Zolbetuximab plus chemotherapy for locally advanced unresectable or metastatic stomach or gastroesophageal junction cancers: a plain language summary.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of two articles. The first article is about a clinical trial called SPOTLIGHT and it was published in the medical journal The Lancet in in April of 2023. The second article is about a clinical trial called GLOW and it was published in the medical journal Nature Medicine in July of 2023. WHAT ARE THE KEY TAKEAWAYS?: Until recently, chemotherapy was the first treatment given to people with stomach cancer or gastroesophageal junction (or GEJ) cancer that is locally advanced unresectable or metastatic. When cancer cells have high amounts of the protein CLDN18.2 but do not have high amounts of the protein HER2, the cancer is known as CLDN18.2-positive (or CLDN18.2+) and HER2-negative (or HER2-). New medicines to treat cancer are being developed. These medicines attach to proteins on cancer cells to help the body recognize and kill cancer cells.The clinical trials SPOTLIGHT and GLOW included participants with CLDN18.2+ and HER2- stomach or GEJ cancer that was locally advanced unresectable or metastatic. These trials looked at whether adding a medicine called zolbetuximab to chemotherapy as the first treatment for cancer helped people live longer before their tumors grew bigger or new tumors grew, after starting the trial. These studies also looked at whether adding zolbetuximab to chemotherapy helped people live longer after starting the trial. WHAT WERE THE MAIN CONCLUSIONS REPORTED BY THE RESEARCHERS?: In SPOTLIGHT and GLOW, on average, participants assigned to zolbetuximab plus chemotherapy lived 1.4 to 1.9 months longer before their tumors grew bigger or new tumors grew, after starting the trial, than participants assigned to a placebo plus chemotherapy. On average, participants assigned to zolbetuximab plus chemotherapy also lived 2.2 to 2.7 months longer, after starting the trial, than participants assigned to a placebo plus chemotherapy. These results suggest that zolbetuximab plus chemotherapy could be a new first treatment for people with CLDN18.2+ and HER2- stomach or GEJ cancer that is locally advanced unresectable or metastatic.Clinical Trial Registration: NCT03504397 (SPOTLIGHT); NCT03653507 (GLOW).

The clinical trials SPOTLIGHT and GLOW showed that, on average, participants with stomach or GEJ cancer assigned to zolbetuximab plus chemotherapy lived 2.2 to 2.7 months longer than participants assigned to a placebo plus chemotherapy.

Advances in diagnosis and management of cancer of the esophagus.

Esophageal cancer is the seventh most common malignancy worldwide, with over 470 000 new cases diagnosed each year. Two distinct histological subtypes predominate, and should be considered biologically separate disease entities.1 These subtypes are esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). Outcomes remain poor regardless of subtype, with most patients presenting with late stage disease.2 Novel strategies to improve early detection of the respective precursor lesions, squamous dysplasia, and Barrett's esophagus offer the potential to improve outcomes. The introduction of a limited number of biologic agents, as well as immune checkpoint inhibitors, is resulting in improvements in the systemic treatment of locally advanced and metastatic esophageal cancer. These developments, coupled with improvements in minimally invasive surgical and endoscopic treatment approaches, as well as adaptive and precision radiotherapy technologies, offer the potential to improve outcomes still further. This review summarizes the latest advances in the diagnosis and management of esophageal cancer, and the developments in understanding of the biology of this disease.

Nivolumab plus chemotherapy or ipilimumab versus chemotherapy in patients with advanced esophageal squamous cell carcinoma (CheckMate 648): 29-month follow-up from a randomized, open-label, phase III trial.

