Immunohistochemical profile of endometrial adenocarcinoma: a study of 61 cases and review of the literature

p53, estrogen and progesterone receptors in diagnostic curettage for endometrial adenocarcinoma and their correlation with morphological data and disease stage at hysterectomy

CONTEXT

Diagnostic staging is an important prognostic factor for endometrial adenocarcinoma. Apart from the histological type and histological grade, some markers seem to be associated with the stage and biological behavior of the disease. Among these are p53, estrogen and progesterone receptors.

OBJECTIVE

The objectives of the present study were: to compare histological type and grading of endometrial carcinoma in curettage and hysterectomy samples; to assess expression of p53, estrogen and progesterone receptors in curettage specimens; and to correlate these data with morphology and staging of the disease in hysterectomy specimens.

TYPE OF STUDY

Retrospective.

SETTING

Department of Pathology, Faculdade de Ciências Médicas, Universidade Estadual de Campinas.

SAMPLE

Histological diagnosis from 51 consecutive files.

PROCEDURES

Immunohistochemical reactions for p53, estrogen and progesterone receptors via the avidin-biotin-peroxidase method in 51 curettage samples endometrial carcinoma were compared with the morphological data and disease stage in hysterectomy. Marker expression was correlated with histological type and grade and the final stage of the disease.

RESULTS

According to the histological type: 44 cases (86%) were of endometrioid and 7 (14%) non-endometrioid carcinoma. p53 expression was observed in 16% of endometrioid and 71% of non-endometrioid cases (p<0.05). Although estrogen expression was more evident in endometrioid (54%) than non-endometrioid cases (29%), this was not statistically significant. Progesterone receptor expression was significantly higher in endometrioid than non-endometrioid cases (70% vs. 14%, p<0.05). According to the histological grade: Estrogen and progesterone receptors were expressed more frequently in grade I endometrioid carcinoma, while p53 was mainly reported in tumor grades II and III. According to final disease stage: p53 and estrogen expression in curettage specimens was not related to stage; progesterone receptors, however, were expressed significantly less in advanced disease.

CONCLUSION

p53 was observed in the majority of non-endometrioid and in high-grade endometrioid carcinoma, but was not related to stage. Estrogen and progesterone receptors were mainly found in grade I endometrioid carcinoma. The markers studied in curettage were no more valuable for predicting the disease stage than classical histological criteria.

Hypermethylation can selectively silence multiple promoters of steroid receptors in cancers

Multiple promoters and differential splicing of 5' upstream exons are often found in various nuclear receptor genes including steroid receptors. Three promoters control the expression of human estrogen receptor alpha (ERalpha) isoforms: ERalpha-A, ERalpha-B, and ERalpha-C, and two promoters control the expression of human progesterone receptor (PR) isoforms: PR-A and PR-B. The expression levels of these isoforms differ with respect to each other in certain target tissues. The role of these isoforms may differ in various types of cells and tissues. The ER and PR contain CpG islands in the 5' upstream regions. One possible mechanism for changing the transcriptional status is methylation of CpG-enriched regions in these isoforms. We have investigated the expression and methylation status of the three different ERalpha promoters and the two different PR gene promoters by using methylation specific PCR (MSP) and direct DNA sequencing in several endometrial and prostate cancer cell lines and tissues. The results of these experiments suggest that ERalpha-A, ERalpha-B, and PR-A were expressed and ERalpha-C and PR-B were inactivated in endometrial cancers. To the contrary, ERalpha-A and ERalpha-B were inactivated and ERalpha-C, PR-A and PR-B were expressed in all prostate cancer. Treatment with demethylating agent (5-aza-2'-deoxycytidine) restored these gene expressions, suggesting that inactivation of this gene is through methylation. Our MSP and direct DNA sequencing showed that ERalpha-A, ERalpha-B, and PR-A genes were unmethylated and ERalpha-C and PR-B were methylated in endometrial cancers although ERalpha-A and ERalpha-B were methylated and ERalpha-C, PRA and PRB were unmethylated in prostate cancers. These reports clearly demonstrate that selective hypermethylation can selectively silence multiple promoters of steroid receptors in carcinogenesis.

