The impact of the preoperative waiting period on the survival in patients with clinical stage II / III gastric cancer

27

Background: Although prolonged preoperative waiting period (PWP) for gastric cancer (GC) may influence the prognosis, the relationship between PWP and survival outcome has not been elucidated. The aim of this study is to identify the impact of PWP on survival in patients with clinical stage (cStage) II / III GC. Methods: A total of 483 patients who underwent surgery for cStage II / III GC according to Japanese classification of GC, 14th edition, between January 2002 and December 2012 were included. The patients who underwent endoscopic submucosal dissection or neoadjuvant chemotherapy, or who had multiple cancer, special histological types of tumor, or urgent symptoms were excluded. We defined PWP as the period from the date of endoscopy for initial diagnose to that of surgery. Patients were divided into two groups according to PWP; short waiting period group (SWPG, PWP ≤ 60 days, n = 357) and long waiting period group (LWPG, PWP > 60 days, n = 126). Survival outcomes were compared between the groups and multivariate analysis for overall survival (OS) was conducted to identify independent prognostic factors. Results: The median PWP was 49 (21-323) days. In LWPG, patients were significantly older (P = 0.001) and had more comorbidities (P = 0.042) than those in SWPG. Preoperative lymph node status was significantly lower in LWPG (P = 0.031), although there were no differences in tumor depth and cStage between the groups. There was no difference in OS between the groups (5-year OS, SWPG: 61.0%, LWPG: 63.2%, P = 0.612). Multivariate analysis for OS identified age, BMI, histological type, and cStage as independent prognostic factors. Conclusions: Preoperative waiting period appears to have no influence on survival in patients with cStage II / III GC.

Histopathological tumor regression or ypN: Which better predicts survival of patients who received neoadjuvant chemotherapy and surgery for non-type 4 locally advanced gastric cancer?

114

Background: Histopathological tumor regression with < 10% residual tumor is a globally accepted prognostic factor in gastric cancer patients who received neoadjuvant chemotherapy (NAC) and curative surgery, however, impact of ypN remains unclear. Methods: Previously, Japan Clinical Oncology Group (JCOG) had conducted 3 phase II trials to evaluate NAC with irinotecan/CDDP (JCOG0001) and S-1/CDDP (JCOG0405) for extensive nodal disease, and with S-1/CDDP (JCOG0210) for large type 3 and type 4 (linitis plastica) disease. Prognostic factors, including ypN and histopathological tumor regression with < 10% residual tumor, were analyzed in patients with curative resection excluding type 4 advanced gastric cancer in these trials by univariable and multivariable analyses using the Cox proportional hazards model. Results: Among 85 patients, 5-year OS was 46.0% (95% CI, 35.0-56.4). Median OS was not reached in patients with < 10% residual tumor (n = 26), whereas that was 2.7 years (95% CI, 1.4-4.5) in patients with > 10% residual tumor (n = 59) (p = 0.008). Median OS was not reached in patients with ypN0-1 (n = 25), whereas that was 2.6 years (95% CI, 1.5-4.0) in patients with ypN2-3 (n = 60) (p = 0.003). On multivariable analysis, only ypN2-3 was an independent predictor of OS (hazard ratio, 3.67; 95% CI, 1.55 to 8.69), whereas < 10% residual tumor was not (hazard ratio, 2.24; 95% CI, 0.98 to 5.10). Conclusions: It is suggested that ypN may have greater impact on the survival than histopathological tumor regression in patients who received NAC and surgery for AGC.

Second primary cancers and recurrence in patients after resection of colorectal cancer: An integrated analysis of trials by Japan Clinical Oncology Group: JCOG0205, JCOG0212, JCOG0404 (JCOG1702A)

561

Background: Improvements in early detection and treatment have resulted in an increasing number of long-term survivors of colorectal cancer (CRC). For the survivors, Second primary cancers and recurrence are important issues, but the evidence for appropriate surveillance strategy is limited. The aim of this study was to investigate the frequency and the timing of second primary cancers and recurrence in patients (pts) after surgery using 3 randomized trials (J0205, J0212 and J0404) conducted by Colorectal Cancer Study Group of JCOG. Methods: Eligibility criteria included histologically proven CRC and having received surgery. The timing, site and frequency of second primary cancer and recurrence were investigated. Risk factors associated with the events were explored. Standardized incidence ratio (SIR) about second primary cancer compared with national database of Japan Cancer Registry was estimated. Results: A total of 2,824 pts with a median follow-up time of 6 years were included. Median age was 62 years old (23-75), male/female was 58%/42%, and stage 0/I/II/III/IV was 0.2%/8.7%/25.4%/64.8%/0.9%. Pts with 5-FU based adjuvant chemotherapy were 63%. Cumulative incidence of second primary cancer increased constantly over time (Table). Among 240 pts, the most common site was lung (37), stomach (35) and colon (32). In multivariable analysis, age (over 64 years old) and sex (male) were risk factors (age HR: 1.60 (95% CI: 1.24-2.07), sex HR: 1.36 (95% CI: 1.04-1.78)). The SIR of any second primary cancers was 1.07 (95% CI: 0.94-1.21). The SIR for second primary cancers of colon was 1.09 (95% CI: 0.79-1.47). On the other hand, cumulative incidence of recurrence almost reached at 3 years. Conclusions: Common surveillance strategy can be applied even for curatively resected CRC pts after 3 years from surgery, because the risk of second primary cancer was almost same as general population over time. The necessity of intensive follow-up to detect recurrence decreases after 3 years. [Table: see text]

