Perioperative Durvalumab in Gastric and Gastroesophageal Junction Cancer

Ramucirumab plus pembrolizumab in patients with previously treated advanced non-small-cell lung cancer, gastro-oesophageal cancer, or urothelial carcinomas (JVDF): a multicohort, non-randomised, open-label, phase 1a/b trial.

160P Phase II study of sintilimab combined with FLOT regimen for neoadjuvant treatment of gastric or gastroesophageal junction (GEJ) adenocarcinoma

In the present study, we aimed to evaluate the efficacy and safety of camrelizumab combined with oxaliplatin plus S-1 in patients with resectable gastric or gastroesophageal junction cancer. In this single-arm, phase II clinical trial, patients with locally advanced gastric or gastroesophageal junction adenocarcinoma were enrolled to receive three cycles of neoadjuvant camrelizumab and oxaliplatin plus S-1 every 3 weeks, followed by surgical resection and adjuvant therapy with the same regimen. The primary endpoint was pathological complete response (pCR) (ypT0) rate and secondary endpoints were R0 resection rate, total pCR (tpCR, ypT0N0) rate, major pathological response (MPR) rate, downstaging, objective response rate (ORR), disease control rate (DCR), event-free survival (EFS), overall survival (OS), and safety. Between September, 2020 and January, 2022, a total of 29 patients were enrolled in the present study, all of whom completed neoadjuvant therapy and underwent surgery. Three (10.3%) (95% CI: 2.2-27.4) patients achieved pCR as well as tpCR, 20 (69.0%) patients had MPR and 28 (96.6%) patients achieved R0 resection. Treatment-emergent adverse events (AEs) of any grade were observed in 24 (82.8%) patients. Immune-related adverse events of any grade were reported in 13 (44.8%) patients, whereas no grade 3 or higher adverse events occurred. The neoadjuvant therapy with camrelizumab in combination with oxaliplatin and S-1 showed a modest pCR rate, and favorable MPR rate and safety profile in patients with gastric or gastroesophageal junction cancer.

BackgroundHER2 status is a predictive biomarker of response to trastuzumab in advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. However, there is relatively little known about the role of HER2 in resected gastric or GEJ adenocarcinoma in the Western population.MethodsRetrospective, observational, single centre study of patients with gastric or GEJ adenocarcinoma undergoing surgery with curative intent between January 2007 and June 2014 in the University Hospital Complex of Santiago de Compostela. The expression of HER2 was determined by immunohistochemistry (IHC) using DAKO-HercepTest™ and gene amplification with DuoCISH using a DAKO-DuoCISH kit. The study of HER2 expression and amplification was carried out in all the patients and it was correlated with classic clinicopathological parameters, survival and recurrence pattern.Results106 patients were included. HER2 expression was as follows: 71.7% HER2 negative, 21.7% HER2 equivocal and 6.6% HER2 positive, or with HER2 overexpression. 13.2% of patients (14/106) had HER2 amplification by DuoCISH. A significant association was seen between overexpression and amplification of HER2 (p < 0.001).HER2 positivity was associated with the intestinal subtype (p = 0.010) and a low grade of differentiation (p = 0.018). Likewise, HER2 was significantly associated with a worse prognosis: overall survival (OS) 32.3 months HER2 positive versus 93.9 months HER2 negative (HR 0.42; confidence interval 95% 0.18–0.93; p = 0.028); and the presence of distant metastasis without accompanying locoregional recurrence (p = 0.048).ConclusionHER2 status defines a subgroup with differentiated clinicopathological characteristics, worse prognosis and distant dissemination, without accompanying locoregional recurrence, in patients with resected gastric or GEJ adenocarcinoma operated on in a Western population.

