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.

How to use anti-PD-1 therapy in gastric cancer: the approach in the United States.

Gastric cancer is a leading global cause of cancer-related mortality. In the past, survival achieved in metastatic disease with chemotherapy was less than 1 year. The advent of immune checkpoint inhibitors has changed the treatment of gastric cancer. With demonstration of single agent activity for anti-programmed cell death protein 1 (anti-PD-1) agents in gastric cancer with a particularly high degree of activity in microsatellite instability (MSI) high cancers, global clinical trials added nivolumab and pembrolizumab to first line chemotherapy. Improvements in progression free survival, overall survival and increased response rates led to regulatory approval of these agents in the U.S. The benefit in survival seems limited, however, to patients with programmed cell death ligand 1 (PD-L1) positive or MSI high cancers. Adjuvant therapy with nivolumab improved disease-free survival after chemoradiotherapy and surgery in esophageal and gastroesophageal junction adenocarcinoma in patients with residual disease resected at surgery, and is a new care standard. Results of ongoing trials adding immune checkpoint inhibitors to perioperative chemotherapy in gastric cancer are anxiously awaited. In locally advanced MSI high gastric cancer, immune checkpoint inhibitor therapy is being explored as preoperative therapy given the demonstration of a high degree of pathologic complete response to these agents. Some trials may offer patients nonoperative management if a complete response is achieved.

Clinical and molecular characteristics of early-onset vs average-onset esophagogastric cancer.

BACKGROUND: The rate of esophagogastric cancer is rising among individuals under 50 years of age. It remains unknown whether early-onset esophagogastric cancer represents a unique entity. This study investigated the clinical and molecular characteristics of early-onset and average-onset esophagogastric cancer . METHODS: We reviewed the Memorial Sloan Kettering Cancer Center gastric, esophageal, and gastroesophageal junction cancer database. Associations between baseline characteristics and tumor and germline molecular alterations were compared between those with early-onset and average-onset esophagogastric cancer using Fisher exact tests and the Benjamini-Hochberg method for multiple-hypothesis correction. RESULTS: We included 1123 patients with early-onset esophagogastric cancer (n = 219; median age = 43 years [range = 18-49 years]) and average-onset esophagogastric cancer (n = 904; median age = 67 years [range = 50-94 years]) treated between 2005 and 2018. The early-onset group had more women (39% vs 28%, P = .002). Patients with early-onset esophagogastric cancer were more likely to have a gastric primary site (64% vs 44%, P < .0001). The signet ring cell and/or diffuse type was 3 times more common in the early-onset esophagogastric cancer group (31% vs 9%, P < .0001). Early-onsite tumors were more frequently genomically stable (31% vs 18%, P = .0002) and unlikely to be microsatellite instability high (2% vs 7%, P = .003). After restricting to adenocarcinoma and signet ring cell and/or diffuse type carcinomas, we observed no difference in stage (P = .40) or overall survival from stage IV diagnosis (median = 22.7 vs 22.1 months, P = .78). CONCLUSIONS: Our study supported a preponderance of gastric primary disease sites, signet ring histology, and genomically stable molecular subtypes in early-onset esophagogastric cancer. Our findings highlight the need for further research to define the underlying pathogenesis and strategies for early detection and prevention.

First-line regorafenib with nivolumab and chemotherapy in advanced oesophageal, gastric, or gastro-oesophageal junction cancer in the USA: a single-arm, single-centre, phase 2 trial.