Randomized phase III study of observation versus adjuvant capecitabine and oxaliplatin in curatively resected small bowel adenocarcinoma: A Japan Clinical Oncology Group study (JCOG1502C)

TPS539

Background: Small bowel adenocarcinoma (SBA) is extremely rare tumor. Surgery is broadly applied as a standard treatment for localized SBA. However, the patients with localized SBA have poor prognosis even after curative resection (5-year survival: 40-65%), and most of them experience relapse. To prevent relapse, postoperative therapies are considered as most promising. However, there is no prospective study of postoperative therapies for curatively resected SBA patients and which regimens improve prognoses is unknown. For metastatic SBA, fluoropyrimidine and oxaliplatin is now regarded as global standard chemotherapy. Therefore, Japan Clinical Oncology Group (JCOG) planned a multicenter randomized phase III trial to confirm the superiority of postoperative capecitabine and oxaliplatin (CAPOX) to observation for curatively resected SBA under the Advanced Medical Care System of the Ministry of Health, Labour and Welfare, Japan. This study is a counterpart trial of BALLAD trial conducted in International Rare Cancer Initiative (IRCI) (clinical trials gov; NCT02502370), and the integrated analysis of BALLAD trial and JCOG1502C is planned. Methods: Eligibility criteria include histologically proven adenocarcinoma located in the duodenum (except Ampulla of Vater) / jejunum / ileum, curatively resected with regional lymph nodes dissection, pathological stage I (T1b-2N0M0) / stage II / stage III. Eligible patients are randomized into observation arm or CAPOX arm. CAPOX (130 mg/m2 of oxaliplatin on day 1, and 1000 mg/m2 of capecitabine twice a day for 14 days) is repeated every 3 weeks for 6 months (total 8 courses). The primary endpoint is RFS. The 3-year RFS of observation arm is assumed to be 70% and expected a 10% increase in CAPOX arm. The sample size was calculated as 150 (75 per arm) with a one-sided alpha level of 10%, a statistical power of 70%, an accrual period of 6.5 years. This study has been registered in the UMIN Clinical Trials Registry (UMIN000027280). This trial was activated in 9 May 2017, and no patients was enrolled as of Sep 2017. We will increase the number of participating sites up to 20 throughout Japan. Clinical trial information: UMIN000027280.

Long-term outcomes of laparoscopy-assisted distal gastrectomy with suprapancreatic nodal dissection for clinical stage I gastric cancer: a multicenter phase II trial (JCOG0703)

BACKGROUND

Laparoscopic gastrectomy has become a common surgical treatment for gastric cancer in eastern Asian countries. However, a large-scale prospective study to investigate the benefit of laparoscopy-assisted distal gastrectomy (LADG) regarding long-term outcomes has never been reported. We have already reported the short-term outcomes of this study. Here we report long-term outcomes as the secondary endpoints of this study after a 5-year follow-up period.

METHODS

This study comprised patients with clinical stage I gastric cancer who were able to undergo a distal gastrectomy. LADG with D1 plus suprapancreatic lymph node dissection was performed by credentialed gastric surgeons who had each conducted at least 30 LADG and 30 open gastrectomy procedures. The primary endpoint was the proportion of patients who developed either anastomotic leakage or pancreatic fistula. The secondary endpoints included overall survival and relapse-free survival.

RESULTS

From November 2007 to September 2008, 176 eligible patients were enrolled, comprising 140 patients with pathological stage IA disease, 23 patients with pathological stage IB disease, 9 patients with pathological stage II disease, and 4 patients with pathological stage IIIA disease. No patients had recurrent disease, and three of the patients died within the follow-up period. The 5-year overall survival was 98.2% (95% confidence interval 94.4-99.4%) and the 5-year relapse-free survival was 98.2% (95% confidence interval 94.4-99.4%).

CONCLUSIONS

The long-term outcomes of stage I gastric cancer patients undergoing LADG seem comparable to those of patients undergoing an open procedure, although this result should be confirmed by a randomized control trial. We have already completed accrual of 921 patients for a multicenter randomized phase III trial (JCOG0912) to confirm the noninferiority of LADG compared with open gastrectomy in terms of relapse-free survival.

Efficacy and safety of sofosbuvir and ledipasvir in Japanese patients aged 75 years or over with hepatitis C genotype 1

AIM

To evaluate the efficacy and safety of a regimen containing sofosbuvir (SOF) and ledipasvir (LDV) in Japanese patients aged ≥ 75 years with hepatitis C genotype 1.

METHODS

This multicenter, retrospective study consisted of 246 Japanese patients with HCV genotype 1 at nine centers in Miyazaki prefecture in Japan. Demographic, clinical, virological, and adverse effects (AE)-related data obtained during and after SOF/LDV therapy were collected from medical records. These patients were divided into two groups, younger (aged < 75 years) and elderly (aged ≥ 75 years). Virological data and AEs were analyzed by age group.

