Histologic correlates and virulence implications of endometrial carcinoma associated with adenomatous hyperplasia

Endometrial Carcinoma and its Precursors

This chapter focuses on premalignant and malignant diseases of the endometrium (lining of the uterus). Endometrial carcinoma is the most common gynecologic cancer in the United States. Women have a 1 in 40 lifetime risk of being diagnosed with endometrial cancer, the fourth most common malignancy among women. An estimated 61,880 new diagnoses of uterine cancer and 12,160 deaths from the disease occurred in 2019 in the United States (American Cancer Society, Facts & Figures, https://www.cdc.gov/cancer/uterine/statistics/index.htm , 2019).

Review of immunohistochemical typing of endometrial carcinoma at the Lagos University Teaching Hospital

BACKGROUND

Categorization of endometrial carcinomas as type I and II provides useful insights into their different risk factors, pathogenesis and biologic behaviours.

AIM

To determine the immunohistochemical classifications of endometrial carcinomas in Nigerian women.

DESIGN

A retrospective review of histopathologic slides of cases of endometrial carcinomas seen at the Lagos University Teaching Hospital (LUTH) over a 5-year period. The slides were reviewed, and the diagnoses made according to the WHO nomenclature. The classification of endometrial carcinomas into Type I and II was made by immunohistochemistry using antibodies to ER, PR, p53 and Ki-67.

RESULTS

Eight cases of endometrial adenocarcinoma were reported accounting for 53.3% of all endometrial malignancies. Of these, only 1 case showed the classic type I immunophenotype while type II staining pattern was seen in 4 cases. The remaining 3 cases had equivocal immunophenotypes: one was p53+ but showed ER+, PR+ and high Ki-67 index; the second was p53-, ER+, PR+ but had a high Ki-67 expression; while the last was p53-, but ER-, PR- and had high Ki-67 expression.

CONCLUSION

Endometrial carcinomas in Nigerian women are more likely to be type II carcinomas. A reasonable proportion of the cases were equivocal thus requiring further categorization with molecular studies.

Small endometrial carcinoma 10 mm or less in diameter: clinicopathologic and histogenetic study of 131 cases for early detection and treatment

Natural history and clinicopathologic features of early endometrial carcinoma are not evident. Its knowledge is essential to make up strategies for prevention, early detection, and treatment of endometrial carcinoma. Especially it is important to know pathways of endometrial carcinogenesis and frequency of endometrial carcinomas arising from endometrial hyperplasia. Clinicopathologically 131 patients with endometrial carcinoma measuring ≤10 mm in diameter (“small endometrial carcinoma”) were studied to get useful information for early diagnosis, treatment, and histogenesis. The entire endometrium of surgically removed uterus was step-cut and examined. The patients were, on average, 5 years younger than the controls whose carcinomas measure >10 mm (P < 0.0001). Of the 131 patients, 20% were asymptomatic although only 5% of the controls were asymptomatic (P < 0.0001). Seventy-six percent had the carcinomas located in the upper third section of the uterine corpus. Macroscopically 44% of the tumors were flat and 56% were elevated. Incidence of nodal and ovarian metastases were <1%. Forty percent of “small endometrial carcinomas” were associated with endometrial hyperplasia and 60% were not. It is logical to believe that there are two pathways of endometrial carcinogenesis: carcinomas occurring from hyperplasia (40%) and carcinomas occurring from normal endometrium (60%). As hyperplasia-carcinoma sequence is not a main route, we cannot probably prevent carcinomas only by treatment of hyperplasia. Effort must be focused on detecting early de novo carcinomas. As most “small endometrial carcinomas” arise in the upper third of the corpus, careful endometrial sampling there is important for early detection.

Candidate biomarkers for genetic and clinicopathological diagnosis of endometrial cancer

The recent increase in the frequency of endometrial cancer has emphasized the need for accurate diagnosis and improved treatment. The current diagnosis is still based on conventional pathological indicators, such as clinical stage, tumor differentiation, invasion depth and vascular invasion. However, the genetic mechanisms underlying endometrial cancer have gradually been determined, due to developments in molecular biology, leading to the possibility of new methods of diagnosis and treatment planning. New candidate biomarkers for endometrial cancer include those for molecular epigenetic mutations, such as microRNAs. These biomarkers may permit earlier detection of endometrial cancer and prediction of outcomes and are likely to contribute to future personalized therapy for endometrial cancer.

