The Short- and Long-Term Surgical Results of Consecutive Hepatopancreaticoduodenectomy for Wide-Spread Biliary Malignancy.

BACKGROUND: Cancer-free resection (R0) is one of the most important factors for the long-term survival of biliary carcinoma. For some patients with widespread invasive cancer located between the hilar and intrapancreatic bile duct, hepatopancreaticoduodenectomy (HPD) is considered a radical surgery for R0 resection. However, HPD is associated with high morbidity and mortality rates. Furthermore, previous reports have not shown lymph node metastasis (LNM) status, such as the location or number, which could influence the prognosis after HPD. In this study, first, we explored the prognostic factors for survival, and second, we evaluated whether the LNM status (number and location of LNM) would influence the decision on surgical indications in patients with widely spread biliary malignancy. METHODS: We retrospectively reviewed the medical records of 54 patients who underwent HPD with hepatectomy in ≥2 liver sectors from January 2003 to December 2021 (HPD-G). We also evaluated 54 unresectable perihilar cholangiocarcinoma patients who underwent chemotherapy from January 2010 to December 2021 (CTx-G). RESULTS: R0 resection was performed in 48 patients (89%). The median survival time (MST) and 5-year overall survival rate of the HPD-G and CTx-G groups were 36.9 months and 31.1%, and 19.6 months and 0%, respectively. Univariate and multivariate analyses showed that pathological portal vein involvement was an independent prognostic factor for survival (MST: 18.9 months). Additionally, patients with peripancreatic LNM had worse prognoses (MST: 13.3 months) than CTx-G. CONCLUSIONS: Patients with peripancreatic LNM or PV invasion might be advised to be excluded from surgery-first indications for HPD.

Phase II Study of Continued Trastuzumab Plus Irinotecan in Patients with HER2-positive Gastric Cancer Previously Treated with Trastuzumab (HGCSG 1201).

BACKGROUND: The efficacy of irinotecan plus continuous trastuzumab beyond progression in patients with gastric cancer previously treated with trastuzumab plus standard first-line chemotherapy has not been reported. METHODS: Patients with human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer who were previously treated with trastuzumab received trastuzumab every 3 weeks and irinotecan every 2 weeks. The primary endpoint was the overall response rate (ORR), and the secondary endpoints included progression-free survival (PFS), 6-month survival rates, safety, and subgroup analysis by HER2 status. RESULTS: Sixteen patients were enrolled in a 3-year pre-planned registration period. This study was prematurely closed due to poor patient accrual. The ORR and disease control rate were 6.7% (95% CI, 0.2-32.0) and 53.3% (95% CI, 26.6-78.7). The median PFS and overall survival (OS) were 2.4 months (95% CI, 0.0-5.2) and 9.7 months (95% CI, 8.2-11.2), respectively. The most frequently reported grades 3-4 adverse events were neutropenia (40%), anemia (27%), anorexia (33%), and fatigue (33%). CONCLUSION: With only 16 patients enrolled, the present study has very low power to detect any clinical benefit of trastuzumab plus irinotecan beyond disease progression in patients with HER2-positive advanced gastric cancer who previously received trastuzumab.Trial Identifier: UMIN000007636.

Phase II Study of Ramucirumab Plus Irinotecan Combination Therapy as Second-Line Treatment in Patients with Advanced Gastric Cancer: HGCSG1603.