RESULTS

The sustained virological response (SVR) rates at 12 wk after treatment were 99.2%, 99.4%, and 98.7% in the overall population and in patients aged < 75 and ≥ 75 years, respectively. Common AEs during therapy were headache, pruritus, constipation, and insomnia. These occurred in fewer than 10% of patients, and their incidence was not significantly different between the younger and elderly groups. Two patients discontinued treatment, one due to a skin eruption and the other due to cerebral bleeding.

CONCLUSION

Compared with younger patients, elderly patients had a similar virological response and tolerance to SOF/LDV therapy.

Collaboration between EORTC and JCOG-how to accelerate global clinical research partnership

The demand for international collaboration in cancer clinical trials has grown stronger to maximize efficiency, avoid duplication of effort and to achieve effective implementation of research results into medical practice. Infrastructures that could facilitate intercontinental collaboration not only between Europe and United States but also between Europe and Asia are urgently needed. The European Organisation for Research and Treatment of Cancer, one of the major cancer clinical research infrastructure in Europe, initiated collaboration with the Japan Clinical Oncology Group, the largest cancer research cooperative group in Japan. Their first pilot trial on unresectable colorectal liver metastasis will commence on fourth quarter of 2016. With similar goals and strategies as well as with similar structures, the two research organizations have a great potential for efficient collaboration that could deliver faster and global therapeutic improvement to cancer patients. However, international collaboration requires careful and structured approach to harmonize activities to ensure success. This article focuses on specific intercontinental differences and the necessary requirements to ensure a successful partnership between European Organisation for Research and Treatment of Cancer and Japan Clinical Oncology Group. This could serve as a model to build more global international academic trials between the East and the West.

Postherpetic abdominal pseudohernia: A diagnostic pitfall

The accurate diagnosis of postherpetic abdominal pseudohernia, the rare complication of herpes zoster, is essential to avoid unnecessary imaging studies or surgery. Close observation and waiting for complete recovery are warranted considering the disease's self‐resolving nature and favorable prognosis.

Esophageal stenosis and the Glasgow Prognostic Score as independent factors of poor prognosis for patients with locally advanced unresectable esophageal cancer treated with chemoradiotherapy (exploratory analysis of JCOG0303)

BACKGROUND

The aim of this study was to investigate the possible prognostic factors and predictive accuracy of the Glasgow Prognostic Score (GPS) for patients with unresectable locally advanced esophageal squamous cell carcinoma (LAESCC) treated with chemoradiotherapy.

METHODS

One hundred forty-two patients were enrolled in JCOG0303 and assigned to the standard cisplatin and 5-fluorouracil (PF)-radiotherapy (RT) group or the low-dose PF-RT group. One hundred thirty-one patients with sufficient data were included in this analysis. A Cox regression model was used to analyze the prognostic factors of patients with unresectable LAESCC treated with PF-RT. The GPS was classified based on the baseline C-reactive protein (CRP) and serum albumin levels. Patients with CRP ≤1.0 mg/dL and albumin ≥3.5 g/dL were classified as GPS0. If only CRP was increased or only albumin was decreased, the patients were classified as GPS1, and the patients with CRP >1.0 mg/dL and albumin <3.5 g/dL were classified as GPS2.

RESULTS

The patients' backgrounds were as follows: median age (range), 62 (37-75); male/female, 119/12; ECOG PS 0/1/2, 64/65/2; and clinical stage (UICC 5th) IIB/III/IVA/IVB, 3/75/22/31. Multivariable analyses indicated only esophageal stenosis as a common factor for poor prognosis. In addition, overall survival tended to decrease according to the GPS subgroups (median survival time (months): GPS0/GPS1/GPS2 16.1/14.9/8.7).

CONCLUSIONS

Esophageal stenosis was identified as a candidate stratification factor for randomized trials of unresectable LAESCC patients. Furthermore, GPS represents a prognostic factor for LAESCC patients treated with chemoradiotherapy.

CLINICAL TRIAL INFORMATION

UMIN000000861.

Fibroblast growth factor receptor 2 expression, but not its genetic amplification, is associated with tumor growth and worse survival in esophagogastric junction adenocarcinoma

Background

Fibroblast growth factor receptor 2 (FGFR2) genetic alterations lead to tumor cell proliferation in various types of cancer. We hypothesized that FGFR2 amplification is associated with FGFR2 expression, resulting in tumor growth and poorer outcome in esophagogastric junction (EGJ) adenocarcinoma.

Patients and Methods

A total of 176 consecutive chemo-naive patients with EGJ adenocarcinoma were enrolled from two academic institutions. FGFR2 amplification was examined by real-time PCR (N = 140) and FGFR2 expression with immunohistochemical staining (N = 176), and compared against clinicopathological factors and patient outcomes. The effects of FGFR2 inhibition or overexpression on cell proliferation, cell cycle, and apoptosis assays were investigated in EGJ adenocarcinoma cell lines. Downstream FGFR2, AKT and ERK were also examined.

Results

Based on the correlation between FGFR2 levels and FGFR2 overexpression in vitro, FGFR2 amplification was defined as copy number > 3.0. In clinical samples, FGFR2 amplification and FGFR2 IHC expression were 15% and 61%, respectively. Although these two statuses were significantly correlated (P < 0.05), only FGFR2 IHC expression was significantly associated with tumor depth (multivariate P < 0.001) and overall survival of patients (univariate P = 0.007). Supporting these findings, FGFR2 overexpression was associated with tumor cell proliferation, cell cycle progression, and anti-apoptosis. Selective inhibition of FGFR2 sufficiently suppressed tumor cell proliferation through de-phosphorylation of AKT and ERK.

