Prognostic and predictive impact of sex in locally advanced microsatellite instability high gastric or gastroesophageal junction cancer: An individual patient data pooled analysis of randomized clinical trials.

BACKGROUND: Surgery plus peri-operative/adjuvant chemotherapy is the standard of care for locally advanced GC/GEJC, though with unsatisfactory results. dMMR/MSI-high tumors have better prognosis and scant benefit from chemotherapy as compared to pMMR/MSS ones. The differential outcome of therapies in terms of safety and efficacy according to sex is still debated in GC/GEJC patients. METHODS: We previously performed an individual patient data pooled analysis of MAGIC, CLASSIC, ITACA-S, and ARTIST trials including GC/GEJC patients treated with surgery alone or surgery plus peri-operative/adjuvant chemotherapy to assess the value of MSI status. We performed a secondary analysis investigating the prognostic and predictive role of sex (female versus male) in the pooled analysis dataset in the overall population and patients stratified for MSI status (MSI-high versus MSS/MSI-low). Disease-free (DFS) and overall survival (OS) were calculated. RESULTS: Patients with MSI-high tumors had improved survival as compared to MSS/MSI-low ones irrespective of sex, whereas in those with MSS/MSI-low tumors, females had numerically longer OS and DFS (5-year OS was 63.2% versus 57.6%, HR 0.842; p = 0.058, and 5-year DFS was 55.8% versus 50.8%, HR 0.850; p = 0.0504 in female versus male patients). The numerical difference for the detrimental effect of chemotherapy in MSI-high GC was higher in females than males, while the significant benefit of chemotherapy over surgery alone was confirmed in MSS/MSI-low GC irrespective of sex. CONCLUSIONS: This pooled analysis including four randomized trials highlights a relevant impact of sex in the prognosis and treatment efficacy of MSI-high and MSS/MSI-low non-metastatic GC/GEJC.

Early Immune Remodeling Steers Clinical Response to First-Line Chemoimmunotherapy in Advanced Gastric Cancer.

Adding anti-programmed cell death protein 1 (anti-PD-1) to 5-fluorouracil (5-FU)/platinum improves survival in some advanced gastroesophageal adenocarcinomas (GEA). To understand the effects of chemotherapy and immunotherapy, we conducted a phase II first-line trial (n = 47) sequentially adding pembrolizumab to 5-FU/platinum in advanced GEA. Using serial biopsy of the primary tumor at baseline, after one cycle of 5-FU/platinum, and after the addition of pembrolizumab, we transcriptionally profiled 358,067 single cells to identify evolving multicellular tumor microenvironment (TME) networks. Chemotherapy induced early on-treatment multicellular hubs with tumor-reactive T-cell and M1-like macrophage interactions in slow progressors. Faster progression featured increased MUC5A and MSLN containing treatment resistance programs in tumor cells and M2-like macrophages with immunosuppressive stromal interactions. After pembrolizumab, we observed increased CD8 T-cell infiltration and development of an immunity hub involving tumor-reactive CXCL13 T-cell program and epithelial interferon-stimulated gene programs. Strategies to drive increases in antitumor immune hub formation could expand the portion of patients benefiting from anti-PD-1 approaches. SIGNIFICANCE: The benefit of 5-FU/platinum with anti-PD-1 in first-line advanced gastric cancer is limited to patient subgroups. Using a trial with sequential anti-PD-1, we show coordinated induction of multicellular TME hubs informs the ability of anti-PD-1 to potentiate T cell-driven responses. Differential TME hub development highlights features that underlie clinical outcomes. This article is featured in Selected Articles from This Issue, p. 695.

Patient-derived exosomes facilitate therapeutic targeting of oncogenic MET in advanced gastric cancer.

Gastric cancer (GC) with peritoneal metastases and malignant ascites continues to have poor prognosis. Exosomes mediate intercellular communication during cancer progression and promote therapeutic resistance. Here, we report the significance of exosomes derived from malignant ascites (EXOAscites) in cancer progression and use modified exosomes as resources for cancer therapy. EXOAscites from patients with GC stimulated invasiveness and angiogenesis in an ex vivo three-dimensional autologous tumor spheroid microfluidic system. EXOAscites concentration increased invasiveness, and blockade of their secretion suppressed tumor progression. In MET-amplified GC, EXOAscites contain abundant MET; their selective delivery to tumor cells enhanced angiogenesis and invasiveness. Exosomal MET depletion substantially reduced invasiveness; an additive therapeutic effect was induced when combined with MET and/or VEGFR2 inhibition in a patient-derived MET-amplified GC model. Allogeneic MET-harboring exosome delivery induced invasion and angiogenesis in a MET non-amplified GC model. MET-amplified patient tissues showed higher exosome concentration than their adjacent normal tissues. Manipulating exosome content and production may be a promising complementary strategy against GC.

