Resected Gastric Adenocarcinoma Research Articles

OGC SO15 - Utility of radiological re-staging following neo-adjuvant chemotherapy and its impact on oncological outcomes in resectable gastric adenocarcinoma

Abstract Background The current perioperative chemotherapy regimen that comprises the multimodal treatment strategy for gastric cancer consists of Fluorouracil, Leucovorin, Oxaliplatin, and Docetaxel. Despite improvement in outcomes at a population level, real-world data suggests that ≤40% of patients show a poor/no response to the neoadjuvant phase of treatment. Identification of these poor/non-responders may facilitate a re-evaluation of their treatment strategy and prevent potentially futile surgery. Radiological re-staging following neoadjuvant treatment is routinely performed despite its debatable accuracy and benefits. This study aimed to define the accuracy of radiological re-staging and its impact on survival following neoadjuvant treatment for resectable GC. Method Patients with resectable gastric cancer who completed 4 cycles of neoadjuvant FLOT and underwent resectional surgery with curative intent between 2018 and 2022 were retrospectively identified. All patients were clinically staged with gastroscopy, CT and staging laparoscopy. The index radiological/clinical stage at diagnosis was compared to the radiological re-staging following neoadjuvant treatment. Patient were re-staged with either a CT or PET-CT. Both were then compared with the final pathological stage to assess for correlation between the radiological and pathological stage. A survival analysis was then performed to evaluate the impact of radiological-pathological staging discrepancy on overall survival Results A total of 65 consecutive patients met the inclusion criteria of this study. On comparison of the index clinical stage with the radiological re-stage post-neoadjuvant treatment, 71% had concordant stages, 25% were downstaged, and 4% were upstaged. On comparison of the index clinical stage with the final pathological stage, 35% had concordant stages, 38% were upstaged and 27% were down staged (Cohen kappa = -0.224, 95% CI -0.390, -0.058). Discrepancy between clinical stage and radiological re-stage did not influence survival. However, discrepancy between clinical and pathological stage highlighted survival differences where upstaged patients had reduced survival (p = 0.018). Conclusion The accuracy of clinical staging compared to final pathological staging in the setting of aggressive tumour biology remains undefined. Radiological re-staging following neoadjuvant treatment proves to be an unreliable tool for assessing treatment response and does not predict long-term survival outcomes. These findings highlight the importance of accurate staging and the need for more precise methods of evaluating treatment response. This may enhance decision-making, individualise treatment regimens, and improve patient outcomes.

Effect of Minimally Invasive Gastrectomy on Return to Intended Oncologic Therapy for Gastric Cancer.

Adjuvant chemotherapy offers survival benefit to patients with gastric cancer. Only 50-65% of patients who undergo neoadjuvant chemotherapy and gastrectomy are able to receive adjuvant therapy. It is optimal to start adjuvant therapy within 8weeks after gastrectomy. We compared the rate of return to intended oncologic therapy (RIOT) between minimally invasive gastrectomy (MIG) and open gastrectomy (OG). Retrospectively, we analyzed patients who underwent gastrectomy within a multi-hospital university-based health system (2019-2022). Data on patient demographics, comorbid conditions, operative approach, and postoperative outcomes were assessed with univariate analysis and multivariable analysis (MVA) to determine the association with RIOT. Among 87 eligible patients, 33 underwent MIG and 54 underwent OG. There were no differences in demographics, performance status, comorbid conditions, or type of gastrectomy between the two groups. MIG patients were significantly more likely to RIOT compared with OG patients (87.9% vs. 63%, p=0.003), with 73.1% of MIG patients starting adjuvant therapy within 8weeks compared with 53.1% of OG patients. Factors associated with higher odds of RIOT included MIG and age <65years, while major postoperative complications (Clavien-Dindo grade ≥IIIa) was associated with lower odds of RIOT. On MVA, MIG was independently associated with higher odds of RIOT compared with OG (odds ratio 6.05, 95% confidence interval 1.47-24.78, p=0.008). The minimally invasive approach may benefit patients undergoing gastrectomy, irrespective of the extent of gastric resection for adenocarcinoma. MIG is associated with a higher likelihood of (1) RIOT and (2) starting adjuvant therapy within the optimal time period after gastrectomy.

