospectively examine whether peptide nucleic acid clamping-assisted fluorescence melting curve analysis (PANAMutyper™) is feasible for the detection of activating and acquired resistant epidermal growth factor receptor (EGFR) mutation in plasma. Patients with non-small cell lung cancer harboring activating EGFR mutations who were scheduled to undergo EGFR-tyrosine kinase inhibitors (EGFR-TKIs) were enrolled between September 2011 and March 2015. A total of 102 patients with EGFR-mutated lung cancer were enrolled, 53 had available plasma samples at disease progression, and 28 underwent serial plasma sampling during EGFR-TKI treatment. EGFR-TKI-sensitizing and T790M mutations were detected in the plasma of 68.6% (70/102) at baseline and 30.2% (16/53) at disease progression, respectively. The concordance rates for matched tissue and plasma samples were 80.4% and 90.2% for E19del and L858R mutations at baseline and 56.3% for T790M mutation at disease progression. The sustained presence of plasma EGFR mutations four weeks after EGFR-TKI predicted a poor objective response rate (30.0% vs. 87.5%, P = 0.025), as well as worse progression-free survival (hazard ratio [HR], 4.381) and overall survival (HR, 5.475). Longitudinal analysis could detect T790M mutations earlier than disease progression based on imaging study (median time from appearance of T790M in plasma samples to progression at imaging scan, 103 days). In conclusion, PANAMutyper™ is reliable for detecting activating and acquired resistant EGFR mutation in plasma, and predicts responses to EGFR-TKI via longitudinal monitoring of EGFR mutation during treatment.

Osteosarcoma in a Patient With Pseudohypoparathyroidism Type 1b Due to Paternal Uniparental Disomy of Chromosome 20q

It is assumed that a persistent high level of parathyroid hormone (PTH) might have a relation with bone malignancy. However, there has been no report of osteosarcoma associated with pseudohypoparathyroidism type 1b (PHP1b), which is accompanied by high PTH. PHP1b is the result of resistance to PTH in certain end-organ tissues, especially the kidney; the response in bone is unaffected because it normally expresses stimulatory G protein equally from both parental alleles. A 21-year-old male, presenting with gum swelling at the right mandible, was referred to a dental clinic. A curative surgical resection by segmental mandibulectomy was performed and the pathologic findings of the mass were consistent with osteoblastic osteosarcoma. His laboratory results showed a low calcium level despite high PTH, and he did not have any features of Albright hereditary osteodystrophy; therefore, PHP1b was suspected. Multiplex ligation-dependent probe amplification and microsatellite marker analyses of chromosome 20 confirmed the diagnosis and identified paternal uniparental disomy of chromosome 20q (patUPD20). To the best of our knowledge, this is the first report of osteosarcoma in a patient with PHP1b due to patUPD20. © 2017 American Society for Bone and Mineral Research.

Preoperative Serum Carcinoembryonic Antigen Level as a Prognostic Factor for Recurrence and Survival After Curative Resection Followed by Adjuvant Chemotherapy in Stage III Colon Cancer

BACKGROUND

Carcinoembryonic antigen (CEA) is the most widely used tumor marker in colon cancer; however, there has been controversy regarding the significance of preoperative serum CEA level as a prognostic factor for recurrence. In this study, we evaluated the optimal cutoff value and prognostic significance of preoperative serum CEA level in stage III colon cancer.

METHODS

Based on a retrospective cohort of 965 patients with stage III colon cancer who underwent elective curative surgery and adjuvant chemotherapy with fluoropyrimidine and oxaliplatin (training set), we determined the optimal cutoff value of CEA for recurrence using the Contal and O'Quigley method. We assessed the prognostic value of this cutoff value in terms of disease-free survival (DFS) and overall survival (OS) in a prospective cohort of 268 patients with stage III colon cancer (validation set). A Cox proportional hazards model was used to explore the association of prognostic variables with DFS and OS.

RESULTS

The statistically determined best cutoff value for CEA was 3 ng/mL in the training set. A high CEA level (≥3 ng/mL) was associated with inferior DFS (hazard ratio [HR] 4.609, 95 % confidence interval [CI] 2.028-10.474) and OS (HR 3.956, 95 % CI 1.127-13.882) in the validation set, while multivariate analysis showed that a high CEA level was an independent risk factor for DFS and OS in both study subsets.

CONCLUSION

Preoperative serum CEA level is an independent prognostic factor for DFS and OS in patients with stage III colon cancer after curative resection and adjuvant chemotherapy.

Effects of microsatellite instability on recurrence patterns and outcomes in colorectal cancers

Background:

Among colorectal cancers (CRCs), high-frequency microsatellite instability (MSI-H) is associated with a better prognosis, compared with low-frequency MSI or microsatellite stability (MSI-L/MSS). However, it is unclear whether MSI affects the prognosis of recurrent CRCs.

Methods:

This study included 2940 patients with stage I–III CRC who underwent complete resection. The associations of MSI status with recurrence patterns, disease-free survival (DFS), overall survival from diagnosis to death (OS1), and overall survival from recurrence to death (OS2) were analysed.

Results:

A total of 261 patients (8.9%) had MSI-H CRC. Patients with MSI-H CRC had better DFS, compared to patients with MSI-L/MSS CRC (hazard ratio (HR): 0.619, P<0.001). High-frequency microsatellite instability CRC was associated with more frequent local recurrence (30.0% vs 12.0%, P=0.032) or peritoneal metastasis (40.0% vs 12.3%, P=0.003), and less frequent lung (10.0% vs 42.5%, P=0.004) or liver metastases (15.0% vs 44.7%, P=0.01). Recurrent MSI-H CRC was associated with worse OS1 (HR: 1.363, P=0.035) and OS2 (HR: 2.667, P<0.001). An analysis of patients with colon cancer yielded similar results.

Conclusions:

Recurrence patterns differed between MSI-H CRC and MSI-L/MSS CRC, and recurrent MSI-H CRCs had a worse prognosis.