The Clinical Implication of Conversion Surgery in Patients with Stage IV Gastric Cancer Who Received Systemic Chemotherapy.

With the advances in chemotherapy and immunotherapy, a small subset of patients may be eligible for conversion surgery after achieving tumor regression with chemotherapy. This is a retrospective cohort study of 118 patients with stage IV gastric cancer who received palliative chemotherapy and conversion surgery with a negative resection margin at Samsung Medical Center. Baseline features included comorbidities, body mass index (BMI), carcinoembryonic antigen (CEA) level, primary tumor size, biopsy histology, distant metastatic sites, and molecular markers-HER2, MSI/MMR, PD-L1, and EBV. Post-chemotherapy features included BMI, CEA level, chemotherapy regimen, objective response to chemotherapy, and number of preoperative chemotherapy cycles. Post-operational features included tumor size, histologic differentiation and Lauren's classification, pathologic tumor and nodal stages, invasion of lymphatics/vessels/nerves, peritoneal cytology, and the receipt of postoperative chemotherapy. Of 118 patients, 60 patients received total gastrectomy and 58 patients received subtotal gastrectomy. In all, 21 patients achieved a pathologic complete response, and 97 patients achieved downstaging to yp stage I, II, or III. Before conversion surgery, patients received first-line capecitabine/oxaliplatin (62%), HER2 inhibitors combined with chemotherapy (18%), immune checkpoint inhibitors (15%), and inhibitors of MET or VEGFR2 (5%). In the multivariable analysis, BMI at the time of diagnosis, either HER2 positive, high MSI, or deficient MMR, and the use of targeted agents were significant prognostic factors. Conversion surgery could be considered in patients with stage IV gastric cancer regardless of the initial disease burden. BMI and molecular markers are important prognostic factors that can be used to select candidates.

Impact of programmed death-ligand 1 (PD-L1) positivity on clinical and molecular features of patients with metastatic gastric cancer.

BACKGROUND: Programmed death-ligand 1 (PD-L1) is an important screening biomarker to select patients with gastric cancer (GC) for optimized treatment, including immune checkpoint inhibitors (ICI). METHODS: In this single-institution retrospective cohort study, patients with metastatic GC with available PD-L1 results between October 2019 and September 2021 were identified by reviewing their electronic medical records. Genomic data were obtained from the Samsung Medical Center Clinical Sequencing Platform. RESULTS: Among the 399 patients, 276 (69%) had a PD-L1 combined positive score (CPS) ≥1, 155 (39%) had a CPS between 1 and 5, and 121 (30%) had a CPS ≥5. Of the 121 patients with CPS ≥5, 28 (23%) had a known etiology for "inflamed tumor," with Epstein-Barr virus (EBV) positivity (N = 11) or high tumor mutational burden (TMB) (N = 17), which included microsatellite instability (MSI) (N = 9). PD-L1 CPS ≥5 was observed in 11/11 (100%) patients with EBV positivity, 9/12 (75%) patients with MSI, and 17/33 (52%) patients with high TMB. For the 108 patients who received ICI therapy, CPS ≥5 was the only predictor significantly associated with survival in multivariable analyses, including TMB, MSI, or EBV. Objective response rate (ORR) was 49% in patients with CPS ≥5, 30% in patients with 1 ≤ CPS <5, and 19% in patients with CPS <1. Among the 31 responders to ICI therapy, 27 (87%) had a CPS of ≥1. Mutations in TET2, IRS2, DOT1L, PTPRT, and LRP1B were associated with a higher ORR (63%-100%), whereas MDC1 mutations were associated with a low ORR (22%). CONCLUSIONS: PD-L1 expression is an independent and sensitive biomarker for ICI therapy. Considering its significant association with several gene alterations, including PIK3CA mutations and MET amplification, combining ICI therapy with other targeted agents may be a promising therapeutic strategy for GC.

Comprehensive molecular analysis to predict the efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer.