Preoperative Chemoradiotherapy for Resectable Gastric Cancer

BackgroundIn Western countries, the current standard of care for resectable gastric cancer is perioperative chemotherapy. Preoperative chemoradiotherapy has been considered, but data are limited regarding this treatment as compared with perioperative chemotherapy alone.MethodsWe conducted an international, phase 3 trial in which patients with resectable adenocarcinoma of the stomach or gastroesophageal junction were randomly assigned to receive preoperative chemoradiotherapy plus perioperative chemotherapy or perioperative chemotherapy alone (control). In both groups, patients received either epirubicin, cisplatin, and fluorouracil or fluorouracil, leucovorin, oxaliplatin, and docetaxel both before and after surgery; the preoperative-chemoradiotherapy group also received chemoradiotherapy (45 Gy in 25 fractions of radiation, plus fluorouracil infusion). The primary end point was overall survival, and secondary end points included progression-free survival, pathological complete response, toxic effects, and quality of life.ResultsA total of 574 patients underwent randomization at 70 sites in Australasia, Canada, and Europe: 286 to the preoperative-chemoradiotherapy group and 288 to the perioperative-chemotherapy group. A higher percentage of patients in the preoperative-chemoradiotherapy group than in the perioperative-chemotherapy group had a pathological complete response (17% vs. 8%) and greater tumor downstaging after resection. At a median follow-up of 67 months, no significant between-group differences in overall survival or progression-free survival were noted. The median overall survival was 46 months with preoperative chemoradiotherapy and 49 months with perioperative chemotherapy (hazard ratio for death, 1.05; 95% confidence interval, 0.83 to 1.31), and the median progression-free survival was 31 months and 32 months, respectively. Treatment-related toxic effects were similar in the two groups.ConclusionsThe addition of preoperative chemoradiotherapy to perioperative chemotherapy did not improve overall survival as compared with perioperative chemotherapy alone among patients with resectable gastric and gastroesophageal junction adenocarcinoma. (Funded by the National Health and Medical Research Council and others; TOPGEAR ClinicalTrials.gov number, NCT01924819.)

Real-World Experience of Clinical Outcomes of Microscopic Margin Positivity After Radical Gastrectomy from a Tertiary Cancer Center in Northeast India

AbstractSurgical resection for gastric adenocarcinoma (GAC) remains the only potentially curative treatment, and the use of neoadjuvant and adjuvant therapy improves survival in patients with advanced gastric cancer. Margin-positive resection is a known poor prognostic factor. A retrospective observational study of patients undergoing radical gastrectomy of any type for GAC was done at a tertiary care cancer center in Northeast India. The study included patients who were operated on from 1 January 2017 to 31 December 2021 (5 years), and they were followed up to 31 March 2024. A total of 172 patients underwent gastrectomy of any type for GAC during the study period of which 13 patients were found to have microscopic positive (R1) histopathological margin (7.6%). The median age of the patients with positive margins was 48 years (range 27 to 69 years). The male-to-female ratio was 9:4. Ten patients (77%) had poorly differentiated or signet-ring cell carcinoma. The distal margin was the most frequent margin which was positive (84.6%). Neoadjuvant chemotherapy was used in only 23.1% patients. At the end of our study period, only 1 patient out of 13 patients was alive. Median disease-free survival (DFS) was 16.2 months (95% confidence interval 1.2 to 31.1 months). Median overall survival (OS) was 20.2 months (95% confidence interval 9.3 to 31.2 months). Patients who have microscopic positive margins after gastrectomy are found to have a high incidence of poorly differentiated or signet-ring cell carcinoma.

Comparison of treatment strategies based on clinical and pathological nodal status in resectable gastric adenocarcinoma.

To determine the optimal multimodal treatment strategy between perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), and postoperative chemotherapy (POC) in resected gastric cancer (GC) patients based on nodal status. In this retrospective analysis, the National Cancer Database was used to identify resected non-metastatic GC (2006-2016). Patients were stratified by clinical nodal status-negative (cLN-) and positive (cLN+). In patients with cLN- disease who underwent upfront resection and were upstaged to pathological LN+, overall survival (OS) was compared between POC and POCR. In patients with cLN- and cLN+ disease, OS was compared between PEC, POCR, and POC. Kaplan-Meier survival estimate, log-rank test, and multivariable Cox proportional hazards analysis were performed. We identified 7827 patients (cLN- 4828; cLN+ 2999). On multivariable analysis in patients with cLN- disease who underwent upfront resection (n = 4314) and were upstaged to pLN+ disease (70%), POCR (n = 2300, aHR 0.78, 95% CI 0.70-0.87, p < 0.001) was associated with improved OS compared to POC (n = 907). No significant difference was noted between POCR (n = 766, aHR 1.11, 95% CI 0.88-1.40, p = 0.39) and POC (n = 341) in patients with pLN- disease. On multivariable analysis in all patients with cLN- disease, POCR (n = 3066) was significantly associated with improved OS (aHR 0.84, 95% CI 0.75-0.92, p < 0.01) compared to POC (n = 1248). No significant difference was noted between POCR (aHR 1.0, 95% CI 0.70-1.01, p = 0.958) and PEC (n = 514). These results remained consistent in patients with cLN+ disease (POCR = 1602, POC = 720, PEC = 677). Postoperative chemoradiation is associated with improved survival in GC patients upstaged from clinically node-negative disease to pathologically node-positive disease. Negative clinical nodal disease status is not a reliable indicator of pathological nodal disease.

