Circulating tumor DNA molecular analyses and real-world evidence outcomes of FGFR2 amplified gastroesophageal cancers.

PURPOSE: In addition to the existing biomarkers HER2 and PD-L1, FGFR2b has become an area of interest for the development of new targeted-based treatment. Given that clinical evaluation of FGFR2 targeted therapy is underway, we sought to elucidate the genomic landscape of FGFR2amp in gastroesophageal cancer (GEC) using a circulating tumor DNA (ctDNA) platform. MATERIALS AND METHODS: We retrospectively evaluated the Guardant Health database from 2017 to 2022 for patients with GECs with Guardant360 ctDNA next-generation sequencing (NGS) performed. We assessed co-occurring genetic alterations for patients who harbored FGFR2amp versus FGFR2null. We also explored real-world evidence database with Guardant Health, publicly available genomic databases (MSK cohort using cBioPortal), and pooled clinical data from large-volume cancer centers for FGFR2amp GECs. RESULTS: Less than 4% of patients with GEC in the Guardant Health database were identified to be FGFR2amp. The most commonly co-occurring gene mutations were TP53, CTNNB1, CDH1, and RHOA. Upon interrogation of the MSK cohort, these same genes were not significant on tissue NGS in the FGFR2amp cohort of GEC. In the pooled institutional cohort, we noted that FGFR2amp tumors were most commonly involving the gastroesophageal junction (GEJ). The overall survival of these patients was noted at 13.1 months. CONCLUSION: FGFR2 is a validated target in GECs, and the contexture of FGFR2amp will be important in defining patient subgroups with responses to FGFR2-directed therapy. Using ctDNA to provide a more detailed genomic landscape in patients with GECs will allow the advancement of targeted therapy in the near future for these aggressive cancers.

Patient metabolic profile defined by liver and muscle 18F-FDG PET avidity is independently associated with overall survival in gastric cancer.

BACKGROUND: PET-CT-based patient metabolic profiling is a novel concept to incorporate patient-specific metabolism into gastric cancer care. METHODS: Staging PET-CTs, demographics, and clinicopathologic variables of gastric cancer patients were obtained from a prospectively maintained institutional database. PET-CT avidity was measured in tumor, liver, spleen, four paired muscles, and two paired fat areas in each patient. The liver to rectus femoris (LRF) ratio was defined as the ratio of SUVmean of liver to the average SUVmean of the bilateral rectus femoris muscles. Kaplan-Meier and Cox-proportional hazards models were used to identify the impact of LRF ratio on OS. RESULTS: Two hundred and one patients with distal gastroesophageal (48%) or gastric (52%) adenocarcinoma were included. Median age was 65 years, and 146 (73%) were male. On univariate analysis, rectus femoris PET-CT avidity and LRF ratio were significantly associated with overall survival (p < 0.05). LRF ratio was significantly higher in males, early-stage cancer, patients with an ECOG 0 or 1 performance status, patients with albumin > 3.5 mg/dL, and those with moderately differentiated tumor histology. In multivariable regression, gastric cancer stage, albumin, and LRF ratio were significant independent predictors of overall survival (LRF ratio HR = 0.73 (0.56-0.96); p = 0.024). Survival curves showed that the prognostic impact of LRF was associated with metastatic gastric cancer (p = 0.009). CONCLUSIONS: Elevated LRF ratio, a patient-specific PET-CT-based metabolic parameter, was independently associated with an improvement in OS in patients with metastatic gastric cancer. With prospective validation, LRF ratio may be a useful, host-specific metabolic parameter for prognostication in gastric cancer.

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.

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.

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.

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.

A Novel Microbiome Signature in Gastric Cancer: A Two Independent Cohort Retrospective Analysis.