BACKGROUND: First-line nivolumab plus chemotherapy and nivolumab plus ipilimumab both demonstrated significant overall survival (OS) benefit versus chemotherapy in previously untreated patients with advanced esophageal squamous cell carcinoma (ESCC) in the CheckMate 648 trial, leading to approvals of both nivolumab-containing regimens in many countries. We report longer-term follow-up data. METHODS: This open-label, phase III trial (NCT03143153) enrolled adults with previously untreated, unresectable, advanced, recurrent, or metastatic ESCC. Patients were randomized 1:1:1 to nivolumab plus chemotherapy, nivolumab plus ipilimumab, or chemotherapy. Primary endpoints were OS and progression-free survival (PFS) by blinded independent central review. Hierarchical testing was performed first in patients with tumor cell programmed death ligand 1 (PD-L1) expression of ≥1% and then in the overall population. RESULTS: A total of 970 patients were randomly assigned. After 29 months of minimum follow-up, nivolumab plus chemotherapy continued to demonstrate improvement in OS versus chemotherapy (hazard ratio [HR] = 0.59 [95% CI: 0.46-0.76]) in patients with tumor cell PD-L1 expression of ≥1% and in the overall population (HR = 0.78 [95% CI: 0.65-0.93]) and with nivolumab plus ipilimumab versus chemotherapy (HR = 0.62 [95% CI: 0.48-0.80]) in patients with tumor cell PD-L1 expression of ≥1% and in the overall population (HR = 0.77 [95% CI: 0.65-0.92]). In patients with tumor cell PD-L1 expression of ≥1%, nivolumab plus chemotherapy demonstrated PFS benefit versus chemotherapy (HR = 0.67 [95% CI: 0.51-0.89]); PFS benefit was not observed with nivolumab plus ipilimumab versus chemotherapy (HR = 1.04 [95% CI: 0.79-1.36]). Among all treated patients (n = 936), Grade 3-4 treatment-related adverse events were reported in 151 (49%, nivolumab plus chemotherapy), 105 (32%, nivolumab plus ipilimumab), and 110 (36%, chemotherapy) patients. CONCLUSIONS: Nivolumab plus chemotherapy and nivolumab plus ipilimumab continued to demonstrate clinically meaningful OS benefit versus chemotherapy with no new safety signals identified with longer follow-up, further supporting use as first-line standard treatment options for patients with advanced ESCC.

State of the art and upcoming trends in claudin-directed therapies in gastrointestinal malignancies.

PURPOSE OF REVIEW: Claudins, components of tight cell junctions in epithelial and endothelial cells, have emerged as a therapeutic target in gastrointestinal (GI) malignancies, particularly claudin 18.2 (CLDN18.2). RECENT FINDINGS: Zolbetuximab, a chimeric anti-CLDN18.2 monoclonal antibody (mAb), is currently under FDA review and may emerge as the first claudin targeted therapy approved. Phase 3 trials show that zolbetuximab in combination with front-line fluoropyrimidine plus oxaliplatin improves survival in advanced CLDN18.2 positive (≥75% of tumor cells) gastric adenocarcinoma (GAC) patients. Many other therapies (mAbs; CART; bispecific; ADCs) are under investigation. SUMMARY: CLDN18.2 will be an important target in GAC. Early understanding of how to target CLDN18.2 based on the level of expression (high, moderate, low) will be the key to success in this area. Studying these as separate entities should be considered. Resistance patterns, loss of CLDN18.2 expression, role in the refractory setting, and if any role in localized disease are questions that remain. Other targets for claudin that target claudin six and four are under investigation. Their role in GI malignancies will soon be further clarified.

Retrospective Study of Claudin 18 Isoform 2 Prevalence and Prognostic Association in Gastric and Gastroesophageal Junction Adenocarcinoma.