Background: Although bevacizumab is an important treatment for metastatic colorectal cancer (CRC), not all patients with CRC benefit from it; in unselected patient populations, only modest survival benefits have been reported. Methods: We evaluated clinical outcomes in 110 patients using comprehensive molecular characterization to identify biomarkers for a response to bevacizumab-containing treatment. The molecular analysis comprised whole-exome sequencing, ribonucleic acid sequencing, and a methylation array on patient tissues. Results: Genomic and molecular characterization was successfully conducted in 103 patients. Six of 103 CRC samples were hypermutated, and none of the non-hypermutant tumors were microsatellite unstable. Among those 103 patients, 89 had adenocarcinoma (ADC), 15 were diagnosed with mucinous ADC, and six had signet-ring cell carcinoma (SRCC). Consensus molecular subtype (CMS) 2 was unique to ADC. Of the four SRCCs, two were CMS1, one was CMS4, and the other was CMS3. APC mutation status was a significantly enriched factor in responders to bevacizumab treatment. Fibroblast growth factor receptor (FGFR) 1/2 signaling was upregulated in non-responders, whereas cell cycle, transfer ribonucleic acid processing, nucleotide excision repair, and oxidative phosphorylation pathways were enriched in responders. In addition, IGF1 was differentially expressed in non-responders (log2 fold change = -1.43, p = 4.11 × 10-5, false discovery rate = 0.098), and FLT1 was highly methylated in non-responders (p = 7.55 × 10-3). When the molecular pathways were reanalyzed separately according to the backbone chemotherapy (FOLFOX vs. FOLFIRI), the significance of the molecular pathways varied according to the backbone chemotherapy. Conclusions: This study sought a subset of CRC patients with a distinct clinical response to chemotherapy containing bevacizumab. Our results need to be validated in a large group of homogenous patient cohort and examined according to the different chemotherapy backbones to create personalized therapeutic opportunities in CRC.

The Optimal Tumor Mutational Burden Cutoff Value as a Novel Marker for Predicting the Efficacy of Programmed Cell Death-1 Checkpoint Inhibitors in Advanced Gastric Cancer.

PURPOSE: The optimal tumor mutational burden (TMB) value for predicting treatment response to programmed cell death-1 (PD-1) checkpoint inhibitors in advanced gastric cancer (AGC) remains unclear. We aimed to investigate the optimal TMB cutoff value that could predict the efficacy of PD-1 checkpoint inhibitors in AGC. MATERIALS AND METHODS: Patients with AGC who received pembrolizumab or nivolumab between October 1, 2020, and July 27, 2021, at Samsung Medical Center in Korea were retrospectively analyzed. The TMB levels were measured using a next-generation sequencing assay. Based on receiver operating characteristic curve analysis, the TMB cutoff value was determined. RESULTS: A total 53 patients were analyzed. The TMB cutoff value for predicting the overall response rate (ORR) to PD-1 checkpoint inhibitors was defined as 13.31 mutations per megabase (mt/Mb) with 56% sensitivity and 95% specificity. Based on this definition, 7 (13.2%) patients were TMB-high (TMB-H). The ORR differed between the TMB-low (TMB-L) and TMB-H (8.7% vs. 71.4%, P=0.001). The progression-free survival and overall survival (OS) for 53 patients were 1.93 (95% confidence interval [CI], 1.600-2.268) and 4.26 months (95% CI, 2.992-5.532). The median OS was longer in the TMB-H (20.8 months; 95% CI, 2.292-39.281) than in the TMB-L (3.31 months; 95% CI, 1.604-5.019; P=0.049). CONCLUSIONS: The TMB cutoff value for predicting treatment response in AGC patients who received PD-1 checkpoint inhibitor monotherapy as salvage treatment was 13.31 mt/Mb. When applying the programmed death ligand-1 status to TMB-H, patients who would benefit from PD-1 checkpoint inhibitors can be selected.

A Phase II Study of Preoperative Chemoradiotherapy with Capecitabine Plus Simvastatin in Patients with Locally Advanced Rectal Cancer.

PURPOSE: The purpose of this phase II trial was to evaluate whether the addition of simvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, to preoperative chemoradiotherapy (CRT) with capecitabine confers a clinical benefit to patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Patients with LARC (defined by clinical stage T3/4 and/or lymph node positivity) received preoperative radiation (45-50.4 Gy in 25-28 daily fractions) with concomitant capecitabine (825 mg/m2 twice per day) and simvastatin (80 mg, daily). Curative surgery was planned 4-8 weeks after completion of the CRT regimen. The primary endpoint was pathologic complete response (pCR). The secondary endpoints included sphincter-sparing surgery, R0 resection, disease-free survival, overall survival, the pattern of failure, and toxicity. RESULTS: Between October 2014 and July 2017, 61 patients were enrolled; 53 patients completed CRT regimen and underwent total mesorectal excision. The pCR rate was 18.9% (n=10) by per-protocol analysis. Sphincter-sparing surgery was performed in 51 patients (96.2%). R0 resection was achieved in 51 patients (96.2%). One patient experienced grade 3 liver enzyme elevation. No patient experienced additional toxicity caused by simvastatin. CONCLUSION: The combination of 80 mg simvastatin with CRT and capecitabine did not improve pCR in patients with LARC, although it did not increase toxicity.

