A method for predicting responsiveness to a HER2-directed therapy by assessing HER2 heterogeneity in a tumor includes contacting a sample of the tumor with a biomarker-specific reagent that specifically binds to HER2 protein and detecting HER2 protein in the sample, contacting the sample of the tumor with a first nucleic acid probe that specifically binds HER2 genomic DNA and detecting HER2 gene amplification status in the sample, contacting the sample of the tumor with a second nucleic acid probe that specifically binds HER2 RNA and detecting HER2 RNA status in the sample scoring the HER2 protein (IHC), HER2 gene (DISH), and HER2 RNA (RNA-ISH), predicting that the tumor is responsive to the HER2-directed therapy if the tumor reveals a first foci having a first score and a second score, in which the first score and the second score are not the same.

The present invention generally provides a therapy for effectively treating and/or preventing diseases associated with cells expressing CLDN18.2, in particular cancer diseases such as gastroesophageal cancer. Data are presented demonstrating that administration of an anti-CLDN18.2 antibody to human patients with gastroesophageal cancer is safe and well-tolerated up to a dose of at least 1000 mg/m.sup.2. Furthermore, data are presented demonstrating that the antibody is fully functional in these patients to execute anti-tumor cell effects and evidence for antitumoral activity was obtained.

The present invention relates to antibodies that bind to human and monkey mucin 17 (MUC17). Moreover, the invention relates to a detection system comprising such antibodies. The antibodies or the detection system may be used for detecting or quantifying MUC17, for diagnosing a disease associated with MUC17, for patient stratification, monitoring disease progression, and evaluating the therapeutic response.

Embodiments described herein provide methods of determining a risk of progression of Barrett's esophagus in a subject, classifying Barrett's esophagus in a subject and detecting a field effect associated with malignant transformation of an esophagus of a subject suffering from Barrett's esophagus. The disclosure also provides kits for determining a risk of progression of Barrett's esophagus in a subject and classifying Barrett's esophagus in a subject.

The invention relates to biomarkers, and to novel biological markers for diagnosing cancer. In particular, the invention relates to the use of these compounds as diagnostic and prognostic markers in assays for detecting cancer, such as oesophagogastric cancer, and corresponding methods of detection. The invention also relates to methods of determining the efficacy of treating these diseases with a therapeutic agent. The assays are qualitative and/or quantitative, and are adaptable to large-scale screening and clinical trials.

The invention relates to biomarkers, and to novel biological markers for diagnosing cancer. In particular, the invention relates to the use of these compounds as diagnostic and prognostic markers in assays for detecting cancer, such as oesophagogastric cancer, and corresponding methods of detection. The invention also relates to methods of determining the efficacy of treating these diseases with a therapeutic agent. The assays are qualitative and/or quantitative, and are adaptable to large-scale screening and clinical trials.

Provided herein are methods, compositions, kits, and systems for detecting Epstein Barr virus infection (EBV) in gastric cancer (GC) patients. In particular, provided herein are methods, composition, kits, and systems for diagnosing and treating EBV-positive gastric cancer (EBV.sup.+ GC) in a biological sample of an individual based on the presence and level of antibodies against particular Epstein Barr virus proteins. EBV.sup.+ GC is a distinct subtype of gastric cancer and is associated with unique molecular profiles. Also provided herein are methods for providing more personalized therapy for each of these distinct cancer subtypes and methods for determining an Epstein Barr virus-positive gastric cancer antibody signature, and kits comprising components and protocols for performing the methods of this disclosure.