Amplification of the human epidermal growth factor receptor 2 (HER2) gene and overexpression of the HER2 protein is found in 15%-20% of patients with gastric and gastroesophageal junction cancer. The degree of HER2 overexpression and amplification varies with the location of the carcinoma, with higher expression in the gastroesophageal and proximal parts compared to the distal parts of the stomach. Further, HER2 overexpression and amplification also seems to be related to the Lauren histological classification, with higher levels found in the intestinal phenotype compared to the diffuse and mixed types. The prognostic properties of HER2 overexpression and amplification are still under debate, but a large number of studies seem to indicate that HER2 is a negative prognostic factor. The usefulness of HER2 targeted therapy in gastric cancer was demonstrated in the ToGA trial, where HER2-positive patients with advanced gastric and gastroesophageal junction adenocarcinoma were randomized to receive 5-FU/capecitabine and cisplatin, either alone or in combination with trastuzumab. A statically significant gain in overall survival was seen in patients who received the combined treatment of trastuzumab and chemotherapy. Patients with a strong overexpression of the HER2 protein (IHC3+) specifically benefited from the treatment, with a median overall survival of 17.9 mo. As a consequence of the positive results of the ToGA trial, patients with advanced gastric or gastroesophageal junction adenocarcinoma are now routinely tested for HER2. The ToGA trial must be characterized as a landmark in the treatment of gastric cancer and it has paved the way for a number of new HER2 targeted compounds such as pertuzumab, ado-trastuzumab emtansine, lapatinib, afatinib, and dacomitinib, which are currently undergoing phase II and III clinical testing. Overall, this review will discuss the current status of HER2 in gastric and gastroesophageal junction cancer and the future direction in relation to HER2 target therapy.

e16040 Background: Surufatinib is a novel small-molecule kinase inhibitor targeting VEGFRs, FGFR and CSF-1R, simultaneous targeting of angiogenesis through VEGFRs/FGFR1 and modulating tumor immune microenvironment through CSF-1R may be a uniquely potent strategy to enhance antitumor activity. Toripalimab is a monoclonal humanized IgG4 PD-1 antibody. Encouraging efficacy of surufatinib plus toripalimab treating patients with advanced solid tumors was reported at 2020 AACR. This is an ongoing, multicenter, open-label, single-arm, phase II study to evaluate the efficacy and safety of surufatinib in combination with toripalimab in various solid tumors. Here we report the results of patients with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. Methods: Patients with histologically confirmed gastric or GEJ adenocarcinoma who have failed first-line of systemic chemotherapy were enrolled. Surufatinib 250 mg once a day (QD) will be orally administrated and toripalimab 240 mg will be intravenously administered every 3 weeks. Primary endpoint was the objective response rate (ORR) per RECIST v1.1. Results: As of Dec 31, 2020, a total of 21 gastric or GEJ adenocarcinoma patients were enrolled. The median age was 58 years old, and 81% of the patients were male. Median duration of treatment was 3 months (surufatinib, 3 months; toripalimab, 3 months). Among 15 patients with at least one post-baseline efficacy evaluation, 2 patients achieved confirmed partial response (PR), with 3 additional unconfirmed PR. And there were 6 in stable disease (SD), 3 in progressive disease (PD) and one not evaluable per RECIST v1.1. There were 5 in PR, 7 in SD and 2 in PD per irRECIST, respectively. The confirmed and unconfirmed ORR were 13.3% (95% CI: 1.7%-40.5%) and 33.3% (95% CI: 11.8%-61.6%), respectively. The disease control rate (DCR) was 73.3% (95% CI: 44.9%-92.2%) per RECIST v1.1. Median PFS was 3.71 months (95% CI: 1.41-unknown). 14.3% (3/21) of patients had treatment-related adverse events (TRAEs) of ≥ Grade 3. The most common TRAEs of ≥ Grade 3 were herpes zoster (4.8%), lymphopenia (4.8%), lymphocyte count decreased (4.8%), white blood cell count decreased (4.8%), liver injury (4.8%) and anaemia (4.8%). 4.8% (1/21) of patients had serious TRAEs. One patient died due to unknown reasons. Conclusions: Surufatinib plus toripalimab appeared to show encouraging activity in advanced gastric or GEJ adenocarcinoma with manageable safety profile. Such combination could be a promising strategy for advanced gastric or GEJ adenocarcinoma in the future. Clinical trial information: NCT04169672.

BackgroundPerioperative chemotherapy with 5-fluorouracil, leucovorin, oxaliplatin, and docetaxel has improved survival in patients with locally advanced resectable gastric or gastroesophageal junction adenocarcinomas in Europe.MethodsWe report two cases of laparoscopic curative resection with perioperative docetaxel-based chemotherapy for advanced gastroesophageal junction or gastric adenocarcinoma and investigated variations in Claudin18.2 expressions associated with chemotherapy.ResultsPreoperative four-cycle docetaxel-based chemotherapy enabled laparoscopic total gastrectomy with distal esophagectomy via trans-hiatal approach or laparoscopic distal gastrectomy with extensive lymph node dissection. Postoperative left inferior pulmonary arterial thrombosis and chylous ascites recovered with pharmacotherapy and lipiodol lymphatic embolization. Despite discontinuing postoperative one-cycle chemotherapy, no recurrence was observed for over 1.5 and 1 year. Immunohistochemical staining showed increased Claudin18.2 expression in undifferentiated adenocarcinomas in the resected specimens than in pre-chemotherapeutic biopsies.ConclusionPerioperative docetaxel-based chemotherapy was effective for Japanese patients with gastroesophageal junction and gastric adenocarcinoma, suggesting a combination treatment with anti-Claudin18.2 antibody as neoadjuvant or first-line chemotherapy.