VEGFA locus amplification potentially predicts a favorable prognosis in gastric adenocarcinoma

Gastric adenocarcinoma harbors a range of genetic and epigenetic alterations, including alterations in DNA copy number. However, the key genes that promote the development and progression of gastric adenocarcinoma remain unknown.To identify the key genes amplified in gastric adenocarcinoma, we performed array comparative genomic hybridization on formalin-fixed paraffin-embedded samples of surgically resected gastric adenocarcinoma. We detected a relatively wide genomic region of gain containing the vascular endothelial growth factor A (VEGFA) gene locus on chromosome 6p. VEGFA locus amplification in gastric adenocarcinoma was validated by fluorescence in situ hybridization. To assess the frequency of VEGFA locus amplification in gastric adenocarcinoma, we conducted multiplex ligation-dependent probe amplification (MLPA) assays using homemade probes designed to target the VEGFA gene locus. Eleven of 54 (20 %) gastric adenocarcinomas with MLPA values above 1.3 were defined as having VEGFA locus amplification. Next, we investigated the effect of VEGFA locus amplification on the clinicopathological characteristics of gastric adenocarcinomas and patient survival. VEGFA locus amplification demonstrated a significantly close relationship with pathological intestinal type and lower rates of venous invasion Furthermore, a Kaplan-Meier analysis showed that patients with VEGFA locus amplification had significantly better overall survival than those without amplification (p = 0.038), particularly in the long-term follow-up period. In conclusion, VEGFA locus amplification can predict modest aggressiveness and good outcomes, suggesting the possibility that it may predict a favorable prognosis in patients with gastric adenocarcinoma.

Correlation between postoperative chemotherapy regimen and survival in patients with resectable gastric adenocarcinoma accompanied with vascular cancer thrombus.

Patients with resectable gastric adenocarcinoma accompanied by vascular cancer thrombus (RGAVCT) have a poor prognosis, with a 5-year survival rate ranging from 18.42%-53.57%. These patients need a reasonable postoperative treatment plan to improve their prognosis. To determine the most effective postoperative chemotherapy regimen for patients with RGAVCT. We retrospectively collected the clinicopathological data of 530 patients who underwent radical resection for gastric cancer between January 2017 and January 2022 and who were pathologically diagnosed with gastric adenocarcinoma with a choroidal cancer embolus. Furthermore, we identified the high-risk variables that can influence the prognosis of patients with RGAVCT by assessing the clinical and pathological features of the patients who met the inclusion criteria. We also assessed the significance of survival outcomes using Mantel-Cox univariate and multivariate analyses. The subgroups of patients with stages I, II, and III disease who received single-, dual-, or triple-drug regimens following surgery were analyzed using SPSS 25.0 and the ggplot2 package in R 4.3.0. In all, 530 eligible individuals with RGAVCT were enrolled in this study. The median overall survival (OS) of patients with RGAVCT was 24 months, and the survival rates were 80.2%, 62.5%, and 42.3% at 12, 24, and 59 months, respectively. Preoperative complications, tumor size, T stage, and postoperative chemotherapy were identified as independent factors that influenced OS in patients with RGAVCT according to the Cox multivariate analysis model. A Kaplan-Meier analysis revealed that chemotherapy had no effect on OS of patients with stage I or II RGAVCT; however, chemotherapy did have an effect on OS of stage III patients. Stage III patients who were treated with chemotherapy consisting of dual- or triple-agent regimens had better survival than those treated with single-agent regimens, and no significant difference was observed in the survival of patients treated with chemotherapy consisting of dual- or triple-agent regimens. For patients with stage III RGAVCT, a dual-agent regimen of postoperative chemotherapy should be recommended rather than a triple-agent treatment, as the latter is associated with increased frequency of adverse events.

Neoadjuvant dual checkpoint inhibition followed by immune-chemoradiation in patients with resectable gastric adenocarcinoma.

4067 Background: Localized gastric cancer is a potentially curable condition and long-term outcomes depend on YP staging. Currently, preferred adjunctive therapy depends on geographic location. Preliminary data from NCT01928394 have shown promising clinical activity of immunotherapy (IO) agents nivolumab (nivo) +/- ipilimumab (ipi) in the metastatic setting. We conducted a single-arm study using IO + chemotherapy followed by immune-chemoradiation prior to surgery, followed by adjuvant IO, in patients with localized gastric adenocarcinoma. Our primary objective was to determine safety and toxicity with this approach. Secondary objectives included efficacy by YP staging and R0 resection rate. Methods: Patients with localized gastric adenocarcinoma were enrolled into NCT03776487 (n=30). Participants received the following: (1) biweekly chemotherapy with 4 doses of 5-Fluorouracil (5-FU)/Oxaliplatin, (2) nivo 240mg q2weeks (x3) and ipi 1mg/kg q6weeks (x1), (3) immune-chemoradiation (biweekly nivo + 5FU Mon-Fri concurrently with a total of 45 Gy given in 25 fractions), and (4) surgical resection. Those with residual disease received adjuvant nivolumab monthly for 6 doses. Correlative studies are planned. To assess preliminary efficacy, the clinical and pathologic complete response rates (pCR) were estimated along with the corresponding exact 95% confidence interval. Adverse events and toxicities were summarized using descriptive statistics. Results: Median follow-up was 27.4 months at the time of data cutoff. Of 30 enrolled, 23 patients completed surgery and seven did not due to progression of disease(n=5) and worsening co-morbidities(n=2). The side effect profile was similar to prior IO studies, with no grade 5 events observed. Three patients (10%) experienced grade 4 events (acute kidney injury, myocarditis, and neutropenia). The most frequent grade 3 toxicity was nausea and vomiting (10%). From the 23 participants that underwent resection, 22 had pathologic data at the time of analysis, with 9 achieving ypT0ypN0 (40.9%, 95% CI: 20.7%, 63.7%). There was an 86% R0 resection rate. Conclusions: Our results are encouraging and support further development of this strategy for localized gastric adenocarcinomas. The regimen is safe and potentially generalizable. Clinical trial information: NCT03776487 .

