B32HER-2 in gastric cancer: a single institution experience

Gastric cancer is the fourth most common cancer disease worldwide and it's the second leading cause of cancer-related death. The study of HER-2 expression and the use of targeted agent trastuzumab have improved the prognosis of many patients. This abstract aims to show a casuistry of patients with gastric cancer related with their HER-2 expression. From May 2010 to November 2015 we observed 157 cases of patients with gastric cancer. Median age was 69,2 years (range 26,7-88 years), 116 were male and 41 were female. At diagnosis 19 patients had I stage disease, 15 patients II stage, 69 patients III stage and 54 patients were metastatic (IV stage). Globally we treated 84 metastatic patients. Among these HER-2 status was not assessable in 34,5% (n 29) because of Performance Status, comorbidities and age of patients. We tested 55 patients (65,5%): of these 72,7% were negative (n 40), 27,3% were positive (n 15). This percentage is higher than literature, maybe for the small number of patients of our casuistry. HER-2 expression was higher in intestinal-type cancer (8 of 23 patients, 34,8%). In relation of gastric site the highest percentage is in cardia (5 of 11 patients, 45,5%), the lowest in antrum (4 of 21, 19%). We treated with chemotherapy 30 of 40 patients HER-2 negative and with chemotherapy and trastuzumab 15 of 15 patients HER-2 positive. The chemotherapy regimen used for HER-2 positive patient were: cisplatin + 5-fluorouracil + trastuzumab (6 patients), weekly PFL (cisplatin, 5-fluorouracil, leucovorin) + trastuzumab (4 patients) and cisplatin + capecitabine + trastuzumab (5 patients). Among all treated patients, the Progression Free Survival was 3,4 months for HER-2 negative subgroup and 9,11 months for HER-2 positive. The Overall Survival was 7,7 months for HER-2 negative group and 13,7 months for HER-2 positives ones. It's interesting to notice that we are treating a young man 36 years old since 2011 with trastuzumab, without any signs of progression. This man has cardia carcinoma, intestinal-type, metastatic at adrenal gland and liver. These data, despite the little sample, confirm how the prognosis of HER-2 positive patients treated with trastuzumab is globally better than HER-2 negative, in agreement with literature.