BACKGROUND: Ramucirumab is a human IgG1 monoclonal vascular endothelial growth factor receptor-2 antibody that inhibits tumor cell growth and affects the tumor cell microenvironment. We assessed the efficacy and safety of ramucirumab plus irinotecan combination therapy as second-line treatment in patients with previously treated advanced gastric cancer. MATERIALS AND METHODS: Patients with advanced gastric cancer refractory or intolerant to primary chemotherapy were included. Ramucirumab 8 mg/kg plus irinotecan 150 mg/m2 combination therapy was administered every 2 weeks. The primary endpoint was progression-free survival rate at 6 months and secondary endpoints were overall survival, progression-free survival, response rate, safety, and dose intensity for each drug. RESULTS: Thirty-five patients were enrolled between January 2018 and September 2019. The progression-free survival rate at 6 months was 26.5% [95%CI, 13.2%-41.8%, P = .1353)]. Median progression-free and overall survivals were 4.2 months (95%CI, 2.5-5.4 months) and 9.6 months (95%CI, 6.4-16.6 months), respectively. The overall response rate was 25.9% (95%CI, 11.1-36.3%) and disease control rate was 85.2% (95%CI, 66.3-95.8%). Grade ≥3 adverse events that occurred in >10% of patients included neutropenia, leucopenia, anemia, anorexia, and febrile neutropenia. No death or new safety signals with a causal relation to the study treatment were observed. CONCLUSION: Although the primary endpoint was not achieved statistically, combination therapy of ramucirumab plus irinotecan showed anticancer activity and a manageable safety profile for second-line treatment of patients with advanced gastric cancer.

Multicenter, prospective, observational study of chemotherapy-induced dysgeusia in gastrointestinal cancer.

PURPOSE: Dysgeusia is an adverse event caused by chemotherapy. Although retrospective studies have shown zinc administration improves dysgeusia, there have been no prospective studies. The present study examined effects of zinc therapy on dysgeusia in patients with gastrointestinal cancer. METHODS: This multicenter, prospective, observational study enrolled patients with dysgeusia during chemotherapy treatment. Patients received no intervention (control), polaprezinc p.o., or zinc acetate hydrate p.o., and serum zinc levels were measured at 0 (baseline), 6, and 12 weeks. Dysgeusia was assessed using CTCAE v5.0 and subjective total taste acuity (STTA) criteria using questionnaires at baseline and 12 weeks. RESULTS: From February 2020 to June 2021, 180 patients were enrolled from 17 institutes. There were no differences in mean baseline serum zinc levels among the groups (67.3, 66.6, and 67.5 µg/dL in the no intervention, polaprezinc, and zinc acetate hydrate groups, respectively. P = 0.846). The changes in mean serum zinc levels after 12 weeks were - 3.8, + 14.3, and + 46.6 µg/dL, and the efficacy rates of dysgeusia were 33.3%, 36.8%, and 34.6% using CTCAE and 33.3%, 52.6%, 32.7% using STTA in the no intervention, polaprezinc, and zinc acetate hydrate groups, respectively. The STTA scores improved in all groups, with significant improvement observed in the polaprezinc group compared with the no intervention group (P = 0.045). CONCLUSION: There was no significant correlation between the degree of serum zinc elevation and improvement in dysgeusia, suggesting that polaprezinc, but not zinc acetate hydrate, was effective in improving chemotherapy-induced dysgeusia. TRIAL REGISTRATION: UMIN000039653. Date of registration: March 2, 2020.

Usefulness of ultrasonography and elastography in diagnosing oxaliplatin-induced sinusoidal obstruction syndrome.

BACKGROUND: Sinusoidal obstruction syndrome (SOS) refers to liver injury caused by hematopoietic stem cell transplantation (HSCT) and anticancer drugs including oxaliplatin. Increased splenic volume (SV) on computed tomography (CT) indicates oxaliplatin-induced SOS. Similarly, ultrasonography and liver stiffness measurement (LSM) by shear-wave elastography (SWE) can help diagnose SOS after HSCT; however, their usefulness for diagnosing oxaliplatin-induced SOS remains unclear. We investigated the usefulness of the Hokkaido ultrasonography-based scoring system with 10 ultrasonographic parameters (HokUS-10) and SWE in diagnosing oxaliplatin-induced SOS early. METHODS: In this prospective observational study, ultrasonography and SWE were performed before and at 2, 4, and 6 months after oxaliplatin-based chemotherapy. HokUS-10 was used for assessment. CT volumetry of the SV was performed in clinical practice, and an SV increase ≥ 30% was considered the diagnostic indicator of oxaliplatin-induced SOS. We assessed whether HokUS-10 and SWE can lead to an early detection of oxaliplatin-induced SOS before an increased SV on CT. RESULTS: Of the 30 enrolled patients with gastrointestinal cancers, 12 (40.0%) with an SV increase ≥ 30% on CT were diagnosed with SOS. The HokUS-10 score was not correlated with an SV increase ≥ 30% (r = 0.18). The change in rate of three HokUS-10 parameters were correlated with an SV increase ≥ 30% (r = 0.32-0.41). The change in rate of LSM by SWE was correlated with an SV increase ≥ 30% (r = 0.40). CONCLUSIONS: The usefulness of HokUS-10 score was not demonstrated; however, some HokUS-10 parameters and SWE could be useful for the early diagnosis of oxaliplatin-induced SOS.