440P Maximal tumor area as an independent prognostic factor: Enhancing prognostic assessment in resectable gastric adenocarcinoma

440P Maximal tumor area as an independent prognostic factor: Enhancing prognostic assessment in resectable gastric adenocarcinoma

Longitudinal circulating tumor DNA (ctDNA) analysis during treatment (Tx) of locally advanced resectable (LAR) gastric or gastroesophageal junction (G/GEJ) adenocarcinoma (ADENOCA): The PLAGAST prospective biomarker study.

4028 Background: After surgery, patients (pts) with LAR G/GEJ ADENOCA have a high recurrence risk despite Tx. Here, we investigate the ability of ctDNA to predict Tx response and improve risk stratification in a sub-cohort of pts from the PLAGAST prospective study (NCT02674373). Methods: Plasma samples were prospectively collected at baseline (before neoadjuvant therapy (NAT)/before surgery for NAT-naive pts), during-NAT, post-NAT, and post-surgery within 2-12 weeks, before adjuvant Tx [molecular residual disease (MRD) window]. Retrospective ctDNA analysis was performed using a clinically validated personalized, tumor-informed 16-plex PCR assay (Signatera, Natera Inc.). ctDNA results were evaluated for their correlation to recurrence-free survival (RFS) and overall survival (OS). Results: Between 07/2015 and 12/2022,plasma samples (n=283) were collected from 63 pts with LAR (≥cT2 and/or cN+), G (N=38/63; 60%) and GEJ (N=25/63; 40%) ADENOCA, median (m) age: 66 years (range: 34-86), and mfollow-up: 31 months (mo) (range: 2-93). ctDNA-clearance from baseline to during-NAT (N=30) or post-NAT (N=28), and MRD (N=50) window was associated with longer RFS and OS. Persistent ctDNA positivity (+ve) during-NAT was associated with a mRFS of 13.3mo vs. not reached (NR) for pts who achieved ctDNA-clearance (HR=4; p=0.032), and a mOS of NR for both groups, with 24mo OS rate at 95.6% vs. 58.6% (HR=5.85; p=0.097), respectively. ctDNA clearance post-NAT was associated with a mRFS of 7.79 vs. 52.04 mo (HR= 3.69; p=0.019) and a mOS of 18.9mo vs. NR (HR=8.78; p=0.007) for ctDNA-cleared vs. pts who did not clear, respectively. During the MRD window, mRFS of 3.57mo vs. NR (HR=12.94; p&lt;0.0001) and mOS of 8.59mo vs. NR (HR=14.54; p&lt;0.0001) was observed for ctDNA+ve and ctDNA negative pts, respectively. ctDNA dynamics revealed pts with early ctDNA clearance (during NAT) had the best outcomes, followed by pts who cleared ctDNA post-NAT, while pts who remained ctDNA+ve at baseline, during-NAT, and post-NAT had worse RFS and OS (24mo RFS rate of 75% vs. 48% vs. NR and 24mo OS rate of 100% vs. 80% vs. 17%, respectively). Of note, pts who achieved ctDNA clearance post-NAT correlated with tumor regression grade (TRG) 1/2/3 when compared to a TRG score of 4/5 in pts who were unable to clear ctDNA post-NAT (p=0.0345). Conclusions: Tumor-informed ctDNA results were predictive of NAT response and correlated with long-term outcomes with early ctDNA clearance associated with superior RFS and OS; meanwhile persistent ctDNA+ve post-NAT/pre-surgery/during MRD correlated with inferior OS and/or RFS as well as poor pathological response. In this initial analysis of the PLAGAST study, longitudinal ctDNA monitoring was prognostic of patient outcomes and may guide NAT clinical decision-making in pts with LAR G/GEJ ADENOCA. Clinical trial information: NCT02674373 .