Trop-2 overexpression in poorly differentiated endometrial endometrioid carcinoma: implications for immunotherapy with hRS7, a humanized anti-trop-2 monoclonal antibody

OBJECTIVE

We evaluated the expression of human trophoblast cell surface marker (Trop-2) in endometrial endometrioid carcinoma (EEC) and the potential application of hRS7, a humanized monoclonal anti-Trop-2 antibody, as a therapeutic agent against poorly differentiated EEC.

METHODS

Trop-2 expression was evaluated by immunohistochemistry in 131 EEC with different degrees of differentiation and 32 normal endometrial controls (NEC). Trop-2 expression was also evaluated by quantitative real-time polymerase chain reaction and flow cytometry in 3 primary EEC cell lines derived from patients harboring poorly differentiated EEC. Finally, the sensitivity of grade 3 EEC cell lines to hRS7 antibody-dependent cellular cytotoxicity was tested in standard 5-hour Cr release assays.

RESULTS

Trop-2 expression was detected in 126 (96.2%) of 131 EEC samples. Tumor tissues showed markedly increased Trop-2 positivity compared with NEC (P = 0.001). Trop-2 expression was significantly higher in all grades of EEC versus NEC. Grade 3 tumors displayed significantly stronger Trop-2 immunostaining compared with grade 1 EEC (P = 0.01). High Trop-2 expression by quantitative real-time polymerase chain reaction and flow cytometry was found in 1 grade 3 EEC primary cell line (EEC-ARK-1). Unlike Trop-2-negative EEC cell lines, EEC-ARK-1 was found highly sensitive to hRS7-mediated antibody-dependent cellular cytotoxicity in vitro (range of killing, 33.9%-50.6%; P = 0.004). Human serum did not significantly inhibit hRS7-mediated cytotoxicity against EEC-ARK-1 (P = 0.773).

CONCLUSIONS

Trop-2 is highly expressed in EEC, and its expression is significantly higher in poorly differentiated EEC when compared with well-differentiated EEC. Primary grade 3 EECs overexpressing Trop-2 are highly sensitive to hRS7-mediated cytotoxicity in vitro. hRS7 may represent a novel therapeutic agent for the treatment of high-grade EEC refractory to standard treatment modalities.

Expression of sonic hedgehog signaling molecules in normal, hyperplastic and carcinomatous endometrium

The aim of the present study was to determine the expression profile of the hedgehog (Hh) signaling molecules in normal, hyperplastic, and carcinomatous uterine endometrium. For this purpose, 271 endometrial tissue samples, (62 of normal endometrium, 127 of endometrial hyperplasias, and 82 endometrial adenocarcinomas) were studied using antibodies recognizing Hh-related signaling proteins, such as, sonic hedgehog (Shh), Patched (PTCH), Smoothened (Smo), Suppressor of fused [Su(Fu)], Gli-1, Gli-2, and Gli-3 by immunohistochemistry. The mRNA expression of these molecules was also assessed on reverse transcription-polymerase chain reaction. In the normal endometrium, the expression of Hh signaling molecules was generally downregulated except for Su(Fu), Gli-2, and Shh. In particular, the expression of both PTCH and Smo was very low or almost absent. Overall expression of Hh signaling molecules increased in hyperplastic endometrium; in particular, PTCH and Smo were significantly highly expressed in complex and atypical hyperplasia. In carcinoma samples extensive alterations were observed in the expression pattern of the signaling molecules. Nuclear Gli-2, cytoplasmic Gli-3, and Su(Fu) were overexpressed, whereas Shh, PTCH, and Smo expression were significantly reduced compared with the hyperplastic endometrium. The results suggest that the alteration of Hh signaling may be implicated in tumorigenesis of the endometrium.