Incidence of Febrile Neutropenia in Korean Female Breast Cancer Patients Receiving Preoperative or Postoperative Doxorubicin/Cyclophosphamide Followed by Docetaxel Chemotherapy

PURPOSE

Doxorubicin/cyclophosphamide followed by docetaxel chemotherapy (AC-D) is an intermediate risk factor (incidence of 10%-20%) for febrile neutropenia (FN) in breast cancer. However, the reported incidence of FN while using this regimen was obtained mostly from Western breast cancer patients, with little data available from Asian patients. This study aimed to assess the incidence of FN in Korean breast cancer patients and to describe clinical variables related to FN.

METHODS

From September 2010 to February 2013, data from the Yonsei Cancer Center registry of breast cancer patients who received neoadjuvant or adjuvant chemotherapy with four cycles of AC-D (60 mg/m(2) doxorubicin, 600 mg/m(2) cyclophosphamide every 3 weeks for four cycles followed by 75 mg/m(2) or 100 mg/m(2) docetaxel every 3 weeks for four cycles) were analyzed. The incidence of FN, FN associated complications, dose reduction/delays, and relative dose intensity (RDI) were investigated.

RESULTS

Among the 254 patients reported to the registry, the FN incidence after AC-D chemotherapy was 29.5% (75/254), consisting of 25.2% (64/254) events during AC and 4.7% (12/254) during docetaxel chemotherapy. Dose reductions, delays, and RDI less than 85.0% during AC were observed in 16.5% (42/254), 19.5% (47/254), and 11.0% (28/254) of patients, respectively. Patients with FN events frequently experienced dose reduction/delays, which eventually led to a decreased RDI.

CONCLUSION

The incidence of FN during AC-D neoadjuvant or adjuvant chemotherapy was higher than expected in Korean breast cancer patients. Whether these patients should be classified as a high-risk group for FN warrants future prospective studies.

Benefit of Adjuvant Chemotherapy After Curative Resection of Lung Metastasis in Colorectal Cancer

BACKGROUND

The survival benefit of adjuvant chemotherapy after colorectal cancer (CRC) lung metastasectomy is uncertain.

METHODS

We enrolled 221 CRC patients who underwent pulmonary metastasectomy between October 2002 and July 2013, including those with previous liver metastasis that had been curatively resected. Disease-free survival (DFS) and overall survival (OS) were calculated from the day of lung metastasectomy.

RESULTS

Among all patients, 176 (79.6%) received adjuvant chemotherapy after lung metastasectomy. Median follow-up was 34.7 months from the time of lung metastasectomy [95% confidence interval (95% CI), 7.4-90.9 months]. Patients treated with adjuvant chemotherapy had longer DFS compared with surgery alone (median 32.7 vs 11.2 months respectively, P = 0.076). Multivariate analysis revealed previous liver metastasis, preoperative carcinoembryonic antigen ≥5 ng/mL, disease-free interval <24 months, and surgery without adjuvant chemotherapy as independent risk factors for recurrence. Low-risk patients who had 0-1 risk factors received a significant survival benefit from adjuvant chemotherapy [hazard ratio (HR) 0.54; 95% CI 0.32-0.91, P = 0.020]; however, high-risk patients with ≥2 risk factors did not (HR 1.02; 95% CI 0.48-2.14, P = 0.964). Patients treated with adjuvant chemotherapy showed no OS benefit compared with patients who received surgery alone (median 89.6 vs 86.8 months respectively, P = 0.833).

CONCLUSIONS

CRC patients received lung metastasectomy could have a DFS benefit from adjuvant chemotherapy, especially in low-risk patients. Larger, prospective studies are needed to evaluate the role of adjuvant chemotherapy after CRC lung metastasectomy.

Long-term metformin use reduces gastric cancer risk in type 2 diabetics without insulin treatment: a nationwide cohort study

BACKGROUND

Metformin use has been associated with a decreased incidence and mortality of various cancers.

AIM

To evaluate the association between metformin use and gastric cancer.

METHODS

We randomly selected 100 000 type 2 diabetic patients from the 2004 Korean National Health Insurance claim database, and assessed gastric cancer incidence among 39 989 patients (aged 30-97 years) who were regularly treated with anti-diabetic drugs and followed-up from 2004 to 2010. In total, 26 690 patients had used metformin out of 32 978 diabetics who had not regularly used insulin (insulin non-users), and 5855 patients had used metformin out of 7011 regular insulin users.

RESULTS

Patients who used metformin showed a lower incidence of gastric cancer than those who did not use metformin, in insulin non-users (P = 0.047, log-rank test). However, in patients on regular insulin, there was no difference of gastric cancer incidence according to metformin use. In insulin non-users, the adjusted hazard ratio (AHR) for metformin use was 0.73 (95% confidential interval [CI], 0.53-1.01) with borderline statistical significance (P = 0.059). Duration of metformin use was associated with the reduction in gastric cancer risk (AHR, 0.88; 95% CI 0.81-0.96, P = 0.003), especially in patients who used metformin for more than 3 years (AHR, 0.57; 95% CI, 0.37-0.87; P = 0.009).

CONCLUSION

Metformin use >3 years in type 2 diabetics who do not use insulin is associated with a significantly reduced gastric cancer risk.

Planar Hall magnetoresistive aptasensor for thrombin detection

The use of aptamer-based assays is an emerging and attractive approach in disease research and clinical diagnostics. A sensitive aptamer-based sandwich-type sensor is presented to detect human thrombin using a planar Hall magnetoresistive (PHR) sensor in cooperation with superparamagnetic labels. A PHR sensor has the great advantages of a high signal-to-noise ratio, a small offset voltage and linear response in the low-field region, allowing it to act as a high-resolution biosensor. In the system presented here, the sensor has an active area of 50 µm × 50 µm with a 10-nm gold layer deposited onto the sensor surface prior to the binding of thiolated DNA primary aptamer. A polydimethylsiloxane well of 600-µm radius and 1-mm height was prepared around the sensor surface to maintain the same specific area and volume for each sensor. The sensor response was traced in real time upon the addition of streptavidin-functionalized magnetic labels on the sensor. A linear response to the thrombin concentration in the range of 86 pM-8.6 µM and a lower detection limit down to 86 pM was achieved by the proposed present method with a sample volume consumption of 2 µl. The proposed aptasensor has a strong potential for application in clinical diagnosis.

