Project description: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.
Project description:ObjectiveEsophageal adenocarcinoma (EAC) continues to be a disease associated with high mortality. Among the factors leading to poor outcomes are innate resistance to currently available therapies, advanced stage at diagnosis, and complex biology. Platinum and ionizing radiation form the backbone of treatment for the majority of patients with EAC. Of the multiple processes involved in response to platinum chemotherapy or ionizing radiation, deoxyribonucleic acid (DNA) repair has been a major player in cancer sensitivity to these agents. DNA repair defects have been described in various malignancies. The purpose of this study was to determine whether alterations in DNA repair are present in EAC compared with normal gastroesophageal tissues.MethodsWe analyzed the expression of genes involved in homologous recombination (HR), nonhomologous end-joining, and nucleotide excision repair (NER) pathways in 12 EAC tumor samples with their matched normal counterparts. These pathways were chosen because they are the main pathways involved in the repair of platinum- or ionizing-radiation-induced damage. In addition, abnormalities in these pathways have not been well characterized in EAC.ResultsWe identified increased expression of at least one HR gene in eight of the EAC tumor samples. Alterations in the expression of EME1, a structure-specific endonuclease involved in HR, were the most prevalent, with messenger (m)RNA overexpression in six of the EAC samples. In addition, all EAC samples revealed decreased expression of at least one of numerous NER genes including XPC, XPA, DDB2, XPF, and XPG.ConclusionOur study identified DNA repair dysregulation in EAC involving two critical pathways, HR and NER, and is the first demonstration of EME1 upregulation in any cancer. These DNA repair abnormalities have the potential to affect a number of processes such as genomic instability and therapy response, and the consequences of these defects deserve further study in EAC.
Project description:Tumors of the upper gastrointestinal tract are increasing in incidence; yet, approaches to the treatment of advanced gastric and/or gastroesophageal junction cancer vary widely, with no internationally agreed first-line regimens. Recent clinical trials have shown that second-line treatment is now possible for selected patients with advanced disease, and current data suggest that the combination of ramucirumab plus paclitaxel may become a standard of care in the second-line setting for metastatic gastric cancer. Several prognostic factors have been identified for overall survival in the second-line setting; this emphasizes the need for careful sequencing of all treatments to ensure that individual patients receive optimum care. This article reviews published data on the treatment of advanced gastric cancer, with a particular emphasis on second-line chemotherapy, and suggests treatment sequences based on current understanding.
Project description:The poor survival of adenocarcinomas of the gastroesophageal junction (GEJ) makes them clinically important. Discovery of host genetic factors that affect outcome may guide more individualized treatment. This study tests whether constitutional genetic variants in matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) genes are associated with outcome of GEJ adenocarcinoma. Single nucleotide polymorphisms (SNPs) at four TIMP (TIMP1-4) and three MMP genes (MMP2, MMP7 and MMP9) were genotyped in DNA samples from a prospective cohort of patients with primary adenocarcinoma of the GEJ admitted to the British Columbia Cancer Agency. Cox proportional hazards regression, with adjustment for patient, disease and treatment variables, was used to estimate the association of SNPs with survival. Genotypes for 85 samples and 48 SNPs were analyzed. Four SNPs across TIMP3, (rs130274, rs715572, rs1962223 and rs5754312) were associated with survival. Interaction analyses revealed that the survival associations with rs715572 and rs5754312 are specific and significant for 5FU+cisplatin treated patients. Sanger sequencing of the TIMP3 coding and promoter regions revealed an additional SNP, rs9862, also associated with survival. TIMP3 genetic variants are associated with survival and may be potentially useful in optimizing treatment strategies for individual patients.
Project description:Background and aims: The aim of this study was to analyze the molecular characteristics of adenocarcinoma of the gastroesophageal junction (AGEJ) compared to esophageal (EAC) and gastric adenocarcinomas (GCFB) from The Cancer Genome Atlas (TCGA) and Seoul National University (SNU) cohorts using next-generation sequencing. Methods: Based on mRNA expression of EAC (n=78) and GCFB (n=102) from the TCGA cohort, a molecular classification model using the Bayesian compound covariate predictor classified AGEJ/cardia (n=48) from the TCGA cohort and AGEJ/upper third gastric adenocarcinoma (n=46) from the SNU cohort into the EAC-like or GCFB-like groups. The molecular characteristics between the EAC-like and GCFB-like groups were compared.
Project description:Gastric cancer is a leading cause of cancer-related death worldwide. Recent evidence suggests that gastric cancer is a complex and heterogenous disease with emerging subtypes shown to affect response to treatment and survival. Immunotherapy is an advancing field and immune checkpoint inhibitors have become standard treatment options in numerous tumor types. In this review, we discuss the current and evolving use of checkpoint blockade, focusing on the anti-PD-1 inhibitor, pembrolizumab, for use in advanced gastric and gastroesophageal cancers.