OBJECTIVE: The microbiome is hypothesized to have a significant impact on cancer development. In gastric cancer (GC), Helicobacter pylori is an established class I carcinogen. However, additional organisms in the intratumoral microbiome play an important role in GC pathogenesis and progression. In this study, we characterize the full spectrum of the microbes present within GC and identify distinctions among molecular subtypes. METHODS: A microbiome bioinformatics pipeline that is generalizable across multiple next-generation sequencing platforms was developed. Microbial profiles for alpha diversity and enrichment were generated for 2 large, demographically distinct cohorts: (1) internal Memorial Sloan Kettering Cancer Center (MSKCC) and (2) The Cancer Genome Atlas (TCGA) cohorts. A total of 520 GC samples were compared with select tumor-adjacent nonmalignant samples. Microbiome differences among the GC molecular subtypes were identified. RESULTS: Compared with nonmalignant samples, GC had significantly decreased microbial diversity in both MSKCC and TCGA cohorts ( P <0.05). Helicobacter , Lactobacillus , Streptococcus , Prevotella , and Bacteroides were significantly more enriched in GC samples when compared with nonmalignant tissue ( P <0.05). Microsatellite instability-high GC had distinct microbial enrichment compared with other GC molecular subtypes. CONCLUSION: Distinct patterns of microbial diversity and species enrichment were identified in patients with GC. Given the varied spectrum of disease progression and treatment response of GC, understanding unique microbial signatures will provide the landscape to explore key microbial targets for therapy.

Survival After Trimodality Therapy in Patients With Locally Advanced Esophagogastric Adenocarcinoma: Does Only a Complete Pathologic Response Matter?

OBJECTIVE: To evaluate whether pCR exclusively defines major pathologic response to treatment with improved survival. SUMMARY BACKGROUND DATA: pCR after trimodality therapy for EAC is infrequent but associated with improved prognosis. Yet most clinical trials and correlative studies designate pCR as the primary endpoint. METHODS: We analyzed our prospectively maintained database for patients who underwent trimodality therapy for locally advanced esophageal adeno-carcinoma between 1995 and 2017. Overall survival (OS) was examined by percentage TR in the primary tumor bed and pathologic nodal stage (ypN0) using Kaplan-Meier plots. Optimal thresholds of TR for differentiating patients in terms of OS were investigated with descriptive plots using restricted cubic spline functions; associations were quantified using Cox multivariable analysis. RESULTS: Among 788 patients, median follow-up was 37.5 months (range, 0.4210.6); median OS was 48.3 months (95% CI, 42.2-58.8). Absence of residual nodal disease was independently associated with improved survival ( P < 0.001). Survival curves for 90% to 99% TR and 100% TR were similar, and a change in probability of improved OS was observed at 90% TR. On multivariable analysis, combining 90% to 99% and 100% TR was independently associated with improved OS, compared with 50% to 89% and <50% TR. CONCLUSIONS: ypN0 status is the strongest indicator of major pathologic response to trimodality therapy, in addition to >90% TR in the primary tumor bed. These findings may allow the definition of major pathologic response to be expanded, from pCR to > 90% TR and ypN0. This has meaningful implications for future clinical trials and correlative studies.

Outcomes of Neoadjuvant Chemotherapy for Clinical Stages 2 and 3 Gastric Cancer Patients: Analysis of Timing and Site of Recurrence.

BACKGROUND: This study aimed to analyze timing and sites of recurrence for patients receiving neoadjuvant chemotherapy for gastric cancer. Neoadjuvant chemotherapy followed by surgical resection is the standard treatment for locally advanced gastric cancer in the West, but limited information exists as to timing and patterns of recurrence in this setting. METHODS: Patients with clinical stage 2 or 3 gastric cancer treated with neoadjuvant chemotherapy followed by curative-intent resection between January 2000 and December 2015 were analyzed for 5-year recurrence-free survival (RFS) as well as timing and site of recurrence. RESULTS: Among 312 identified patients, 121 (38.8%) experienced recurrence during a median follow-up period of 46 months. The overall 5-year RFS rate was 58.9%, with RFS rates of 95.8% for ypT0N0, 81% for ypStage 1, 77.4% for ypStage 2, and 22.9% for ypStage 3. The first site of recurrence was peritoneal for 49.6%, distant (not peritoneal) for 45.5%, and locoregional for 11.6% of the patients. The majority of the recurrences (84.3%) occurred within 2 years. Multivariate analysis showed that ypT4 status was an independent predictor for recurrence within 1 year after surgery (odds ratio, 2.58; 95% confidence interval, 1.10-6.08; p = 0.030). CONCLUSIONS: The majority of the recurrences for patients with clinical stage 2 or 3 gastric cancer who received neoadjuvant chemotherapy and underwent curative resection occurred within 2 years. After neoadjuvant chemotherapy, pathologic T stage was a useful risk predictor for early recurrence.

