Case Report Importance of HER2 Work-Up and Treatment Even in Patients with Poor Performance Status: A Case Report Ali Suner, 1 Hakan Buyukhatipoglu, 1 Ozan Balakan, 1 Mehmet Emin Kalender, 1 Turgay Ulas, 2 Alper Sevinc, 1 and Celalettin Camci 1 1 Department of Medical Oncology, School of Medicine, Gaziantep University, Kilis Yolu Uzeri, 27310 Gaziantep, Turkey 2 Depatment of Internal Medicine, Harran University School of Medicine, Sanliurfa, Turkey Correspondence should be addressed to Hakan Buyukhatipoglu; buyukhatipoglu@gmail.com Received 21 February 2014; Accepted 31 March 2014; Published 13 April 2014 Academic Editor: Sercan Aksoy Copyright © 2014 Ali Suner et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Gastric cancer is one of most common types of cancers. Metastatic gastric cancer has a poor prognosis and is accepted as incurable at this stage. Treatment of metastatic gastric cancer did not progress substantially until new targeted agents have come out. Recently published ToGA trial showed promising results in HER2 overexpressing metastatic gastric cancer. In this case we present a case with an excellent complete response with anti-HER2 treatment. Most importantly, we wanted to emphasize (1) the importance of early determination of HER2 overexpression, and (2) to draw attention of anti-HER2 agents in the frst line treatment even in patients with a poor performance status. 1. Introduction In USA, through the year 2014 approximately 22000 new gastric cancers and 11000 gastric cancer-related deaths have been expected [1]. In the past 10 years a signifcant decreasing trend has been observed in gastric cancer incidence and mortality rates especially in US and European countries [2]. Te most important prognostic factor is tumor stage in gastric cancer; however, most of the patients are diagnosed either in inoperable locally advanced stage or in metastatic stage [3, 4]. Te 5-year overall survival is 5 to 20%, and median survival time is less than 1 year in these groups [5]. Meta-analyses of several randomized trials demonstrated that combination treatments yielded better results than single agent chemotherapy and best supportive care [6]. While fuoropyrimidine based regimens—either or not combined with platinum—have been widely used in frst step treatment, taxanes and irinotecan have been used in later steps [7]. Even combination treatments beneft and prognosis of advanced stage gastric and gastroesophageal cancers are still not good; hence less toxic new therapies are needed. Human epidermal growth factor receptor 2 (HER2, CerbB2) is a well-defned target for new treatments. It is overexpressed in 7 to 34% of gastric cancers [8]. Te beneft of trastuzumab in advanced gastric or gastroesophageal cancer was addressed in trastuzumab for gastric cancer (ToGA) trial. According to ToGA trial the overall survival beneft was 2.7 months (11.1 months in chemotherapy arm and 13.8 months in chemotherapy + trastuzumab arm), which was statistically signifcant [9]. In this paper we present a case of metastatic gastric cancer that showed excellent response under trastuzumab, despite poor prognostic factors and the advanced stage he had. 2. Case Report A 35-year-old male patient was referred to our medical oncology department with a gastric tumor that surrounded the gastric cardia leading to partial obstruction. Endoscopic biopsy result was adenocarcinoma. Afer screening for stag- ing, the patient was found to have multiple lung and hepatic metastases (Figures 1(a) and 1(d); Figures 2(a) and 2(d)). According to Eastern cooperative oncology group (ECOG) his performance status was 3. His pathology specimens that were reevaluated for HER2 overexpression were both positive with immunohistochemistry and fsh staining. Terefore, Hindawi Publishing Corporation Case Reports in Oncological Medicine Volume 2014, Article ID 731581, 4 pages http://dx.doi.org/10.1155/2014/731581