PURPOSE: Claudin 18 isoform 2 (CLDN18.2) is an emerging biomarker and therapeutic target in gastric and gastroesophageal junction (G/GEJ) adenocarcinoma. This study aimed to obtain deeper understanding of CLDN18.2 positivity patterns, prognostic implications, and associations with various demographic, clinical, and molecular characteristics in G/GEJ adenocarcinoma. METHODS: Archived tumor tissue samples from 304 patients with G/GEJ adenocarcinoma in the United States were assessed for CLDN18.2 positivity by immunohistochemistry. CLDN18.2 positivity was defined as ≥50% or ≥75% of tumor cells with CLDN18 staining intensity ≥2+. CLDN18.2 positivity patterns were analyzed for association with prognosis and clinicopathologic/demographic characteristics. Where possible, CLDN18.2 positivity was analyzed for matched tissue samples to assess concordance between primary and metastatic tumors and concordance before and after chemotherapy. RESULTS: The overall prevalence of CLDN18.2-positive tumors (with ≥75% cutoff) was 44.4% (n = 135 of 304). CLDN18.2-positive tumors had a prevalence of 51.4% (n = 91 of 177) in gastric and 34.6% (n = 44 of 127) in GEJ adenocarcinoma. With a ≥50% cutoff, the prevalence of CLDN18.2-positive tumors was 64.4% (n = 114 of 177) in gastric adenocarcinoma and 44.9% (n = 57 of 127) in GEJ adenocarcinoma. There was no association between overall survival and CLDN18.2 positivity using either threshold. Statistically significant associations were noted between CLDN18.2 positivity and sex, histologic type of G/GEJ adenocarcinoma, and adenocarcinoma subtype (≥75% cutoff), and metastasis site and tumor grade (≥50% cutoff). The overall concordance of CLDN18.2 positivity (≥75% cutoff) was 73% (27 of 37) for matched primary versus metastatic tumor samples and 74% (29 of 39) for matched samples before and after chemotherapy. CONCLUSION: This study demonstrated that CLDN18.2 positivity did not correlate with survival in G/GEJ adenocarcinoma, consistent with published data. On the basis of matched sample analysis, CLDN18.2 appears to demonstrate >70% concordance as a biomarker. Observed correlations with certain patient/tumor characteristics warrant further study.

SMARCA4 Mutations in Gastroesophageal Adenocarcinoma: An Observational Study via a Next-Generation Sequencing Panel.

BACKGROUND: The clinical impact of SMARCA4 mutations (SMARCA4ms) in gastroesophageal adenocarcinoma (GEA) remains underexplored. This study aimed to examine the association of SMARCA4ms with clinical outcomes and co-occurrence with other gene mutations identified through a next-generation sequencing (NGS) panel in GEA patients. METHODS: A total of 256 patients with metastatic or recurrent GEA who underwent NGS panel profiling at the MD Anderson Cancer Center between 2016 and 2022 were included. Comparative analyses were performed to assess clinical outcomes related to SMARCA4ms. The frequency and types of SMARCA4ms and their co-occurrence with other gene mutations were also examined. RESULTS: SMARCA4ms were identified in 19 patients (7.4%). These SMARCA4ms were significantly associated with non-signet ring cell subtype (p = 0.044) and PD-L1 positive expression (p = 0.046). No difference in survival between the SMARCA4m and SMARCA4-normal group was observed (p = 0.84). There were significant associations between SMARCA4ms and FANCA, IGF1R, KRAS, FANCL, and PTEN alterations. Notably, 15 of the 19 SMARCA4m cases involved SNV missense mutations, with frequent co-occurrences noted with TP53, KRAS, ARID1A, and ERBB2 mutations. CONCLUSIONS: These results serve as the first comprehensive examination of the relationship between SMARCA4ms and clinical outcomes in GEA.

Chemotherapy Plus Atezolizumab Pre- and Post-Resection in Localized Esophageal or Gastroesophageal Junction Adenocarcinomas: A Phase I/II Single-Arm Study.