Updated results of perioperative PD-1 antibody toripalimab plus FLOT chemotherapy for locally advanced resectable gastric or gastro-esophageal junction adenocarcinoma: A one-arm open-table phase II trial.

e16128 Background: Perioperative chemotherapy is the standard treatment for resectable gastric/gastroesophageal junction (GEJ) adenocarcinoma. Immune checkpoint inhibitors have activity in advanced gastric/GEJ cancer. This trial to assess the efficacy of the addition of toripalimab to FLOT for resectable patients and explore the immune microenvironment prospectively related to treatment response of neoadjuvant immunotherapy by multiplex immunohistochemistry. Methods: This is a prospective, single-arm, investigator-initiated phase II trial. Patients with histologically confirmed, resectable, gastric and GEJ adenocarcinoma (≥ cT2 or cN+) were enrolled to receive 4 pre- and post-operative cycles of toripalimab (240mg, q2w) plus FLOT (docetaxel 50 mg/m2; oxaliplatin 85 mg/m2; leucovorin 200 mg/m2; 5-Fu 2600 mg/m2, q2w). The primary endpoint were 3-year disease-free survival rate, overall survival and pathological complete response rate (pCR). Planned sample size of 36 operated patients. if the pCR rate is greater than 16% (n = 6), an additional 20 cases will be added. Multiplex immunohistochemistry is used to quantify in situ biomarker at subcellular resolution. Results: Study accrual completed at August 2022, 55 patients were enrolled, 40M/15F, age 57 (28-76), ECOG 0 (39) and 1 (16). 4 patients had not received surgery were excluded from efficacy analysis (Three patients withdrew consent after two treatment cycles and one refused surgery after 4 cycles pre-operative treatment). Fifty-one had completely neoadjuvant treatment and received surgery. Pathological response was TRG 0/ 1/ 2/ 3 in 10/ 6/ 21/ 14 patients with pCR seen in 10 (19.6%). Major pathologic response (TRG 0 and 1) was seen in 16 (31.4%) patients. At 36.6 (17.6-57.8) months follow up, the median disease-free survival (DFS) and overall survival (OS) were not reached for all patients. DFS rate at 1, 2, and 3 year is 78.4%, 56.9%, and 54.3%. OS rate at 1, 2, and 3 year is 94.1%, 69.5%, and 65.2%. Compared with TRG 2 or 3, patients with MPR showed significant longer survival (p = 0.01). Twenty-four patients underwent immune microenvironment analysis on their pre-treatment specimens by multiplex immunohistochemisty. Compared with TRG 2 or 3 (n = 11), NK cells with positive CD56 expression in tumor parenchyma microenvironment in patients with MPR (n = 13) were significant decreased (p = 0.024). Conclusions: Perioperative toripalimab in combination with FLOT showed promising efficacy with high pCR and MPR rate in patients with resectable gastric/GEJ adenocarcinoma. MPR rate and NK cells in tumor microenvironment have a predictive on therapeutic efficacy, with deserves further study. Clinical trial information: NCT04354662 .

494TiP Efficacy and safety of cadonilimab and COX-2 inhibitor combined with oxaliplatin and capecitabine (XELOX) in perioperative treatment for locally advanced resectable gastric adenocarcinoma: A prospective, single-center, randomized, phase II trial

494TiP Efficacy and safety of cadonilimab and COX-2 inhibitor combined with oxaliplatin and capecitabine (XELOX) in perioperative treatment for locally advanced resectable gastric adenocarcinoma: A prospective, single-center, randomized, phase II trial

Overall Volume of Upper Gastrointestinal Surgery Positively Impacts Gastric Cancer Outcomes at Centers with Low Gastrectomy Volume.

The relationship between hospital volume and surgical mortality is well documented. However, complete centralization of surgical care is not always feasible. The present study investigates how overall volume of upper gastrointestinal surgery at hospitals influences patient outcomes following resection for gastric adenocarcinoma. National Cancer Database (2010-2019) patients with pathologic stage 1-3 gastric adenocarcinoma who underwent gastrectomy were identified. Three cohorts were created: low-volume hospitals (LVH) for both gastrectomy and overall upper gastrointestinal operations, mixed-volume hospital (MVH) for low-volume gastrectomy but high-volume overall upper gastrointestinal operations, and high-volume gastrectomy hospitals (HVH). Chi-squared tests were used to analyze sociodemographic factors and surgical outcomes and Kaplan-Meier method for survival analysis. In total, 26,398 patients were identified (LVH: 20,099; MVH: 539; HVH: 5,760). The 5-year survival was equivalent between MVH and HVH for all stages of disease (MVH: 56.0%, HVH 55.6%; p = 0.9866) and when stratified into early (MVH: 69.9%, HVH: 65.4%; p = 0.1998) and late stages (MVH: 24.7%, HVH: 32.0%; p = 0.1480), while LVH had worse survival. After matching patients, postoperative outcomes were worse for LVH, but there was no difference between MVH and HVH in terms of adequate lymphadenectomy, margin status, readmission rates, and 90-day mortality rates. Despite lower gastrectomy volume for cancer, postoperative gastrectomy outcomes at centers that perform a high number of upper gastrointestinal cancer surgeries were similar to hospitals with high gastrectomy volume. These hospitals offer a blueprint for providing equivalent outcomes to high volume centers while enhancing availability of quality cancer care.