Immune checkpoint inhibitors are new targeted treatments that harness the body's immune system to attack cancers. Drugs that are most extensively used among checkpoint inhibitors inhibit the PD-L1 or PD-1 (programmed death 1) ligand or receptor pair and are currently approved for many cancer indications. In gastric or gastroesophageal junction adenocarcinomas one inhibitor, pembrolizumab has regulatory approval for PD-L1 positive carcinomas. This meta-analysis investigates available data on the efficacy of PD-L1 or PD-1 inhibitors as a class in gastric or gastroesophageal junction adenocarcinomas. The literature was reviewed to identify clinical studies that included arms with PD-L1 or PD-1 inhibitors as monotherapy in gastric or gastroesophageal junction adenocarcinomas. Relevant patient characteristics, outcomes, and adverse effects were recorded. Summary estimates of response rates (RR) and survival were calculated using a random or fixed effect model, depending on heterogeneity. Six studies with a total of 1068 patients were included in the analysis. The summary RR was 10.63% (95% confidence interval (CI) 5.36–15.89%). The summary disease control rate (DCR) was 28.11% (95% CI 24.60–31.63%). Summary progression-free survival (PFS) was 1.59 months (95% CI 1.24–1.94 months). Summary overall survival (OS) was 5.72 months (95% CI 0–12.19 months). A subset of patients derived long-term benefits as seen in other cancer locations. The adverse effect rate was low and consistent with that in other disease locations. Low efficacy of immune checkpoint inhibitors as a class in gastric or gastroesophageal junction adenocarcinomas is observed in this analysis and stresses the need for effective biomarker use for the identification of most probable responders.How to cite this article: Voutsadakis IA. A Systematic Review and Meta-analysis of PD-1 and PD-L1 Inhibitors Monotherapy in Metastatic Gastric and Gastroesophageal Junction Adenocarcinoma. Euroasian J Hepato-Gastroenterol 2020;10(2):56–63.

Treatment with anti-programmed cell death protein 1 (PD-1) therapy and chemotherapy prolongs the survival of patients with unresectable advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma. The benefit from anti-PD-1 therapy is enriched in patients with programmed cell death 1 ligand 1 (PD-L1) combined positive score (CPS)-positive or CPS-high tumors compared with patients with PD-L1 CPS-negative or CPS-low tumors. In this phase 1b/2 study, we evaluated the efficacy and safety of cadonilimab, a bispecific antibody targeting PD-1 and cytotoxic T-lymphocyte antigen-4, plus chemotherapy as first-line treatment in patients with human epidermal growth factor receptor 2-negative unresectable advanced or metastatic gastric or GEJ adenocarcinoma. The primary endpoint was the recommended phase 2 dose (RP2D) for phase 1b and the objective response rate for phase 2. Secondary endpoints included disease control rate, duration of response, time to response, progression-free survival, overall survival (OS) and safety. The primary endpoint was met. No dose-limiting toxicities were observed during dose escalation in phase 1b; the recommended phase 2 dose was determined as 6 mg kg-1 every 2 weeks. The objective response rate was 52.1% (95% confidence interval (CI) = 41.6-62.5), consisting of complete and partial responses in 4.3% and 47.9% of patients, respectively. The median duration of response, progression-free survival and OS were 13.73 months (95% CI = 7.79-19.12), 8.18 months (95% CI = 6.67-10.48) and 17.48 months (95% CI = 12.35-26.55), respectively. The median OS in patients with a PD-L1 CPS ≥ 5 was 20.32 months (95% CI = 4.67-not estimable); in patients with a PD-L1 CPS < 1, the median OS reached 17.64 months (95% CI = 11.63-31.70). The most common treatment-related grade 3 or higher adverse events were decreased neutrophil count (19.1%), decreased platelet count (16.0%), anemia (12.8%) and decreased leukocyte count (8.5%). No new safety signal was identified. The current regimen showed promising clinical activity and manageable safety in patients with gastric or GEJ adenocarcinoma regardless of PD-L1 expression. Chinadrugtrials.org.cn registration: CTR20182027.