Hormonal heterogeneity of endometrial cancer

Endometrial cancer is the most common malignant tumor of the female genital tract in the developed world. Increasing evidence suggests that the majority of cases can be divided into two different types ofendometrial cancer based on clinico-pathological and molecular characteristics. Type I is associated with an endocrine milieu of estrogen predominance. These tumors are ofendometroid histology and develop from endometrial hyperplasia. They have good prognosis and are sensitive to endocrine treatment. Type II endometrial cancers are not associated with a history of unopposed estrogens and develop from the atrophic endometrium of elderly women. Mainly, they are of serous papillary or clear cell morphology, have a poor prognosis and do not react to endocrine treatment. Both types of endometrial cancer probably differ markedly with regard to the molecular mechanisms of transformation. The transition from normal endometrium to a malignant tumor is thought to involve a stepwise accumulation of alterations in cellular mechanisms leading to dysfunctional cell growth. This chapter reviews the current knowledge of the molecular mechanisms commonly associated with development of type I and type II endometrial cancer.

Is Body Mass Index an Independent Risk Factor of Survival Among Patients With Endometrial Cancer?

OBJECTIVE

To evaluate whether body mass index (BMI) is an independent risk factor for survival in patients with endometrial adenocarcinoma.

METHODS

Women treated for endometrial cancer at the State University of New York (SUNY), Downstate and Kings County Hospital between January 1982 and September 2003 were eligible. Patients were divided into groups based upon their histology at the time of diagnosis. The first included patients with low-grade endometrioid adenocarcinoma (FIGO grades 1 and 2); the second included grade 3 endometrioid adenocarcinoma; and the third contained papillary serous and clear cell carcinomas. Data regarding BMI, patient age, race, grade, and stage of disease and overall survival, were assessed by survival analysis, with P < 0.05 considered significant throughout.

RESULTS

The analysis included 442 patients. Mean BMI was 32.6 +/- 8.2. There were 312 patients (70%) treated for low-grade endometrial adenocarcinoma; 64 patients (14%) for grade 3 endometrioid adenocarcinoma; and 71 patients (16%) for papillary serous and clear cell adenocarcinoma. Increased BMI was associated with improved overall survival (P = 0.003). BMI was also correlated to tumor grade, stage at diagnosis, age, and race. Tumor grade, stage, age, and race were correlated to survival. Statistical analyses revealed the majority of the association between BMI and survival can be attributed to the association between BMI and these other risk factors for survival in endometrial cancer.

CONCLUSIONS

Increased BMI is associated with survival advantage among patients with endometrial cancer. Because of the relationship between obesity and other confounding variables obesity alone is not an independent predictor of survival.

The diagnostic value of beta-catenin immunohistochemistry

beta-catenin is a 92-kDa protein that binds to the cytoplasmic tail of E-cadherin. It acts in the nucleus to stimulate cell proliferation and is degraded by complexing with the adenomatous polyposis coli gene. When it is mutated, it is ineffectively degraded and results in unchecked proliferative activity that plays a role in a subset of neoplasms. When there are alterations in beta-catenin degradation, it accumulates to a sufficient extent to be detected in the nuclei of tumor cells immunohistochemically, a feature that can be exploited in the differential diagnosis of selected neoplasms. Immunohistochemistry for beta-catenin may be useful in the differential diagnosis of selected tumors of soft tissue, the gastrointestinal tract, including the pancreas, lung, and female genital tract.

Which surgical procedure for patients with atypical endometrial hyperplasia?

OBJECTIVE

To determine the occult coexistence of endometrial carcinoma in patients with atypical endometrial hyperplasia and to compare histological prognostic factors according to lymph node status in occult endometrial carcinoma.

MATERIALS AND METHODS

Two hundred and four patients from two referral centers (during the period 1990-2003) who were operated on within 1 month of endometrial biopsy for symptomatic endometrial hyperplasia without receiving any medical treatment were included retrospectively. Patients having preoperative endometrial biopsy results of concomitant endometrial hyperplasia and carcinoma were excluded from the study. Fifty-six patients having atypia in preoperative biopsy (group I) were compared with 148 patients without atypia (group II). Chi-square and Mann-Whitney U-tests were used for statistical analyses.