BACKGROUND: The addition of nivolumab to chemotherapy improves survival in patients with advanced oesophagogastric (oesophageal, gastric, or gastro-oesophageal junction) adenocarcinoma; however, outcomes remain poor. We assessed the safety and activity of regorafenib in combination with nivolumab and chemotherapy in the first-line treatment of advanced oesophagogastric adenocarcinoma. METHODS: This investigator-initiated, single-arm, phase 2 trial in adult patients (aged ≥18 years) with previously untreated, HER2-negative, metastatic oesophagogastric adenocarcinoma was done at the Memorial Sloan Kettering Cancer Center (New York, NY, USA). Eligible patients had measurable disease or non-measurable disease that was evaluable (defined by Response Evaluation Criteria in Solid Tumours [RECIST] version 1.1) and Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received FOLFOX chemotherapy (fluorouracil [400 mg/m2 bolus followed by 2400 mg/m2 over 48 h], leucovorin [400 mg/m2], and oxaliplatin [85 mg/m2]) and nivolumab (240 mg) intravenously on days 1 and 15, and oral regorafenib (80 mg) on days 1-21 of a 28-day cycle. Treatment was continued until disease progression (defined by RECIST version 1.1), unacceptable toxicity, or withdrawal of consent. The primary endpoint was 6-month progression-free survival in the per-protocol population (ie, all participants who received a dose of all study treatments). The regimen would be considered worthy of further investigation if at least 24 of 35 patients were progression free at 6 months. Safety was assessed in all participants who received at least one dose of any study treatment. This trial is registered with ClinicalTrials.gov, NCT04757363, and is now complete. FINDINGS: Between Feb 11, 2021, and May 4, 2022, 39 patients were enrolled, received at least one dose of study drug, and were included in safety analyses. 35 patients were evaluable for 6-month progression-free survival. Median age was 57 years (IQR 52-66), nine (26%) patients were women, 26 (74%) were men, 28 (80%) were White, and seven (20%) were Asian. At data cutoff (March 3, 2023), median follow-up was 18·1 months (IQR 12·7-20·4). The primary endpoint was reached, with 25 (71%; 95% CI 54-85) of 35 patients progression free at 6 months. Nine (26%) of 35 patients had disease progression and one (3%) patient died; the death was unrelated to treatment. The most common adverse event of any grade was fatigue (36 [92%] of 39). The most common grade 3 or 4 adverse events were decreased neutrophil count (18 [46%]), hypertension (six [15%]), dry skin, pruritus, or rash (five [13%]), and anaemia (four [10%]). Serious treatment-related adverse events occurred in ten (26%) patients, which were acute kidney injury (three [8%]), hepatotoxicity (two [5%]), sepsis (two [5%]), dry skin, pruritus, or rash (one [3%]), nausea (one [3%]), and gastric perforation (one [3%]). There were no treatment-related deaths. INTERPRETATION: Regorafenib can be safely combined with nivolumab and chemotherapy and showed promising activity in HER2-negative metastatic oesophagogastric cancer. A randomised, phase 3 clinical trial is planned. FUNDING: Bristol Myers Squibb, Bayer and National Institutes of Health/National Cancer Institute.

Advances in the treatment of gastric cancer: 2022-2023.

PURPOSE OF REVIEW: To review 2022-2023 studies in gastric cancer. RECENT FINDINGS: Important studies report the role of laparoscopic surgery in gastric cancer, the activity of immune checkpoint inhibitors in metastatic, locally advanced and adjuvant therapy in gastric cancer, and the effectiveness of zolbetuximab in claudin 18.2-positive metastatic disease. From the Japanese JLSSG0901 Trial, equivalent survival was reported for laparoscopically assisted versus conventional open gastrectomy. Adding nivolumab to adjuvant chemotherapy in resected stage III gastric cancer failed to improve 3-year disease-free survival over chemotherapy alone. Ipilimumab and nivolumab as preoperative therapy in MSI-high gastric cancer resulted in a high rate of pathologic complete response. Trastuzumab added to chemoradiotherapy and surgery in HER2-positive locally advanced esophageal and gastroesophageal junction adenocarcinoma did not improve overall survival over chemoradiotherapy and surgery alone. Adding pembrolizumab to trastuzumab/chemotherapy in metastatic HER2-positive gastric cancer improved antitumor response rate. Addition of zolbetuximab, an antibody targeting claudin 18.2, to first-line chemotherapy in metastatic claudin 18.2-positive gastric cancer improved overall survival. SUMMARY: Immune checkpoint inhibition has a role in locally advanced MSI-high and metastatic gastric cancer. Laparoscopic gastrectomy is acceptable in gastric cancer. Zolbetuximab in metastatic gastric cancer will emerge as a new therapy option.

Prognostic value of circumferential radial margin involvement in esophagectomy for esophageal cancer: a case series.