Stomach cancer is the third most common cause of cancer mortality worldwide. Most are adenocarcinomas. Adenocarcinomas of the stomach fall into two obvious groups based on site of origin; those arising in the area of the gastroesophageal junction (GEJ) and those arising from a more distal location, which we term gastric in this study. Adenocarcinomas of the stomach fall into four obvious groups based on a combination of genomic, molecular biologic, clinical and histopathologic characteristics (Nagara A, Kikuchi O, Bass AJ, Cancer Discovery 2019; DOI: 10.1158/2159-8290.CD-19-0487). We are reporting herein a study of 99 patients with adenocarcinoma of the stomach. This study evaluates the location of the tumor, the histopathologic features of the tumor, the immunohistochemically determined nuclear and cytoplasmic expression of P21 activated kinase (Pak 1), Transforming Growth Factor α (TGFα), and Ki67, a marker of cell proliferation. This study correlates these findings with patient survival. The study reveals: 1. significantly lower survival in patients with diffuse type adenocarcinoma compared to intestinal type, in both GEJ and gastric locations. 2. both GEJ and gastric adenocarcinomas had a poor prognosis. 3. increased expression of both TGFα and Pak1 in GEJ adenocarcinomas. 4. Ki67 expression is significantly less in diffuse type than the intestinal type (p=0.01 for GEJ and 0.03 for gastric). 5. cytoplasmic Pak1 and cytoplasmic TGFα were highly positively correlated (p=0.0001). 6. Ki67 expression was significantly inversely correlated with both nuclear Pak1 (p=0.04) and nuclear TGFα (p=0.02). 7. significantly increased expression of nuclear Pak1 in gastric diffuse type compared with gastric intestinal (p=0.0002) and GEJ intestinal (p=0.0001). These data suggest that Pak1 and TGFα might serve as diagnostic biomarkers of subtypes of adenocarcinomas of the stomach and gastroesophogeal junction. Citation Format: Larry E. Douglass, Michael Parritt, Adam Neltner, Mariah Dooley, Michelle Robillard, Molly Frydl, Leah Focke, Kyle Damen, James A. Deddens, Julia H. Carter. Pak1, TGFα, Ki 67 and survival in human gastric and gastroesophageal junction adenocarcinomas [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 747.

HER2 testing in gastric and gastroesophageal junction adenocarcinomas

BackgroundNeoadjuvant chemotherapy followed by radical cystectomy is the standard treatment for cisplatin-eligible patients with muscle-invasive bladder cancer. Adding perioperative immunotherapy may improve outcomes.MethodsIn this phase 3, open-label, randomized trial, we assigned, in a 1:1 ratio, cisplatin-eligible patients with muscle-invasive bladder cancer to receive neoadjuvant durvalumab plus gemcitabine–cisplatin every 3 weeks for four cycles, followed by radical cystectomy and adjuvant durvalumab every 4 weeks for eight cycles (durvalumab group), or to receive neoadjuvant gemcitabine–cisplatin followed by radical cystectomy alone (comparison group). Event-free survival was one of two primary end points. Overall survival was the key secondary end point.ResultsIn total, 533 patients were assigned to the durvalumab group and 530 to the comparison group. The estimated event-free survival at 24 months was 67.8% (95% confidence interval [CI], 63.6 to 71.7) in the durvalumab group and 59.8% (95% CI, 55.4 to 64.0) in the comparison group (hazard ratio for progression, recurrence, not undergoing radical cystectomy, or death from any cause, 0.68; 95% CI, 0.56 to 0.82; P<0.001 by stratified log-rank test). The estimated overall survival at 24 months was 82.2% (95% CI, 78.7 to 85.2) in the durvalumab group and 75.2% (95% CI, 71.3 to 78.8) in the comparison group (hazard ratio for death, 0.75; 95% CI, 0.59 to 0.93; P=0.01 by stratified log-rank test). Treatment-related adverse events of grade 3 or 4 in severity occurred in 40.6% of the patients in the durvalumab group and in 40.9% of those in the comparison group; treatment-related adverse events leading to death occurred in 0.6% in each group. Radical cystectomy was performed in 88.0% of the patients in the durvalumab group and in 83.2% of those in the comparison group.ConclusionsPerioperative durvalumab plus neoadjuvant chemotherapy led to significant improvements in event-free survival and overall survival as compared with neoadjuvant chemotherapy alone. (Funded by AstraZeneca; NIAGARA ClinicalTrials.gov number, NCT03732677; EudraCT number, 2018-001811-59.)