A Phase I Trial of Oxaliplatin, Irinotecan, and S-1 Combination Therapy (OX-IRIS) as Chemotherapy for Unresectable Pancreatic Cancer (HGCSG 1403).

LESSONS LEARNED: Because S-1 is orally administered, OX-IRIS does not necessitate the continuous infusion of 5-FU and is more convenient. The recommended dose of OX-IRIS was determined to be level -1 (oxaliplatin, 65 mg/m2 ; irinotecan, 100 mg/m2 ; S-1, 80 mg/m2 ), which has manageable safety and promising anticancer activities. BACKGROUND: OX-IRIS is a new combination therapy of oxaliplatin, irinotecan, and S-1 for unresectable pancreatic ductal adenocarcinoma (PDAC), which may be beneficial because S-1 is administered orally and continuous infusion of 5-fluorouracil (5-FU) is not needed. METHODS: Patients who had not received prior therapy for unresectable PDAC were enrolled. Adenocarcinoma or adenosquamous histology was required. Oxaliplatin and irinotecan were administered on days 1 and 15; S-1 was administered orally twice a day on days 1-14, followed by 14 days of rest (one cycle). Primary endpoints were dose-limiting toxicity (DLT) and maximum tolerated dose (MTD). Secondary endpoints were safety, overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). RESULTS: In level 0 (oxaliplatin, 85 mg/m2 ; irinotecan, 100 mg/m2 ; S-1, 80 mg/m2 ), two of five patients experienced DLT. In level -1 (oxaliplatin, 65 mg/m2 ; irinotecan, 100 mg/m2 ; S-1, 80 mg/m2 ), DLT could not be evaluated in two of eight patients because one cycle was not completed; one of the remaining six patients experienced DLT. Anemia, thrombocytopenia, fatigue, nausea, anorexia, diarrhea, and peripheral sensory neuropathy were seen frequently in levels 0 and -1. ORR was 30% in levels 0 and -1. Median progression-free survival and median overall survival were 4.1 months (95% confidence interval [CI], 0.0-8.9 months) and 13.7 months (95% CI, 4.8-22.6 months), respectively. CONCLUSION: MTD of OX-IRIS therapy was estimated to be level 0, and the recommended dose (RD) for future trial was level -1.

Feasibility of a modified search, coagulation, and clipping method with and without the use of polyglycolic acid sheets and fibrin glue for preventing delayed bleeding after gastric endoscopic submucosal dissection.

BACKGROUND: Methods have been developed for preventing delayed bleeding (DB) after gastric endoscopic submucosal dissection (GESD). However, none of the methods can completely prevent DB. We hypothesized that DB could be prevented by a modified search, coagulation, and clipping (MSCC) method for patients at low risk for DB and by combining the use of polyglycolic acid sheets and fibrin glue with the MSCC method (PMSCC method) for patients at high risk for DB (antibleeding [ABI] strategy). This study assessed the technical feasibility of this novel strategy. METHOD: We investigated 123 lesions in 121 consecutive patients who underwent GESD in Kushiro Rosai Hospital between April 2018 and January 2020. The decision for continuation or cessation of antithrombotic agents was based on the Guidelines for Gastroenterological Endoscopy in Patients Undergoing Antithrombotic Treatment. RESULTS: Oral antithrombotic agents were administered to 28 patients (22.8%). The en bloc R0 resection rate was 98.4%. The MSCC method and the PMSCC method for preventing DB were performed in 114 and 9 lesions, respectively. The median time of the MSCC method was 16 min, and the median speed (the resection area divided by the time of method used) was 3.6 cm2/10 min. The median time of the PMSCC method was 59 min, and the median speed was 1.3 cm2/10 min. The only delayed procedural adverse event was DB in 1 (0.8%) of the 123 lesions. CONCLUSIONS: The ABI strategy is feasible for preventing DB both in patients at low risk and in those at high risk for DB after GESD, whereas the PMSCC method may be necessary for reduction of time.