Randomized phase II study of capecitabine plus cisplatin with or without sorafenib in patients with metastatic gastric cancer (STARGATE).

BACKGROUND: In this randomized phase II study, we evaluated the efficacy and safety of sorafenib in combination with capecitabine and cisplatin (XP) as first-line chemotherapy in advanced gastric cancer. PATIENTS AND METHODS: Patients with metastatic gastric or gastroesophageal junction adenocarcinoma were randomized (1:1) to receive either sorafenib plus XP (S + XP) or XP alone. In cases of disease progression in the XP arm, crossover to sorafenib alone was allowed. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS), response rates, safety profiles, and biomarkers, and the response rates and PFS with secondline sorafenib alone after progression in the XP arm. RESULTS: Between Jan 2011 and Feb 2013, a total of 195 patients were accrued (97 in the S + XP arm and 98 in the XP alone arm). The overall response rate was 54% with S + XP, and 52% with XP alone (p = 0.83). With a median follow-up of 12.6 months (range, 0.1-29.2), the median PFS assessed by independent review was 5.6 months in the S + XP arm and 5.3 months in the XP arm (hazard ratio [HR] 0.92, 95% confidence interval [CI] 0.67-1.27, p = 0.61). Overall survival was not different between the two arms (median 11.7 vs. 10.8 months; HR 0.93, 95% CI 0.65-1.31, p = 0.66). Frequencies of grade 3/4 toxicities were similar between the S + XP and XP alone arms, except for neutropenia (21% vs. 37%), anorexia (0% vs. 5%), and hand-foot skin reaction (7% vs. 1%). Among 51 patients who crossed over to sorafenib alone after disease progression in the XP arm, there was no objective response and their median PFS was 1.3 months (95% CI, 1.2-1.7). CONCLUSION: The addition of sorafenib to XP chemotherapy was safe but not more effective than XP alone for first-line treatment of metastatic gastric cancer.

The role of ramucirumab plus paclitaxel as second-line therapy after failure of nivolumab plus doublet chemotherapy in patients with advanced gastric cancer.

Background: Adding nivolumab to fluoropyrimidines and platinum agents has been considered a new standard first-line treatment in previously untreated human epidermal growth factor receptor 2 (HER2)-negative advanced gastric cancer (AGC). However, there were few data on the role of ramucirumab plus paclitaxel as second-line treatment after failure of nivolumab plus doublet chemotherapy. Herein, we analyzed the efficacy and safety of second-line ramucirumab plus paclitaxel in AGC patients refractory to nivolumab plus chemotherapy. Methods: This analysis included AGC patients with ramucirumab plus paclitaxel as second-line therapy after failing to respond to nivolumab plus doublet chemotherapy [capecitabine plus oxaliplatin (XELOX) or 5-fluorouracil plus oxaliplatin (FOLFOX)] at Samsung Medical Center, Korea. Twenty patients who progressed on nivolumab plus chemotherapy as first-line therapy were treated with ramucirumab plus paclitaxel between December 2021 and September 2022. Results: The median age was 56 (range, 24-76) years, and 13 (65.0%) were men. Of the 20 patients, 15 (75.0%) patients received nivolumab plus capecitabine, and oxaliplatin, while 5 (25.0%) patients received nivolumab plus 5-fluorouracil, and oxaliplatin. Two showed a partial response (PR) to ramucirumab plus paclitaxel, a response rate of 10%. Patients with stable disease (SD) accounted for a disease control rate (DCR) of 55.0%. The median progression-free survival (PFS) to ramucirumab plus paclitaxel was 2.7 months [95% confidence interval (CI): 1.7-3.7]. Subgroup analysis showed that responders (n=7) to first-line therapy had a PFS of 6.9 months compared to 2.3 months in non-responders (n=13) to first-line therapy. The median overall survival (OS) was 6.3 months (95% CI: 5.5-8.3), representing 6.9 months (95% CI: not calculated) in responders and 6.3 months (95% CI: 3.7-8.9) in non-responders (P=0.401). Conclusions: This analysis suggested that ramucirumab plus paclitaxel as second-line therapy might be further studied in AGC patients after failure of nivolumab plus chemotherapy. A new second-line therapy is needed in AGC patients after nivolumab plus chemotherapy.

Effect of ramucirumab plus paclitaxel in advanced gastric cancer according to the status of programmed cell death-ligand 1 (PD-L1) expression.

