Clinicopathological, Epigenetics And Her-2 Gene Study Of Type Ⅰ And Type Ⅱ Endometrial Cancer

Endometrial cancer(EC)is one of the most common gynecological malignancies. Two different clinicopathologic subtypes are recognized:the estrogen-related(typeⅠ, endometrioid) and the non-estrogen-related types(typeⅡ,nonendometrioid such as papillary serous and clear cell).Although recent studies have revealed several molecular differences in these two types of endometrial cancer,there are still many mechanisms remained unclear.Therefore,further research was needed to divide new molecular subtypes and find the mechanisms of the aggressive typeⅡendometrial cancer,more molecular biomarkers are urged needed.The current research project is comprised of the following three parts.PartⅠ.Clinicopathological Characteristics of TypeⅠand TypeⅡEndometrial CancerObjectives:To study the different clinicopathological characteristics and prognostic factors of typeⅠand typeⅡendometrial cancer.Methods:Five hundreds and sixty-three patients with endometrial cancer were treated in our hospital between January,1996 and December,2006.The clinico-pathologic characteristics,treatment and prognosis were retrospectively analyzed.Results:563 patients included 503(89.3%) typeⅠcases and 60(10.7%) typeⅡcases.Mean age of typeⅠand typeⅡpatients was 55 and 63,respectively.In typeⅠpatients,the early stage(stageⅠ～Ⅱ) accounted for 81.1%,while late stage(stageⅢ～Ⅳ) only accounted for 18.9%.In typeⅡcases,the early stage and late stage accounted for 55%and 45%,respectively.For typeⅠpatients,82.5%tumors were G1～2 differentiation and 78.3%invaded less than half myometrium,while for typeⅡcases,65%were G3 and 43.3%invaded more than half myometrium.Mean follow-up duration was 33 months.During follow-up,48 cases died.The 3-year overall survival (OS) for typeⅠand typeⅡpatients was 92.1%and 56.5%,and the 5-year OS was 91%and 46.8%,respectively(P＜0.01).The 3-year disease free survival(DFS) for typeⅠand typeⅡpatients was 91.6%and 62.5%,and the 5-year OS was 89.5%and 56.5%,respectively(P＜0.01).In univariate analysis,FIGO stages,myometrial invasion,tumor cell differentiation,Body-mass Index,menopause,lymph-vascular space invasion were significant for typeⅠpatients(P＜0.05),with only FIGO stages, myometrial invasion and lymph node metastasis significant for typeⅡpatients (P＜0.05).In multivariate analysis,FIGO stages,myometrial invasion and tumor cell differentiation were found to be associated with poor prognoses for typeⅠand FIGO stages for typeⅡpatients,and considered as independent prognostic factors for them, respectively(P＜0.05).Conclusion:Patients with typeⅡendometrial cancer,compared with typeⅠcases, were much older,with more advanced stage,poorer differentiation,more LVSI and deeper myometrial invasion.Therefore,the rate of recurrence and metastases were higher for typeⅡpatients than typeⅠ.Since typeⅡendometrial cancer was very aggressive and had a rather poor prognosis,more attention and postoperative treatment should be given to improve their prognoses。PartⅡ.DNA Hypermethylation of Wnt pathway-related genes in TypeⅠand TypeⅡEndometrial CancerObjectives:To investigate promoter methylation status of WIF-1,E-cadherin and PTEN genes and protein expression of E-cadherin,PTEN andβ-cateninin in endometrial cancer,and to discuss the different molecular characters of typeⅠand typeⅡendometrial cancer.Medthods:Methylation-specific PCR(MSP) was performed to detect the promoter methylation status of WIF-1,E-cadherin and PTEN genes in 105 endometrial cancer and 46 paired normal endometrium,with immunohistochemistry (IHC) to detect protein expression of E-cadherin,PTEN andβ-cateninin genes. Results:105 patients included 81 typeⅠand 24 typeⅡcases,with median age of 57.The frequency of promoter methylation of WIF-1,E-cadherin and PTEN genes was 26.7%(28/105),27.6%(29/105)and 18.1%(19/105),respectively.The methylation frequency of endometrial tissues was higher than that of corresponding normal tissues(P＜0.05).E-cadherin promoter hypermethylation was associated with pathological subtypes(typeⅠand typeⅡEC),WIF-1 promoter methylation was correlated with FIGO stage,and PTEN promoter methylation was correlated with p53 expression(P＜0.05).Reduced E-cadherin expression was observed in 60.0% (63/105) of the cases,being more frequent in typeⅡcases,more advanced stage and carcinomas of deep myometrial invasion(P＜0.05).Abnormalβ-catenin expression was observed in 29.5%(31/105) of the cases,being more frequent in typeⅠEC(P＜0.05).In univariate analysis,patients with WIF-1 promoter methylation, E-cadherin promoter hypermethylation,and reduced PTEN expression were associated with worse prognoses in typeⅠpatients and reduced E-cadherin expression associated with worse prognoses in typeⅡpatients(P＜0.05).Conclusions:There were different molecular charcaters between typeⅠand typeⅡEC,including more E-cadherin promoter hypermethylation and reduced E-cadherin expression in typeⅡand more abnormalβ-catenin expression in typeⅠ.Promoter hypermethylation was one of the important mechanisms of gene silence.WIF-1 promoter methylation,E-cadherin promoter hypermethylation,reduced PTEN expression and reduced E-cadherin expression were associated with worse prognoses for patients with typeⅠand typeⅡEC,respectively.PartⅢ,Clinical Significance of Her-2/neu Status in Patients with Uterine Papillary Serous CarcinomaObjectives:Uterine papillary serous carcinoma(UPSC) is a highly aggressive subtype of endometrial cancer.It is characterized by early metastasis,resistance to therapy,and a high mortality rate.The purpose of this study was to evaluate gene amplification by chromogenic in situ hybridization(CISH) and the protein expression of Her-2/neu gene in Asian patients with UPSC and to determine its prognostic value.Methods:Thirty-six patients with confirmed pathologic diagnosis of UPSC in Cancer Hospital of Fudan University from 1/1/1996 to 1/1/2006 were analysed retrospectively.Chromogenic in situ hybridization(CISH) was performed to assess Her-2/neu gene amplification,and protein expression was evaluated by immunohistochemistry(IHC).Results:In 36 cases with UPSC,13 patients(36.1%) showed moderate staining (2+) to strong staining(3+) for Her-2/neu protein,with 10 patients 2+ and 3 patients 3+.Amplification of the Her-2/neu gene by CISH was observed in 4 of the 36(11.1%) cases.Her-2/neu protein overexpression was significantly associated with advanced surgical stage and worse overall survival(P=0.015 and P=0.0093,respectively).Conclusion:Her-2/neu protein overexpression was significantly associated with advanced surgical stage UPSC and poor survival outcome.CISH analysis is a convenient method used for confirmation of gene amplification in UPSC.Herceptin might be considered as an attractive therapy in the clinical management of patients with chemotherapy-resistant,recurrent,or metastatic UPSC.