Feasibility of a new ligation using the double-loop clips technique without an adhesive agent for ulceration after endoscopic submucosal dissection of the colon (with video).

BACKGROUND AND AIMS: Several ligation techniques for ulceration after endoscopic submucosal dissection (ESD) have been reported, but none have been established for clinical use because of technical complexity and the need for expensive equipment. Therefore, the technical feasibility of a new ligation method using the double-loop clips (D-L clips) technique without an adhesive agent for ulceration after ESD of the colon was assessed. METHODS: Among 35 patients who underwent ESD of the colon in Kushiro Rosai Hospital between April 2019 and September 2019, 26 patients who underwent ligation using the D-L clips technique for the post-ESD ulcer bed were included in this retrospective study. Continuation or cessation of antithrombotic agents was based on the Guidelines for Gastroenterological Endoscopy in Patients Undergoing Antithrombotic Treatment. RESULTS: The rate of en bloc R0 resection was 97.1%, the median length of the resected specimen was 3.2 cm (interquartile range [IQR], 2.8-3.8 cm), and the complete ligation rate was 88.5% (23 of 26). Excluding patients with lesion sites in the rectum below the peritoneal reflection, the complete ligation rate was 95.5% (21 of 22). The median duration of the ligation procedure was 20 minutes (IQR, 16-24 minutes). The only delayed procedural adverse event was post-ESD coagulation syndrome in 1 patient. Incomplete ligation was significantly more frequent in patients with lesion sites in the inferior rectal valve/anal verge area (P = .0269). CONCLUSIONS: Ligation using the D-L clips technique without an adhesive agent is feasible for closing ulceration after ESD of the colon, whereas other techniques may be necessary for lesions in the rectum below the peritoneal reflection.

Impact of single-heterozygous UGT1A1 on the clinical outcomes of irinotecan monotherapy after fluoropyrimidine and platinum-based combination therapy for gastric cancer: a multicenter retrospective study.

BACKGROUND: It is unclear whether the UGT1A1 status, single heterozygous (SH) or wild type (WT), is associated with the efficacy and toxicity of irinotecan monotherapy in advanced gastric cancer (AGC). We investigated the association between clinical outcomes (efficacy and safety) and UGT1A1 status in patients who received irinotecan monotherapy. METHODS: We evaluated AGC patients who received irinotecan monotherapy between January 2011 and December 2017. Efficacy was assessed according to overall survival (OS) and progression-free survival (PFS). Toxicity was graded using the Common Toxicity Criteria for Adverse Events (version 4.0). RESULTS: A total of 100 patients were evaluated (62 and 38 patients with UGT1A1 WT and SH, respectively). In the WT and SH groups, the irinotecan dose was reduced in 19 (30.6%) and 18 (47.2%) patients (p = 0.135), respectively; treatment was delayed due to adverse events (AEs) in 19 (30.6%) and 13 (34.2%) patients (p = 0.826), respectively; the median PFS was 3.15 and 3.25 months (HR, 0.734; 95% CI 0.465-1.158; p = 0.184), respectively; and the median OS was 10.4 and 7.26 months (HR, 1.137; 95% CI 0.752-1.721; p = 0.543), respectively. Severe hematological AEs (Grade ≥ 3) were significantly more frequent in the SH group than in the WT group (63% vs. 36%; p = 0.008), while severe non-hematological AEs was not significantly different (16.0% vs. 6.5%; p = 0.173). CONCLUSION: There was no significant difference in the efficacy of irinotecan monotherapy between UGT1A1 WT and UGT1A1 SH, but UGT1A1 SH was associated with a high frequency of severe hematological toxicity.

Comparison of attitudes towards persons with dementia, knowledge of dementia and ageism amongst students in Taiwan and Japan: A cross-sectional study.