Background: Ramucirumab, an anti-vascular endothelial growth factor receptor (VEGFR) monoclonal antibody (mAb), inhibits angiogenesis and reduces tumor activity. Programmed cell death-ligand 1 (PD-L1) might act upon VEGFR2 to induce cancer cell angiogenesis and metastasis. Herein, we investigated the efficacy of combining ramucirumab and paclitaxel according to the status of PD-L1 expression in patients with advanced gastric cancer (AGC). Methods: This analysis included AGC patients who received ramucirumab plus paclitaxel as 2nd line therapy between December 1, 2018, and February 28, 2022, at Samsung Medical Center. All patient data analyses included an evaluation of PD-L1 expression using the combined positive score (CPS). We analyzed the efficacy and the survival of patients according to their PD-L1 expression. Results: We included 117 patients in this analysis, and 80 patients (68.4%) had a PD-L1 CPS of one or more, 37 (31.6%) had five or more, and 19 (16.2%) had ten or more scores. Progression-free survival (PFS) and overall survival (OS) did not differ significantly between patients with a PD-L1 CPS of less than one and one or more {PD-L1 <1% vs. PD-L1 ≥1%; PFS: median 3.6 months [95% confidence interval (CI): 2.4-4.8 months] vs. median 4.1 months (95% CI: 3.5-4.7 months), P=0.93; PD-L1 <1% vs. PD-L1 ≥1%; OS: median 7.0 months (95% CI: 5.4-8.6 months) vs. median 8.1 months (95% CI: 6.4-9.8 months), P=0.32}. PFS and OS did not differ significantly between patients with a PD-L1 CPS of less than 5 and 5 or more [PD-L1 <5% vs. PD-L1 ≥5%; PFS: 3.9 months (95% CI: 3.3-4.5 months) vs. 4.4 months (95% CI: 3.0-5.8 months), P=0.57; OS: 7.4 months (95% CI: 6.5-8.3 months) vs. 10.0 months (95% CI: 1.1-18.9 months), P=0.07]. Interestingly, with a PD-L1 CPS cutoff of 10, PFS and OS did differ significantly [PD-L1 <10% vs. PD-L1 ≥10%; PFS: 3.8 months (95% CI: 3.3-4.3 months) vs. 5.7 months (95% CI: 4.1-7.3 months), P=0.05; OS: 7.2 months (95% CI: 6.5-7.9 months) vs. 18.9 months (95% CI: 6.5-31.3 months), P=0.04]. Conclusions: No biomarkers have been established to predict survival times after ramucirumab plus paclitaxel treatment. This analysis suggests that a PD-L1 CPS cutoff of 10 might be novel a biomarker to predict the survival of AGC patients treated with ramucirumab and paclitaxel.

MET gene alterations predict poor survival following chemotherapy in patients with advanced cancer.

Background: To aid in oncology drug development, we investigated MET proto-oncogene receptor tyrosine kinase gene aberrations in 2,239 oncology patients who underwent next-generation sequencing (NGS) in clinical practice. Materials and methods: From November 2019 to January 2021, 2,239 patientswith advanced solid tumors who visited oncology clinics underwent NGS. The NGS panel included >500 comprehensive NGS tests using archival tissue specimens. Programmed death-ligand 1(PD-L1) 22C3 assay results and clinical records regarding initial chemotherapy were available for 1,137 (50.8%) and 1,761 (78.7%) patients, respectively for overall survival (OS) analysis. Results: The 2,239 patients represented 37 types of cancer. The NGS panel included >500 genes, microsatellite instability status, tumor mutational burden, and fusions. The most common cancer types were colorectal (N = 702), gastric (N = 481), and sarcoma (N = 180). MET aberrations were detected in 212 patients. All MET-amplified tumors had microsatellite stable status, and 8 had a high tumor mutational burden. Of 46 patients with MET-amplified cancers, 8 had MET-positive protein expression by immunohistochemistry (2+ and 3+). MET fusion was detected in 10 patients. Partner genes of MET fusion included ST7, TFEC, LRRD1, CFTR, CAV1, PCM1, HLA-DRB1, and CAPZA2. In survival analysis, patients with amplification of MET gene fusion had shorter OS and progression-free survival (PFS) than those without. Thus, MET aberration was determined to be a factor of response to chemotherapy. Conclusion: Approximately 2.1% and 0.4% of patients with advanced solid tumors demonstrated MET gene amplification and fusion, respectively, and displayed a worse response to chemotherapy and significantly shorter OS and PFS than those without MET gene amplification or fusion.

Clinical Significance of Preoperative Hematological Parameters in Patients with D2-Resected, Node-Positive Stomach Cancer.