BACKGROUND: Residual tumor at the proximal or distal margin after esophagectomy is associated with worse survival outcomes; however, the significance of the circumferential resection margin (CRM) remains controversial. In this study, we sought to evaluate the prognostic significance of the CRM in patients with esophageal cancer undergoing resection. MATERIALS AND METHODS: We identified patients who underwent esophagectomy for pathologic T3 esophageal cancer from 2000 to 2019. Patients were divided into three groups: CRM- (residual tumor >1 mm from the CRM), CRM-close (residual tumor >0 to 1 mm from the CRM), and CRM+ (residual tumor at the surgical CRM). CRM was also categorized and analyzed per the Royal College of Pathologists (RCP) and College of American Pathologists (CAP) classifications. RESULTS: Of the 519 patients included, 351 (68%) had CRM-, 132 (25%) had CRM-close, and 36 (7%) had CRM+. CRM+ was associated with shorter disease-free survival [DFS; CRM+ vs. CRM-: hazard ratio (HR), 1.53 [95% CI, 1.03-2.28]; P =0.034] and overall survival (OS; CRM+ vs. CRM-: HR, 1.97 [95% CI, 1.32-2.95]; P <0.001). Survival was not significantly different between CRM-close and CRM-. After adjustment for potential confounders, CAP+ was associated with poor oncologic outcomes (CAP+ vs. CAP-: DFS: HR, 1.47 [95% CI, 1.00-2.17]; P =0.050; OS: HR, 1.93 [95% CI, 1.30-2.86]; P =0.001); RCP+ was not (RCP+ vs. RCP-: DFS: HR, 1.21 [95% CI, 0.97-1.52]; P =0.10; OS: HR, 1.21 [95% CI, 0.96-1.54]; P =0.11). CONCLUSION: CRM status has critical prognostic significance for patients undergoing esophagectomy: CRM+ was associated with worse outcomes, and outcomes between CRM-close and CRM- were similar.

Determinants of Survival with Combined HER2 and PD-1 Blockade in Metastatic Esophagogastric Cancer.

PURPOSE: We report updated clinical outcomes from a phase II study of pembrolizumab, trastuzumab, and chemotherapy (PTC) in metastatic esophagogastric cancer in conjunction with outcomes from an independent Memorial Sloan Kettering (MSK) cohort. PATIENTS AND METHODS: The significance of pretreatment 89Zr-trastuzumab PET, plasma circulating tumor DNA (ctDNA) dynamics, and tumor HER2 expression and whole exome sequencing was evaluated to identify prognostic biomarkers and mechanisms of resistance in patients treated on-protocol with PTC. Additional prognostic features were evaluated using a multivariable Cox regression model of trastuzumab-treated MSK patients (n = 226). Single-cell RNA sequencing (scRNA-seq) data from MSK and Samsung were evaluated for mechanisms of therapy resistance. RESULTS: 89Zr-trastuzumab PET, scRNA-seq, and serial ctDNA with CT imaging identified how pre-treatment intrapatient genomic heterogeneity contributes to inferior progression-free survival (PFS). We demonstrated that the presence of intensely avid lesions by 89Zr-trastuzumab PET declines in tumor-matched ctDNA by 3 weeks, and clearance of tumor-matched ctDNA by 9 weeks were minimally invasive biomarkers of durable PFS. Paired pre- and on-treatment scRNA-seq identified rapid clearance of HER2-expressing tumor clones with expansion of clones expressing a transcriptional resistance program, which was associated with MT1H, MT1E, MT2A, and MSMB expression. Among trastuzumab-treated patients at MSK, ERBB2 amplification was associated with improved PFS, while alterations in MYC and CDKN2A/B were associated with inferior PFS. CONCLUSIONS: These findings highlight the clinical relevance of identifying baseline intrapatient heterogeneity and serial ctDNA monitoring of HER2-positive esophagogastric cancer patients to identify early evidence of treatment resistance, which could guide proactive therapy escalation or deescalation.

ILUSTRO: Phase II Multicohort Trial of Zolbetuximab in Patients with Advanced or Metastatic Claudin 18.2-Positive Gastric or Gastroesophageal Junction Adenocarcinoma.

