%0 Journal Article %A Gustavo dos Santos Fernandes %A Daniel da Motta Girardi %A Luiza Dib Batista Bugiato Faria %A João Paulo Giacomini Bernardes %A Renata de Almeida Coudry %T Impressive response to immunotherapy in a metastatic gastric cancer patient: could somatic copy number alterations help patient selection? %D 2017 %R 10.1186/s40425-017-0291-9 %J Journal for ImmunoTherapy of Cancer %P 84 %V 5 %N 1 %X Background Metastatic gastric cancer (GC) is an incurable and aggressive disease with a poor prognosis. Immunotherapy is an attractive approach for treating patients with cancer, and studies using immunotherapy have shown promising results in melanoma, kidney and non-small cell lung cancers, among others.Case presentation We present a case of a 50-year-old woman with metastatic GC whose cancer had progressed after first-line chemotherapy and who received pembrolizumab as an experimental treatment. Molecular analyses showed that her tumor was negative for PD-L1 expression, contained microsatellite stability and several focal somatic copy number alterations. The patient experienced an almost complete response after eleven cycles of treatment. Her symptoms related to the disease disappeared, and the medication was well tolerated.Conclusions Despite reports of promising responses in some patients, immunotherapy is not suitable for all patients; therefore, we explored the molecular characteristics that could explain the exceptional response and clinical benefits observed in our patient.Abbreviations:CTComputed tomographydMMRDeficiencies in mismatch repairEBVMeasured Epstein Barr vírusEGJEsophagogastric junctionFM-CGPFoundation Medicine Cancer Gene PanelGCGastric cancerIHCImmunohistochemistryMMRMismatch repairMSIMicrosatellite instabilityNGSNext-generation sequencingOSOverall survivalPET/CTPositron emission tomography/computed tomographyPFSProgression-free survivalpMMRProficient in mismatch repairSCNAsSomatic copy number alterationsTCGAThe Cancer Genome Atlas %U https://jitc.bmj.com/content/jitc/5/1/84.full.pdf