Perfil epidemiológico e expressão de HER2 em pacientes com carcinoma gástrico atendidos em dois centros de referência na cidade de Manaus-AM

Abstract

Introduction: The gastric cancer has been considered the second leading cause of cancer mortality in the world and the fourth most common cause of malignant tumors diagnosed each year. In northern Brazil, gastric cancer has higher incidence compared than other regions of the country. Many studies of the HER2 protein are intended to improve the overall survival of gastric cancer patients, especially in advanced stages, as this protein acts as an oncogene and its overexpression is related to malignant transformation. Since the advent of adjuvant therapy for HER2 positive for breast cancer, the interest in the use of trastuzumab in gastric cancer patients has increased. However, the lack of profile patients information for that biomarker in northern Brazil, including the Amazonas state, makes it difficult even more. The importance of performing studies on the expression of HER2 is confirmed as regional incidence rates exceed the national gastric cancer rates annually. Objective: The aim of this study is to characterize the epidemiological profile of patients in Manaus-AM reference centers, with endoscopic diagnosis of gastric cancer, and verifying HER2 expression. Methods: It was a prospective study to evaluate the epidemiological profile gastric carcinoma’s pacients, submitted to radical or palliative gastrectomy, and those not eligible for surgical resection. After filling out the form, reviewing histological findings of the biopsy with diagnosis of gastric carcinoma in previously collected materials, and the investigation of HER2 expression were performed. This was performed by immunohistochemical method (IHC), using the anti-HER2/neu kit (4B5), with interpretation according to Hofmann’s criteria. Patients who underwent surgical resection during the development of the study, the surgical specimen was processed for macro and microscopic evaluations, and tissue selection for HER2. Results: In the period of April 2016 to June 2017, 59 patients were included in the project. Among them, 71.19% were males, 61.02% were under 65 years old, ranging from 26 to 85 years. On endoscopic examination, 74.58% of lesions were at antrum, and 45.76% of patients presented Borrmann III lesion and 37.29%, Borrmann IV lesion, 47.46% of the patients were submitted to surgical resection and 66.10% were staging IV. The overexpression of HER2 were investigated by IHC in 26 samples of gastric resection, with a rate of 11.54%. Conclusions: In this group of patients, gastric carcinoma was more frequent in male patients, Lauren's intestinal type, in the antrum topography, older than 65 years, with presence of lymph node metastasis, and with advanced stage. The overexpression of HER2 was 11.54% in the gastrectomy samples. The results obtained in this study is relevant for the development of future researches, with the purpose of improving the treatment and patient survival with gastric cancer in the northern region of Brazil, and especially in the state of Amazonas.