Staging of intestinal- and diffuse-type gastric cancers with the OLGA and OLGIM staging systems

BACKGROUND

Operative link on gastritis assessment (OLGA) and Operative link on gastric intestinal metaplasia assessment (OLGIM) staging systems have been proposed for gastric cancer (GC) risk estimation.

AIM

To validate the OLGA and OLGIM staging systems in a region with high risk of GC.

METHODS

This retrospective study included 474 GC patients and age- and sex-matched health screening control persons in a cancer centre hospital. We classified gastritis patterns according to the OLGA and OLGIM systems using the histological database that a pathologist prospectively evaluated using the updated Sydney system. GC risk according to the OLGA and OLGIM stages was evaluated using logistic regression analysis.

RESULTS

More GC patients had OLGA stages III-IV (46.2%) than controls (26.6%, P < 0.001), particularly among patients with intestinal-type GCs (62.2%) compared with diffuse-type GCs (30.9%). OLGA stages III and IV were significantly associated with increased risk of GC [odds ratios (ORs), 2.09; P = 0.008 and 2.04; P = 0.014 respectively] in multivariate analysis. The association was more significant for intestinal-type (ORs, 4.76; P = 0.001 and 4.19; P = 0.002 respectively), but not diffuse-type GC. OLGIM stages from I to IV were significantly associated with increased risk of both intestinal-type (ORs, 3.64, 5.15, 7.89 and 13.20 respectively) and diffuse-type GC (ORs, 1.84, 2.59, 5.08 and 6.32 respectively) with a significantly increasing trend.

CONCLUSION

As high OLGA and OLGIM stages are independent risk factors for gastric cancer, the staging systems may be useful for risk assessment in high-risk regions, especially for intestinal-type gastric cancer.

Lentiviral modification of enriched populations of bovine male gonocytes

Undifferentiated germ cells have the capacity to develop into sperm capable of fertilizing oocytes and contributing genetic material to subsequent generations. The most primitive prepubertal undifferentiated germ cells include gonocytes and undifferentiated spermatogonia, including spermatogonial stem cells (SSC). Gonocytes, present in the testis at birth, differentiate into SSC, which maintain spermatogenesis for the remainder of the male's life. Because of their capacity to contribute to lifelong spermatogenesis, undifferentiated germ cells are attractive targets for genetic modification to produce transgenic animals, including cattle. To maximize the efficiency of genetic modification of bovine gonocytes and SSC, effective enrichment techniques need to be developed. Selection of bovine gonocytes using differential plating was improved 8-fold (P < 0.001) when using a combination of extracellular matrix proteins, including laminin, fibronectin, collagen type IV, and gelatin, compared to using laminin and gelatin alone. Selected cells labeled with PKH26 formed colonies of donor-derived germ cells after transplantation into recipient mouse testes, indicating putative stem cell function. Significantly more colonies (P < 0.001) per 1 × 10(5) viable transplanted cells were formed from isolated nonadherent cells (203 ± 23.2) compared to adherent (20 ± 2.7) or Percoll (45.5 ± 4.5) selected cells. After selection, some gonocytes were transduced using a lentiviral vector containing the transgene for the enhanced green fluorescent protein. Transduction efficiency was 17%. Collectively, these data demonstrate effective methods for the selection and genetic modification of bovine undifferentiated germ cells.

Randomised clinical trial: the effects of Helicobacter pylori eradication on glandular atrophy and intestinal metaplasia after subtotal gastrectomy for gastric cancer

BACKGROUND

Helicobacter pylori eradication is recommended for early gastric cancer (GC) patients after resection.

AIM

To evaluate whether H. pylori eradication improves glandular atrophy and intestinal metaplasia (IM) in GC patients undergoing subtotal gastrectomy.

METHODS

This randomised, double-blind trial was performed in tertiary care setting. Distal GC patients with H. pylori infection were randomised to receive proton pump inhibitor-based triple therapy or placebo. The histology was evaluated using the updated Sydney system before and at 36 months after surgery. The endpoints were the comparison of atrophy and IM score changes between the allocated groups and according to final H. pylori status.

RESULTS

Overall, 190 patients were randomised to the treatment and placebo groups. For lesser curvature of the corpus, mean atrophy and IM scores did not differ between the treatment and placebo groups. However, the H. pylori-eradicated patients had significantly lower mean scores than the H. pylori-persistent patients regarding atrophy (0.55 ± 0.95 vs. 1.05 ± 1.10 respectively; P = 0.0046) and IM (0.66 ± 0.99 vs. 1.05 ± 1.16 respectively; P = 0.0284). The percentage change from baseline was more marked in the H. pylori-negative than in the H. pylori-positive groups (-58.6% vs. -11.0% for atrophy and -60.5% vs. -35.6% for IM respectively). For greater curvature, mean atrophy score was lower in the H. pylori-negative group than in the H. pylori-positive group (0.14 ± 0.50 vs. 0.41 ± 0.75 respectively; P = 0.0281). The percentage change was -36.4% vs. 86.3%.

CONCLUSION

Helicobacter pylori eradication in GC patients is beneficial, as reflected by lower scores of atrophy and IM at 36 months after subtotal gastrectomy. (ClinicalTrials.gov number, NCT01002443).

Effect of chemotherapy on the outcome of self-expandable metallic stents in gastric cancer patients with malignant outlet obstruction

BACKGROUND AND STUDY AIM

Chemotherapy has been suggested to affect the outcome of pyloric stent placement. This study aimed to investigate the association between the response to chemotherapy and pyloric stent outcome.

