Herceptin should only be used in patients with metastatic gastric cancer whose tumours have HER2 overexpression...

Herceptin is a HER2/neu receptor antagonist indicated for...The treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma.

Trastuzumab should be added to first-line chemotherapy for HER2 overexpressing metastatic adenocarcinoma

Trastuzumab, a monoclonal antibody against human epidermal growth factor receptor 2 (HER2; also known as ERBB2), was investigated in combination with chemotherapy for first-line treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer...Median follow-up was 18.6 months (IQR 11-25) in the trastuzumab plus chemotherapy group and 17.1 months (9-25) in the chemotherapy alone group. Median overall survival was 13.8 months (95% CI 12-16) in those assigned to trastuzumab plus chemotherapy compared with 11.1 months (10-13) in those assigned to chemotherapy alone (hazard ratio 0.74; 95% CI 0.60-0.91; p=0.0046).

...The proportion of HER2 overexpression in gastric cancer patients...

...- Histologically confirmed HER2/neu-overexpressing (2+ or 3+) malignancy by any standardized assay (fluorescence in-situ hybridization allowed)...

...- HER2 positive tumors (primary or metastatic) with overexpression HER2 determinated by IHQ +++ (IHQ3+) o IHQ ++ confirmed by FISH/SISH positive (IHQ2+/FISH+)...

...Patients with cancers overexpressing HER2 by Immunohistochemistry test( IHC) 3+ and/or IHC 2+ with positive gene amplification by FISH (confirmation on archived tissue needed) 3....

...- Patients must have a histologically proven Her2 overexpressing malignancy as determined by any standardized assay currently in clinical use...

...HER2 overexpression and/or amplification as determined by immunohistochemistry (3+) or FISH (≥2.0)...

...Age > 18 years (ethnical group: any; gender: female and male) Progression under or after one prior platinum-based or 5-fluoropyrimidine-based chemotherapy in metastatic disease At least four weeks from the last platinum-based or 5-fluoropyrimidin-based chemotherapy Histological proof of gastric adenocarcinoma including adenocarcinoma of the gastroesophageal junction with HER2 overexpression of the primary or metastatic tumor tissue determined by immunohistochemistry and FISH (Score IHC 3+ or Score IHC 2+ and FISH +) Metastatic (M1) or locally advanced disease At least one measurable lesion evaluable for response (RECIST criteria) Estimated life expectancy of > 3 months ECOG Performance Status: 0-2 Adequate cardiac function: LVEF > 50% (detected by echocardiogram) Absolute neutrophil count > 1,500/µl Absolute platelet count > 100,000 /µl Serum total bilirubin: < 2.0 x upper normal limit (UNL) Creatinine < 1.5 x UNL AST and ALT < 2.5 x UNL; < 5 x UNL in patients with documented liver metastases Alkaline phosphatase: < 2.5 UNL Negative pregnancy test Willingness to give written informed consent, written consent for data protection and willingness to participate and comply with the study...

...- HER2 overexpression (IHC [2+] or [3+])....

...9 (30%) harbored HER2 mutation/overexpression (received RC48-ADC or trastuzumab, cohort B)…In cohort B, ORR was 44% (4/9), DCR was 78% (7/9), mPFS and mOS was 3.1 months and 5.5 months, respectively.