Herceptin® is also indicated as first-line treatment of (i) HER2-overexpressing metastatic breast cancer, in combination with paclitaxel and (ii) HER2-overexpressing metastatic gastric and gastroesophageal junction adenocarcinoma, in combination with cisplatin and capecitabine or 5-fluorouracil [39], in those patients who have not received prior treatment for metastatic disease. This evidence concerns the gene ERBB2 and gastroesophageal junction adenocarcinoma.