PATIENTS AND METHODS

Data from 113 patients with inoperable gastric cancer who received chemotherapy after pyloric stent placement at the National Cancer Center hospital were analyzed retrospectively. Chemotherapy response was assessed using the Response Evaluation Criteria in Solid Tumors. A Cox proportional hazards model was used to evaluate the effect of chemotherapy response on the complications of stents.

RESULTS

The stent migration rate was 15.9% (18/113) and the re-stenosis rate was 30.1% (34/113). The response rates to chemotherapy were higher in the first-line group than in the salvage chemotherapy group (second-line or more) (44.8% [26/58] vs. 3.6% [2/55], respectively; P < 0.001). The proportion of patients with long time-to-progression (> 8 weeks) was also higher in the first-line than the salvage chemotherapy group (81.0% [47 /58] vs. 61.8% [34 /55], respectively; P = 0.036). Although, the response to chemotherapy was not associated with stent migration or re-stenosis, a long time-to-progression (adjusted hazard ratio [aHR] = 0.29, 95% confidence interval [CI] 0.13-0.67) and first-line chemotherapy (aHR = 0.45, 95%CI 0.22-0.93) were protective factors against re-stenosis in the multivariate analysis. In patients who received first-line chemotherapy, the median duration of patency of covered and uncovered stents was 20 weeks (95%CI 11-29) and 33 weeks (95 %CI 18-48), respectively (P = 0.317).

CONCLUSIONS

A long time-to-progression and first-line chemotherapy were significant protective factors against re-stenosis. In chemotherapy-naïve gastric cancer patients with pyloric obstruction, placement of an uncovered stent followed by chemotherapy can be considered to increase stent patency.

Aspirin use and bleeding risk after endoscopic submucosal dissection in patients with gastric neoplasms

BACKGROUND AND STUDY AIM

The risk of bleeding after endoscopic submucosal dissection (ESD) in patients with early gastric neoplasms who do not discontinue aspirin for the procedure has not been established. We aimed to investigate whether post-ESD gastric bleeding is increased in patients who take aspirin.

PATIENTS AND METHODS

Patients who underwent ESD for early gastric neoplasms at the National Cancer Center Hospital, Korea, between November 2008 and January 2011 were enrolled. The risk of post-ESD bleeding was evaluated using Poisson regression analysis.

RESULTS

We categorized 514 patients into three groups according to aspirin intake at the time of the procedure: patients who never used aspirin (n=439), patients who interrupted aspirin use for 7 days or more (n=56), and patients who continuously used aspirin (n=19). Post-ESD bleeding occurred in 4.1% (21/514) overall, and was more frequent in continuous aspirin users (4/19 [21.1%]) than in those who never used aspirin (15/439 [3.4%]) (P=0.006) and those with interrupted aspirin use (2/56 [3.6%]) (P=0.033). Multivariate analysis showed that use of aspirin by itself was associated with post-ESD bleeding (relative risk [RR] 4.49; 95% confidence interval [95%CI] 1.09-18.38). The resumption of clopidogrel combined with aspirin use (RR 26.71, 95%CI 7.09-100.53), and increased iatrogenic ulcer size (RR 1.52, 95%CI 1.14-2.02), were significantly associated with post-ESD bleeding.

CONCLUSIONS

Continuous aspirin use increases the risk of bleeding after gastric ESD. Aspirin use should be stopped in patients with a low risk for thromboembolic disease to minimize bleeding complications.

Intravitreal bevacizumab and ranibizumab injections for patients with polypoidal choroidal vasculopathy

PURPOSE

To compare the effectiveness of intravitreal injection of bevacizumab and ranibizumab in patients with treatment-naïve polypoidal choroidal vasculopathy (PCV).

METHODS

A total of 66 and 60 eyes of 121 consecutive patients who received intravitreal bevacizumab (1.25 mg) or ranibizumab (0.5 mg) injection for treatment of PCV were retrospectively reviewed. After initial three loading injections by month, injection was performed as needed. Main outcome measures included best corrected visual acuity (BCVA), foveal center thickness (FCT) as assessed by spectral domain optical coherence tomography (SD-OCT), and change in polypoidal lesion on indocyanine green angiography (ICGA).

RESULTS

At 12 months, average number of injections was 4.72±1.84 in the bevacizumab group and 5.52±1.54 in the ranibizumab group. Mean logarithm of the minimum angle of resolution of BCVA from baseline at 12 months after injection improved by 0.11 in the bevacizumab group (P=0.02) and by 0.14 in the ranibizumab group (P=0.01). Average FCT decreased from 368±62.48 to 298±40.77 μm in the bevacizumab group (P=0.01) and from 371±50.79 to 286±36.93 μm in the ranibizumab group (P=0.01). Polyp regression rate was 24.2% (16 eyes out of 66 eyes) in the bevacizumab group and 23.3% (14 eyes out of 60 eyes) in the ranibizumab group. There was no statistically significant difference in BCVA improvement achieved, FCT improvement achieved, and polyp regression rate between groups.

CONCLUSION

Intravitreal injections of bevacizumab and ranibizumab have similar effects in stabilization of visual acuity, macular edema, and regression of polypoidal complex with PCV eyes.

Comparison of surgical performance and short-term clinical outcomes between laparoscopic and robotic surgery in distal gastric cancer

AIMS

The authors aimed to compare the surgical performance and the short-term clinical outcomes of robotic assisted laparoscopic distal gastrectomy (RADG) with laparoscopy-assisted distal gastrectomy (LADG) in distal gastric cancer patients.

METHOD

From April 2009 to August 2010, 62 patients underwent LADG and 30 patients underwent RADG for preoperative stage I distal gastric cancer by one surgeon at the National Cancer Center, Korea. Surgical performance was measured using lymph node (LN) dissection time and number of retrieved LNs, which were viewed as surrogates of technical ease and oncologic quality.