Association of Obesity with Worse Operative and Oncologic Outcomes for Patients Undergoing Gastric Cancer Resection.

BACKGROUND: How obesity has an impact on operative and oncologic outcomes for gastric cancer patients is unclear, and the influence of obesity on response to neoadjuvant chemotherapy (NAC) has not been evaluated. METHODS: Patients who underwent curative gastrectomy for primary gastric cancer between 2000 and 2018 were retrospectively identified. After stratification for NAC, operative morbidity, mortality, overall survival (OS), and disease-specific survival (DSS) were compared among three body mass index (BMI) categories: normal BMI (< 25 kg/m2), mild obesity (25-35 kg/m2), and severe obesity (≥ 35 kg/m2). RESULTS: During the study period, 984 patients underwent upfront surgery, and 484 patients received NAC. Tumor stage did not differ among the BMI groups. However, the rates of pathologic response to NAC were significantly lower for the patients with severe obesity (10% vs 40%; p < 0.001). Overall complications were more frequent among the obese patients (44.3% for obese vs 24.9% for normal BMI, p < 0.001). Intraabdominal infections were also more frequent in obese patients (13.9% for obese vs 4.7% for normal BMI, p = 0.001). In the upfront surgery cohort, according to the BMI, OS and DSS did not differ, whereas in the NAC cohort, severe obesity was independently associated with worse OS [hazard ratio (HR) 1.87; 95% confidence interval (CI) 1.01-3.48; p = 0.047] and disease-specific survival (DSS) (HR 2.08; 95% CI 1.07-4.05; p = 0.031). CONCLUSION: For the gastric cancer patients undergoing curative gastrectomy, obesity was associated with significantly lower rates of pathologic response to NAC and more postoperative complications, as well as shorter OS and DSS for the patients receiving NAC.

First-line pembrolizumab and trastuzumab in HER2-positive oesophageal, gastric, or gastro-oesophageal junction cancer: an open-label, single-arm, phase 2 trial.

BACKGROUND: Addition of trastuzumab to first-line chemotherapy improves overall survival in patients with HER2-positive metastatic gastric cancer. We assessed the safety and activity of pembrolizumab in combination with trastuzumab and chemotherapy in first-line HER2-positive metastatic oesophagogastric (gastric, oesophageal, or gastroesophageal junction) cancer. METHODS: This study was an investigator-initiated, open-label, non-randomised, single-arm, single centre, phase 2 trial in patients aged 18 years or older with HER2-positive metastatic oesophagogastric cancer. Eligible patients had measurable or evaluable non-measurable disease, Eastern Cooperative Oncology Group performance status of 0, 1, or 2, and left ventricular ejection fraction of at least 53%. Patients were eligible to receive an initial induction cycle of 200 mg flat dose of intravenous pembrolizumab and 8 mg/kg loading dose of intravenous trastuzumab. For subsequent cycles, patients received 130 mg/m2 of intravenous oxaliplatin or 80 mg/m2 of cisplatin on day 1, 850 mg/m2 of oral capecitabine twice a day for 2 weeks followed by 1 week off (or intravenous 5-fluorouracil, 800 mg/m2 per day on days 1-5), and a 200 mg flat dose of intravenous pembrolizumab, and 6 mg/kg of trastuzumab, administered on day 1 of each 3-week cycle. The primary endpoint was 6-month progression-free survival, defined as the proportion of patients alive and free of progression at 6 months, assessed in patients who received at least one dose of trastuzumab and pembrolizumab. The regimen would be considered worthy of further investigation if 26 or more of 37 patients were progression-free at 6 months. This trial is registered with ClinicalTrials.gov, NCT02954536, and is ongoing, but closed to enrolment. FINDINGS: Between Nov 11, 2016, and Jan 23, 2019, 37 patients were enrolled. At the time of data cutoff on Aug 6, 2019, median follow-up among survivors was 13·0 months (IQR 11·7-23·5). The primary endpoint was achieved; 26 (70%; 95% CI 54-83) of 37 patients were progression-free at 6 months. The most common treatment-related adverse event of any grade was neuropathy, which was reported in 36 (97%) of 37 patients. The most common grade 3 or 4 adverse events were lymphocytopenia (seven [19%] patients with grade 3 and two [5%] with grade 4), grade 3 decreased electrolytes (six [16%] patients), and grade 3 anaemia (four [11%] patients). Serious adverse events occurred in two patients patients (both grade 3 nephritis leading to treatment discontinuation). Four patients discontinued pembrolizumab because of immune-related adverse events. There were no treatment-related deaths. INTERPRETATION: Pembrolizumab can be safely combined with trastuzumab and chemotherapy and has promising activity in HER2-positive metastatic oesophagogastric cancer. A randomised phase 3 clinical trial assessing the efficacy and safety of pembrolizumab versus placebo in combination with trastuzumab and chemotherapy in first-line HER2-positive metastatic oesophagogastric cancer is underway. FUNDING: Merck & Co.