CYP1B1 gene in endometrial cancer

Metabolic activation of estradiol has been shown to be a key factor in endometrial carcinogenesis. 4-hydroxy estrogens (CYP1B1 metabolites) received particular attention because of their causative role in malignant transformation of various organs including endometrium. CYP1B1 displays the highest level of expression in endometrium. 4-hydroxy estrogens can bind to DNA via their quinone metabolites and cause oxidative damage in endometrial cancer. Moreover, the 4-hydroxy estrogens bind to the estrogen receptor and have estrogenic effects on target tissues. Six polymorphisms of the CYP1B1 gene have been described of which four result in amino acid substitutions; 1-13C-->T, codon 48C-->G, codon 119G-->T, codon 432C-->G, codon 449T-->C and codon 453A-->G. The polymorphisms on exons 2 and 3 have significant effects on the catalytic function of CYP1B1. Polymorphisms on specific regions of CYP1B1 gene result in hyperactivation of the protein and can lead to a higher susceptibility in the incidence of various cancers. Thus, inherited alterations in CYP1B1 hydroxylation activity may be associated with significant changes in estrogen metabolism and, thereby, may possibly explain inter-individual differences in endometrial cancer risk associated with estrogen-mediated carcinogenesis.

Apoptosis and apoptosis-related factors Bcl-2, Bax, tumor necrosis factor-alpha, and NF-kappaB in human endometrial hyperplasia and carcinoma

BACKGROUND

Apoptosis controls cell homeostasis in the endometrium during normal menstrual cycles, and morphologic studies have suggested its association with the development of endometrial carcinoma. Apoptosis is regulated by several genes, especially those of the Bcl-2 gene family, but their significance in endometrial pathologies is not well understood.

METHODS

To study the role and regulation of apoptosis in endometrial hyperplasia and carcinoma, human endometrial specimens were analyzed using in situ 3'-end labeling of apoptotic cells and in situ hybridization and immunohistochemistry of apoptosis-related factors.

RESULTS

Apoptosis was scarce in normal proliferating endometrium as well as in simplex, complex, and atypical hyperplasia and was low in Grade I adenocarcinoma. In Grade II adenocarcinoma a significant increase in the rate of apoptosis was observed. Apoptosis decreased in Grade III adenocarcinoma, but it was still higher than in normal or hyperplastic endometrium. Bcl-2 and Bax were expressed in normal and hyperplastic endometrium, and the Bcl-2/Bax ratio was lower in endometrial carcinoma. Tumor necrosis factor-alpha was expressed in normal endometrium and simplex and complex hyperplasia, but it was down-regulated in atypical hyperplasia and endometrial carcinoma. The transcription factor NF-kappaB was present in proliferating endometrium and in endometrial hyperplasia, but its expression was lower in carcinoma.

CONCLUSIONS

In endometrial proliferation and hyperplasia a low rate of apoptosis is present. In Grade I carcinoma the rate of apoptosis is decreased, but the rate is subsequently increased in advanced carcinoma. The decrease in the rate of apoptosis in Grade III adenocarcinoma may reflect loss of control of cell homeostasis, decreased differentiation, and increased malignancy.

Apoptosis-related proteins and steroid hormone receptors in normal, hyperplastic, and neoplastic endometrium

The purpose of this study was to evaluate the distribution and frequency of apoptosis-related proteins and their correlation with estrogen, progesterone, and androgen receptors in endometrial tissues. Immunohistochemical analyses of bcl-2, bax, bcl-x, and steroid receptors were performed in 22 endometrial carcinomas, 26 endometrial hyperplasias, and 19 cases of normal cyclical endometrium. Bcl-2 was expressed in 45.4% of carcinomas and 92.3% of hyperplasias. Bax immunostaining was found in 90.9% of carcinomas and 76.9% of hyperplasias. Bcl-x positivity was similar in carcinomas (68.1%) and endometrial hyperplasias (76.9%). In normal cyclical endometria, bcl-2 staining was intense and diffuse in the proliferative phase, but decreased dramatically in the early and mid-secretory phase to reappear in the late secretory phase. Bax was expressed throughout the menstrual cycle but more strongly in the secretory phase. Bcl-x displayed a similar degree of expression in proliferative and secretory endometria. Nineteen carcinomas (86.3%), 25 hyperplasias (96.1%), and 18 normal cyclical endometria (94.7%) were positive for estrogen receptor (ER). Progesterone receptor (PR) was observed in 20 carcinomas (90.9%), all hyperplasias (100%), and 18 normal cyclical endometria (94.7%). Androgen receptor (AR) positivity was seen in 7 carcinomas (31.8%), 6 hyperplasias (23.0%), and 3 normal cyclical endometria (15.7%). There was a statistically positive correlation between bcl-x and ER and a tendency toward significant correlation between bcl-x and PR and between ER and PR in carcinomas. In hyperplasias, there was a significant positive correlation between bcl-2 and PR and between bcl-2 and bax and a negative correlation between ER and bax. There was a statistically significant difference for bcl-2 (p = 0.001) and bax (p = 0.001) between the hyperplasia and carcinoma groups. There was increased expression of bax, decreased expression of bcl-2, and persistence of bcl-x protein in advanced endometrial carcinomas. Our findings show that ovarian hormones have a regulatory role on bcl-2 protein and that there is a correlation between other members of the bcl-2 family (bcl-x and bax) and steroid hormone receptors. Bax/bcl-x may be the major control mechanisms of apoptosis in advanced carcinomas; other members of the bcl-2 family may also be under hormonal control.

