Expression And Significance Of Syncytin-1 In Endometrioid Carcinoma Tissue With Different Degree Of Differentiation

Background and objectiveEndometrial carcinoma(EC)is the most common tumor in women in developed countries,second only to breast cancer,lung cancer and colorectal cancer.Endometrioid carcinoma is the most common pathological type of endometrial cancer,which is related to the increase of estrogen.The first choice of treatment is surgery,and the prognosis is good.However,patients with higher pathological stages,such as stage Ⅲ or Ⅳ,have a worse prognosis.At present,it is generally believed that the pathological stage of surgery,the degree of tumor differentiation,the depth of myometrial invasion,and lymph node metastasis affect the prognosis of patients with endometrioid cancer.The Cancer Genome Atlas(TCGA)divides endometrial cancer into four types:POLE mutant,MSI hypermutation,low copy number,and high copy number.This classification method can better predict the five-year survival rate of patients with endometrioid cancer,but its cumbersome operation and high price are not suitable for widespread clinical use.We currently need to understand the underlying mechanism of endometrioid cancer occurrence and recurrence,discover new predictive biological markers to evaluat patient prognosis,improve the survival rate of endometrioid cancer,and improve the prognosis.Syncytin-1 is a member of the human endogenous retrovirus W gene family(HERVW1).It is highly expressed in human placental tissue and plays an important role during pregnancy.Its main function is to promote cell fusion and immunosuppression.Studies have found that syncytin-1 can be expressed in a variety of different tumor tissues,and its main role is related to the prognosis of tumors.In most tumors,the expression of syncytin-1 is positively correlated with the prognosis of the tumor.The more protein expression,the worse the prognosis.We found that syncytin-1 is highly expressed in endometrial carcinoma,but its specific expression in endometrioid carcinoma has not been reported.In this study,immunohistochemistry(IHC)was adopted to investigated the expression of syncytin-1 in normal endometrial tissues and diferently differentiated endometrioid carcinoma tissues,to study its relationship with clinicopathological parameters,and to explore the expression intensity of syncytin-1 significance in endometrioid carcinoma tissues of varying degrees of differentiation.Methods1.A total of 159 cases of endometrioid carcinoma admitted to the First Affiliated Hospital of Zhengzhou University from January 2014 to December 2019 and pathologically diagnosed by laparoscopic hysterectomy were collected.The age of these patients is from 23 to 73 years old,with 54.4 being the mean figure.From January 2018 to December 2019,31 cases of uterine leiomyoma underwent hysterectomy and pathologically diagnosed as normal endometrial cases were collected.The age of these patients is from 29 to 55 years old,with 43.8 being the mean figure2.Use IHC to detect the protein expression of syncytin-1 in normal endometrium and endometrioid carcinoma with different degrees of differentiation.3.Use SPSS 22.0 software for statistical analysis.The data of count types are represented by frequency,rate and cross-tabulation,and the comparison between groups is performed by χ2 test.For survival time and survival status,I used Kaplan-Meier method to calculate survival analysis,then Log-rank test was adopted to compare the difference in overall survival rate between the two groups;Cox proportional hazard regression model was used to analyze influencing factors.The test level a is 0.05,and P<0.05 means the difference is statistically significant.Result1.Syncytin-1 was highly expressed in 2 cases(6.1%)of 31 normal endometrium tissues and 123 cases(77.4%)of 159 endometrioid carcinoma tissues(χ2=61.148,P<0.05),the difference was statistically significant.2.The percentages of syncytin-1 expression intensity of "3+" in endometrioid carcinomas of different levels of differentiation were 5.6%(highly differentiated),40.4%(moderately differentiated),and 62.3%(poorly differentiated).The differences were statistically significant(P<0.05).3.Infiltration of the muscle wall depth(r=0.487,P<0.05),degree of differentiation(r=0.616,P<0.05),FIGO staging(r=0.520,P<0.05),lymph node metastasis(r=0.439,P<0.05)and The expression intensity of syncytin-1 was significantly positively correlated;Lympho-vascular space involvement(LVSL)(r=0.190,P=0.054)was weakly positively correlated with the expression intensity of syncytin-1;Age(r=-0.070,P>0.05),menopausal status(r=0.019,P>0.05)has no correlation with the expression intensity of syncytin-1.4.Kaplan-Meier survival analysis showed that the depth of infiltrated muscle wall,the degree of differentiation,FIGO stage,lymph node metastasis,and the expression intensity of syncytin-1 had significant effects on the prognosis of patients.Average survival time of the patiens with infiltrating muscular wall depth(1/2)or higher,differentiation(low differentiation),stage(phase Ⅲ+Ⅳ),lymph node metastasis(with),express strength of syncytin-1(3+)is significantly shorter than that with infiltrating muscular wall depth(<1/2),differentiated(high differentiation),stage(phase 1),lymph node metastasis(no),express strength of syncytin-1(1+)(P<0.05).5.COX univariate regression analysis showed that age,menopause,and LVSI are not factors influencing the prognosis of endometrioid carcinoma(P>0.05);Depth of infiltrating muscle wall(HR=6.742,P=0.001<0.05),differentiation degree(P=0.002<0.05),FIGO staging(P=0.00<0.05),lymph node metastasis(HR=20.859,P=0.000<0.05),syncytin-1(P-0.001<0.05)were the prognosis of endometrioid carcinoma risk factors.6.COX multivariate regression analysis showed that differentiation was an independent risk factor for prognosis,poorly differentiated versus well differentiated as an independent risk factor for the prognosis of endometrioid carcinoma(HR=18.077,P=0.023<0.05);FIGO staging was an independent prognostic risk factor,of which stage Ⅲ+Ⅳ relative to stage I was an independent risk factor for the prognosis of endometrioid cancer(HR=17.178,P=0.009<0.05);lymph node metastasis was an independent risk factor for prognosis(HR=5.083,P=0.022<0.05).ConclusionThe expression intensity of syncytin-1 is different in endometrioid carcinomas of different levels of differentiation.Syncytin-1 can be used as a biological indicator to predict the prognosis of patients with endometrioid carcinoma,but the prognosis of endometrioid carcinoma needs to be combined with the degree of differentiation,FIGO staging,lymph node metastasis etc.clinicopathological parameters to be evaluated.