HER2 Status and Its Heterogeneity in Gastric Carcinoma of Vietnamese Patient

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) is related to the pathogenesis and poor outcome of numerous types of carcinomas, including gastric carcinoma. Gastric cancer patients with HER2 positivity have become potential candidates for targeted therapy with trastuzumab. METHODS: We investigated 208 gastric cancer specimens using immunohistochemistry (IHC), fluorescence in situ hybridization and dual in situ hybridization (ISH). We also investigated the concordance between IHC and ISH. The correlation between HER2 status and various clinicopathological findings was also investigated. RESULTS: In total, 15.9% (33/208) and 24.5% (51/208) of gastric cancers showed HER2 gene amplification and protein overexpression, respectively. A high level of concordance between ISH and IHC analyses (91.3%, κ = 0.76) was found. A significant correlation between HER2 status and intestinal-type (p < .05) and differentiated carcinomas (p < .05) was also noted. The HER2 heterogeneity was high in gastric cancers; we found 68.8% phenotypic heterogeneity and 57.6% genotypic heterogeneity. Heterogeneity in HER2 protein expression and gene amplification showed a close association with diffuse histologic type and IHC 2+. CONCLUSIONS: HER2 protein overexpression and gene amplification were detected in 24.5% and 15.9% of gastric cancer specimens, respectively. Intestinal-type showed a higher level of HER2 protein overexpression and gene amplification than diffuse type. HER2 status also showed a significant relationship with well- and moderately-differentiated carcinomas. The ratio of phenotypic and genotypic heterogeneity of HER2 was high in gastric carcinomas and was associated with HER2 IHC 2+ and diffuse histologic type.

P53 and MDM2 overexpression in oral cancer in Vietnamese

The previous study detected 15/18 cases of oral squamous cell carcinoma expressing p53 positive immunostaining: 7/8 cases with p53 mutation and 8/10 cases without p53 mutation. In this study, immunohistochemical staining showed mdm2 overexpresion in 7/18 cases, combined p53/mdm2 overexpression in 6/18 cases, mdm2 overexpression in 5/8 p53-positive without mutation cases. These results indicated that p53 overexpression can be associated with p53 gene mutation, as well as mdm2 overexpression in the oral carcinogenensis

The alteration of p16 protein in invasive cervical cancer / 대한산부인과학회잡지

OBJECTIVE: Recently p16 gene has been found as a new factor for cervical carcinogenesis. The purpose of this study is to investigate the p16 protein alteration in invasive cervical cancers, and to find the correlation with the p53 protein overexpression, HPV infection and the clinicopathologic prognostic parameters, as well as to predict the prognosis by examining the influences of the p16 gene, p53 gene, HPV to the survival rate. MATERIAL & METHODS: We examined 29 invasive cervical cancer patients who visited and operated in Obstetrics & Gynecology department of Kosin University Gospel Hospital from Jan. 1994 to Dec. 1995. We investigated clinicopathologic parameters and p16 protein alteration, p53 protein overexpression, HPV 16, 18 infection in these patients. p16 protein and p53 protein were examined by immunohistochemistry method and HPV was done by PCR method. The survival rate was examined by Kaplan-Meier method. RESULTS: The rate of p16 protein alteration, p53 protein overexpression, HPV infection were respectively 31% (9/29), 72.4% (21/29), 80.6% (26/29), and all of these factors had no statistical correlations with the clinicopathologic parameters (p>0.05).Among the 21 positive cases for p53 protein overexpression, p16 protein alteration was positive in 6 (28.6%), negative in 15 (71.4%) cases and among the 8 negative cases for p53 overexpression, p16 showed positive in 3 (37.5%), negative in 5 (62.5%). Finally among the 26 positive cases of HPV infection, p16 alteration was positive in 9 (34.6%) and negative in 17 (65.4%) and all of the 3 HPV infection negative cases showed no p16 alteration. The p16 alteration had no significant correlation with the p53 overexpression and HPV infection.The total 5 years survival rate in 29 cases of invasive cervical cancer patients was 86.2%. In the negative group of p16 protein alteration the survival rate was 80% and the positive group was all alive. In the positive groups of p53 protein overexpression and HPV infection the survival rate were 80.9% and 84.6% respectively and the negative groups were all alive. And these factors had no significant correlation with the survival rates. CONCLUSION: This results indicate that p16 protein alteration had no correlation with clinicopathologic prognostic parameters and survival rates in invasive cervical cancer. In addition p16 protein alteration had no correlation with p53 protein overexpression and HPV infection respectively.