PURPOSE: Zolbetuximab, an IgG1 monoclonal antibody, binds to claudin 18.2 (CLDN18.2) and mediates tumor cell death through antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. We sought to examine zolbetuximab combinations in CLDN18.2-positive HER2-negative gastric/gastroesophageal junction (G/GEJ) adenocarcinoma. PATIENTS AND METHODS: This phase II study assessed efficacy and safety of zolbetuximab, alone or with modified FOLFOX6 (mFOLFOX6) or pembrolizumab, in CLDN18.2-positive advanced/metastatic G/GEJ adenocarcinoma. Patients received zolbetuximab as monotherapy in third/later-line (Cohort 1A, n = 30), with mFOLFOX6 in first-line (Cohort 2, n = 21), or with pembrolizumab in third/later-line (Cohort 3A, n = 3) treatment. The primary endpoint for Cohort 1A was objective response rate (ORR). Key secondary endpoints were ORR (Cohorts 2 and 3A), overall survival (OS; Cohort 1A), and progression-free survival (PFS) and safety (all cohorts). RESULTS: ORR was 0% in Cohorts 1A and 3A, and 71.4% [95% confidence interval (CI), 47.82-88.72] in Cohort 2. Median PFS was 1.54 months (95% CI, 1.31-2.56) in Cohort 1A, 2.96 months (95% CI, 1.48-4.44) in Cohort 3A, and 17.8 months (95% CI, 8.05-25.69) in Cohort 2. Median OS in Cohort 1A was 5.62 months (95% CI, 2.27-11.53). Gastrointestinal adverse events occurred across cohorts [nausea, 63%-90% (grade ≥ 3, 4.8%-6.7%) and vomiting, 33%-67% (grade ≥ 3, 6.7%-9.5%)]. CONCLUSIONS: Zolbetuximab plus mFOLFOX6 demonstrated promising efficacy in previously untreated patients with CLDN18.2-positive G/GEJ adenocarcinoma. These data support the first-line development of zolbetuximab in patients whose tumors are CLDN18.2-positive. Across cohorts, zolbetuximab treatment was tolerable with no new safety signals.

Perioperative versus total neoadjuvant chemotherapy in gastric cancer.

Background: Perioperative chemotherapy is standard of care management for locally advanced gastric cancer (GC), but a substantial proportion of patients do not complete adjuvant therapy due to postoperative complications and prolonged recovery. Administration of all chemotherapy prior to surgery in the form of total neoadjuvant therapy (TNT) may optimize complete delivery of systemic therapy. Methods: We performed a retrospective review of GC patients who had surgery at Memorial Sloan Kettering Cancer Center (MSKCC) from May 2014 to June 2020. Results: One hundred and forty-nine patients were identified; 121 patients received perioperative chemotherapy and 28 patients received TNT. TNT was chosen if patients had interim radiographic and/or clinical response to treatment. Baseline characteristics were well-balanced between the two group except for chemotherapy regimen; more TNT patients received FLOT compared to the perioperative group (79% vs. 31%). There was no difference in the proportion of patients who completed all planned cycles, but TNT patients received a higher proportion of cycles containing all chemotherapy drugs (93% vs. 74%, P<0.001). Twenty-nine patients (24%) in the perioperative group did not receive intended adjuvant therapy. There was no significant difference in hospital length of stay or surgical morbidity. The overall distribution of pathologic stage was similar between the two groups. Fourteen percent of TNT patients and 5.8% of perioperative patients achieved a pathologic complete response (P=0.6). There was no significant difference in recurrence free survival (RFS) or overall survival (OS) between the TNT and perioperative groups [24-month OS rate 77% vs. 85%, HR 1.69 (95% CI: 0.80-3.56)]. Conclusions: Our study was limited by a small TNT sample size and biases inherent to a retrospective analysis. TNT appears to be feasible in a select population, without any increase in surgical morbidity.

Esophageal and Esophagogastric Junction Cancers, Version 2.2023, NCCN Clinical Practice Guidelines in Oncology.

Cancers originating in the esophagus or esophagogastric junction constitute a major global health problem. Esophageal cancers are histologically classified as squamous cell carcinoma (SCC) or adenocarcinoma, which differ in their etiology, pathology, tumor location, therapeutics, and prognosis. In contrast to esophageal adenocarcinoma, which usually affects the lower esophagus, esophageal SCC is more likely to localize at or higher than the tracheal bifurcation. Systemic therapy can provide palliation, improved survival, and enhanced quality of life in patients with locally advanced or metastatic disease. The implementation of biomarker testing, especially analysis of HER2 status, microsatellite instability status, and the expression of programmed death-ligand 1, has had a significant impact on clinical practice and patient care. Targeted therapies including trastuzumab, nivolumab, ipilimumab, and pembrolizumab have produced encouraging results in clinical trials for the treatment of patients with locally advanced or metastatic disease. Palliative management, which may include systemic therapy, chemoradiation, and/or best supportive care, is recommended for all patients with unresectable or metastatic cancer. Multidisciplinary team management is essential for all patients with locally advanced esophageal or esophagogastric junction cancers. This selection from the NCCN Guidelines for Esophageal and Esophagogastric Junction Cancers focuses on the management of recurrent or metastatic disease.