The purpose of the present study was to investigate the clinical significance of preoperative hematological parameters in patients with advanced stomach cancer, and to explore who might benefit from adjuvant concurrent chemoradiotherapy (CCRT) compared to chemotherapy alone. Among 1032 patients with node-positive stomach cancer who had a confirmed diagnosis after complete D2 resection, and who received adjuvant chemotherapy alone or CCRT, a total of 692 patients was selected using propensity score matching. Among absolute neutrophil count, absolute lymphocyte count (ALC), absolute monocyte count (AMC), platelet count, neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and platelet-to-lymphocyte ratio, AMC was the most relevant prognostic factor for overall survival and recurrence-free survival (hazard ratio (HR) 1.674, 95% confidence interval (CI) 1.180-2.376; HR 1.908, 95% CI 1.650-2.695, respectively). In a subgroup with a high ALC, patients treated with adjuvant CCRT had a favorable recurrence-free survival (HR 0.620, 95% CI 0.393-0.980) compared to those treated with chemotherapy alone. Further study is needed to confirm our findings and to develop tailored adjuvant treatment.

Phase II study of ceralasertib (AZD6738) in combination with durvalumab in patients with advanced gastric cancer.

BACKGROUND: Targeting the DNA damage repair (DDR) pathways is an attractive strategy for boosting cancer immunotherapy. Ceralasertib (AZD6738) is an oral kinase inhibitor of ataxia telangiectasia and Rad3 related protein, which is a master regulator of DDR. We conducted a phase II trial of ceralasertib plus durvalumab in patients with previously treated advanced gastric cancer (AGC) to demonstrate the safety, tolerability, and clinical activity of the combination. METHODS: This phase II, open-label, single-center, non-randomized study was designed to evaluate the efficacy and safety of ceralasertib in combination with durvalumab in patients with AGC. The study drug regimen was ceralasertib (240 mg two times a day) days 15-28 in a 28-day cycle in combination with durvalumab (1500 mg) at day 1 every 4 weeks. The primary end point was overall response rate (ORR) by Response Evaluation Criteria in Solid Tumors (V.1.1). Exploratory biomarker analysis was performed using fresh tumor biopsies in all enrolled patients. RESULTS: Among 31 patients, the ORR, disease control rate, median progression-free survival (PFS), and overall survival were 22.6% (95% CI 9.6% to 41.1%), 58.1% (95% CI 39.1% to 75.5%), 3.0 (95% CI 2.1 to 3.9) months, and 6.7 (95% CI 3.8 to 9.6) months, respectively. Common adverse events were manageable with dose modification. A subgroup of patients with a loss of ataxia telangiectasia mutated (ATM) expression and/or high proportion of mutational signature attributable to homologous repair deficiency (sig. HRD) demonstrated a significantly longer PFS than those with intact ATM and low sig. HRD (5.60 vs 1.65 months; HR 0.13, 95% CI 0.045 to 0.39; long-rank p<0.001). During the study treatment, upregulation of the innate immune response by cytosolic DNA, activation of intratumoral lymphocytes, and expansion of circulating tumor-reactive CD8 +T cell clones were identified in responders. Enrichment of the tumor vasculature signature was associated with treatment resistance. CONCLUSIONS: Ceralasertib plus durvalumab has promising antitumor activity, with durable responses in patients with refractory AGC. Thus, a biomarker-driven trial is required. TRIAL REGISTRATION: NCT03780608.

Determining Which Patients Require Preoperative Pelvic Radiotherapy Before Curative-Intent Surgery and/or Ablation for Metastatic Rectal Cancer.

BACKGROUND: The aim of this study is to determine the optimal indications for preoperative pelvic radiotherapy (RT) in patients with metastatic rectal cancer who underwent curative-intent surgical resection and/or ablation. METHODS: Between January 2000 and October 2019, 246 patients who met our inclusion criteria were enrolled. Preoperative RT was performed in 22 patients (8.9%). Lower margin below the peritoneal reflection (p < 0.001), mesorectal fascia (MRF) invasion (p = 0.02), and lateral pelvic lymph node (LPLN) involvement (p = 0.005) were more frequent in the preoperative RT group. RESULTS: During the median follow-up period of 13.3 months (interquartile range [IQR]: 6.0-36.3 months), local recurrence (LR) was identified in 60 patients (24.4%). It was the first site of recurrence in 45 of them (18.3%). Among them, three patients were in the preoperative RT group. On multivariable analysis, lower margin below the peritoneal reflection, MRF invasion, LPLN involvement, carcinoembryonic antigen (CEA) level ≥ 10 ng/mL before treatment, and preoperative RT were significant prognostic factors for LR-free survival (LRFS). In the patient group without any risk factors, the 2-year LRFS rate was 94.9% without preoperative RT. In the patient group with one or more risk factors, the 2-year LRFS was 64.4% without and 95.2% with preoperative RT. CONCLUSION: LR developed in about 25% of patients within 2 years. Preoperative RT should be considered, especially in patients with a risk factor for LR, including lower margin below the peritoneal reflection, MRF invasion, LPLN involvement, or CEA ≥ 10 ng/mL before treatment.