242 Background: T-DXd is an antibody-drug conjugate comprising an anti-HER2 antibody, a cleavable tetrapeptide-based linker, and a topoisomerase I inhibitor. DESTINY-Gastric01 (DS8201-A-J202; ClinicalTrials.gov, NCT03329690) is an open-label, multicenter, randomized, phase 2 trial of T-DXd in patients with HER2–positive advanced gastric cancer (GC) or GEJ adenocarcinoma. In the primary analysis (101 OS events; median survival follow-up, 12.3 mo), T-DXd showed statistically significant benefit vs standard chemotherapy in objective response rate (ORR) and OS (Shitara K, et al. N Engl J Med. 2020;382:2419-2430); here, we present the final OS analysis as well as updated efficacy and safety. Methods: Patients (pts) with locally advanced or metastatic, centrally confirmed HER2–positive (IHC3+ or IHC2+/ISH+ on archival tissue) GC or GEJ cancer that had progressed after ≥2 previous lines of therapy including trastuzumab were randomly assigned 2:1 (T-DXd 6.4 mg/kg Q3W or physician’s choice [PC] of irinotecan [I] or paclitaxel [P]). Pts were stratified by country, ECOG performance status (0, 1), and HER2 status. Primary endpoint was ORR by independent central review. Key secondary endpoints were OS, duration of response (DOR), progression-free survival (PFS), disease control rate (DCR), confirmed ORR, and safety. Final OS analysis was performed at 133 OS events. Results: 187 pts received T-DXd (n = 125) or PC (n = 62 [55 I; 7 P]); 79.7% of pts were Japanese and 20.3% were Korean. Pts had a median of 2 prior lines of therapy, and 44.4% had ≥3. At data cutoff (June 3, 2020), 8% of T-DXd and 0% of PC pts remained on treatment (median survival follow-up, 18.5 mo). OS was improved with T-DXd vs PC (median OS, 12.5 vs 8.9 mo; hazard ratio [HR], 0.60 [95% CI, 0.42-0.86]); 12-month OS, 52.2% vs 29.7%. ORR was 51.3% (61/119; 11 CR; 50 PR) with T-DXd vs 14.3% (8/56; all PR) with PC ( P&lt; 0.0001); confirmed ORR, 42.0% (50/119; 10 CR; 40 PR) vs 12.5% (7/56; all PR) ( P= 0.0001); DCR, 85.7% vs 62.5% ( P= 0.0005); confirmed median DOR, 12.5 vs 3.9 mo; median PFS, 5.6 vs 3.5 mo (HR, 0.47 [95% CI, 0.31-0.71]; P= 0.0003). Grade ≥3 AEs occurred in 85.6% of T-DXd pts vs 56.5% with PC; the most common were neutrophil count decreased (51.2%, 24.2%), anemia (38.4%, 22.6%), and white blood cell count decreased (20.8%, 11.3%). 16 pts (12.8%) had T-DXd–related interstitial lung disease (ILD; 13 grade 1/2, 2 grade 3, 1 grade 4, no grade 5) vs 0 with PC. As reported in the primary analysis, there was 1 T-DXd–related death from pneumonia (non-ILD). Conclusions: With additional follow-up after the primary analysis, T-DXd continued to demonstrate OS benefit and clinically relevant improvement in ORR compared with standard chemotherapy, and a manageable safety profile, in HER2–positive advanced GC or GEJ adenocarcinoma. Clinical trial information: NCT03329690.