RESULTS

In clinicopathologic characteristics, mean age, depth of invasion and stage were significantly different between the LADG and RADG group. Mean dissection time at each LN station was greater in the RADG group, but no significant intergroup difference was found for numbers of retrieved LNs. Furthermore, proximal resection margins were smaller, and hospital costs were higher in the RADG group. In terms of the RADG learning curve, mean LN dissection time was smaller in the late RADG group (n = 15) than in the early RADG group (n = 15) for 4sb/4d, 5, 7-12a stations, but numbers of retrieved LNs per station were similar.

CONCLUSION

With the exception of operating time and cost, the numbers of retrieved LNs and the short-term clinical outcomes of RADG were found to be comparable to those of LADG, despite the surgeon's familiarity with LADG and lack of RADG experience. Further studies are needed to evaluate objectively ergonomic comfort and to quantify the patient benefits conferred by robotic surgery.

Risk of high-grade dysplasia or carcinoma in gastric biopsy-proven low-grade dysplasia: an analysis using the Vienna classification

BACKGROUND AND AIMS

Therapeutic guidelines have not yet been established for low-grade gastric adenomas/dysplasias (LGD), which have a low risk of progression to high-grade adenomas/dysplasias (HGD) or to invasive carcinomas. This study aimed to evaluate risk factors for HGD/carcinoma that indicate a need for resection in biopsy-proven LGD lesions.

PATIENTS AND METHODS

In total, 236 LGD lesions from 208 consecutive patients treated with endoscopic resection (ER) were retrospectively studied between 2004 and 2008. The Vienna classification was used for histological diagnosis. A generalized estimating equation (GEE) logistic regression model was used for multivariate analysis.

RESULTS

Among the 236 LGD lesions, the final pathology diagnosed 9 (3.8 %) as invasive carcinoma (category 5), 71 (30.1 %) as HGD (category 4), 148 (62.7 %) as LGD (category 3), and 8 (3.4 %) as negative/indefinite for dysplasia (category 1/2). Lesions ≥ 1 cm were classified as HGD/carcinoma in 39.4 % of patients (65/165). Multivariate analysis indicated that size of ≥ 1 cm (OR 1.93 [95 % CI, 1.06 - 3.52]), depressed morphology (OR 3.81 [95 % CI, 1.22 - 11.9]), and erythema (OR 2.49 [95 % CI, 1.31 - 4.72]) were significantly associated with HGD/carcinoma. The OR increased to 47.6 (95 % CI, 4.27 - 530.65) when the risk factors were all positive. The sensitivity and negative predictive value for ≥ 1 risk factors were 93.8 % and 90.9 %, respectively. As the number of risk factors of a lesion increased, the specificity and positive predictive value also increased.

CONCLUSIONS

Endoscopic resection can be recommended if a low-grade dysplastic lesion has at least one of the following risk factors: depressed morphology, surface erythema, or a size of 1 cm or greater. For lesions that have none of the three risk factors, follow-up endoscopy is recommended.

CYP2A6 and ERCC1 polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients

Background:

We evaluated the association between polymorphisms of cytochrome P450 2A6 (CYP2A6)/excision repair cross-complementation group 1 (ERCC1)/X-ray repair cross-complementing group 1(XRCC1) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin.

Methods:

Among MGC patients (n=108), who received S-1 (40 mg m⁻² b.i.d., days 1–14) and cisplatin (60 mg m⁻², day 1) every 3 weeks, we analysed the wild-type allele (W) and variants (V) of CYP2A6 (*4, *7, *9, *10), and the polymorphisms of ERCC1 (rs11615, rs3212986) and XRCC1 (rs25487).

Results:

Patients having fewer CYP2A6 variants had better response rates (W/W vs W/V other than *1/*4 vs V/V or *1/*4=66.7 vs 58.3 vs 32.3% P=0.008), time to progression (TTP) (7.2 vs 6.1 vs 3.5 months, P=0.021), and overall survival (23.2 vs 15.4 vs 12.0 months, P=0.004). ERCC1 19442C>A (rs3212986) was also associated with response rate (C/C, 46.7% vs C/A, 55.3% vs A/A, 87.5%) (P=0.048) and TTP (4.4 vs 7.6 vs 7.9 months) (P=0.012). Patients carrying both risk genotypes of CYP2A6 (V/V or 1/*4) and ERCC1 19442C>A (C/C) vs those carrying none showed an adjusted odds ratio of 0.113 (P=0.004) for response, and adjusted hazard ratios of 3.748 (P=0.0001) for TTP and 2.961 (P=0.006) for death.

Conclusion:

Polymorphisms of CYP2A6 and ERCC1 19442C>A correlated with the efficacy of S-1/cisplatin.

Polyaniline-carboxymethyl cellulose nanocomposite for cholesterol detection

Cholesterol oxidase (ChOx) has been covalently immobilized onto polyaniline-carboxymethyl cellulose (PANI-CMC) nanocomposite film deposited onto indium-tin-oxide (ITO) coated glass plate using glutaraldehyde as a cross-linker. Fourier transform infrared (FTIR) spectroscopic and electrochemical studies have been used to characterize the PANI-CMC/ITO nanocomposite electrode and ChOx/PANI-CMC/ITO bioelectrode. Scanning electron microscopy (SEM) studies reveal the formation of PANI-CMC nanocomposite fibers of size approximately 150 nm in diameter. The ChOx/PANI-CMC/ITO bioelectrode exhibits linearity as 0.5-22 mM, detection limit as 1.31 mM, sensitivity as 0.14 mA/mM cm2, response time as 10 s and shelf-life of about 10 weeks when bioelectrode is stored at 4 degrees C. The low value of Michaelis-Menten constant (K(m)) obtained as 2.71 mM reveals high affinity of immobilized ChOx for PANI-CMC/ITO nanocomposite electrode.

Phase II study of a triplet regimen of S-1 combined with irinotecan and oxaliplatin in patients with metastatic gastric cancer: clinical and pharmacogenetic results

BACKGROUND

The aim of this study was to investigate the efficacy and safety of S-1/irinotecan/oxaliplatin (TIROX) in metastatic gastric cancer (MGC) and the association between treatment outcome and uridine diphosphate-glucuronosyltransferase (UGT) 1A polymorphisms.