Conclusions

FGFR2 amplification was significantly associated with FGFR2 expression. FGFR2 expression (but not FGFR2 amplification) was associated with tumor growth and patient outcomes. Our findings support FGFR2 as a novel therapeutic target for EGJ adenocarcinoma.

Dose-finding and efficacy confirmation trial of the superselective intra-arterial infusion of cisplatin and concomitant radiotherapy for locally advanced maxillary sinus cancer (Japan Clinical Oncology Group 1212): Dose-finding phase

BACKGROUND

We are currently undertaking a multi-institutional prospective trial of the superselective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy for patients with T4aN0M0 or T4bN0M0 locally advanced maxillary sinus squamous cell carcinomas (SCC). We herein report the results of the dose-finding phase.

METHODS

The dose-finding phase sought to evaluate the incidence of dose-limiting toxicities and determine the recommended number of cycles of the intra-arterial infusion of cisplatin. In this phase, 100 mg/m² of cisplatin was administered intra-arterially weekly for 7 weeks with concomitant radiotherapy (70 Gy).

RESULTS

All 18 patients received a full dose of radiotherapy. The number of cycles of cisplatin was 7 in 13 patients and 6 in 5 patients. The dose-limiting toxicities were observed in 5 patients.

CONCLUSION

These results indicated that this therapy is safe and well-tolerated at 7 cycles of cisplatin, which was determined to be the recommended number of cycles for locally advanced maxillary sinus SCC.

Fusobacterium nucleatum in gastroenterological cancer: Evaluation of measurement methods using quantitative polymerase chain reaction and a literature review

The human microbiome Fusobacterium nucleatum, which primarily inhabits the oral cavity, causes periodontal disease and has also been implicated in the development of colorectal cancer. However, whether F. nucleatum is present in other gastroenterological cancer tissues remains to be elucidated. The present study evaluated whether quantitative polymerase chain reaction (qPCR) assays were able to detect F. nucleatum DNA and measure the quantity of F. nucleatum DNA in esophageal, gastric, pancreatic and liver cancer tissues. The accuracy of the qPCR assay was determined from a calibration curve using DNA extracted from cells from the oral cavity. Formalin-fixed paraffin-embedded (FFPE) tumor tissues from 20 patients with gastroenterological [esophageal (squamous cell carcinoma), gastric, colorectal, pancreatic and liver] cancer and 20 matched normal tissues were evaluated for F. nucleatum DNA content. The cycle threshold values in the qPCR assay for F. nucleatum and solute carrier organic anion transporter family member 2A1 (reference sample) decreased linearly with the quantity of input DNA (r²>0.99). The F. nucleatum detection rate in esophageal, gastric and colorectal cancer tissues were 20% (4/20), 10% (2/20) and 45% (9/20), respectively. F. nucleatum was not detected in liver and pancreatic cancer tissues. The qPCR results from the frozen and FFPE tissues were consistent. Notably, F. nucleatum was detected at a higher level in superficial areas compared with the invasive areas. F. nucleatum in esophageal, gastric and colorectal cancer tissues was evaluated by qPCR using FFPE tissues. F. nucleatum may be involved in the development of esophageal, gastric and colorectal cancer.

Utility of Bayesian Single-Arm Design in New Drug Application for Rare Cancers in Japan: A Case Study of Phase 2 Trial for Sarcoma

Investigational drugs for rare cancers are often approved based solely on a single-arm phase II trial that primarily evaluates response rate in Japan. Such trials typically use a fixed sample size determined on the basis of the frequentist manner. However, since predicting the speed of patient enrollment is challenging because of the disease rarity, the time needed to complete the enrollment of the fixed number of patients is prolonged in some cases. A Bayesian design without fixing the sample size is useful for single-arm phase II trials of rare cancers. However, the arbitrariness of prior distribution specifications and the frequentist operating characteristics are regulatory issues. We recently started a Bayesian single-arm phase II trial of nivolumab in patients with sarcoma for new drug application in Japan and examined the statistical rationale and design consideration. In the Bayesian design, we specify the minimum and maximum numbers of enrolled patients during the enrollment period and the prior distributions of response rates. Considering these parameters, we obtain the minimum number of responders needed for the positive conclusion of the efficacy of nivolumab for each sample size. Simulation studies demonstrated that the operating characteristics of this design would be acceptable from the frequentist view. The Bayesian design provided an adaptive decision rule for efficacy conclusion for the drug without fixing the sample size. We hope our trial's success will provide a new drug development option for rare cancers in Japan.

Prognostic Impact of Postoperative Morbidity After Esophagectomy for Esophageal Cancer: Exploratory Analysis of JCOG9907

OBJECTIVE

To investigate the influence of infectious complications on the outcome of current standard preoperative chemotherapy followed by surgery for clinical stage II/III esophageal cancer.

BACKGROUND

The impact of postoperative infectious complications on survival after transthoracic esophagectomy remains controversial.