Incidence of FGFR2 Amplification and FGFR2 Fusion in Patients with Metastatic Cancer Using Clinical Sequencing.

Aberrations in the fibroblast growth factor receptor2 (FGFR2) gene, including genetic alterations and chromosomal rearrangements, lead to the development and progression of cancer with poor prognosis. However, the mechanisms underlying the FGFR2 signaling pathway to facilitate the development of FGFR2-targeted therapies have not been fully explored. Here, we examined the clinicopathological features of FGFR2 amplification and fusion in gastrointestinal tract/genitourinary tract cancers. FGFR2 amplification and fusion were identified in approximately 1.5% and 1.1% of all cancer types in 1,373 patients, respectively, with both FGFR2 amplification and fusion occurring together at a rate of approximately 0.6%. Of all cancer types screened, gastric cancer (GC) was the most common cancer type with FGFR2 amplification (87.5% of all FGFR2 amplification case) or fusion (46.7% of all cases). In addition, FGFR2 alteration had poorer overall survival (OS, 13.7 months vs. 50.2 months, P = 0.0001) and progression-free survival (PFS, 5.6 months vs. 11.4 months, P = 0.0005) than did those without FGFR2 alteration, respectively. Taken together, our data underscore to screen solid cancer patients for FGFR2 aberrations in oncology clinic.

Safety and anti-tumor effects of vismodegib in patients with refractory advanced gastric cancer: A single-arm, phase-II trial.

This phase-II study (ClinicalTrials.gov identifier: NCT03052478) aimed to evaluate the efficacy and safety of vismodegib, an inhibitor targeting the Hedgehog signaling pathway, in patients with refractory advanced gastric cancer. Patients with refractory advanced gastric cancer, whose disease had progressed after undergoing standard therapies, were enrolled in this phase-II trial of vismodegib. Vismodegib (150 mg) was administered orally once a day for a 21-day cycle. The primary endpoint was objective response rate, and the secondary endpoints were overall survival and safety profile. Tumor biopsies were obtained before vismodegib treatment. We conducted whole-exome and transcriptome sequencing to analyze biomarkers. Twenty-three patients were enrolled in this study. Among 19 patients who were eligible for response evaluation, only one showed stable disease, yielding a disease control rate of 5.3%. Median overall survival was 74 days (95% confidence interval, 74-151 days). Treatment-related adverse events of any grade were reported in seven patients (31.8%), and most were grade 1 or 2. Whole transcriptome data showed that the Hedgehog signaling pathway was not enriched in patient samples. This is the first clinical trial demonstrating the clinical activity and safety of vismodegib monotherapy in refractory advanced gastric cancer patients. Further well-designed clinical trials should be conducted to select advanced gastric cancer patients who are likely to benefit from vismodegib.

Exploration of predictors of benefit from nivolumab monotherapy for patients with pretreated advanced gastric and gastroesophageal junction cancer: post hoc subanalysis from the ATTRACTION-2 study.

BACKGROUND: The phase 3 ATTRACTION-2 study demonstrated that nivolumab monotherapy was superior to placebo for patients with pretreated advanced gastric or gastroesophageal junction cancer, but early progression of tumors in some patients was of concern. METHODS: This post hoc analysis statistically explored the baseline characteristics of the ATTRACTION-2 patients and extracted a single-factor and double-factor combinations associated with early disease progression or early death. In the extracted patient subgroups, the 3-year restricted mean survival times of progression-free survival and overall survival were compared between the nivolumab and placebo arms. RESULTS: Two single factors (age and peritoneal metastasis) were extracted as independent predictors of early progression, but none of them, as a single factor, stratified patients into two subgroups with significant differences in restricted mean survival time. In contrast, two double-factor combinations (serum sodium level and white blood cell count; serum sodium level and neutrophil-lymphocyte ratio) stratifying patients into two subgroups with significant differences in the restricted mean survival time were extracted. Additional exploratory analysis of a triple-factor combination showed that patients aged < 60 years with peritoneal metastasis and low serum sodium levels (approximately 7% of all patients) might receive less benefit from nivolumab, and patients aged ≥ 60 years with no peritoneal metastasis and normal serum sodium levels might receive higher benefit. CONCLUSIONS: A combination of age, peritoneal metastasis, and serum sodium level might predict benefit from nivolumab as salvage therapy in advanced gastric or gastroesophageal junction cancer patients, especially less benefit for patients having all three risk factors.