INTRODUCTION: This study aimed to compare the attitudes towards people with dementia, knowledge of dementia and ageism amongst Taiwanese and Japanese dental hygiene students. MATERIAL AND METHODS: A total of 328 students participated in this cross-sectional study. Attitudes, knowledge and ageism were assessed using self-reports. Participants' association with older adults or persons with dementia was also assessed. Primary outcomes included attitude, knowledge and ageism amongst students. Secondary outcomes were the factors related to their desire to work with persons with dementia. RESULTS: Data of 175 Taiwanese and 91 Japanese students were analysed. There were significantly more Japanese (69.2%) than Taiwanese (33.2%) students without experience of cohabitation with older adults. More Taiwanese (45.1%) than Japanese students (30.8%) gave a neutral answer regarding their desire to work with persons with dementia. Japanese students scored significantly higher on the attitude and ageism scales than did Taiwanese students; however, the scores of knowledge assessment were approximately the same. Attitude or ageism did not correlate with knowledge amongst students from either country. Logistic regression analysis revealed that the desire to work with persons having dementia was related to ageism and the relationship with these people, irrespective of country. CONCLUSION: Although the students had comparable levels of knowledge, there existed significant difference in the attitudes and the degree of ageism between students from Taiwan vs Japan. This finding may prompt improvement of education on dementia, where differences in nationality and lifestyle, including the rate of ageing and family structure, are taken into consideration.

Soluble factors derived from neuroblastoma cell lines suppress dendritic cell differentiation and activation.

Dendritic cells (DC) play a key role in the initiation of both antitumor immunity and immunological tolerance. It has been demonstrated that exposure to soluble factors produced by tumor cells modulates DC functions and induces tolerogenic DC differentiation. In this study, we investigated the effects of neuroblastoma cell line-derived soluble factors on DC differentiation. Monocytes isolated from healthy volunteers were incubated with interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor in the presence of culture supernatants from neuroblastoma cell lines. The culture supernatants from neuroblastoma cell lines, such as NLF and GOTO, partially blocked both downregulation of CD14 and upregulation of CD1a, and dramatically decreased IL-12 and tumor necrosis factor (TNF)-α production from mature DC, while no effect of SH-SY5Y cell supernatant was noted. In addition, IL-6 and IL-10 production from monocytes was increased by the supernatants of NLF and GOTO cells at 24 hours after incubation. Furthermore, we evaluated DC functions through stimulation of invariant natural killer T (iNKT) cells. α-Galactosylceramide-pulsed DC co-cultured with supernatants of NLF cells were unable to sufficiently stimulate iNKT cells. The decreased ability of iNKT cells to produce interferon (IFN)-γ after stimulation with neuroblastoma cell line supernatant-cultured DC was reversed by addition of IL-12. CD40 expression and IL-12 production in NLF-sup-treated DC were increased by addition of exogenous IFN-γ. These results indicate that tolerogenic DC are induced in the neuroblastoma tumor microenvironment and attenuate the antitumor effects of iNKT cells. Interactions between iNKT cells and αGalCer-pulsed DC have the potential to restore the immunosuppression of tolerogenic DC through IFN-γ production.

Comparative sequence analysis of patient-matched primary colorectal cancer, metastatic, and recurrent metastatic tumors after adjuvant FOLFOX chemotherapy.

BACKGROUND: In the era of genome-guided personalized cancer treatment, we must understand chemotherapy-induced genomic changes in tumors. This study evaluated whether adjuvant FOLFOX chemotherapy modifies the mutational profile of recurrent colorectal cancer (CRC). METHODS: Whole exome sequencing was performed on samples from primary CRC tumors, untreated metastatic tumors, and recurrent tumors following adjuvant FOLFOX chemotherapy. The samples were resected from four patients. RESULTS: The number of mutations or the mutation spectrum in individual patients was nearly identical. Copy number variants persisted regardless of FOLFOX therapy administration. The genomic signature of oxaliplatin exposure (G > T/C > A, T > A/A > T) was not enriched after FOLFOX chemotherapy. Overlapping single nucleotide variants (SNVs) and indels remained in 26-65% of the patient-matched tumor samples. One patient harbored an AKT1 E17K mutation in the recurrent tumor, whereas PIK3CA E542K and E88Q mutations were detected in the primary and untreated metastatic tumor samples. Genes related to intracellular Ca2+ homeostasis were enriched among the genes uniquely mutated after FOLFOX chemotherapy. CONCLUSIONS: We found that the mutation rates, mutation spectrum, and copy number variants were nearly identical regardless of the administration of FOLFOX therapy in the four CRC cases. The mutational discordance between the patient-matched tumor samples is likely caused by tumor heterogeneity and chemotherapy-induced clonal selection. These findings might be useful as pilot data for larger studies to clarify the changes in the mutational landscape induced by adjuvant FOLFOX chemotherapy.