Endometrioid carcinoma of the uterine corpus: a review of its pathology with emphasis on recent advances and problematic aspects

This review considers the pathologic features of endometrioid carcinoma of the uterine corpus, which accounts for approximately 80% of endometrial adenocarcinomas, with an emphasis on its histologic features, recent advances, and problematic aspects. In addition to typical endometrioid carcinoma, the variants of endometrioid carcinoma covered include secretory carcinoma, villoglandular endometrioid carcinoma, endometrioid carcinoma with small nonvillous papillae, endometrioid carcinomas with microglandular and sertoliform patterns, and endometrioid carcinomas with metaplastic changes. These changes include a variety of different appearances of squamous epithelia (ranging from mature and keratinizing to immature with only subtle evidence of a squamous nature), clear cells, surface changes resembling syncytial metaplasia or microglandular hyperplasia, ciliated cells, oxyphilic cells, and spindled epithelial cells (sarcomatoid carcinoma). The last is one of several variants that may cause a biphasic appearance, all of which should be distinguished from the malignant müllerian mixed tumor. Rare findings in endometrioid carcinomas include hyalinization, psammoma bodies, and foci of stromal metaplasia such as osteoid. Unusual growth patterns of endometrioid carcinomas include involvement of adenomyosis, the "diffusely" infiltrating pattern of myoinvasion, and a previously unemphasized pattern of myoinvasion with "pinched off" glands that may be cystic or have a pseudovascular appearance, often with a myxoid stromal reaction. Other aspects of endometrioid carcinoma discussed are its immunoprofile, grading, cervical involvement (including a hitherto undescribed "burrowing" pattern of extension within the cervix that can result in underdiagnosis of stage IIB disease), carcinoma arising in the lower uterine segment, carcinoma arising in polyps and adenomyomas, carcinoma in young women, tamoxifen-related carcinoma, associated ovarian endometrioid carcinoma, and peritoneal keratin granulomas. Finally, the differential diagnosis of endometrioid carcinoma is briefly considered with a section on benign mimics, including curettage-related changes, menstrual changes, adenomyosis-related problems, metaplastic changes, atypical polypoid adenomyoma, radiation atypia, and papillary proliferations, and a section on metastatic colonic carcinoma.

Bcl-2, iNOS, p53 and PCNA expression in normal, disordered proliferative, hyperplastic and malignant endometrium

We attempted to determine Bcl-2, inducible nitric oxide synthase (iNOS), p53 and proliferating cell nuclear antigen (PCNA) expression, and the relationships between them, in endometrioid adenocarcinomas and precursor lesions. Expression of Bcl-2, iNOS, p53 and PCNA were investigated immunohistochemically in 91 samples from benign (proliferative (pEM), secretory (sEM), disordered proliferative (dEM), inactive/atrophic (aEM), hyperplastic endometrium) and malignant endometrial tissue. Staining scores for Bcl-2 in the dEM, endometrial hyperplasia (EMH) and endometrioid cancer (ECA) groups were higher than in the pEM group (P = 0.004; P = 0.036 and P = 0.020, respectively). A significant difference in proliferating cell nuclear antigen staining was found between simple and complex EMH samples (P = 0.000). An inverse relationship was found between iNOS and p53 in the hyperplasia group (r = -0.533, P = 0.019). While a significant difference was found in p53 staining in ECA between the pEM, dEM and EMH groups, no such difference was found in iNOS staining. In addition, there was no direct relationship between iNOS and p53 in the ECA group. It was concluded that the interaction between iNOS, p53 and Bcl-2 in proliferative processes in the development of type 1 endometrioid adenocarcinomas is different from that in tumors originating in other organs.