Facilities that service economically advantaged neighborhoods perform surgical metastasectomy more often for patients with colorectal liver metastases.

BACKGROUND: Metastasectomy of isolated colorectal liver metastases (CRLM) requires significant clinical expertise and may not be readily available or offered. The authors hypothesized that hospitals that treat a greater percentage of patients from higher income catchment areas are more likely to perform metastasectomies regardless of patient or tumor characteristics. METHODS: Using the National Cancer Data Base, the authors classified facilities into facility income quartiles (FIQs) based on the percentage of patients from the wealthiest neighborhoods (by zip code). Quartile 1 included facilities with <2.1% of the patients residing within the highest income zip codes, quartile 2 included facilities with 2.2% to 15.6% of patients residing within the highest income zip codes, quartile 3 included facilities with 15.7% to 40.2% of patients residing within the highest income zip codes, and quartile 4 included facilities with 40.3% to 90.5% of patients residing within the highest income ZIP codes. Patient, tumor, and facility characteristics were analyzed using a multivariate logistic regression to identify associations between metastasectomy and FIQ. RESULTS: Patients with CRLM were more likely to undergo metastasectomy at facilities in the highest FIQ compared with the lowest FIQ (18% vs 11% in FIQ4; P = .001). This trend was not observed in the resection of primary tumors for nonmetastatic CRLM (rates of 95% vs 93%; P = .94). After adjusting for individual insurance status, distance traveled, zip code-level individual income, tumor, and host, patients who were treated at the highest FIQ facilities were found to be more likely to undergo metastasectomy (odds ratio, 1.29; 95% CI, 1.02-1.72 [P = .03]). CONCLUSIONS: Metastasectomy for CRLM is more likely to occur at facilities that serve a greater percentage of patients from high-income catchment areas, regardless of individual patient characteristics. This disparity uniquely affects those patients with advanced cancers for which specialized expertise for therapy is necessary.

Initial Report of Second-Line FOLFIRI in Combination with Ramucirumab in Advanced Gastroesophageal Adenocarcinomas: A Multi-Institutional Retrospective Analysis.