Efforts to improve the prognosis for patients with locally advanced esophageal or gastroesophageal junction (GEJ) adenocarcinoma have focused on neoadjuvant approaches to increase the pathological complete response (pathCR) rate, improve surgical resection, and prolong event-free and overall survival (OS). Building on the recent evidence that PD-1 inhibition plus chemotherapy improves the OS of patients with metastatic GEJ adenocarcinoma, we evaluated whether the application of this strategy in the neoadjuvant setting would improve the pathological response. This single-center phase I/II trial evaluated the safety, toxicity, and efficacy of neoadjuvant atezolizumab with oxaliplatin and 5-fluorouracil (modified FOLFOX) followed by esophagectomy followed by atezolizumab. The primary objective goal was to achieve 20% pathCR. From the twenty enrolled patients, eighteen underwent resection and two (10%, 95% CI: 1.24-31.7%) achieved pathCR. After a median follow-up duration of 40.7 months, 11 patients had disease recurrence and 10 had died. The median disease-free and OS were 28.8 (95% CI: 14.7, NA) and 38.6 months (95% CI: 30.5, NA), respectively. No treatment-related adverse events led to death. Although modified FOLFOX plus atezolizumab did not achieve the expected pathCR, an acceptable safety profile was observed. Our results support the continued development of a more refined strategy (neoadjuvant chemotherapy plus perioperative immunotherapy/targeted agents) with molecular/immune profiling in parallel.

Gastroesophageal Adenocarcinomas With Defective Mismatch Repair: Current Knowledge and Clinical Management.

Esophageal, gastroesophageal junction, and gastric adenocarcinomas, referred to collectively as gastroesophageal adenocarcinomas (GEAs), are a major cause of global cancer-related mortality. Our increasing molecular understanding has led to the addition of biomarker-directed approaches to defined subgroups and has improved survival in selected patients, such as those with HER2 and Claudin18.2 overexpression. Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer, including GEA, but biomarkers beyond PD-L1 expression are lacking. Mismatch repair deficiency and/or high microsatellite instability (dMMR/MSI-H) is observed in 8% to 22% of nonmetastatic GEA, and 3% to 5% of patients with metastatic disease. dMMR/MSI-H tumors are associated with more favorable prognosis and significant benefit from ICIs, although some heterogeneity exists. The activity of ICIs in advanced dMMR/MSI-H cancer is seen across lines of therapy and should be recommended in the frontline setting. In patients with nonmetastatic dMMR/MSI-H cancer, increasing evidence suggests that perioperative and adjuvant chemotherapy may not provide benefit to the dMMR/MSI-H subgroup. The activity of perioperative chemotherapy-free immune checkpoint regimens in patients with nonmetastatic dMMR/MSI-H cancer is highly promising and underscores the need to identify this unique subgroup. We recommend MMR/MSI testing for all patients with GEA at diagnosis, and review the key rationale and clinical management implications for patient with dMMR/MSI-H tumors across disease stages.

First-In-Human Phase I Study of Tinengotinib (TT-00420), a Multiple Kinase Inhibitor, as a Single Agent in Patients With Advanced Solid Tumors.

PURPOSE: This first-in-human phase I dose-escalation study evaluated the safety, pharmacokinetics, and efficacy of tinengotinib (TT-00420), a multi-kinase inhibitor targeting fibroblast growth factor receptors 1-3 (FGFRs 1-3), Janus kinase 1/2, vascular endothelial growth factor receptors, and Aurora A/B, in patients with advanced solid tumors. PATIENTS AND METHODS: Patients received tinengotinib orally daily in 28-day cycles. Dose escalation was guided by Bayesian modeling using escalation with overdose control. The primary objective was to assess dose-limiting toxicities (DLTs), maximum tolerated dose (MTD), and dose recommended for dose expansion (DRDE). Secondary objectives included pharmacokinetics and efficacy. RESULTS: Forty-eight patients were enrolled (dose escalation, n = 40; dose expansion, n = 8). MTD was not reached; DRDE was 12 mg daily. DLTs were palmar-plantar erythrodysesthesia syndrome (8 mg, n = 1) and hypertension (15 mg, n = 2). The most common treatment-related adverse event was hypertension (50.0%). In 43 response-evaluable patients, 13 (30.2%) achieved partial response (PR; n = 7) or stable disease (SD) ≥ 24 weeks (n = 6), including 4/11 (36.4%) with FGFR2 mutations/fusions and cholangiocarcinoma (PR n = 3; SD ≥ 24 weeks n = 1), 3/3 (100.0%) with hormone receptor (HR)-positive/HER2-negative breast cancer (PR n = 2; SD ≥ 24 weeks n = 1), 2/5 (40.0%) with triple-negative breast cancer (TNBC; PR n = 1; SD ≥ 24 weeks n = 1), and 1/1 (100.0%) with castrate-resistant prostate cancer (CRPC; PR). Four of 12 patients (33.3%; HR-positive/HER2-negative breast cancer, TNBC, prostate cancer, and cholangiocarcinoma) treated at DRDE had PRs. Tinengotinib's half-life was 28-34 hours. CONCLUSIONS: Tinengotinib was well tolerated with favorable pharmacokinetic characteristics. Preliminary findings indicated potential clinical benefit in FGFR inhibitor-refractory cholangiocarcinoma, HER2-negative breast cancer (including TNBC), and CRPC. Continued evaluation of tinengotinib is warranted in phase II trials.