Outcomes of locally advanced gastric and gastroesophageal adenocarcinoma cancers treated with neoadjuvant FLOT in a tertiary care hospital in Pakistan.

Docetaxel, oxaliplatin, leucovorin and 5-fluorouracil (FLOT) may improve overall survival (OS) in patients with locally advanced gastric and gastroesophageal cancer. Our study aims to determine the pathological response in these patients with the FLOT chemotherapy in the Neoadjuvant setting. This is the first study conducted in our country. We conducted a retrospective cross-sectional study from March 2018 to December 2020. After ethical review committee approval, all patients who fulfilled the inclusion criteria and received treatment at our tertiary care center were included in the study. SPSS version 22 was used for data analysis. Frequencies and percentages were calculated for categorical. Values were presented as mean ± standard deviation (SD) for continuous variables. The chi-square test was used to determine the difference between categorical variables. A p-value of ≤0.05 was considered the level of significance. Kaplan-Meier curves were used to calculate survival analysis. Out of 41, 35 patients with locally advanced resectable gastric or gastroesophageal adenocarcinoma were included in our study analysis. The entire cohort had a male predominance, with a mean age of 59. All patients received neoadjuvant FLOT. Pathological treatment response achieved was 77%, of which 66% had partial and 11% had complete response. There is a significant association of pathological response with age, gender, stage, grade, co-morbid and number of chemotherapy cycles received (p-value =<0.05). The OS was 80% with the mean OS was 2.6 years (31 months). Our study shows comparable response rates to other studies conducted internationally. Our findings confirm that FLOT is an effective and well-tolerated perioperative regimen with reasonable response rates in the Pakistani population. A more extensive longitudinal study would ensure these preliminary results in the local patient population.

Comparison of the survival outcomes between retrocolic and antecolic Roux-en-Y reconstruction after gastrectomy for gastric cancer.

There are two methods of Roux-en-Y (RY) reconstruction after gastrectomy: the antecolic route (ACR) and retrocolic route (RCR). There is no evidence to support that the ACR achieves comparable long-term survival. This was a multi-center historical cohort study. Patients diagnosed with clinical T3/4a and any N stage who underwent open gastrectomy and R0 resection for gastric adenocarcinoma between January 2006 and December 2012 were enrolled. The primary outcome was the hazard ratio of ACR for overall survival, with adjustment for confounding factors by propensity score matching, and a Cox proportional hazards model. A total of 1758 eligible patients were identified from the database. After matching, 410 patients in the ACR and RCR groups were included in the final analysis. The adjusted hazard ratio (95% CI) for ACR was 1.148 (0.870-1.492). The five-year survival rates in the ACR and RCR groups were 74.3% (69.5-78.4) and 77.3% (72.3-81.2), respectively. The short-term surgical outcomes of the two groups did not differ to a statistically significant extent. The route used to lift the jejunum in RY reconstruction did not affect the incidence of long-term survival or postoperative complications. The ACR and RCR are both acceptable options for RY reconstruction during gastric cancer surgery.

Phase I trial of short-course chemoradiotherapy followed by chemotherapy as total neoadjuvant therapy for patients with potentially resectable gastric cancer.

362 Background: The purpose of this phase I trial was to evaluate the safety and toxicity of preoperative short-course chemoradiotherapy (CXRT) in patients with potentially resectable gastric or gastroesophageal adenocarcinoma as part of a total neoadjuvant therapy (TNT) approach. Methods: Patients with potentially resectable gastric or gastroesophageal adenocarcinoma received CXRT consisting of 30 Gy in 10 fractions with concurrent capecitabine or fluorouracil, followed by systemic therapy for 2 months and then surgery. The primary objective was safety of CXRT with secondary endpoints of pathologic complete response, perioperative complications, and overall survival (OS). Results: A total of 24 patients were treated between March 2021 and December 2022. Ten patients (42%) presented with bleeding and 3 (13%) presented with gastric outlet obstruction. Two patients (8%) had cirrhosis. Clinical nodal involvement was reported in 12 patients (50%). Twenty patients (83%) had poorly differentiated tumors, and 13 (54%) had signet ring cell histology. All patients completed CXRT. CXRT treatment-related toxic effects included grade 3 lymphopenia in 7 patients (29%), grade 4 lymphopenia in 1 (4%), and grade 3 anemia in 1 (4%). After CXRT, 22 patients (92%) completed 2 months of chemotherapy, 1 patient (4%) with a microsatellite-high tumor completed immunotherapy, and 1 patient (4%) underwent resection without systemic therapy. All patients underwent attempted resection, and gastrectomy was performed in 20 (83%). R0 resection rate was 95%. Pathologic complete response was observed in 2 patients (8%), and ≤ 1% viability was observed in an additional 4 (17%). Three patients had surgical complications (grade I in 1 patient [4%], grade IIIb in 1 [4%], and grade IVa in 1 [4%]); there were no deaths within 90 days. The median follow-up time was 20 months, and median OS was not reached. One- and 3-year OS rates from the date of diagnosis were 96% and 80%, respectively. Conclusions: Short-course CXRT (30 Gy in 10 fractions) may be safely used as part of a planned TNT approach. Rates of treatment completion, pathologic response, and survival were promising, supporting further research into TNT for gastric cancer. Clinical trial information: NCT04523818 .

