Impressive response to immunotherapy in a metastatic gastric cancer patient: could somatic copy number alterations help patient selection?

• Published in: Journal for immunotherapy of cancer Vol. 5; no. 1; p. 84
• Main Authors: Dos Santos Fernandes, Gustavo, da Motta Girardi, Daniel, Dib Batista Bugiato Faria, Luiza, Giacomini Bernardes, João Paulo, de Almeida Coudry, Renata
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 21.11.2017; BMJ Publishing Group LTD; BioMed Central; BMJ Publishing Group
• Subjects: Cancer; Cancer metastasis; Cancer patients; Cancer research; Cancer therapies; Case Report; Chemotherapy; Chromosomes; Classification; Clinical trials; Cytotoxicity; DNA Copy Number Variations - immunology; Drug therapy; Female; Gastric cancer; Genes; Genomes; Humans; Immunotherapy; Immunotherapy - methods; Lymphatic system; Magnetic resonance imaging; Medical prognosis; Melanoma; Metastasis; Middle Aged; Molecular targeted therapy; Molecular Targeted Therapy - methods; Neoplasm Metastasis; Non-small cell lung cancer; Patients; Prognosis; Proteins; Remission (Medicine); Somatic copy number alteration; Stomach cancer; Stomach neoplasms; Stomach Neoplasms - immunology; Stomach Neoplasms - pathology; Stomach Neoplasms - therapy; Tumors; Molecular targeted therapy; Somatic copy number alteration; Immunotherapy; Stomach neoplasms
• ISSN: 2051-1426; 2051-1426
• DOI: 10.1186/s40425-017-0291-9

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. 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. 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.