RESULTS

No significant difference was observed between the two groups according to age or menopausal status. Patients in group II had significantly higher parity than patients in group I. In group I, 62.5% of the patients had endometrial carcinoma, 21.4% had endometrial hyperplasia, and 16.1% had normal endometrium in hysterectomy specimens. In group II, the percentages were 5.4, 38.5, and 56.1%, respectively. Complete surgical staging was performed in 20 patients. Four patients had metastatic lymph nodes. All of them had grade 2 tumors with lymphovascular space involvement. Three of them had nonendometrioid tumors.

CONCLUSION

Careful intraoperative and preoperative evaluation of the endometrium must be the sine qua non for patients with atypical endometrial hyperplasia. It is reasonable to do frozen section at the time of hysterectomy for atypical endometrial hyperplasia, and if grade 2/3 of nonendometrioid cancer with lymphovascular space involvement is found, complete surgical staging should be performed.

Endometrial hyperplasia/adenocarcinoma. A conventional approach

Hyperplasia of the endometrium is a process characterized by an irregular, noninvasive proliferation of glands with a variable amount of stroma. Precise classification of endometrial hyperplasia in biopsy material is important in order to identify those hyperplasias that are likely to be precursors of endometrial adenocarcinoma. The current World Health Organization (WHO) classification provides a scheme that has become widely accepted, primarily dividing hyperplasias in to those with and those without cytologic atypia while the degree of glandular crowding (simple vs. complex) has secondary importance. A wide variety of other endometrial changes, ranging from artifacts, metaplasias and polyps to well-differentiated adenocarcinoma must be considered in the differential diagnosis. Well-differentiated adenocarcinoma is diagnosed when one of 3 essential criteria is found in biopsy specimens: (1) a confluent gland pattern; (2) an extensive papillary pattern; or (3) a desmoplastic stromal response. Using the WHO classification allows segregation of endometrial hyperplasia into clinically meaningful categories. Strict morphologic criteria also enable separation of hyperplasia from well-differentiated adenocarcinoma.

Endometrial adenocarcinoma: beliefs and scepticism

The incidence of endometrial adenocarcinoma is high in North America and northern Europe, and low in Asia and Africa. This variance in frequency rates occurred in the late 1970s and its real cause has remained in question since. There is a widespread belief that endometrial adenocarcinomas associated with endometrial hyperplasia have a much better prognosis than those related to endometrial atrophy. This view is, in general terms, true but only because a high proportion of tumors arising from an atrophic endometrium are of serous/papillary, clear cell, or Grade 2-3 endometrioid carcinomas, in contrast to those developing from a hyperplastic endometrium, which are nearly all G1 endometrioid adenocarcinomas. These adenocarcinomas have, however, an excellent prognosis, no matter whether they are related to hyperplasia or atrophy, and taxonomically they form a single tumor group. In this regard, it is most reasonable to separate endometrial carcinomas into low- and high-grade tumors. The first are formed solely of G1 or "authentic" endometrioid adenocarcinomas, i.e., endometrioid neoplasms composed in their entirety of glandular elements without having traces of nonsquamous solid components. The high-grade tumors are formed of both endometrioid Grade 2-3 adenocarcinomas and nonendometrioid carcinomas-all of particularly aggressive behavior. The question of grading endometrioid adenocarcinomas in a precise and reproducible way becomes obvious. It is also believed that endometrial adenocarcinomas associated with endometrial hyperplasia are estrogen-primed, while those related to endometrial atrophy are deprived of hormonal stimulation. However, as we have shown in this laboratory recently, estrogen stimulation may be very common in endometrial neoplasms developing in an atrophic endometrium. For indeed most, if not all, postmenopausal atrophic endometria harboring adenocarcinomas contain actively proliferating glands, with high Ki-67 proliferation index, high epidermal growth factor receptor (EGFR) activity, high microvessel density (MVD), and rich in estrogen and progesterone receptors (ER and PR), indicative of a continuous low-level estrogenic stimulation. That there is a number of endometrial carcinomas that tend to develop in a milieu of antiestrogenic domination, following treatment for breast carcinoma, this may well represent a form of breast-endometrial hereditary disease and, certainly, merits further investigation.