Co-clinical Trial of Novel Bispecific Anti-HER2 Antibody Zanidatamab in Patient-Derived Xenografts.

Zanidatamab is a bispecific human epidermal growth factor receptor 2 (HER2)-targeted antibody that has demonstrated antitumor activity in a broad range of HER2-amplified/expressing solid tumors. We determined the antitumor activity of zanidatamab in patient-derived xenograft (PDX) models developed from pretreatment or postprogression biopsies on the first-in-human zanidatamab phase I study (NCT02892123). Of 36 tumors implanted, 19 PDX models were established (52.7% take rate) from 17 patients. Established PDXs represented a broad range of HER2-expressing cancers, and in vivo testing demonstrated an association between antitumor activity in PDXs and matched patients in 7 of 8 co-clinical models tested. We also identified amplification of MET as a potential mechanism of acquired resistance to zanidatamab and demonstrated that MET inhibitors have single-agent activity and can enhance zanidatamab activity in vitro and in vivo. These findings provide evidence that PDXs can be developed from pretreatment biopsies in clinical trials and may provide insight into mechanisms of resistance. SIGNIFICANCE: We demonstrate that PDXs can be developed from pretreatment and postprogression biopsies in clinical trials and may represent a powerful preclinical tool. We identified amplification of MET as a potential mechanism of acquired resistance to the HER2 inhibitor zanidatamab and MET inhibitors alone and in combination as a therapeutic strategy. This article is featured in Selected Articles from This Issue, p. 695.

Evidence to Date on the Therapeutic Potential of Zolbetuximab in Advanced Gastroesophageal Adenocarcinoma.

Gastric adenocarcinoma (GAC) continues to be a prevalent worldwide malignancy and a leading cause of cancer death, and it is frequently cited as incurable. Targeted therapy in GAC has lagged behind other solid tumors. The human epidermal growth factor receptor-2 (HER-2) represented the single target in GACs for many years, seen in approximately 20% of patients with advanced GAC. Recent advances in management now include the addition of immunotherapy checkpoint inhibition to select front-line advanced GACs. Unfortunately, outcomes remain poor for most patients. We anticipate finding a key to future discoveries in GACs in next-generation sequencing and more targeted approaches. Claudin 18.2 (CLDN18.2) has emerged as a therapeutic target in GACs. CLDN18.2 is reportedly expressed in 14-87% of GACs, and CLDN18.2 is available for monoclonal antibody (mAb) binding as it is expressed on the outer cell membrane. Here, we review the exploration of CLDN18.2 as a target in GACs via the use of zolbetuximab (IMAB362). Zolbetuximab is now under priority FDA review for GACs, and we eagerly await the review outcome.

E-cadherin loss drives diffuse-type gastric tumorigenesis via EZH2-mediated reprogramming.