PATIENTS AND METHODS

Patients with previously untreated MGC received S-1 40 mg/m(2) b.i.d. on days 1-14 and irinotecan 150 mg/m(2) plus oxaliplatin 85 mg/m(2) on day 1 every 3 weeks.

RESULTS

Forty-four patients were enrolled. In intent-to-treat analysis, the objective response rate was 75%, including the complete response (CR) rate of 14%. The median time to progression and overall survival was 10.2 and 17.6 months, respectively. Ten (26%) of the 39 patients with primary gastric tumor showed biopsy-confirmed gastric CR. Grade 3/4 neutropenia developed in 66% of patients and grade 3 febrile neutropenia in 16%. The most common grade 3 nonhematologic toxic effects were abdominal pain (18%), anorexia (16%), and diarrhea (14%). UGT1A polymorphisms were associated with significantly higher incidence of grade 4 leukopenia (UGT1A1*6), neutropenia (UGT1A1*6, UGT1A6*2, and UGT1A7*3), grade 3/4 febrile neutropenia (UGT1A1*6), and grade 3 abdominal pain (UGT1A1*6).

CONCLUSIONS

The TIROX regimen induced marked tumor reduction and promising survival with a manageable toxicity profile in MGC patients. UGT1A genotype may be predictive of TIROX toxicity.

Risk of hemorrhagic gastropathy associated with colonoscopy bowel preparation using oral sodium phosphate solution

BACKGROUND AND STUDY AIMS

Oral sodium phosphate (NaP) solution is widely used for colonoscopy bowel preparation and it may cause aphthous ulcers in the colon. Our aim was to evaluate whether oral NaP solution is associated with gastric mucosal lesions.

METHODS

A total of 20 070 individuals underwent esophagogastroduodenoscopy (EGD) with colonoscopy, and 4271 individuals underwent EGD without colonoscopy, for cancer screening. Oral NaP solutions were used for bowel preparation prior to colonoscopy. Hemorrhagic gastropathy was graded using a five-point scale for erosive mucosal injury. The effect of NaP bowel preparation on hemorrhagic gastropathy was estimated using multiple logistic regression analysis with odds ratios (ORs) and 95 % confidence intervals (CIs).

RESULTS

The incidence of hemorrhagic gastropathy was 1.6 % (70/4271) in the EGD only group and 4.0 % (809/20 070) in the EGD with colonoscopy group ( P < 0.001, unadjusted OR 2.55, 95 %CI 1.99 - 3.27). The ORs for mild (grade 1 - 2), moderate (grade 3), and severe (grade 4) hemorrhagic gastropathy according to NaP use were 1.92 (95 %CI 1.45 - 2.54), 4.72 (95 %CI 2.65 - 8.47), and 5.99 (95 %CI 1.46 - 24.63), respectively. After adjustment for confounding factors, NaP solution was a significant risk factor for acute hemorrhagic gastropathy in the multivariate analysis (OR 1.92, 95 %CI 1.34-2.74). In addition, male sex, a body mass index (kg/m (2)) of less than 20, concurrent use of antihypertensive or nonsteroidal anti-inflammatory drugs, and duodenal ulcers were independently associated with the development of hemorrhagic gastropathy. HELICOBACTER PYLORI infection and atrophic gastritis were negatively associated with hemorrhagic gastropathy.

CONCLUSION

Oral NaP bowel preparation for colonoscopy was associated with hemorrhagic gastropathy.

Obesity and weight gain as risk factors for erosive oesophagitis in men

BACKGROUND

Although obesity and weight gain increase the risk for symptoms of gastro-oesophageal reflux disease, their association with erosive oesophagitis is still unclear in the male population.

AIM

To evaluate, in men, the association of body mass index (BMI) and weight gain with endoscopically proven erosive oesophagitis.

METHODS

A total of 8571 Korean men in a comprehensive screening cohort were enrolled. Effects of BMI and abdominal obesity on erosive oesophagitis were estimated with odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression analysis. We also evaluated the association between erosive oesophagitis and BMI change after 1-3 years.

RESULTS

The prevalence of erosive oesophagitis was 6.4% (552/8571). In univariate analysis, the ORs for erosive oesophagitis increased as BMI or waist circumference increased (P for trend <0.001, both). In multivariate analysis, OR for erosive oesophagitis increased as BMI increased (P for trend = 0.002), while the significance of waist circumference was attenuated (P for trend = 0.13). Increase in BMI (>or=1 kg/m2) was associated with persistence of erosive oesophagitis (OR = 2.83, 95% CI: 1.01-7.92, P = 0.04) and new development of the disease (OR = 2.13, 95% CI: 1.38-3.28, P = 0.001) compared with BMI change less than 1 kg/m2.

CONCLUSIONS

Elevated BMI and weight gain have a significant association with erosive oesophagitis.

Obesity and weight gain as risk factors for erosive oesophagitis in men

BACKGROUND

Although obesity and weight gain increase the risk for symptoms of gastro-oesophageal reflux disease, their association with erosive oesophagitis is still unclear in the male population.

AIM

To evaluate, in men, the association of body mass index (BMI) and weight gain with endoscopically proven erosive oesophagitis.

METHODS

A total of 8571 Korean men in a comprehensive screening cohort were enrolled. Effects of BMI and abdominal obesity on erosive oesophagitis were estimated with odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression analysis. We also evaluated the association between erosive oesophagitis and BMI change after 1-3 years.

RESULTS

The prevalence of erosive oesophagitis was 6.4% (552/8571). In univariate analysis, the ORs for erosive oesophagitis increased as BMI or waist circumference increased (P for trend <0.001, both). In multivariate analysis, OR for erosive oesophagitis increased as BMI increased (P for trend = 0.002), while the significance of waist circumference was attenuated (P for trend = 0.13). Increase in BMI (>or=1 kg/m2) was associated with persistence of erosive oesophagitis (OR = 2.83, 95% CI: 1.01-7.92, P = 0.04) and new development of the disease (OR = 2.13, 95% CI: 1.38-3.28, P = 0.001) compared with BMI change less than 1 kg/m2.