Atezolizumab and trastuzumab plus chemotherapy in patients with HER2+ locally advanced resectable gastric cancer or adenocarcinoma of the gastroesophageal junction: A multicenter, randomized, open-label phase II study.

312 Background: Currently, there are no standard perioperative regimens for human epidermal growth factor receptor 2 positive (HER2+) gastric cancer (GC) or gastroesophageal junction (GEJ) cancer. Furthermore, despite advances in neoadjuvant or perioperative chemotherapy, the efficacy of treatment for locally resectable advanced GC or GEJ cancer remains unsatisfactory. To address this need, we evaluated the effectiveness of adding atezolizumab (programmed death ligand-1 inhibitor) to treatment with trastuzumab (a HER2 antibody) + capecitabine and oxaliplatin (XELOX) compared with trastuzumab + XELOX in patients eligible for surgery with HER2+ locally advanced GC or adenocarcinoma of the GEJ. Methods: Patients aged 18–75 years were randomized 1:1 to atezolizumab + trastuzumab + XELOX (Arm A) or trastuzumab + XELOX (Arm B) and received the regimen for three neoadjuvant cycles (3 weeks per cycle) and five adjuvant cycles. Treatment administration was atezolizumab 1200 mg, trastuzumab 6 mg/kg, oxaliplatin 130 mg/m2 intravenously on Day 1, and capecitabine 1000 mg/m2 orally twice daily on Days 1–14 of each 3-week cycle. The primary endpoint was the pathological complete regression (pCR) rate. Secondary endpoints were the objective response rate (ORR) during neoadjuvant systemic therapy (NAST) and the R0 resection rate. Time-to-event endpoints are not reported because of immaturity. Efficacy endpoints were analyzed in the intention-to-treat population. The clinical cutoff date for the primary analysis was 12 March 2023. Results: Forty-two Asian patients who provided informed consent were screened and randomized to Arm A (n = 21) or Arm B (n = 21); all patients completed NAST. Most patients were male (92.9%), and the median (range) age was 61 (33–72) years in Arm A and 65 (49–72) years in Arm B. The pCR rate was 38.1% (8/21) in Arm A and 14.3% (3/21) in Arm B (treatment difference: 23.8% [90% confidence interval (CI), 1.3%–44.7%]). The pCR rate was significantly better in Arm A than in Arm B (P = 0.079 &lt;0.1; lower limit of the 90% CI &gt;0). Subgroup analysis showed that age &lt;65 years, male sex, and intestinal Lauren classification were associated with a better pCR rate for the atezolizumab inclusive treatment arm (Arm A); however, these results require further confirmation in future studies. No significant difference was detected between the two arms in ORR during NAST or the R0 resection rate. Conclusions: The addition of atezolizumab to trastuzumab + XELOX therapy was effective in patients with HER2+ locally advanced resectable GC or adenocarcinoma of the GEJ. Clinical trial information: NCT04661150 .

Neoadjuvant and adjuvant pembrolizumab plus chemotherapy in locally advanced gastric or gastro-oesophageal cancer (KEYNOTE-585): an interim analysis of the multicentre, double-blind, randomised phase 3 study