METHODS

Data from a randomized controlled trial (JCOG9907) were used. Infectious complications were classified into three groups: pneumonia, anastomotic leakage, and others. Univariate and multivariate analyses using the Cox proportional hazard model were performed.

RESULTS

Among the 152 analyzed patients, the incidence of pneumonia, leakage, and overall infectious complication were 22 (14%), 21 (14%), and 54 (36%). Overall survival (OS) of patients with any infectious complication was shorter than that of patients without infectious complication [hazard ratio, HR 1.66, 95% confidence interval, CI, (1.02-2.71)] and progression-free survival (PFS) also tended to be shorter in patients with any infectious complication [HR 1.44, (0.92-2.24)]. The OS of patients with pneumonia was shorter than that of patients without pneumonia [HR 1.82, (1.01-3.29)], and PFS also tended to be shorter in patients with pneumonia [HR 1.50, (0.85-2.62)]. The OS of patients with anastomotic leakage (n = 21) was nearly identical to that for patients without leakage [HR 1.06, (0.52-2.13)] and PFS showed the same tendency [HR 1.28, (0.71-2.32)]. Multivariate analysis revealed that pneumonia tended to compromise OS and PFS [HR 1.66, (0.87-3.17) and HR 1.37, (0.75-2.51)].

CONCLUSIONS

These results indicate that postoperative infectious complications may worsen patient prognosis after esophagectomy. Performing esophagectomy without postoperative complications, especially pneumonia, may be beneficial for improving survival outcomes.

Establishment and characterization of cell lines derived from complete hydatidiform mole

Gestational trophoblastic diseases (GTDs) are a group of diseases characterized by abnormal cellular proliferation of atypical trophoblasts. A hydatidiform mole is an abnormal pregnancy caused by genetic fertilization disorders, and it can be classified as a complete hydatidiform mole (CHM) or a partial hydatidiform mole. The aim of this study was to establish cell lines from CHMs and to characterize the cells for future studies concerning GTD. HMol1-2C, HMol1-3B, HMol1-8 and HMol3-1B were established from primary cultures of CHM explants following the introduction of different combinations of genes including human telomerase reverse transcriptase (hTERT), a mutant form of CDK (CDK4R24C), cyclin D1, p53C234, MYC and HRAS. HMol1-2C, HMol1-3B, and HMol3-1B were confirmed to originate from trophoblasts of androgenic, homozygous CHMs. These three cell lines exhibited low human chorionic gonadotropin secretion, low migration and invasion abilities, and the potential to differentiate into syncytiotrophoblastic cells via forskolin treatment. These results suggest that these cells exhibit characteristics of trophoblastic cells, especially cytotrophoblastic cells. HMol1-8 was found to consist of diploid cells and originated from maternal cells, suggesting that they were derived from decidual cells. In conclusion, we successfully established three cell lines from CHMs by introduction of hTERT and other genes. Analysis revealed that the genetic origin of each cell line was identical with that of the original molar tissue, and the cell lines exhibited characteristics of trophoblastic cells, which are similar to undifferentiated cytotrophoblasts.

Abstract 4825: Functional role of Ring Finger Protein 43 in intestinal stem cell during colorectal tumorigenesis

Background: Colorectal cancer is one of the most general causes of cancer related death. Ring Finger Protein 43(RNF43) is an E3 ubiquitin ligase that suppresses the Wint signaling pathway and is known as a tumor suppressor gene. Previous studies reported RNF43 mutation leads to inactivation of RNF43 in pancreatic, ovarian, colorectal cancer and so on. Subsequently, Wnt signaling activation is associtated with tumor progression in these types of cancers. However, functional role of RNF43 for tumor formation is not clear in colorectal cancer.

Aim: To investigate the functional role of RNF43 in colorectal cancer by using RNF43 knockout mice.

Method: We prepared RNF43 knockout mice by using CRISPR/Cas9 system. To induce colorectal tumor in mice, we used Azoxymethane-Dextran sulfate sodium (AOM-DSS) model. First, we injected AOM 10mg/kg into the peritoneal cavity. After 7days from injection, drunk 2% DSS water to mice for 7days. We sacrificed the mice and evaluated the tumor incidence and tumor size after 8, 10, 12, and 16 weeks from injection. Next, we prepared the small intestine organoid from RNF43 wild and knockout mice. Then we compared the organoid size and formation rate. In vitro analysis, we prepared colon cancer cell lines (COLO205, SW620, HCT116) and evaluated the effect on cell proliferation in suppression of RNF43 and normal condition.

Result: There was no significant difference in the tumor incidence and tumor size at 8, 10, and 12weeks after AOM injection. However, at 16 weeks, the tumor size of RNF43 knockout mice was significantly bigger than that of RNF43 wild type mice. (p&lt;0.001) Further examination of the intestinal organoid revealed that the organoids derived from RNF43 knockout mice tended to get bigger than those from wild type mice. In vitro analysis, cell proliferation of RNF43 mutant cell line (HCT116) was significantly increased compared with RNF43 wild type cell lines (COLO205, SW620). RNF43 silencing significantly increased cell proliferation in RNF43 wild type cell lines (p&lt;0.001), whereas did not affected in RNF43 mutant cell line.

Conclusion: Our results suggest that RNF43 expression suppresses epithelial cell growth in the intestine, and the dysregulation of Wint signaling via RNF43 disruption promote intestinal stem cell expansion and colorectal tumorigenesis.