BACKGROUND: The randomized phase III RAINBOW trial established paclitaxel (pac) plus ramucirumab (ram) as a global standard for second-line (2L) therapy in advanced gastric and gastroesophageal junction adenocarcinoma, together gastroesophageal adenocarcinoma (GEA). Patients (pts) receiving first-line (1L) FOLFOX often develop neuropathy that renders continued neurotoxic agents in the 2L setting unappealing and other regimens more desirable. As such, FOLFIRI-ram has become an option for patients with 2L GEA. FOLFIRI-ramucirumab (ram) has demonstrated safety and activity in 2L colorectal cancer, but efficacy/safety data in GEA are lacking. SUBJECTS, MATERIALS, AND METHODS: Patients with GEA treated with 2L FOLFIRI-ram between August 2014 and April 2018 were identified. Clinicopathologic data including oxaliplatin neurotoxicity rates/grades (G), 2L treatment response, progression-free survival (PFS), overall survival (OS), safety, and molecular features were abstracted from three U.S. academic institutions. Kaplan-Meier survival analysis was used to generate PFS/OS; the likelihood ratio test was used to determine statistical significance. RESULTS: We identified 29 pts who received 2L FOLFIRI-ram. All pts received 1L platinum + fluoropyrimidine, and 23 of 29 (79%) had post-1L neuropathy; 12 (41%) had G1, and 11 (38%) had G2. Patients were evenly split between esophagus/gastroesophageal junction (12; 41%) and gastric cancer (17; 59%). Among evaluable pts (26/29), the overall response rate was 23% (all partial response) with a disease control rate of 79%. Median PFS was 6.0 months and median OS was 13.4 months among all evaluable pts. Six- and 12-month OS were 90% (n = 18/20) and 41% (n = 7/17). There were no new safety signals. CONCLUSION: We provide the first data suggesting FOLFIRI-ram is a safe, non-neurotoxic regimen comparing favorably with the combination of pac + ram used in the seminal RAINBOW trial. IMPLICATIONS FOR PRACTICE: Results of this study provide initial support for the safety and efficacy of second-line (2L) FOLFIRI-ramucirumab (ram) after progression on first-line platinum/fluoropyrimidine in patients with gastroesophageal adenocarcinoma (GEA). The overall response, progression-free survival, overall survival, and toxicity profile compare favorably with paclitaxel (pac) + ram and highlight the importance of the ongoing phase II RAMIRIS trial examining FOLFIRI-ram versus pac + ram in 2L GEA (NCT03081143). FOLFIRI-ram may warrant consideration for inclusion as an alternate regimen in consensus guidelines for GEA.

FGFR2-Altered Gastroesophageal Adenocarcinomas Are an Uncommon Clinicopathologic Entity with a Distinct Genomic Landscape.

BACKGROUND: With the exception of trastuzumab, therapies directed at receptor tyrosine kinases (RTKs) in gastroesophageal adenocarcinomas (GEA) have had limited success. Recurrent fibroblast growth factor receptor 2 (FGFR2) alterations exist in GEA; however, little is known about the genomic landscape of FGFR2-altered GEA. We examined FGFR2 alteration frequency and frequency of co-occurring alterations in GEA. SUBJECTS, MATERIALS, AND METHODS: A total of 6,667 tissue specimens from patients with advanced GEA were assayed using hybrid capture-based genomic profiling. Tumor mutational burden (TMB) was determined on up to 1.1 Mb of sequenced DNA, and microsatellite instability was determined on 95 or 114 loci. Descriptive statistics were used to compare subgroups. RESULTS: We identified a total of 269 (4.0%) FGFR2-altered cases consisting of FGFR2-amplified (amp; 193, 72% of FGFR2-altered), FGFR2-mutated (36, 13%), FGFR2-rearranged (re; 23, 8.6%), and cases with multiple FGFR2 alterations (17, 6.3%). Co-occurring alterations in other GEA RTK targets including ERBB2 (10%), EGFR (8%), and MET (3%) were observed across all classes of FGFR2-altered GEA. Co-occurring alterations in MYC (17%), KRAS (10%), and PIK3CA (5.6%) were also observed frequently. Cases with FGFR2amp and FGFR2re were exclusively microsatellite stable. The median TMB for FGFR2-altered GEA was 3.6 mut/mb, not significantly different from a median of 4.3 mut/mb seen in FGFR2 wild-type samples. CONCLUSION: FGFR2-altered GEA is a heterogenous subgroup with approximately 20% of FGFR2-altered samples harboring concurrent RTK alterations. Putative co-occurring modifiers of FGFR2-directed therapy including oncogenic MYC, KRAS, and PIK3CA alterations were also frequent, suggesting that pretreatment molecular analyses may be needed to facilitate rational combination therapies and optimize patient selection for clinical trials. IMPLICATIONS FOR PRACTICE: Actionable receptor tyrosine kinase alterations assayed within a genomic context with therapeutic implications remain limited to HER2 amplification in gastroesophageal adenocarcinomas (GEA). Composite biomarkers and heterogeneity assessment are critical in optimizing patients selected for targeted therapies in GEA. Comprehensive genomic profiling in FGFR2-altered GEA parallels the heterogeneity findings in HER2-amplified GEA and adds support to the utility of genomic profiling in advanced gastroesophageal adenocarcinomas.

Pembrolizumab for treatment of advanced gastric and gastroesophageal junction adenocarcinoma.