Frequency and proliferative response of circulating invariant natural killer T cells in pediatric patients with malignant solid tumors.

BACKGROUND: Invariant natural killer T (iNKT) cells play an important role in tumor immunity, enhancing both innate and acquired immunity. We have previously shown the enhancement of antibody-dependent cellular cytotoxicity against neuroblastoma by activated iNKT cells. As a first step towards clinical application, we studied the frequency and proliferative response of circulating iNKT cells in children with and without cancer. METHODS: Blood samples were collected from 10 patients with pediatric malignant solid tumors and 11 patients with non-neoplastic diseases (control). The frequency of circulating iNKT cells was quantified by flow cytometry. Whole peripheral blood mononuclear cells were then stimulated with α-galactosylceramide (α-GalCer) for 7 days, and the expansion rate of the iNKT-cell fraction was assessed. RESULTS: The frequency of iNKT cells in the patients of the cancer and control group did not differ to a statistically significant extent. The iNKT-cell population increased after α-GalCer stimulation in all cases. The iNKT cells of patients who had undergone intensive chemotherapy also had the potential to expand in vitro. CONCLUSIONS: Unlike adult cancer patients, the numbers of circulating iNKT cells were not decreased in pediatric cancer patients. α-GalCer stimulation induced a proliferative response in all of the patients.

Invariant natural killer T infiltration in neuroblastoma with favorable outcome.

BACKGROUND: Tumor immunity has been suggested to play a key role in clinical and biological behavior of neuroblastomas. Given that CD1-restricted invariant natural killer T (iNKT) cells enhance both innate and acquired tumor immunity, we investigated the expression of the iNKT-cell-specific T-cell receptor Vα24-Jα18 in neuroblastoma tissues and its correlation with clinical and biological characteristics. METHODS: Using real- time quantitative PCR, we quantified the expression of Vα24-Jα18 in untreated tumor samples from 107 neuroblastoma cases followed in our institution and analyzed the correlation between the presence of infiltrated iNKT cells and clinical characteristics or patients' outcome. RESULTS: Vα24-Jα18 receptor was detected in 62 untreated cases (57.9%). The expression was significantly higher in stages 1, 2, 3, or 4S (P = 0.0099), in tumors with low or intermediate risk (P = 0.0050), with high TrkA expression (P = 0.0229), with favorable histology (P = 0.0026), with aneuploidy (P = 0.0348), and in younger patients (P = 0.0036). The overall survival rate was significantly higher in patients with iNKT-cell infiltration (log-rank; P = 0.0089). CONCLUSIONS: Since tumor-infiltrating iNKT cells were predominantly observed in neuroblastomas undergoing spontaneous differentiation and/or regression, we suggest that iNKT cells might play a key role in these processes.

Study protocol of HGCSG1404 SNOW study: a phase I/II trial of combined chemotherapy of S-1, nab-paclitaxel and oxaliplatin administered biweekly to patients with advanced gastric cancer.

