Palliative chemotherapy in patients with advanced gastric cancer yields better results regarding the improvement of OS and the relief of symptoms with minimal mortality and morbidity compared to patients treated with the best supportive care (BSC). A meta-analysis showed a trend toward improved survival with combination therapy.
The Classic trial showed that Xelox is effective in the adjuvant setting. For metastatic disease, as far as I can see, only case reports and small studies show responses.
NCCN on GAST-F, 3 lists trastuzumab in “combinaiton with other chemotherapy agents” as category 2B. It is not clear that this includes Xelox.
NCCN, Gastric 2017
Gastric Cancer: ESMO Clinical Practice Guidelines
Published in 2016 Ann Oncol (2016) 27 (suppl 5): v38-v49
Authors: E. C. Smyth, M. Verheij, W. Allum, D. Cunningham, A. Cervantes and D. Arnold