The Study Of Latent Precancer In Endometrial Serous Carcinoma And Its Application

Endometrial serous carcinomas(ESC) constitute only approximately 10%of endometrial cancers,but have a substantially higher case-fatality rate than their more common endometrioid counterparts.The precise composite of factors driving endometrial serous carcinogenesis and progression remain largely unknown.ESC probably do not evolve through a single pathway,and their underlying molecular events probably occur early in their evolution,p53 gene mutations occur in 22.7 to 96%of cases,and p53 protein overexpression is seen in approximately 76%. At the morphologic level,evidence that indicates that endometrial glandular dysplasia (EmGD) is the most likely morphologically recognizable precursor lesion to ESC is presented.We advocate use of the term endometrial intraepithelial carcinoma(EIC,or its other appellations) only as a morphologic descriptor and never as a diagnostic/ pathologic statement of biologic potential.Given its potential for extrauterine extension,we consider the lesions described as EIC,when present in isolation,as examples of localized ESC,and patients should be managed as such.Morphologically normal,p53 immunoreactive endometrial cells(the so-called "p53 signatures"),show a statistically significant association with ESC,display p53 mutations in a significant subset,and form the start of a progression model,outlined herein,from p53 signatures to EmGD to localized ESC to the more conventionally invasive neoplasm.The identification of a morphologically-recognizable precursor holds the promise of early detection of ESC,with the attendant reduction in its overall associated mortality rate. Deciphering the molecular basis for endometrial serous carcinogenesis should uncover potential targets for diagnosis,therapy,and/or disease surveillance.The improvement of cervical cytological examination made a great progress in treatment and prevention of cervical cancer.While the diagnosis of endometrial disease still based on fractional curettage by now.And there is no method can be used for the screening.The endometrial cytology developed quickly recently.And if we combine the p53 signature detection with the endometrial cytology,we could uncover potential targets for diagnosis,therapy,and/or disease surveillance.Based on the reasons above,the project included two parts:PartⅠThe Study of p53 Signature in Endometrial Serous CarcinomaBackground and Purpose:Endometrial serous carcinoma(ESC) represents one of the most aggressive human cancers.Alteration of p53 occurs not only in well developed ESC,but also in its early form(endometrial intraepithelial carcinoma,EIC) and precancerous form(endometrial glandular dysplasia,EmGD).We have recently identified a group of benign appearing endometrial epithelia with diffuse p53 nuclear staining,which was designated as p53 signature.In this study,we investigated and characterized the endometrial correlate of these p53 signatures and evaluated the possibility of their being "latent" precursors for endometrial serous carcinoma(ESC).Materials and Methods:Immunohistochemistry was used to identify p53 signatures in 182 hysterectomy specimens(60 ESC as study group,60 endometrioid carcinoma and 60 benign uteri as controls).Laser capture microdissection and subsequent DNA sequence analysis for p53 gene were performed in a total of 126 informative samples including 38 p53 signatures and varies samples from serous lesions and controls.Results:The p53 signatures were specifically associated with ESC,being frequently found in the benign-appearing endometrium adjacent to ESC and only rarely in the endometrium adjacent to endometrioid carcinomas or in non-cancerous uteri. Forty-two percent of the p53 signature samples showed at least one p53 gene mutation. There were 8 ESC uteri with p53 signatures showing p53 gene mutations.In 4(50%) of these cases,at least one identical p53 gene mutation was found in signature glands, precancers and cancerous areas within the same uterus.Conclusions:p53 gene mutations apparently precede the morphologic changes in the affected endometrial cells.The finding of identical p53 mutations in the p53 signatures,precancers and ESC in a subset of the uteri provides further evidence of a probable shared lineage between these lesions,and suggests that the epithelia displaying these p53 signatures are likely latent precancers of ESC.These findings underline the significance of p53 signature as a target for further research in the early detection and prevention of ESC.PartⅡThe Pilot Study of p53 in Endometrial Serous Carcinoma ScreeningBackground and purpose:The incidence of endometrial carcinoma increased quickly in recent years.It accounts for 20%～30%of all the female genital malignant carcinoma.Endometrial serous carcinomas(ESC) constitute only approximately 10% of endometrial cancers,but have a substantially higher case-fatality rate than their more common endometrioid counterparts.By now,the method of endometrial cytology examination was widely accepted by researchers and doctors.Since p53 signature is closely related to ESC,we combine it with endometrial cytology and try to find a more accuracy method for endometrial disease screening. Materials and Methods:We use the SPEC-2 cell line as the p53 positive cells and the Ishikawa cell line as the negative one.When the two cell lines are mix up with different ratio,we use Western Blot and ELISA to detect the p53 protein and record the threshold value.Then try to detect the p53 expression in the endometrial sample by using the endometrial sampling device.Results:The minimum number of SPEC-2 cells which could be detected by Western Blot is 1～2×10~4.When mixed SPEC-2 and Ishikawa cells together,the ratio could be 1:100 when use the method of Western Blot.And we found that ELISA is too sensitive to test the mixed cells.Conclusions:Combine the endometrial cytology with p53 signature is a practical, easily operates,safer,less bleeding and painless method to detect the early form of the endometrial serous carcinoma.But enormous work need to be done to find a more accurate method and make it widely used for clinic and large scale screening, especially for the regular screening of the high risk population.