Project description:BackgroundDue to negative results in clinical trials of postoperative chemoradiation for gastric cancer, at present, there is a tendency to move chemoradiation therapy forward in gastric and gastroesophageal junction (GEJ) adenocarcinoma. Several randomized controlled trials (RCTs) are currently recruiting subjects to investigate the effect of neo-adjuvant radiotherapy (NRT) in gastric and GEJ cancer. Large retrospective studies may be beneficial in clarifying the potential benefit of NRT, providing implications for RCTs.MethodsWe retrieved the clinicopathological and treatment data of gastric and GEJ adenocarcinoma patients who underwent surgical resection and chemotherapy between 2004 and 2015 from Surveillance, Epidemiology, and End Results (SEER) database. We compared survival between NRT and non-NRT patients among four clinical subgroups (T1-2N-, T1-2N+, T3-4N-, and T3-4N+).ResultsOverall, 5272 patients were identified, among which 1984 patients received NRT. After adjusting confounding variables, significantly improved survival between patients with and without NRT was only observed in T3-4N+ subgroup [hazard ratio (HR) 0.79, 95% confidence interval (CI): 0.66-0.95; P = 0.01]. Besides, Kaplan-Meier plots showed significant cause-specific survival advantage of NRT in intestinal type (P < 0.001), but not in diffuse type (P = 0.11) for T3-4N+ patients. In the multivariate competing risk model, NRT still showed survival advantage only in T3-4 N+ patients (subdistribution HR: 0.77; 95% CI: 0.64-0.93; P = 0.006), but not in other subgroups.ConclusionsNRT might benefit resectable gastric and GEJ cancer patients of T3-4 stages with positive lymph nodes, particularly for intestinal-type. Nevertheless, these results should be interpreted with caution, and more data from ongoing RCTs are warranted.
Project description:PurposeTo determine the incidence and predictors of gastric bleeding after chemoradiation for esophageal or gastroesophageal junction cancer.Methods and materialsWe reviewed patients receiving chemoradiation to at least 41.4 Gy for localized esophageal cancer whose fields included the stomach and who did not undergo surgical resection. The primary endpoint was grade ≥3 gastric hemorrhage (GB3+). Comprehensive stomach dose-volume parameters were collected, and stomach dose-volume histograms were generated for analysis.ResultsA total of 145 patients met our inclusion criteria. Median prescribed dose was 50.4 Gy (range, 41.4-56 Gy). Median stomach Dmax was 53.0 Gy (1.0-62.7 Gy), and median stomach V40, V45, and V50 Gy were 112 cm3 (0-667 cm3), 84 cm3 (0-632 cm3), and 50 cm3 (0-565 cm3), respectively. Two patients (1.4%) developed radiation-induced GB3+. The only dosimetric factor that was significantly different for these patients was a higher stomach Dmax (58.1 and 58.3 Gy) than the cohort median (53 Gy). One of these patients also had cirrhosis, and the other had a history of nonsteroidal anti-inflammatory drug use. Five other patients had GB3+ events associated with documented tumor progression. A Cox proportional hazards model based on stomach Dmax with respect to the development of GB3+ was found to be statistically significant. Time-to-event curves and dose-volume atlases were generated, demonstrating an increased risk of GB3+ only when stomach Dmax was >58 Gy (P < .05).ConclusionsWe observed a low rate of GB3+ events in patients who received chemoradiation to a median dose of 50.4 Gy to volumes that included a significant portion of the stomach. These results suggest that when prescribing 50.4 Gy for esophageal cancer, there is no need to minimize the irradiated gastric volume or dose for the sake of preventing bleeding complications. Limiting stomach maximum doses to <58 Gy may also avoid bleeding, and particular caution should be taken in patients with other risk factors for bleeding, such as cirrhosis.
Project description:PURPOSE:Esophageal, gastroesophageal junction, and gastric adenocarcinoma (herein gastroesophageal adenocarcinomas) are associated with poor prognosis and limited systemic treatment options. To further understand the genomic landscape of gastroesophageal cancers and its clinical correlations, circulating tumor DNA (ctDNA) from patients' plasma was evaluated using next-generation sequencing (NGS). EXPERIMENTAL DESIGN:We analyzed genomic alterations of 55 patients (mostly advanced disease; 9, surgically resectable) with gastroesophageal adenocarcinomas using clinical-grade NGS performed on plasma-derived ctDNA (54-73 gene panel). The test detects single-nucleotide variants, as well as copy number amplifications, fusions, and indels in selected genes. RESULTS:Seventy-six percent of patients (42/55) had ?1 genomic alteration [including variants of unknown significance (VUS)] and 69.1% (38/55) had ?1 characterized alteration (excluding VUSs). The median number of alterations per patient was 2 (range, 0-15). TP53 (50.9%, 28/55), PIK3CA (16.4%, 9/55), ERBB2 (14.5%, 8/55), and KRAS (14.5%, 8/55) genes were most frequently affected characterized alterations. Thirty-one patients also had tissue NGS. Concordance between tissue and ctDNA ranged from 61.3% (TP53 alterations) to 87.1% (KRAS alterations). ERBB2 alterations were significantly associated with poor overall survival (HR, 14.06; 95% confidence interval, 2.44-81.03; P = 0.003 multivariate analysis). Among patients with ?1 alteration, no 2 patients had identical molecular portfolios. All patients with ?1 characterized alteration had theoretically targetable alterations by an FDA-approved agent (on- or off-label). Illustrative case treated with cognate agent is presented. CONCLUSIONS:Evaluation of ctDNA by NGS among patients with gastroesophageal adenocarcinoma is feasible. Patients harbored heterogeneous patterns of genomics, with most having alterations that are potentially pharmacologically tractable.