CONCLUSIONS

Elevated BMI and weight gain have a significant association with erosive oesophagitis.

Learning curve for identification of sentinel lymph node based on a cumulative sum analysis in gastric cancer

BACKGROUND/AIMS

Lymph node metastasis is the most important point to consider when deciding on the modality of resection in patients with early gastric cancer. This study was conducted to evaluate the learning curve for identification of sentinel lymph nodes in patients with gastric cancer.

METHODS

The investigators included the results from 2 prospective series of sentinel lymph node mapping. Cumulative sum (CUSUM) analysis was performed to assess the learning curves for identification of sentinel lymph nodes at CUSUM target success rates of 95%.

RESULTS

One surgeon performed 135 sentinel lymph node mappings for 2 prospective series. The success rate exceeded 90%. The learning period for gastric cancer sentinel node mapping was calculated to be 26 cases for achieving a 95% success rate. Multiple logistic regression analysis for successful detection of sentinel nodes showed that surgical experience of sentinel lymph node mapping was an independent factor for successful detection of sentinel nodes.

CONCLUSIONS

This study suggests that the learning period for identification of sentinel lymph nodes in gastric cancer would be 26 cases. In clinical trials for gastric cancer with sentinel lymph node mapping, the learning curve should be considered to minimize bias due to surgical factors.

Optimization of biological wastewater treatment conditions for 1,4-dioxane decomposition in polyester manufacturing processes

The solvent stabilizer 1,4-dioxane could have harmful effects on an ecosystem. The discharge limit of 1,4-dioxane in a body of water will be regulated at 5 mg/L in Republic of Korea. Thus, the currently operating activated sludge used in the manufacture of polyester should be properly treated to meet the regulations. Accordingly, the removal rate of 1,4-dioxane and its microbial properties was assessed at K, H and T corporations. The highest removal efficiencies were recorded at H. However, the concentration of 1,4-dioxane in the effluent of T exceeded the criterion. In addition, a microbial degradation test was conducted on 100 mg/L of 1,4-dioxane inoculated with the activated sludge from each of the three corporations. After 7 days, the 1,4-dioxane was completely removed with the H sludge and efficiencies were 67% in the T sludge and 52% in the K sludge. These results confirm that the biodegradability of 1,4-dioxane may vary in relation to the microbial properties. The microbial diversity of activated sludge of each company was therefore investigated by 16S rDNA cloning methods. In conclusion, the activated sludge of H is the most effective for the biodegradation of 1,4-dioxane. This fact is of significant concern for the industrial sector.

Microbiological monitoring of acid mine drainage treatment systems and aquatic surroundings using real-time PCR

In general, acid mine drainage (AMD) causes low pH and high metal concentrations in mining areas and surroundings. The aim of this research was to achieve microbiological monitoring for AMD and to assess whether mine water outflows have any ecological effects on the aqueous ecosystem receiving effluents from different types of treatment system. The water quality of aquatic sample was analyzed and the molecular biological diversity of the samples was assessed using 16S rRNA methods, which were implemented to determine which bacteria existed throughout various unit processes for different AMD treatment systems and their receiving water environments. Acidiphilium cryptum, a heterotrophic acidophile, was found at the AMD sites, and Rhodoferax ferrireducens, which can reduce iron using insoluble Fe(III) as an electron acceptor, was detected at many AMD treatment facilities and downstream of the treatment processes. Subsequently, quantitative real-time PCR was conducted on specific genes of selected bacteria. Surprisingly, obvious trends were observed in the relative abundance of the various bacteria that corresponded to the water quality analytical results. The copy number of Desulfosporosinus orientus, a sulfate reducing bacteria, was also observed to decrease in response to decreases in metals according to the downstream flow of the AMD treatment system.

Comparative assessment of gene quantification using real-time PCR and water quality parameters in unsanitary landfill

Because of increasing demanding for development of direct ecological landfill monitoring methods, there is a requirement for the condition of landfills and their influence on the environment to be characterized by the behavior of enzymes and bacteria mainly concerned with biochemical reaction in the landfills. This study was thus conducted to understand the fates of contaminants in association with groundwater quality parameters. For the study, groundwater was seasonally sampled from four closed unsanitary landfills in which microbial diversity was simultaneously obtained by 16S rDNA methods. Subsequently, a number of the specific genes of representative bacteria and encoding enzymes were quantified by real-time PCR. The relationship between water quality parameters and gene quantification were compared based on correlation factors. Correlation between DSR gene and BOD was greater than 0.8 while NSR gene and nitrate were related more than 0.9. For MTOT, it was at the highest related at 100% over BOD/COD and Dde genes were correlated over 0.8. In addition, anaerobic genes and DO were also related more than 0.8, showing anaerobic reactions generally dependent upon DO. As demonstrated in the study, molecular biological investigation and water quality parameters are highly co-linked, so that quantitative real-time PCR could be cooperatively used for assessing landfill stabilization in association with the conventional monitoring parameters.

Decomposition of 1,4-dioxane by photo-Fenton oxidation coupled with activated sludge in a polyester manufacturing process

The cyclic ether 1,4-dioxane is a synthetic industrial chemical that is used as a solvent in producing paints and lacquers. The EPA and the International Agency for Research on Cancer(IARC) classified 1,4-dioxane as a GROUP B2(probable human) carcinogen. 1,4-dioxane is also produced as a by-product during the manufacture of polyester. In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, Korea was investigated regarding the release of high concentrations of 1,4-dioxane (about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2010). A 10 ton/day pilot-scale treatment system using photo-Fenton oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2800 ppm H(2)O(2) and 1,400 ppm FeSO(4) were maintained along with 10 UV-C lamps (240 microW/cm(2)) installed and operated continuously during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L where TOC concentration in the effluent had been moreover increased due to decomposed products such as aldehydes and organic acids. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane and their by-products (i.e., TOC). As a result, 1,4-dioxane in the effluent has been decreased as low as 0.5 mg/L. The optimal conditions for the activated sludge process that were obtained are as follows: DO, 3-3.5 mg/L; HRT, 24 h; SRT 15 d; MLSS, 3,000 mg/L. Consequently, photo-Fenton oxidation coupled with activated sludge can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.

