Study On Expression Of EGFR And IGF1R,EGFR Gene Mutation And Clinical Significance In Thymoma

This topic collected 63 cases of thymoma specimens, including male 39, female 24, age 22 to 73 years old, the average age is 48 years old. HE staining paraffin sections were read and determined histological types by two experiented pathologists respectively. According to WHO histological type: 10 cases of type A, 3 cases of type AB, 5 cases of type B1, 23 cases of type B2, 22 cases of type B3. According to Masaoka stage:Ⅰin 13 cases, Ⅱin 26 cases, Ⅲ in 17 cases, Ⅳ in 7 cases.Take 15 cases of thymus follicular hyperplasia tissues as a control group, 6 cases of male, 9 cases of female, age 30-73 years old, mean age is 47 years old. Immunohistochemistry(IHC)technique was used to detect the protein expression of EGFR and IGF1 R in thymoma tissue and thymus follicular hyperplasia tissue. The gene mutations of EGFR was detected by using realtime fluorescent quantitative polymerase chain reaction(QPCR) in the experimental group and a control group. To study relationship between two factors and clinical pathological characteristics of thymoma and explore the correlation between two factors,from the perspective of clinical pathology revealed its roles and possible mechanisms in the occurrance and progression of the disease, to provide a reliable theoretical basis for clinical diagnosis, judging the degree of malignancy,the choice of treatment methods and so on.The positive expression rate of EGFR in thymus follicular hyperplasia tissue was 0(0/15) and the positive expression rate in thymoma tissue was 50.8%(32/63), the expression between two groups was statistically significant(P<0.01). The positive expression rate of IGF1 R in thymus follicular hyperplasia tissue was 20%(3/15) and the positive expression rate in thymoma tissue was 55.6%,(35/63), the expression between two groups was statistically significant(P<0.03).The positive expression rate of EGFR in type of A,AB, B1, B2,B3 was 60%(6/10, 33.3%(1/3), 20%(1/5), 43.5%(10/23), 63.6%(14/22)respectively. The positive expression differences between each subtype was not statistically significant(P>0.05); the positive expression rate of IGF1 R in each subtype of thymoma was 60%(6/10)、0(0/3)、80%(4/5)、60.9%(14/23)、50%(11/22)respectively. The positive expression differences between each subtype was not statistically significant(P>0.05).The expression of EGFR in the clinical stages of thymoma: the positive expression rate in stage ofⅠ,Ⅱ was 35.9%(14/39), the positive expression rate in stage of Ⅲ, Ⅳ was 75%(18/24), the positive expression was associated with Masaoka stage(P < 0.01); the expression of IGF1 R in the clinical stages of thymoma: the positive expression rate in stage ofⅠ,Ⅱ was 41.0%(16/39),, the positive expression rate in stage of Ⅲ, Ⅳ was 79.2%(19/24), the positive expression was associated with Masaoka stage(P < 0.01). The statistical analysis showed that the positive expressions of EGFR and IGF1 R were not correlated with the age, gender, tumor size, whether the merger of myasthenia gravis(P > 0.05). The protein positive expressions of EGFR and IGF1 R in thymoma group were positively correlated(r=0.270, P=032). EGFR gene mutations were not detected in thymoma group and thymus follicular hyperplasia group.The above results suggest,the high expression of EGFR and IGF1 R protein may play an important role in the occurrance and development of thymoma, and its expression level may reflect the staging of thymoma, and provide useful tools to predict the degree of tumor invasion. The expressions of EGFR and IGF1 R protein were not related with whether the merger of myasthenia gravis. The abnormal expression of two common impact production and progression of disease, combined detection contributes to improve the judgment of tumor malignant degree, formulate clinical reasonable treatments, and provide help to judge prognosis.