The prevalence of homologous recombination deficiency (HRD) in various solid tumors and the role of HRD as a single biomarker to immune checkpoint inhibitors.

PURPOSE: Homologous recombination deficiency (HRD) is related to tumorigenesis. Currently, the possibility of HRD as a prognostic biomarker to immune checkpoint inhibitors is unknown. We aimed to investigate whether HRD has potential as a biomarker for immunotherapy. METHODS: The status of homologous recombination deficiency (HRD) was assessed with the next-generation sequencing (NGS) TruSight™ Oncology 500 assay in 501 patients with advanced solid tumor including gastrointestinal (GI), genitourinary (GU), or rare cancer. RESULTS: among the 501 patients, HRD was observed as follows: 74.7% (347/501) patients; GU cancer (92.0%, 23 of 25), colorectal cancer (CRC) (86.1%, 130 of 151), hepatocellular carcinoma (HCC) (83.3%, 10 of 12), pancreatic cancer (PC) (76.2%, 32 of 42), biliary tract cancer (BTC) (75.0%, 36 of 48), sarcoma (65.0%, 39 of 60), melanoma (52.4%, 11 of 21), other GI cancers (50.0%, 11 of 22), and rare cancer (50.0%, 2 of 4). Sixty-five of the 501 patients had received immune checkpoint inhibitors (ICIs) during the course of the disease. Tumor types of 65 patients treated with ICIs are as follows: melanoma (95.2%, 20 of 21), HCC (33.3%, 4 of 12), rare cancer (25.0%, 1 of 4), GC (12.2%, 14 of 116), BTC (10.4%, 5 of 48), and sarcoma (5.0%, 3 of 60). The most frequently reported mutations were BRCA2 (n = 90), ARID1A (n = 77), ATM (n = 71), BARD1 (n = 67). Patients without HRD exhibited an objective response rate (ORR) of 33.3% (4 of 12), and patients with HRD exhibited an ORR of 34.0% (18 of 53). There was no significant difference in ORR between patients with and without HRD (P = 0.967). Progression-free survival (PFS) was 6.5 months (95% CI 0.000-16.175) in patients without HRD and 4.1 months (95% CI 2.062-6.138) in patients with HRD, revealing no statistical significance (P = 0.441). CONCLUSION: Herein, we reported the status of HRD using a cancer-panel for various solid tumor patients in routine clinical practice and demonstrated that HRD as a single biomarker was not sufficient to predict efficacy of ICIs in solid tumor patients.

Prediction of epithelial-to-mesenchymal transition molecular subtype using CT in gastric cancer.

OBJECTIVES: To develop a prediction model with computed tomography (CT) images and to build a nomogram incorporating known clinicopathologic variables for individualized estimation of epithelial-to-mesenchymal transition (EMT) subtype gastric cancer. METHODS: Patients who underwent primary resection of gastric cancer (GC) and molecular subgroup analysis (n = 451) were reviewed. Multivariable analysis using a stepwise variable selection method was performed to build a predictive model for EMT subtype GC. A nomogram using the results of the multivariable analysis was constructed. An optimal cutoff value of total prognostic points of the nomogram for the prediction of EMT subtype was determined. The predictive model for the EMT subtype was internally validated by bootstrap resampling method. RESULTS: There were 88 patients with EMT subtype and 363 patients with non-EMT subtype based on transcriptome analysis. The patient's age, Lauren classification, and mural stratification on CT were variables selected for the predictive model. The area under the curve (AUC) of the model was 0.865, and the validated AUC of the bootstrap sample was 0.860. The optimal cutoff value of total prognostic points for the prediction of EMT subtype was 94.622, with 90.9% sensitivity, 67.2% specificity, and 71.8% accuracy. CONCLUSION: A predictive model using patient's age, Lauren classification, and mural stratification on CT for EMT molecular subtype GC was made. A nomogram was built which would serve as a useful screening tool for an individualized estimate of EMT subtype. KEY POINTS: • A predictive model for epithelial-to-mesenchymal transition (EMT) subtype incorporating patient's age, Lauren classification, and mural stratification on CT was built. • The predictive model had high diagnostic accuracy (area under the curve (AUC) = 0.865) and was validated (bootstrap AUC = 0.860). • Adding CT findings to clinicopathologic variables increases the accuracy of the predictive model than using only.