Durvalumab and PET-Directed Chemoradiation in Locally Advanced Esophageal Adenocarcinoma: A Phase Ib/II Study.

OBJECTIVE: To determine the safety and efficacy of adding the anti-PD-L1 antibody durvalumab to induction FOLFOX and preoperative chemotherapy in locally advanced esophageal adenocarcinoma. BACKGROUND: Neoadjuvant induction FOLFOX followed by positron emission tomography (PET) directed chemoradiation has demonstrated improved survival for esophageal adenocarcinoma. There is clear benefit now for the addition of immune checkpoint inhibitors both in early and advanced stage disease. Given these results we investigated the safety and efficacy of adding durvalumab to induction FOLFOX and preoperative chemoradiotherapy. METHODS: Patients with locally advanced resectable esophageal/gastroesophageal junction adenocarcinoma received PET-directed chemoradiation with durvalumab before esophagectomy. Patients who had R0 resections received adjuvant durvalumab 1500 mg every 4 weeks for 6 treatments. The primary endpoint of the study was pathologic complete response. RESULTS: We enrolled 36 patients, 33 of whom completed all preoperative treatment and underwent surgery. Preoperative treatment was well tolerated, with no delays to surgery nor new safety signals. Pathologic complete response was identified in 8 [22% (1-sided 90% lower bound: 13.3%)] patients with major pathologic response in 22 [61% (1-sided 90% lower bound: 50%)] patients. Twelve and 24-month overall survival was 92% and 85%, respectively. CONCLUSIONS: The addition of durvalumab to induction FOLFOX and PET-directed chemoradiotherapy before surgery is safe, with a high rate of pathologic response, as well as encouraging survival data.

Waiting to Operate: The Risk of Salvage Esophagectomy.

OBJECTIVE: To assess postoperative morbidity, disease-free survival (DFS), and overall survival (OS) in patients treated with salvage esophagectomy (SE). BACKGROUND DATA: A shift toward a "surgery as needed" approach for esophageal cancer has emerged, potentially resulting in delayed esophagectomy. METHODS: We identified patients with clinical stage I-III esophageal adenocarcinoma or squamous cell carcinoma who underwent chemoradiation followed by esophagectomy from 2001 to 2019. SE was defined as esophagectomy performed >90 days after chemoradiation ("for time") and esophagectomy performed for recurrence after curative-intent chemoradiation ("for recurrence"). The odds of postoperative serious complications were assessed by multivariable logistic regression. The relationship between SE and OS and DFS were quantified using Cox regression models. RESULTS: Of 1137 patients identified, 173 (15%) underwent SE. Of those, 61 (35%) underwent SE for recurrence, and 112 (65%) underwent SE for time. The odds of experiencing any serious complication [odds ratio, 2.10 (95% CI, 1.37-3.20); P =0.001] or serious pulmonary complication [odds ratio, 2.11 (95% CI, 1.31-3.42); P =0.002] were 2-fold higher for SE patients; SE patients had a 1.5-fold higher hazard of death [hazard ratio, 1.56 (95% CI, 1.25-1.94); P <0.0001] and postoperative recurrence [hazard ratio, 1.43 (95% CI, 1.16-1.77); P =0.001]. Five-year OS for nonsalvage esophagectomy was 45% [(95% CI, 41.6%-48.6%) versus 26.5% (95% CI, 20.2%-34.8%) for SE (log-rank P <0.001)]. Five-year OS for SE for time was 27.1% [(95% CI, 19.5%-37.5%) versus 25.2% (95% CI, 15.3%-41.5%) for SE for recurrence ( P =0.611)]. CONCLUSIONS: SE is associated with a higher risk of serious postoperative complications and shorter DFS and OS.

Clinical Importance of Clonal Hematopoiesis in Metastatic Gastrointestinal Tract Cancers.

