Immunohistochemical Expression of Her2 in Adenocarcinoma of the Stomach

Abstract

-Background -Worldwide, gastric cancer is the fourth cancer in incidence and the second most common cause of cancer death. Gastric cancer is asymptomatic in the early stages and very often diagnosed at advanced stages, determining a dismal prognosis. Expression of the HER2 gene has been identified in about 20% of gastric cancer cases, and its hyper-expression is associated with poor prognosis. Objective -To investigate HER2 immunohistochemical expression in gastric adenocarcinoma and its relationship to the histological type and anatomic location. Methods -A cross-sectional retrospective study analyzed the immunohistochemical expression of HER2 in a sample of 48 specimens of gastric cancer. Immunohistochemical analysis were performed using avidin-biotin-peroxidase method with C-erb B2 (clone EP1045Y), as a primary antibody (Biocare Medical, USA). Standardized gastric adenocarcinoma's HER2 expression criteria has been used in the analysis of samples. Results -There were seven cases with reactivity for HER2. Five were of intestinal-type while two cases were of mixed-type in which the expression occurred in the intestinal component. It was identified a significant association of HER2 expression in the intestinal subtype of gastric adenocarcinoma (P=0.003).Regarding the anatomical site, HER2 was positive in only one (16.6%) of the six proximal cases and six (14.28%) of the 42 distal cases (P=0.88). Conclusion -HER2 immunoexpression was identified in 14.6% of the samples, and the expression was significantly associated to Lauren's intestinal subtype. HEADINGS -Immunohistochemistry. Stomach neoplasms. erbB-2 genes.

Association between HER2 status in gastric cancer and clinicopathological features: a retrospective study using whole-tissue sections

“…However, the grading score for breast cancer was used for HER2 status assessment, in which the entire cell membrane should be stained, and not only lateral or basolateral walls, which suggests underestimation of HER2 positivity. In more recent research using specific HER2 scoring criteria for GC, IHC 3+ cases ranged from 0.8 % to 11.6 % [ 19 – 22 , 25 , 26 ]. Studies showing the lowest rates (0.8 %, 3 % and 6 %) used tumor tissue microarrays (TMAs) obtained from surgical specimens and other anti-HER2 antibodies rather than 4B5 [ 19 , 20 , 22 ].…”

“…A large systematic review including data from 49 studies found a median rate of 18 % of HER2 positivity in 11,337 patients with GC [ 18 ]. Nevertheless, the prevalence of HER2-positive cases among Brazilian patients remains unknown, with few data published [ 19 – 26 ]. Since the Brazilian public health system has not yet endorsed the use of TZB for GC treatment in this country, we believe that the detection of HER2-positive GC in Brazilian patients may provide scientific basis for the establishment of new public health policies and define better clinical protocols to improve treatment of these patients in Brazil.…”

HER2 protein expression correlates with Lauren classification and P53 in gastric cancer patients

“…Such nding is similar to those of various other studies from American and European researchers who have reported gastric cancer HER2 protein positive rates ranging from 10 to 22.8% 4,5 . However, some Asian studies have reported rates ranging from 11.7 to 15.74% 14,19,20 . The importance of the HER2 protein status in GC remains controversial and more and more researchers are studying the signi cance of HER2 protein expression in GC.…”

“…Also, in such studies the HER2 protein expression status was measured by immunohistochemistry (IHC) and the (normal, deletion or ampli cation) status was evaluated by uorescence in situ hybridization (FISH) analysis; those patients with IHC 3+ or IHC grade 2+ and FISH+ were considered HER2 protein overexpression. Recently, several studies reported the clinical characteristics and prognosis relating with HER2 protein overexpression in GCs 2,13,14 . However, the conclusions drawn from such studies were varied.…”

Analysis of Prognostic Factors and Design of Prognosis Model for Patients with Stage IV Gastric Cancer Following First-Line Palliative Chemotherapy

“…Although trastuzumab in combination with chemotherapy can prolong the survival of patients with HER2-positive advanced gastric cancer, 3–5 several studies show that the HER2-positive rate of gastric cancer patients in China is only around 12%–13%. 6 , 7 The role of chemotherapy is still of paramount importance in treatment of HER2-negative gastric cancer. In a sense, chemotherapy can prolong the survival time and improve the life quality of these patients, 8 but the response rate of first-line chemotherapy for advanced gastric cancer patients is no more than 50%, and the median overall survival (mOS) is about 13 to 16 months, 9 , 10 which is not expected in the clinical setting.…”