Pembrolizumab is a monoclonal antibody directed against PD-1 that is US FDA approved for treatment of advanced PD-L1 positive gastric and gastroesophageal junction adenocarcinoma in patients who have progressed on at least two prior lines of chemotherapy. This article summarizes the clinical evidence regarding safety, tolerability and efficacy of pembrolizumab in this setting. In addition, this article describes the investigational use of pembrolizumab as first- and second-line therapy and in combination with other treatments. Finally, this review compares other checkpoint inhibitors to pembrolizumab for the treatment of this disease, and explores predictive biomarkers of response to PD-1 blockade.

The Prognostic Nutritional Index in patients with microsatellite instability-high metastatic gastric or gastroesophageal cancers receiving immune checkpoint inhibitors.

BACKGROUND: Microsatellite instability high (MSI-H) and/or mismatch repair deficient (dMMR) status is the strongest predictive factor for immune checkpoint inhibitors (ICIs) benefit in patients with metastatic gastroesophageal cancer (mGC). Primary resistance to ICIs is a relevant issue, but prognostic and predictive factors are lacking. MATERIALS AND METHODS: In this multinational, retrospective cohort of patients with MSI-H/dMMR mGC treated with ICIs without chemotherapy we collected baseline laboratory values to establish the prognostic nutritional index (PNI). We evaluated the association between baseline PNI with the activity and efficacy of ICIs. RESULTS: At a median follow-up of 31.6 months, median progression-free survival (PFS) and 2-year PFS rate were not reached and 73.6 % in the PNI-high subgroup versus 6.3 months and 38.3 % in the PNI-low one (HR 0.32, 95 % CI: 0.16-0.61, p < .001). Median overall survival (OS) and 2-year OS rate were not reached and 81.9 % in the PNI-high subgroup versus 24.4 months and 50.5 % in the PNI-low one (HR 0.26, 95 % CI: 0.12-0.56, p < .001). In multivariable models, high PNI was associated with longer PFS and OS (HR 0.30, 95 % CI: 0.15-0.61, p <0.001 and 0.37, 95 % CI: 0.15-0.91, p = .031). CONCLUSIONS: High PNI is associated with longer PFS and OS, in patients with MSI-H mGC receiving ICIs. Patients with low baseline PNI may benefit from intensive therapeutic approaches.

18F-BMS-986229 PET to Assess Programmed-Death Ligand 1 Status in Gastroesophageal Cancer.

Anti-programmed death 1 (PD-1) inhibitors are the standard of care for advanced gastroesophageal cancer. Although recommendations and approval by regulatory agencies are often based on programmed death ligand 1 (PD-L1) expression, pathologic assessments of PD-L1 status have several limitations. Single-site biopsies do not adequately capture disease heterogeneity within individual tumor lesions or among several lesions within the same patient, the PD-L1 combined positive score is a dynamic biomarker subject to evolution throughout a patient's disease course, and repeated biopsies are invasive and not always feasible. Methods: This was a prospective pilot study of the PD-L1-targeting radiotracer, 18F-BMS-986229, with PET imaging (PD-L1 PET) in patients with gastroesophageal cancer. Patients were administered the 18F-BMS-986229 radiotracer intravenously at a dose of 370 MBq over 1-2 min and underwent whole-body PET/CT imaging 60 min later. The primary objective of this study was to evaluate the safety and feasibility of 18F-BMS-986229. The trial is registered with ClinicalTrials.gov (NCT04161781). Results: Between February 3, 2020, and February 2, 2022, 10 patients with gastroesophageal adenocarcinoma underwent PD-L1 PET. There were no adverse events associated with the 18F-BMS-986229 tracer, and imaging did not result in treatment delays; the primary endpoint was achieved. Radiographic evaluation of PD-L1 expression was concordant with pathologic assessment in 88% of biopsied lesions, and 18F-BMS-986229 uptake on PET imaging correlated with pathologic evaluation by the combined positive score (Spearman rank correlation coefficient, 0.64). Seventy-one percent of patients with 18F-BMS-986229 accumulation on PET imaging also had lesions without 18F-BMS-986229 uptake, highlighting the intrapatient heterogeneity of PD-L1 expression. Patients treated with frontline programmed death 1 inhibitors who had 18F-BMS-986229 accumulation in any lesions on PET imaging had longer progression-free survival than patients without tracer accumulation in any lesions (median progression-free survival, 28.4 vs. 9.9 mo), though the small sample size prevents any definitive conclusions. Conclusion: PD-L1 PET imaging was safe, feasible, and concordant with pathologic evaluation and offers a potential noninvasive tool to assess PD-L1 expression.