Comparision of nirS, cnorB, MCR genes against water quality parameters to monitor uncontrolled landfills

This study was conducted to investigate the possible relationship between a molecular biological investigation and water quality parameters in monitoring groundwater pollution at the immediate boundary of uncontrolled landfills and their downgradient aquifers, which may consequently facilitate unbiased monitoring for the sites. Two closed landfills, Jicksan and Taejang in Korea, were chosen for this study, where the diversity of the microbial community was characterized and three specific genes, i.e. nirS (nitrite reductase coding gene), cnorB (nitric oxide reductase coding gene) and MCR (methyl coenzyme M reductase coding gene), were quantified. The quantified genes were then compared with conventional water quality parameters. From the analyzed DNA sequences, Proteobacteria phylum was most dominantly observed. A quantitative analysis revealed that the copy numbers (gene abundance) of denitrification enzyme coding genes, i.e. nirS gene and cnorB gene in Jicksan (J) site, are seven and four times, respectively, higher than Taejang (T) site. This simply implied that denitrification was possibly higher in J site than T site. In addition, a methane production enzyme coding gene, i.e. MCR, in a J1 bore immediately bordering the sources in the J site showed the greatest concentration, but it was precipitously decreased in the downgradient direction toward the outer boundary of landfill. A comparative investigation between the copy numbers of three genes, i.e. nirS, cnorB, and MCR, and conventional monitoring parameters, i.e. Cl-, alkalinity, TOC, NH3-N, and NO2-N, showed that they had overall correlation as given by more than 0.99 of the squared correlation coefficient (R2) for almost all of the concerned bores. It was concluded that the comparison between the molecular biological investigation and the conventional groundwater monitoring parameters showed good relationship between them, so that both tools could be more efficiently used for assessing the levels of contamination and prediction of the fate of pollutants, rather than being applied separately.

Synchronous gastric cancer in primary sporadic colorectal cancer patients in Korea

BACKGROUND AND AIMS

Colorectal cancer has been reported to be the malignancy most frequently associated with gastric cancer in Korea. The aim of this study was to define the frequency and clinical characteristics of synchronous gastric cancer detected at preoperative esophagogastroduodenoscopy (EGD) in colorectal cancer patients.

MATERIALS AND METHODS

This prospective study analyzed the EGD results from 1,542 consecutive colorectal cancer patients who underwent surgery from January 2003 to December 2005 at the Center for Colorectal Cancer, National Cancer Center, Korea.

RESULTS

Of the 1,542 cases, 1,155 (74.9%) underwent EGD at our center and 387 underwent EGD at other hospitals within 6 months before surgery. Of the 1,542 cases, synchronous gastric cancers were detected in 31 cases (2.0%). Of these 31 cases, 26 had early gastric cancer (EGC; 83.9%) and 5 had advanced gastric cancer. Ten (38.5%) of the 26 EGC cases were managed using endoscopic mucosal resection. Compared to colorectal cancer patients without synchronous gastric cancer, the group of patients with synchronous gastric cancer was older (65.5+/-9.6 vs 58.4+/-11.3 years, p=0.001) and had a greater proportion of males (77.4 vs 59.4%, p=0.043).

CONCLUSION

This study found that 2% of Korean sporadic colorectal cancer patients had synchronous gastric cancer. A preoperative EGD for colorectal cancer patients is likely to greatly assist in the diagnosis of synchronous gastric cancer at an early stage and the implementation of appropriate minimally invasive treatment.

Drug–protein interaction with Vpu from HIV-1: proposing binding sites for amiloride and one of its derivatives

Vpu is an 81-amino-acid auxiliary protein of the genome of HIV-1. It is proposed that one of its roles is to enhance particle release by self-assembling to form water-filled channels enabling the flux of ions at the site of the plasma membrane of the infected cell. Hexamethylene amiloride has been shown to block Vpu channel activity when the protein is reconstituted into lipid bilayers. In a docking approach with monomeric, pentameric and hexameric bundle models of Vpu corresponding to the transmembrane part of the protein, a putative binding site of hexamethylene amiloride is proposed and is compared with the site for the nonpotent amiloride. The binding mode for both ligands is achieved by optimizing hydrogen bond interactions with serines. Binding energies and binding constants are the lowest for protonated hexamethylene amiloride in the pentameric bundle.

Phase II study of docetaxel and irinotecan combination chemotherapy in metastatic gastric carcinoma

The current treatment for metastatic gastric cancer (MGC) consists of cisplatin and/or fluorouracil (5-FU) based combination chemotherapy, but cisplatin-based regimens are associated with considerable toxicity. We evaluated the efficacy and safety of a noncisplatin-, non-5-FU-containing regimen, docetaxel/irinotecan in MGC. Chemo-naive patients with MGC received docetaxel (30 mg m(-2)) and irinotecan (70 mg m(-2)) on days 1 and 8 every 3 weeks. The 48 eligible patients (median age 56 years) received a median of four cycles of docetaxel/irinotecan (range 1-18). Of the 46 patients in whom efficacy could be evaluated, 21 showed a partial response (response rate=45.7%; 95% confidence interval (CI) 31.3-60.1%). At a median follow-up of 15.0 months, the median time to progression was 4.5 months (95% CI 3.8-5.2 months) and overall survival was 8.2 months (95% CI, 5.8-10.6 months). Grade 3/4 neutropenia developed in 57.4% of patients, and febrile neutropenia/neutropenic infection in 19.1%. Nonhaematological toxicities were moderate; grade 3/4 diarrhoea occurred in 19.1% of patients, however, was manageable by a dose reduction. There was one possible treatment-related death. In conclusion, weekly docetaxel/irinotecan is a promising outpatient regimen in MGC, with appropriate dose modification.