BACKGROUND: In Japan, S-1 plus cisplatin (SP) regimen has become a standard therapy for patients with advanced gastric cancer. Moreover, the S-1 plus oxaliplatin regimen is now a standard treatment. Nab-paclitaxel was developed for chemotherapy of gastric cancer in Japanese clinical practice. Nab-paclitaxel, created with albumin-bound paclitaxel particles, has high transferability to tumour tissues and does not cause hypersensitivity reactions because of a different chemical composition compared with docetaxel and paclitaxel. A combination of S-1, nab-paclitaxel and oxaliplatin (which we named 'SNOW regimen') can be a promising triplet therapy for advanced gastric cancer. Although we have to pay attention to chemotherapy-induced neuropathy, we aim to investigate the recommended dose of this regimen in a phase I study. Furthermore, we will investigate its efficacy and toxicity in a phase II study. METHODS: The phase I study is a dose-escalation study using a standard 3 plus 3 design, followed by expansion cohorts. The SNOW regimen involves 28-day cycles with escalated doses of nab-paclitaxel (100-175 mg/m2 on days 1 and 15) and fixed doses of oxaliplatin (65 mg/ m2 on days 1 and 15) and S-1 (80 mg/m2/day on day 1 to 14). The primary endpoints are assessment of dose limiting toxicities and determination of maximum tolerated dose to investigate the recommended dose in the subsequent phase II study. In the phase II study, the primary endpoint is objective response rate. Secondary endpoints are assessment of safety, progression-free survival, disease control rate, overall survival and time to treatment failure. Adverse events were monitored and graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. DISCUSSION: Triplet therapies for advanced gastric cancer patients have been evaluated in clinical trials. The SNOW regimen can be a promising new triplet therapy. TRIAL REGISTRATION: This study is performed at institutes that participate in Hokkaido Gastrointestinal Cancer Study Group (HGCSG) and registered as UMIN000016788 . Registrated 16 March 2015.

Antibody-dependent cellular cytotoxicity toward neuroblastoma enhanced by activated invariant natural killer T cells.

Anti-ganglioside GD2 antibodies mainly work through antibody-dependent cellular cytotoxicity (ADCC) and have demonstrated clinical benefit for children with neuroblastoma. However, high-risk neuroblastoma still has a high recurrence rate. For further improvement in patient outcomes, ways to maximize the cytotoxic effects of anti-GD2 therapies with minimal toxicity are required. Activated invariant natural killer T (iNKT) cells enhance both innate and type I acquired anti-tumor immunity by producing several kinds of cytokines. In this report, we investigated the feasibility of combination therapy using iNKT cells and an anti-GD2 antibody. Although some of the expanded iNKT cells expressed natural killer (NK) cell markers, including FcγR, iNKT cells were not directly associated with ADCC. When co-cultured with activated iNKT cells, granzyme A, granzyme B and interferon gamma (IFNγ) production from NK cells were upregulated, and the cytotoxicity of NK cells treated with anti-GD2 antibodies was increased. Not only cytokines produced by activated iNKT cells, but also NK-NKT cell contact or NK cell-dendritic cell contact contributed to the increase in NK cell cytotoxicity and further IFNγ production by iNKT cells and NK cells. In conclusion, iNKT cell-based immunotherapy could be an appropriate candidate for anti-GD2 antibody therapy for neuroblastoma.

Blockade of programmed death-1/programmed death ligand pathway enhances the antitumor immunity of human invariant natural killer T cells.

The role of invariant natural killer T (iNKT) cells in antitumor immunity has been studied extensively, and clinical trials in patients with advanced cancer have revealed a prolonged survival in some cases. In recent years, humanized blocking antibodies against co-stimulatory molecules such as PD-1 have been developed. The enhancement of T cell function is reported to improve antitumor immunity, leading to positive clinical effects. However, there are limited data on the role of PD-1/programmed death ligand (PDL) molecules in human iNKT cells. In this study, we investigated the interaction between PD-1 on iNKT cells and PDL on antigen-presenting cells (APCs) in the context of iNKT cell stimulation. The blockade of PDL1 at the time of stimulation resulted in increased release of helper T cell (Th) 1 cytokines from iNKT cells, leading to the activation of NK cells. The direct antitumor function of iNKT cells was also enhanced after stimulation with anti-PDL1 antibody-treated APCs. According to these results, we conclude that the co-administration of anti-PDL1 antibody and alpha-galactosylceramide (αGalCer)-pulsed APCs enhances iNKT cell-mediated antitumor immunity.