Diffuse-type gastric adenocarcinoma (DGAC) is a deadly cancer often diagnosed late and resistant to treatment. While hereditary DGAC is linked to CDH1 mutations, the role of CDH1/E-cadherin inactivation in sporadic DGAC tumorigenesis remains elusive. We discovered CDH1 inactivation in a subset of DGAC patient tumors. Analyzing single-cell transcriptomes in malignant ascites, we identified two DGAC subtypes: DGAC1 (CDH1 loss) and DGAC2 (lacking immune response). DGAC1 displayed distinct molecular signatures, activated DGAC-related pathways, and an abundance of exhausted T cells in ascites. Genetically engineered murine gastric organoids showed that Cdh1 knock-out (KO), KrasG12D, Trp53 KO (EKP) accelerates tumorigenesis with immune evasion compared with KrasG12D, Trp53 KO (KP). We also identified EZH2 as a key mediator promoting CDH1 loss-associated DGAC tumorigenesis. These findings highlight DGAC's molecular diversity and potential for personalized treatment in CDH1-inactivated patients.

First-Line Nivolumab Plus Chemotherapy for Advanced Gastric, Gastroesophageal Junction, and Esophageal Adenocarcinoma: 3-Year Follow-Up of the Phase III CheckMate 649 Trial.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We report 3-year efficacy and safety results from the phase III CheckMate 649 trial. Patients with previously untreated advanced or metastatic gastroesophageal adenocarcinoma were randomly assigned to nivolumab plus chemotherapy or chemotherapy. Primary end points were overall survival (OS) and progression-free survival (PFS) by blinded independent central review (BICR) in patients whose tumors expressed PD-L1 combined positive score (CPS) ≥5. With 36.2-month minimum follow-up, for patients with PD-L1 CPS ≥5, the OS hazard ratio (HR) for nivolumab plus chemotherapy versus chemotherapy was 0.70 (95% CI, 0.61 to 0.81); 21% versus 10% of patients were alive at 36 months, respectively; the PFS HR was 0.70 (95% CI, 0.60 to 0.81); 36-month PFS rates were 13% versus 8%, respectively. The objective response rate (ORR) per BICR was 60% (95% CI, 55 to 65) with nivolumab plus chemotherapy versus 45% (95% CI, 40 to 50) with chemotherapy; median duration of response was 9.6 months (95% CI, 8.2 to 12.4) versus 7.0 months (95% CI, 5.6 to 7.9), respectively. Nivolumab plus chemotherapy also continued to show improvement in OS, PFS, and ORR versus chemotherapy in the overall population. Adding nivolumab to chemotherapy maintained clinically meaningful long-term survival benefit versus chemotherapy alone, with an acceptable safety profile, supporting the continued use of nivolumab plus chemotherapy as standard first-line treatment for advanced gastroesophageal adenocarcinoma.

Mesothelial cells with mesenchymal features enhance peritoneal dissemination by forming a protumorigenic microenvironment.

Malignant ascites accompanied by peritoneal dissemination contain various factors and cell populations as well as cancer cells; however, how the tumor microenvironment is shaped in ascites remains unclear. Single-cell proteomic profiling and a comprehensive proteomic analysis are conducted to comprehensively characterize malignant ascites. Here, we find defects in immune effectors along with immunosuppressive cell accumulation in ascites of patients with gastric cancer (GC) and identify five distinct subpopulations of CD45(-)/EpCAM(-) cells. Mesothelial cells with mesenchymal features in CD45(-)/EpCAM(-) cells are the predominant source of chemokines involved in immunosuppressive myeloid cell (IMC) recruitment. Moreover, mesothelial-mesenchymal transition (MMT)-induced mesothelial cells strongly express extracellular matrix (ECM)-related genes, including tenascin-C (TNC), enhancing metastatic colonization. These findings highlight the definite roles of the mesenchymal cell population in the development of a protumorigenic microenvironment to promote peritoneal dissemination.

Gastric Extent of Tumor Predicts Peritoneal Metastasis in Siewert II Adenocarcinoma.