Importance: Clonal hematopoiesis (CH) has been associated with development of atherosclerosis and leukemia and worse survival among patients with cancer; however, the association with cancer therapy efficacy, in particular immune checkpoint blockade (ICB), and toxicity has not yet been established. Given the widespread use of ICB and the critical role hematopoietic stem cell-derived lymphocytes play in mediating antitumor responses, CH may be associated with therapeutic efficacy and hematologic toxicity. Objective: To determine the association between CH and outcomes, hematologic toxicity, and therapeutic efficacy in patients with metastatic gastrointestinal tract cancers being treated with systemic therapy, both in the first-line metastatic treatment setting and in ICB. Design, Setting, and Participants: This retrospective cohort study included 633 patients with stage IV colorectal (CRC) and esophagogastric (EGC) cancer who were treated with first-line chemotherapy and/or ICB at Memorial Sloan Kettering Cancer Center. Patients underwent matched tumor and peripheral blood DNA sequencing using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets next-generation sequencing assay between January 1, 2006, and December 31, 2020. Exposures: Clonal hematopoiesis-related genetic alterations were identified by next-generation sequencing of patients' tumor and normal blood buffy coat samples, with a subset of these CH alterations annotated as likely putative drivers (CH-PD) based upon previously established criteria. Main Outcomes and Measures: Patients with CH and CH-PD in peripheral blood samples were identified, and these findings were correlated with survival outcomes (progression-free survival [PFS] and overall survival [OS]) during first-line chemotherapy and ICB, as well as baseline white blood cell levels and the need for granulocyte colony-stimulating factor (G-CSF) support. Results: Among the 633 patients included in the study (390 men [61.6%]; median age, 58 [IQR, 48-66] years), the median age was 52 (IQR, 45-63) years in the CRC group and 61 (IQR, 53-69) years in the EGC group. In the CRC group, 161 of 301 patients (53.5%) were men, compared with 229 of 332 patients (69.0%) in the EGC group. Overall, 62 patients (9.8%) were Asian, 45 (7.1%) were Black or African American, 482 (76.1%) were White, and 44 (7.0%) were of unknown race or ethnicity. Presence of CH was identified in 115 patients with EGC (34.6%) and 83 with CRC (27.6%), with approximately half of these patients harboring CH-PD (CRC group, 44 of 83 [53.0%]; EGC group, 55 of 115 [47.8%]). Patients with EGC and CH-PD exhibited a significantly worse median OS of 16.0 (95% CI, 11.6-22.3) months compared with 21.6 (95% CI, 19.6-24.3) months for those without CH-PD (P = .01). For patients with CRC and EGC, CH and CH-PD were not associated with PFS differences in patients undergoing ICB or first-line chemotherapy. Neither CH nor CH-PD were correlated with baseline leukocyte levels or increased need for G-CSF support. Conclusions and Relevance: These findings suggest CH and CH-PD are not directly associated with the treatment course of patients with metastatic gastrointestinal tract cancer receiving cancer-directed therapy.

Survival of Locally Advanced MSI-high Gastric Cancer Patients Treated With Perioperative Chemotherapy: A Retrospective Cohort Study.

OBJECTIVE: To evaluate the efficacy of chemotherapy in patients with microsatellite instability (MSI)-high gastric cancer. BACKGROUND: Although MSI-high gastric cancer is associated with a superior prognosis, recent studies question the benefit of perioperative chemotherapy in this population. METHODS: Locally advanced gastric adenocarcinoma patients who either underwent surgery alone or also received neoadjuvant, perioperative, or adjuvant chemotherapy between 2000 and 2018 were eligible. MSI status, determined by next-generation sequencing or mismatch repair protein immunohistochemistry, was determined in 535 patients. Associations among MSI status, chemotherapy administration, overall survival (OS), disease-specific survival, and disease-free survival were assessed. RESULTS: In 535 patients, 82 (15.3%) had an MSI-high tumor and ∼20% better OS, disease-specific survival, and disease-free survival. Grade 1 (90%-100%) pathological response to neoadjuvant chemotherapy was found in 0 of 40 (0%) MSI-high tumors versus 43 of 274 (16%) MSS. In the MSI-high group, the 3-year OS rate was 79% with chemotherapy versus 88% with surgery alone ( P =0.48). In the MSS group, this was 61% versus 59%, respectively ( P =0.96). After multivariable interaction analyses, patients with MSI-high tumors had superior survival compared with patients with MSS tumors whether given chemotherapy (hazard ratio=0.53, 95% confidence interval: 0.28-0.99) or treated with surgery alone (hazard ratio=0.15, 95% confidence interval: 0.02-1.17). CONCLUSIONS: MSI-high locally advanced gastric cancer was associated with superior survival compared with MSS overall, despite worse pathological chemotherapy response. In patients with MSI-high gastric cancer who received chemotherapy, the survival rate was ∼9% worse compared with surgery alone, but chemotherapy was not significantly associated with survival.

Induction FOLFOX and PET-Directed Chemoradiation for Locally Advanced Esophageal Adenocarcinoma.