Predicting response to immune checkpoint blockade therapy among mismatch repair-deficient patients using mutational signatures.

Despite the overall efficacy of immune checkpoint blockade (ICB) for mismatch repair deficiency (MMRD) across tumor types, a sizable fraction of patients with MMRD still do not respond to ICB. We performed mutational signature analysis of panel sequencing data (n = 95) from MMRD cases treated with ICB. We discover that T>C-rich single base substitution (SBS) signatures-SBS26 and SBS54 from the COSMIC Mutational Signatures catalog-identify MMRD patients with significantly shorter overall survival. Tumors with a high burden of SBS26 show over-expression and enriched mutations of genes involved in double-strand break repair and other DNA repair pathways. They also display chromosomal instability (CIN), likely related to replication fork instability, leading to copy number losses that trigger immune evasion. SBS54 is associated with transcriptional activity and not with CIN, defining a distinct subtype. Consistently, cancer cell lines with a high burden of SBS26 and SBS54 are sensitive to treatments targeting pathways related to their proposed etiology. Together, our analysis offers an explanation for the heterogeneous responses to ICB among MMRD patients and supports an SBS signature-based predictor as a prognostic biomarker for differential ICB response.

Clinicogenomic predictors of survival and intracranial progression after stereotactic radiosurgery for colorectal cancer brain metastases.

OBJECTIVE: Brain metastases (BM) from colorectal cancer (CRC) are associated with dismal prognosis. When BM-directed therapy is considered, better methods are needed to identify patients at risk of poor oncological outcomes in order to optimize patient selection for closer surveillance or escalated therapy. The authors sought to identify clinicogenomic predictors of survival and intracranial disease progression after CRC BM have been treated with stereotactic radiosurgery (SRS). METHODS: Patients with newly diagnosed CRC BM treated with SRS between 2009 and 2022 who had next-generation genomic sequencing data available were included. Frameless SRS was delivered in 1-5 fractions, alone or after neurosurgical resection. Outcomes included overall survival (OS) and intracranial progression (IP), evaluated per patient treated with SRS, and local progression (LP), evaluated per BM. Associations between baseline clinicogenomic features and outcomes were evaluated with Cox regression and competing risk regression, with death as a competing risk. RESULTS: This analysis included 123 patients with 299 BM. At BM diagnosis, 111 patients (90%) had progressive extracranial disease, and 79 patients (64%) had ≥ 3 sites of extracranial metastasis. The median (IQR) number of BM was 2 (1-3) per patient. The median (IQR) biologically effective dose (BED) was 51.3 (51.3-65.1) Gy, corresponding to a prescription of 27 Gy in 3 fractions. OS, IP, and LP estimates at 1 year after SRS were 36%, 55%, and 12%, respectively. OS was independently associated with progressive extracranial disease (HR 4.26, 95% CI 1.63-11.2, p = 0.003) and ≥ 3 extracranial metastatic sites (HR 1.84, 95% CI 1.12-3.01, p = 0.02). LP was less likely when BM received BED ≥ 51.3 Gy (HR 0.24, 95% CI 0.07-0.78, p = 0.02), independent of BM diameter (HR 1.21/cm, 95% CI 0.8-1.84, p = 0.4). IP was independently associated with genomic alterations; TP53 driver alterations were associated with higher risk of IP (HR 2.71, 95% CI 1.26-5.79, p = 0.01), whereas MYC pathway alterations were associated with lower risk (HR 0.15, 95% CI 0.03-0.68, p = 0.01). CONCLUSIONS: The authors identified clinicogenomic features associated with adverse outcomes after SRS for CRC BM. Progressive and extensive extracranial metastases predicted worse OS. Insufficient SRS doses predicted greater risk of LP. Wild-type TP53 and alterations in the MYC pathway were independently associated with lower risk of IP. Patients at high risk of IP may be considered for closer surveillance or escalated therapy.