BACKGROUND: Whereas current guidelines recommend staging laparoscopy for most patients with potentially resectable gastric cancer, such a recommendation for patients with adenocarcinoma of the gastroesophageal junction (AEG) is lacking. This study sought to identify baseline clinicopathologic characteristics associated with peritoneal metastasis (PM) among patients with Siewert II AEG. METHODS: Trimodality therapy-eligible patients with Siewert II AEG (2000-2015, single institution) were retrospectively identified. A composite PM outcome was defined as follows: (1) PM at staging laparoscopy; (2) PM diagnosed during neoadjuvant chemoradiation; or (3) PM ≤6 months postoperatively. Logistic regression was used to identify features associated with PM; bootstrapped analysis (Youden J) identified the distal tumor extension that best discriminated the composite outcome. RESULTS: Of 188 patients, a composite PM outcome was observed in 26 of 188 (13.8%); 12 of 26 had positive staging laparoscopy, 10 of 26 experienced PM during chemoradiation, and 4 of 26 had PM ≤6 months postoperatively. Tumor extension below the GEJ was greater in patients with PM (median, 4.0 cm [interquartile range, 3.0-5.0] vs 3.0 cm [interquartile range, 2.0-3.0]; P < .001). All patients with PM had cT3 to cT4 tumors. Among patients with cT3 to cT4 tumors (n = 168 of 188; 89.4%), distal tumor extent (odds ratio, 1.67/cm; 95% CI, 1.23-2.28; P = .001) was independently associated with increased odds of PM. Gastric tumor extension ≥4 cm remained independently associated with PM (OR, 5.14; 95% CI, 2.11-12.53; P < .001) after adjustment for signet ring cell status. CONCLUSIONS: Distal tumor extent beyond the GEJ is independently associated with increased odds of PM in patients with Siewert II AEG. Patients with extensive gastric involvement should therefore be considered for staging laparoscopy before trimodality therapy.

Tislelizumab in advanced/metastatic esophageal squamous cell carcinoma: health-related quality of life in Asian patients.

OBJECTIVE: Post-hoc analysis examined health-related quality of life and esophageal squamous cell carcinoma (ESCC) symptoms in the Asian subgroup of patients in RATIONALE-302 (NCT03430843). METHODS: Patients were randomized 1:1 to either tislelizumab or investigator-chosen chemotherapy (paclitaxel, docetaxel, or irinotecan). Health-related quality of life was measured using the EORTC QLQ-C30 and the QLQ-OES18. Least-squares mean score changes from baseline to weeks 12 and 18 in health-related quality-of-life scores were assessed using a mixed model for repeated measurements. Reported nominal p-values are for descriptive purposes only. RESULTS: Of the 512 patients, this analysis was conducted in 392 Asian patients (tislelizumab, n = 192; investigator-chosen chemotherapy, n = 200). The tislelizumab arm had stable global health status/quality of life, but fatigue scores worsened in both arms. The change from baseline was similar for physical functioning in both arms at weeks 12 and 18. Eating and dysphagia scores remained stable in the tislelizumab arm. Reflux improved at week 12 in the tislelizumab arm and worsened in the investigator-chosen chemotherapy arm. CONCLUSIONS: Overall, the health-related quality of life and ESCC-related symptoms of patients receiving tislelizumab in the Asian subgroup remained stable or improved, while patients receiving investigator-chosen chemotherapy experienced worsening. These results in Asian patients corroborate the findings in the intent-to-treat population, suggesting tislelizumab is a potential new second-line treatment option for patients with advanced or metastatic ESCC. TRIAL REGISTRATION: The RATIONALE-302 study is registered on clinicaltrials.gov as NCT03430843.

Independent Stage Classification for Gastroesophageal Junction Adenocarcinoma.