Citation Format: Tsugio Eto, Takatsugu Ishimoto, Eri Oda, Daisuke Kuroda, Kota Arima, Mayuko Ohuchi, Kenichi Nakamura, Hiroshi Sawayama, Koichi Kinoshita, Masaaki Iwatsuki, Yoshifumi Baba, Yasuo Sakamoto, Naoya Yoshida, Hideo Baba. Functional role of Ring Finger Protein 43 in intestinal stem cell during colorectal tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4825. doi:10.1158/1538-7445.AM2017-4825

Abstract 4407: Glucose transporter 1 is associated with proliferation and prognosis on esophageal squamous cell carcinoma

Purpose: Cancer cells exhibit altered glucose metabolism, termed glycolysis which is described by the increased uptake of glucose and the conversion of glucose to lactate in cancer cells under adequate oxygen tension. Alternating glucose transporters (GLUTs) expression was detected in the cancer specific metabolism to adapt to the rapid growth and tumor microenvironment in diverse malignant tumors. In this study, GLUTs profiling of ESCC patients, the relation between proliferation and GLUT1 expression using siRNA for GLUT1 were analyzed. Furthermore, the prognostic features according to GLUT1 expression was evaluated on esophageal squamous cell carcinoma (ESCC) patients.

Methods: The ratio of the 11 GLUTs (GLUT1- GLUT14) expression between tumor and normal tissue (T/N) were analyzed in silico (GDS3838). GLUT1 expression was down-regulated using 3 siRNAs in vitro. Immunohistochemical staining of GLUT1 was performed using paraffin sections of tissues obtained from 145 resectable ESCC patients without preoperative treatment.

Results: Expression of GLUT1 (T/N 2.44; 95% confidence interval (CI): 1.78-3.34, P&lt;0.001), GLUT3 (T/N 1.96; 95%CI: 1.23-3.13, P=0.01) and GLUT6 (T/N 1.31; 95%CI: 1.12-1.54, P&lt;0.001) increased in tumor tissue compared with normal tissue. TE-1 and TE-8 cells were treated with 3 siRNAs for GLUT1 and control siRNA for 72 hours in vitro. The proliferation of TE-1 and TE-8 cells after siRNAs for GLUT1 compared with control siRNA decreased 72.9-84.5% and 44.8-53.3%, respectively. GLUT1 expression was evaluated with 145 ESCC patients. Glut1 positivity was observed in 41 patients (28.2%) and associated with depth of invasion (odds ratio (OR)=2.984; 95%CI: 1.208-7.371, P=0.018) and vascular invasion (OR=2.771; 95% CI: 1.118-6.871, P=0.028) in multivariate analysis. GLUT1 positivity was a significant disadvantage to both relapse-free survival (hazard ratio (HR)=2.021; 95%CI: 1.100-3.712; P=0.023) and esophageal cancer-specific survival (HR=2.223; 95%CI: 1.121-4.411; P=0.022) in univariate Cox hazard analysis.

Conclusions: GLUTs expression was altered in ESCC patients and GLUT1 expression was most up-regulated among the 11 GLUTs. Growth assay with siRNAs for GLUT1 revealed that GLUT1 played a curial role of ESCC cells proliferation. High expression of GLUT1 was associated with depth of invasion and poor prognosis of ESCC patients. These findings provide evidence of the significance of GLUT1 expression as a biomarker and GLUT1 may be therapeutic target in ESCC patient.

Citation Format: Hiroshi Sawayama, Masaaki Iwatsuki, Naoya Yoshida, Yoshifumi Baba, Yasuo Sakamoto, Koichi Kinoshita, Kenichi Nakamura, Daisuke Kuroda, Eto Tsugio, Tasuku Toihata, Tomoyuki Uchihara, Eri Oda, Taisuke Yagi, Mayuko Ohuchi, Takatugu Ishimoto, Hideo Baba. Glucose transporter 1 is associated with proliferation and prognosis on esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4407. doi:10.1158/1538-7445.AM2017-4407

Evaluation of value in non-inferiority trials by ASCO’s conceptual framework

e18304

Background: ASCO released a conceptual framework assessing the value of cancer treatment options in 2015 and its updated version in 2016 as a tool to evaluate clinical benefit and toxicity in clinical trials. This framework was developed as a facilitator of discussions on the individual treatment between physicians and their patients. This tool consists of the elements of clinical benefit, toxicity, and symptom palliation, and these elements are combined into a score termed the net health benefit (NHB). However, in the clinical setting, not only these elements but also various factors benefit patients such as more convenient treatment schedule, shorter administration time, or non-invasive route of administration. Especially, test treatment in non-inferiority trials is likely to have these merits in addition to the benefit in toxicity. Therefore, we investigated whether the ASCO framework can identify reasonable NHB in test treatment regimens of non-inferiority trials. Methods: A systematic literature search of randomized non-inferiority trials for cancer reported from 2009 to 2015 was performed using PubMed. Inclusion criteria were English, a full-length article, available toxicity data, non-inferiority trial with a positive result, and chemotherapy. We calculated clinical benefit, toxicity score, bonus points, and NHB according to the ASCO framework. Results: We found 20 non-inferiority trials. Median sample size was 419. The common cancer types were colorectal (7 trials), lung (5), hematologic (2), and breast (2). Of 20 trials, 8 were conducted internationally, 4 in Japan, and 3 in Germany. In the ASCO framework, median NHB was 4.5 points, and 7 of 20 trials (35%) showed negative impact of test treatment, which means that NHB was minus points (-0.6 to -24.53). In 6 of these 7 trials, test treatment was in more convenient schedule or administered by non-invasive route compared with standard treatment. Conclusions: In the ASCO framework, merits in treatment schedule or route of administration may not be fully captured, and the test treatments in some non-inferiority trials showed negative NHB. It is desirable to assess not only NHB but also such merits in considering the risk-benefit balance in non-inferiority trials.

