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

J Immunother Cancer. 2017 Nov 21;5(1):84. doi: 10.1186/s40425-017-0291-9.

Abstract

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.

Keywords: Immunotherapy; Molecular targeted therapy; Somatic copy number alteration; Stomach neoplasms.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Copy Number Variations / immunology*
  • Female
  • Humans
  • Immunotherapy / methods*
  • Middle Aged
  • Molecular Targeted Therapy / methods*
  • Neoplasm Metastasis
  • Stomach Neoplasms / immunology
  • Stomach Neoplasms / pathology
  • Stomach Neoplasms / therapy*