The benefit of combination neoadjuvant and adjuvant chemotherapy and immune checkpoint inhibition in patients with locally advanced, resectable gastric or gastro-oesophageal adenocarcinoma is unknown. We assess the antitumor activity of neoadjuvant and adjuvant pembrolizumab plus chemotherapy in patients with locally advanced resectable gastric or gastro-oesophageal adenocarcinoma. The KEYNOTE-585 study is a multicentre, randomised, placebo-controlled, double-blind, phase 3 study done at 143 medical centres in 24 countries. Eligible patients were aged 18 years or older with untreated, locally advanced, resectable gastric or gastro-oesophageal adenocarcinoma, and an Eastern Cooperative Oncology Group performance status 0-1. Patients were randomly assigned (1:1) by an interactive voice response system and integrated web response system to neoadjuvant pembrolizumab 200 mg intravenously or placebo (saline) plus cisplatin-based doublet chemotherapy (main cohort) every 3 weeks for 3 cycles, followed by surgery, adjuvant pembrolizumab or placebo plus chemotherapy for 3 cycles, then adjuvant pembrolizumab or placebo for 11 cycles. A small cohort was also randomly assigned (1:1) to pembrolizumab or placebo plus fluorouracil, docetaxel, and oxaliplatin (FLOT)-based chemotherapy (FLOT cohort) every 2 weeks for four cycles, followed by surgery, adjuvant pembrolizumab, or placebo plus FLOT for four cycles, then adjuvant pembrolizumab or placebo for 11 cycles. Patients were stratified by geographic region, tumour stage, and chemotherapy backbone. Primary endpoints were pathological complete response (reviewed centrally), event-free survival (reviewed by the investigator), and overall survival in the intention-to-treat population, and safety assessed in all patients who received at least one dose of study treatment. The study is registered at ClinicalTrials.gov, NCT03221426, and is closed to accrual. Between Oct 9, 2017, and Jan 25, 2021, of 1254 patients screened, 804 were randomly assigned to the main cohort, of whom 402 were assigned to the pembrolizumab plus cisplatin-based chemotherapy group and 402 to the placebo plus cisplatin-based chemotherapy group, and 203 to the FLOT cohort, of whom 100 were assigned to the pembrolizumab plus FLOT group and 103 to placebo plus FLOT group. In the main cohort of 804 participants, 575 (72%) were male and 229 (28%) were female. In the main cohort, after median follow-up of 47·7 months (IQR 38·0-54·8), pembrolizumab was superior to placebo for pathological complete response (52 [12·9%; 95% CI 9·8-16·6] of 402 vs eight [2·0%; 0·9-3·9] of 402; difference 10·9%, 95% CI 7·5 to 14·8; p<0·00001). Median event-free survival was longer with pembrolizumab versus placebo (44·4 months, 95% CI 33·0 to not reached vs 25·3 months, 20·6 to 33·9; hazard ratio [HR] 0·81, 95% CI 0·67 to 0·99; p=0·0198) but did not meet the threshold for statistical significance (p=0·0178). Median overall survival was 60·7 months (95% CI 51·5 to not reached) in the pembrolizumab group versus 58·0 months (41·5 to not reached) in the placebo group (HR 0·90, 95% CI 0·73 to 1·12; p=0·174). Grade 3 or worse adverse events of any cause occurred in 312 (78%) of 399 patients in the pembrolizumab group and 297 (74%) of 400 patients in the placebo group; the most common were nausea (240 [60%] vs 247 [62%]), anaemia (168 [42%] vs 158 [40%]), and decreased appetite (163 [41%] vs 172 [43%]). Treatment-related serious adverse events were reported in 102 (26%) and 97 (24%) patients. Treatment-related adverse events that led to death occurred in four (1%) patients in the pembrolizumab group (interstitial ischaemia, pneumonia, decreased appetite, and acute kidney injury [n=1 each]) and two (<1%) patients in the placebo group (neutropenic sepsis and neutropenic colitis [n=1 each]). Although neoadjuvant and adjuvant pembrolizumab versus placebo improved the pathological complete response, it did not translate to significant improvement in event-free survival in patients with untreated, locally advanced resectable gastric or gastro-oesophageal cancer. Merck Sharp & Dohme.

Great Debate: Chemoradiation Should be Added to Chemotherapy as a Neoadjuvant Treatment Strategy for Resectable Gastric Adenocarcinoma.

Most patients with resectable gastric cancer present with locally advanced disease and warrant neoadjuvant chemotherapy based on level 1 evidence. However, the incremental benefit of adding radiation to chemotherapy as a neoadjuvant treatment strategy for these patients is less clear. While awaiting the results of two ongoing randomized clinical trials attempting to specifically address this question (TOPGEAR and CRITICS-II), this article presents the debate between two gastric cancer surgery experts supporting each side of the argument on the use or omission of neoadjuvant radiation in this setting. On the one hand, neoadjuvant radiation may be better tolerated compared with modern triplet chemotherapy and may be associated with higher rates of major pathologic response. Additionally, there is evidence to suggest that radiation may offer a survival benefit when the tumor is located at the gastroesophageal junction or there is concern for a margin-positive resection. However, in the setting of adequate surgery, no survival benefit has been demonstrated by adding radiation to modern chemotherapy, likely reflecting the fact that death from gastric cancer is a result of distant recurrence, which is not addressed by local treatment such as radiotherapy. While awaiting the results of the TOPGEAR and CRITICS-II trials, this discussion of current evidence can facilitate the refinement of an optimal neoadjuvant therapy strategy in patients with resectable gastric cancer.

1512MO Perioperative camrelizumab (C) combined with rivoceranib (R) and chemotherapy (chemo) versus chemo for locally advanced resectable gastric or gastroesophageal junction (G/GEJ) adenocarcinoma: The first interim analysis of a randomized, phase III trial (DRAGON IV)

1512MO Perioperative camrelizumab (C) combined with rivoceranib (R) and chemotherapy (chemo) versus chemo for locally advanced resectable gastric or gastroesophageal junction (G/GEJ) adenocarcinoma: The first interim analysis of a randomized, phase III trial (DRAGON IV)