OBJECTIVE: To compare the efficacy and safety of induction FOLFOX followed by PET-directed nCRT, induction CP followed by PET-directed nCRT, and nCRT with CP alone in patients with EAC. SUMMARY OF BACKGROUND DATA: nCRT with CP is a standard treatment for locally advanced EAC. The results of cancer and leukemia group B 80803 support the use of induction chemotherapy followed by PET-directed chemo-radiation therapy. METHODS: We retrospectively identified all patients with EAC who underwent the treatments above followed by esophagectomy. We assessed incidences of pathologic complete response (pCR), near-pCR (ypN0 with ≥90% response), and surgical complications between treatment groups using Fisher exact test and logistic regression; disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method and evaluated using the log-rank test and extended Cox regression. RESULTS: In total, 451 patients were included: 309 (69%) received induction chemotherapy before nCRT (FOLFOX, n = 70; CP, n = 239); 142 (31%) received nCRT with CP. Rates of pCR (33% vs. 16%, P = 0.004), near-pCR (57% vs. 33%, P < 0.001), and 2-year DFS (68% vs. 50%, P = 0.01) were higher in the induction FOLFOX group than in the induction CP group. Similarly, the rate of near-pCR (57% vs. 42%, P = 0.04) and 2-year DFS (68% vs. 44%, P < 0.001) were significantly higher in the FOLFOX group than in the no-induction group. CONCLUSIONS: Induction FOLFOX followed by PET-directed nCRT may result in better histopathologic response rates and DFS than either induction CP plus PET-directed nCRT or nCRT with CP alone.

Outcomes and Molecular Features of Brain Metastasis in Gastroesophageal Adenocarcinoma.

Importance: Brain metastasis (BrM) in gastroesophageal adenocarcinoma (GEA) is a rare and poorly understood phenomenon associated with poor prognosis. Objectives: To examine the clinical and genomic features of patients with BrM from GEA and evaluate factors associated with survival. Design, Setting, and Participants: In this single-institution retrospective cohort study, 68 patients with BrM from GEA diagnosed between January 1, 2008, and December 31, 2020, were identified via review of billing codes and imaging reports from the electronic medical record with follow-up through November 3, 2021. Genomic data were derived from the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets clinical sequencing platform. Exposures: Treatment with BrM resection and/or radiotherapy. Main Outcomes and Measures: Overall survival after BrM diagnosis. Results: Sixty-eight patients (median age at diagnosis, 57.4 years [IQR, 49.8-66.4 years]; 59 [86.8%] male; 55 [85.9%] White) participated in the study. A total of 57 (83.8%) had primary tumors in the distal esophagus or gastroesophageal junction. Median time from initial diagnosis to BrM diagnosis was 16.9 months (IQR, 8.5-27.7 months). Median survival from BrM diagnosis was 8.7 months (95% CI, 5.5-11.5 months). Overall survival was 35% (95% CI, 25%-48%) at 1 year and 24% (95% CI, 16%-37%) at 2 years. In a multivariable analysis, an Eastern Cooperative Oncology Group performance status of 2 or greater (hazard ratio [HR], 4.66; 95% CI, 1.47-14.70; P = .009) and lack of surgical or radiotherapeutic intervention (HR, 7.71; 95% CI, 2.01-29.60; P = .003) were associated with increased risk of all-cause mortality, whereas 3 or more extracranial sites of disease (HR, 1.85; 95% CI, 0.64-5.29; P = .25) and 4 or more BrMs (HR, 2.15; 95% CI, 0.93-4.98; P = .07) were not statistically significant. A total of 31 patients (45.6%) had ERBB2 (formerly HER2 or HER2/neu)-positive tumors, and alterations in ERBB2 were enriched in BrM relative to primary tumors (8 [47.1%] vs 7 [20.6%], P = .05), as were alterations in PTPRT (7 [41.2%] vs 4 [11.8%], P = .03). Conclusions and Relevance: This study suggests that that a notable proportion of patients with BrM from GEA achieve survival exceeding 1 and 2 years from BrM diagnosis, a more favorable prognosis than previously reported. Good performance status and treatment with combination surgery and radiotherapy were associated with the best outcomes. ERBB2 positivity and amplification as well as PTPRT alterations were enriched in BrM tissue compared with primary tumors; therefore, further study should be pursued to identify whether these variables represent genomic risk factors for BrM development.