EORTC1527/JCOG1609INT: Diffusion-weighted MRI (DW-MRI) assessment of liver metastasis to improve surgical planning (DREAM)

TPS3633

Background: For patients with initially unresectable colorectal liver metastases (CRLM) with good clinical response to chemotherapy, the presence of disappearing liver metastases (DLMs) diagnosed by CT is a major independent prognostic factor. DW-MRI as well as contrast enhanced (CE)-MRI is recommended to detect and characterize CRLM. However, the correlation between radiological and pathological complete response has not been fully investigated using these latest imaging and pathology techniques. Our main aim is to demonstrate the added value of DW-MRI, CE-MRI to that of CT alone to provide precise assessment of the viability of DLMs. In addition, we aim to optimize the therapeutic management of CRLM patients. No prospective study has been conducted to determine the predictive value of DW-MRI combined with CE-MRI in confirming sites of DLMs and assessing their true status. Methods: This is the first collaborative study between EORTC, ESSO and JCOG with an integrated quality assurance program for imaging, surgery and pathology. Patients with unresectable CRLM will receive standard systemic chemotherapy and liver resection if resectable. Both CT and MRI (DW-MRI, CE-MRI and T1/T2) will be used to identify confirmed DLMs (cDLMs). cDLMs will be either resected or, if resection is not possible, followed-up without resection until 2 years after surgery to evaluate the true status of the cDLMs. The primary endpoint is negative predictive value (NPV) of DW-MRI, CE-MRI, T1/T2 and CT in confirming the status of cDLMs using as reference either the histopathological complete response or the absence of a local recurrence at the site of cDLMs during the follow up period of 2 years. The study aims at excluding a NPV≤0.85 and is powered under the alternative that the NPV≥0.95. The planned sample size is 92 evaluable (resected or left behind) cDLMs, with a 1-sided alpha of 5% and a power of 90% adjusting for within-patient correlation between cDLMs of 0.2 and an average number of 2 cDLMs per patient. Approximately 400 patients will be registered from European, Japanese and US sites over 3 years. As of February 2017, 2 patients have been enrolled. Clinical trial information: NCT02781935.

POU4F3 mutation screening in Japanese hearing loss patients: Massively parallel DNA sequencing-based analysis identified novel variants associated with autosomal dominant hearing loss

A variant in a transcription factor gene, POU4F3, is responsible for autosomal dominant nonsyndromic hereditary hearing loss, DFNA15. To date, 14 variants, including a whole deletion of POU4F3, have been reported to cause HL in various ethnic groups. In the present study, genetic screening for POU4F3 variants was carried out for a large series of Japanese hearing loss (HL) patients to clarify the prevalence and clinical characteristics of DFNA15 in the Japanese population. Massively parallel DNA sequencing of 68 target candidate genes was utilized in 2,549 unrelated Japanese HL patients (probands) to identify genomic variations responsible for HL. The detailed clinical features in patients with POU4F3 variants were collected from medical charts and analyzed. Novel 12 POU4F3 likely pathogenic variants (six missense variants, three frameshift variants, and three nonsense variants) were successfully identified in 15 probands (2.5%) among 602 families exhibiting autosomal dominant HL, whereas no variants were detected in the other 1,947 probands with autosomal recessive or inheritance pattern unknown HL. To obtain the audiovestibular configuration of the patients harboring POU4F3 variants, we collected audiograms and vestibular symptoms of the probands and their affected family members. Audiovestibular phenotypes in a total of 24 individuals from the 15 families possessing variants were characterized by progressive HL, with a large variation in the onset age and severity with or without vestibular symptoms observed. Pure-tone audiograms indicated the most prevalent configuration as mid-frequency HL type followed by high-frequency HL type, with asymmetry observed in approximately 20% of affected individuals. Analysis of the relationship between age and pure-tone average suggested that individuals with truncating variants showed earlier onset and slower progression of HL than did those with non-truncating variants. The present study showed that variants in POU4F3 were a common cause of autosomal dominant HL.