Surgical resection has a potential benefit for patients with metastatic adenocarcinoma of the stomach and gastroesophageal junction. To evaluate outcome in patients with limited metastatic disease who receive chemotherapy first and proceed to surgical resection. The AIO-FLOT3 (Arbeitsgemeinschaft Internistische Onkologie-fluorouracil, leucovorin, oxaliplatin, and docetaxel) trial is a prospective, phase 2 trial of 252 patients with resectable or metastatic gastric or gastroesophageal junction adenocarcinoma. Patients were enrolled from 52 cancer care centers in Germany between February 1, 2009, and January 31, 2010, and stratified to 1 of 3 groups: resectable (arm A), limited metastatic (arm B), or extensive metastatic (arm C). Data cutoff was January 2012, and the analysis was performed in March 2013. Patients in arm A received 4 preoperative cycles of fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) followed by surgery and 4 postoperative cycles. Patients in arm B received at least 4 cycles of neoadjuvant FLOT and proceeded to surgical resection if restaging (using computed tomography and magnetic resonance imaging) showed a chance of margin-free (R0) resection of the primary tumor and at least a macroscopic complete resection of the metastatic lesions. Patients in arm C were offered FLOT chemotherapy and surgery only if required for palliation. Patients received a median (range) of 8 (1-15) cycles of FLOT. The primary end point was overall survival. In total, 238 of 252 patients (94.4%) were eligible to participate. The median (range) age of participants was 66 (36-79) years in arm A (n = 51), 63 (28-79) years in arm B (n = 60), and 65 (23-83) years in arm C (n = 127). Patients in arm B (n = 60) had only retroperitoneal lymph node involvement (27 patients [45%]), liver involvement (11 [18.3%]), lung involvement (10 [16.7%]), localized peritoneal involvement (4 [6.7%]), or other (8 [13.3%]) incurable sites. Median overall survival was 22.9 months (95% CI, 16.5 to upper level not achieved) for arm B, compared with 10.7 months (95% CI, 9.1-12.8) for arm C (hazard ratio, 0.37; 95% CI, 0.25-0.55) (P < .001). The response rate for arm B was 60% (complete, 10%; partial, 50%), which is higher than the 43.3% for arm C. In arm B, 36 of 60 patients (60%) proceeded to surgery. The median overall survival was 31.3 months (95% CI, 18.9-upper level not achieved) for patients who proceeded to surgery and 15.9 months (95% CI, 7.1-22.9) for the other patients. Patients with limited metastatic disease who received neoadjuvant chemotherapy and proceeded to surgery showed a favorable survival. The AIO-FLOT3 trial provides a rationale for further randomized clinical trials. clinicaltrials.gov identifier: NCT00849615.

Trastuzumab prolonged the overall survival in patients with advanced gastric cancer with human epidermal growth factor receptor 2 (HER2) overexpression in combination with chemotherapy. In this phase II open-label prospective study, the tolerability and safety of trastuzumab with chemotherapy, and chemoradiotherapy for curatively resected patients with HER2-positive gastric carcinoma was investigated. The patients with HER2-positive gastric, or gastroesophageal junction adenocarcinoma, after gastrectomy plus D2 dissection, were included. They received 3 cycles of oxaliplatin (100 mg/m2 intravenously day 1) plus capecitabine (850 mg/m2 orally days 1 to 14), trastuzumab (8 mg/kg intravenously day 1 in cycle 1, 6 mg/kg thereafter) every 21 days, followed by chemoradiotherapy. Trastuzumab was given for 1 year. Of the 212 patients screened, 35 were eligible, and 34 were treated. The median age was 56 years (minimum to maximum: 35 to 75 y), male patients constituted 73.5% (n=25), and 33 (97.1%) had gastric adenocarcinoma. R0 resection was performed in 30 (88.2%). The majority (26, 61.7%) were in stage III disease. Most of the adverse events were grade I/II, the most frequent grade III side effects were nausea (3, 8.8%), vomiting (3, 8.8%), diarrhea (2, 5.9%), and weight loss (n=2, 5.9%). Two patients died during the first 3 cycles of chemotherapy and chemoradiotherapy; 1 secondary to pulmonary thromboembolism, and the other due to cerebral ischemia. After excluding 2 with early progression and 1 consent withdrawal, of the remaining 31 patients, 28 (90.3%) were able to complete the chemotherapy and chemoradiotherapy part of the trial. After the 25 months follow-up period, 21 patients (61.8%) were alive. Overall survival at 12 and 24 months was 75.0% and 58.0%, while disease-free survival at 12 and 24 months was 65.7% and 55.0%, respectively. Trastuzumab in combination with capecitabine, oxaliplatin following chemoradiotherapy as the adjuvant therapy for gastric or gastroesophageal junction adenocarcinoma was considered as safe and tolerable. The frequency of HER2 overexpression in curatively resected patients is comparable to that in patients with metastatic disease (trial registration: clinicaltrials.gov the identifier: NCT01748773, December 13, 2012, https://clinicaltrials.gov/ct2/show/NCT01748773).