In gastroesophageal junction (GEJ) adenocarcinoma cases, a prognosis based on ypTNM staging could be affected by preoperative therapy. Patients with esophageal adenocarcinoma and gastric adenocarcinoma who underwent preoperative therapy followed by surgical resection from 2006 through 2017 were identified in the National Cancer Database. To enable stage-by-stage OS comparisons, tumors were classified into four gross ypTNM groups: ypT1/2, N-negative; ypT1/2, N-positive; ypT3/4, N-negative; and ypT3/4, N-positive. Prognostic factors were examined, and an OS prediction nomogram was developed for patients with abdominal/lower esophageal and gastric cardia adenocarcinoma, representing GEJ cancers. We examined 25,463 patient records. When compared by gross ypTNM group, the abdominal/lower esophageal and gastric cardia adenocarcinoma groups had similar OS rates, differing from those of other esophageal or gastric cancers. Cox regression analysis of patients with GEJ cancers showed that preoperative chemoradiotherapy was associated with shorter OS than preoperative chemotherapy after adjustment for the ypTNM group (hazard ratio 1.31, 95% CI 1.24-1.39, p < 0.001), likely owing to downstaging effects. The nomogram had a concordance index of 0.833 and a time-dependent area under the curve of 0.669. OS prediction in GEJ adenocarcinoma cases should include preoperative therapy regimens. Our OS prediction nomogram provided reasonable OS prediction for patients with GEJ adenocarcinoma, and future validation is needed.

Human Epidermal Growth Factor Receptor-2 Gastric Adenocarcinoma: Expanding Therapy of a Recognized Target.

Human epidermal growth factor receptor-2 (HER2) is a well-known cancer target. Many HER2-targeted agents are marketed and being investigated. Unfortunately, these therapies lack consistent responses and outcomes amongst different tumors. Questions remain as to why HER2 biology is different in different tumor types. Gastric adenocarcinomas (GACs) demonstrate both intra- and inter-tumor HER2 expression heterogeneity and show discordance amongst primary and metastatic disease sites. This creates barriers in determining HER2 agents' effectiveness and contributes to the failure of some HER2-targeted agents in the treatment of HER2-positive advanced GACs. Trastuzumab deruxtecan, an antibody drug conjugate of trastuzumab with a topoisomerase inhibitor, was recently approved for the treatment of refractory HER2-positive advanced GAC patients. There are exciting and newer therapies under investigation. Examining resistance patterns (both adaptive and acquired) along with establishing a better understanding of the intra- and inter-tumor heterogeneity is necessary to ensure successful progress. Here we review the current status of HER2-targeted therapy in GACs. We additionally review newer therapies under investigation and their potential role in HER2 GACs.

Challenges and Prospects of Patient-Derived Xenografts for Cancer Research.

We discuss the importance of the in vivo models in elucidating cancer biology, focusing on the patient-derived xenograft (PDX) models, which are classic and standard functional in vivo platforms for preclinical evaluation. We provide an overview of the most representative models, including cell-derived xenografts (CDX), tumor and metastatic cell-derived xenografts, and PDX models utilizing humanized mice (HM). The orthotopic models, which could reproduce the cancer environment and its progression, similar to human tumors, are particularly common. The standard procedures and rationales of gastric adenocarcinoma (GAC) orthotopic models are addressed. Despite the significant advantages of the PDX models, such as recapitulating key features of human tumors and enabling drug testing in the in vivo context, some challenges must be acknowledged, including loss of heterogeneity, selection bias, clonal evolution, stroma replacement, tumor micro-environment (TME) changes, host cell carryover and contaminations, human-to-host cell oncogenic transformation, human and host viral infections, as well as limitations for immunologic research. To compensate for these limitations, other mouse models, such as syngeneic and humanized mouse models, are currently utilized. Overall, the PDX models represent a powerful tool in cancer research, providing critical insights into tumor biology and potential therapeutic targets, but their limitations and challenges must be carefully considered for their effective use. Lastly, we present an intronic quantitative PCR (qPCR) method to authenticate, detect, and quantify human/murine cells in cell lines and PDX samples.