The BCR/ABL tyrosine kinase inhibitor, nilotinib, stimulates expression of IL-1β in vascular endothelium in association with downregulation of miR-3p

BCR/ABL tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis for in dividuals with chronic myeloid leukemia (CML). However, many patients treated with TKIs suffer from TKI-related complications. In particular, vascular events such as peripheral artery occlusive disease have become aserious clinical problem for patients who receive the TKI, nilotinib. At present, the molecular mechanisms by which TKIs cause vascular endothelial cell insults remain unknown.This study explored the effects of the TKIs, imatinib, nilotinib and dasatinib, on vascular endothelial cells in vitro, and found that only nilotinib induced expression of interleukin-1β (IL-1β) by vascular endothelial cells. Nilotinib-induced IL-1β expression stimulated the adhesion of monocytes to vascular endothelial cells in association with an increase in levels of adhesion molecules. MicroRNA database searching identified miR-3121-3p binding sites in the 3'-UTR of the IL-1β gene. Exposure of endothelial cells to nilotinib caused downregulation of miR-3121-3p in these cells. Importantly, forced-expression of miR-3121-3p counteracted nilotinib-induced expression of IL-1β. Importantly, serum levels if IL-1β were significantly elevated in CML patients receiving nilotinib (n=14) compared to those receiving other TKIs (n=16) (3.76±1.22pg/ml vs 0.27±0.77pg/ml, p<0.05). Taken together, our data suggest that nilotinib decreases levels of miR-3121-3p resulting in an increase in expression of IL-1β and adhesion molecules in vascular endothelial cells. The miR-3121-3p/IL-1β axis could be a potential target to prevent vascular events in CML patients with high risk of vascular events.

Institutional variation in short- and long-term outcomes after surgery for gastric or esophagogastric junction adenocarcinoma: correlative study of two randomized phase III trials (JCOG9501 and JCOG9502)

BACKGROUND

A critical issue in multicenter randomized trials focusing on surgical techniques is quality control, as the quality of the surgery usually varies widely if the procedure employed is complicated. Few studies have evaluated interinstitutional variation in randomized trials in order to check not only the generalizability of the results but also the reliability of the study group itself.

METHODS

Two randomized phase III trials (JCOG9501 and JCOG9502) were conducted that compared standard and experimental surgery for gastric and esophagogastric junction adenocarcinomas. Mixed effects models were used to examine short- and long-term outcome data for 521 patients from 23 hospitals in JCOG9501 and 157 patients from 21 hospitals in JCOG9502.

RESULTS

In both trials, some variation was observed in the number of dissected lymph nodes, the operative time, and the volume of blood lost. Estimated 5-year overall survival after standard surgery differed among hospitals (JCOG9501, 58.0-75.1 %; JCOG9502, 49.1-58.7 %), while there was little variation in the hazard ratio for overall survival (OS) for experimental versus standard surgery (JCOG9501, 1.05-1.48; JCOG9502, 1.44-1.48). Higher hospital gastrectomy volume was significantly correlated with a lower proportion of postoperative complications in JCOG9501 (ρ = -0.524, P = 0.010) and reduced blood loss in JCOG9502 (ρ = -0.442, P = 0.045). OS was not correlated with hospital or surgeon volume.

CONCLUSIONS

There was some degree of interinstitutional variation in outcomes after standard surgery, but there was little variation in the hazard ratio for OS for experimental surgery, indicating that the final conclusions of the two randomized phase III trials can be generalized to their respective target populations.

TET2 mutation in diffuse large B-cell lymphoma

Ten-eleven translocation-2 (TET2) mutation is frequently observed in myeloid malignancies, and loss-of-function of TET2 is essential for the initiation of malignant hematopoiesis. TET2 mutation presents across disease entities and was reported in lymphoid malignancies. We investigated TET2 mutations in 27 diffuse large B-cell lymphoma (DLBCL) patients and found a frameshift mutation in 1 case (3.7%). TET2 mutation occurred in some populations of DLBCL patients and was likely involved in the pathogenesis of their malignancies.

Laparoscopic subtotal gastrectomy for advanced gastric cancer: technical aspects and surgical, nutritional and oncological outcomes

BACKGROUND

Higher morbidity in total gastrectomy than in distal gastrectomy has been reported, but laparoscopic subtotal gastrectomy (LsTG) has been reported to be safe and feasible in early gastric cancer (GC). We determined the surgical, nutritional and oncological outcomes of LsTG for advanced gastric cancer (AGC).

METHODS

Of the 816 consecutive patients with GC who underwent radical gastrectomy at our institution between 2008 and 2012, 253 who underwent curative laparoscopic gastrectomy (LG) for AGC were enrolled. LsTG was indicated for patients with upper stomach third tumors, who hoped to avoid total gastrectomy, <4 cm to the esophagogastric junction and a 2-cm proximal margin with cut end negative in frozen section, whereas laparoscopic conventional distal gastrectomy (LcDG) and laparoscopic total gastrectomy (LTG) were performed otherwise. Surgical outcomes and postoperative nutritional status were primarily assessed.

RESULTS

Of 253 patients, the morbidity (Clavien-Dindo classification grade ≥ III) was 17.0% (43 patients). The 3-year overall survival and 3-year recurrence-free survival rates were 80.2 and 73.5%, respectively. LcDG, LsTG and LTG were performed in 121, 27 and 105 patients, individually. Morbidity was strongly associated with LTG (P = 0.001). Postoperative loss of body weight was significantly greater after LTG in comparison with LcDG or LsTG (P < 0.001). No difference in morbidity and postoperative loss of body weight were observed between LcDG and LsTG group.

CONCLUSIONS

LG for AGC was feasible and safe surgically and oncologically. LsTG for AGC may be safer than LTG from surgical and postoperative nutritional point of view.