Progestin suppresses matrix metalloproteinase production in endometrial cancer

OBJECTIVES

Endometrial carcinoma (EC) is one of the few cancers where there is a clear relationship between excessive hormone stimulation and malignant transformation. In this study we have analyzed the effects of the female sex steroids estrogen and progesterone on matrix metalloproteinases (MMP-9 and -2) production in primary EC cells and EC cell lines. MMPs are implicated in cancer invasion via mechanisms including extracellular matrix degradation and the processing of a range of molecules, including growth factors and cytokines.

METHODS

Cells were isolated from biopsies collected from three cancer patients undergoing hysterectomy for grade 1 endometrial adenocarcinoma and two patients undergoing procedures unrelated to EC. These cells plus the EC cell lines Ishikawa and HEC-1A were cultured without hormones or with medroxyprogesterone acetate (MPA), estradiol (E(2)), or these hormones in combination. Gelatin and reverse zymography were used to analyze MMPs and TIMPs, respectively, in culture medium. RT-PCR was used to characterize steroid receptor expression.

RESULTS

Cell lines differed from primary cells in the range and abundance of MMPs secreted. Treatment with MPA significantly reduced proMMP-9, proMMP-2, and MMP-2 release from primary EC cancer and stromal cells. Treatment with E(2) alone or MPA + E(2) had no significant effect on MMP expression. Primary EC and stromal cells also showed a loss of the progesterone B receptor isoform.

CONCLUSION

EC cells retain the suppression of MMPs by progesterone, seen in normal endometrial cells. These data provide a rationale for the use of progestin therapy in the treatment of early stage grade 1 endometrial carcinomas.

Differential diagnosis between normal endometrium and endometrial hyperplasia with immunostaining cytology using anti-LeY monoclonal antibody

We have previously reported that both endometrial cancer and endometrial hyperplasia stain positively for the anti-LeY monoclonal antibody, whereas normal endometrium does not. Endometrial hyperplasia is a premalignant change associated with the eventual development of endometrial carcinoma. However, it can be difficult to differentiate hyperplasia from normal endometrium in cytology. This study illustrates the use of immunocytochemical cytology using anti-LeY monoclonal antibody to differentiate between endometrial hyperplasia and normal endometrium. Immunostaining using anti-LeY monoclonal antibody was performed on cytologic specimens obtained from 17 normal endometria, 25 endometria with endometrial hyperplasia, and 13 endometria with endometrial carcinoma. All normal endometria displayed negative staining for anti-LeY monoclonal antibody, whereas all endometria with endometrial carcinoma displayed positive staining. Of the endometrial hyperplasia cases, 21 displayed positive staining. However, four displayed negative staining due to the small number of cells available for diagnosis. We believe that immunostaining cytology using anti-LeY monoclonal antibody is a useful method for differentiating between normal endometrium and endometrial hyperplasia.

[Effect of estrogens and antiestrogens on the endometrium]

Estrogens act through specific receptors located in the nuclei of epithelial and stromal cells of the endometrium. Estrogens stimulate the synthesis of these receptors and the progesterone inhibits their synthesis. Estrogens induce the proliferation of the mucosa during the proliferative phase. They also stimulate the synthesis of receptors for the progesterone, which is a prerequisite for progesterone activity. Hyperplasias most of the time do not contain cytological atypia and are developed under a hyperestrogenic background. They contain receptors for estrogen and progesterone, and are able to respond to progestogens. Hyperplasias with cytological atypia are precancerous lesions, associated with an hyperestrogenic or atrophic background. In the later case, they may be focal and are better diagnosed by hysteroscopy. They are best managed by simple hysterectomy. Progesterone may be used if the patient desires to conceive. Endometrial cancers are either associated with an hyperestrogenic or atrophic background. In the later case, they are often of serous or clear cell type. Endometrial effects of antiestrogens are known only for tamoxifene. Tamoxifene has an atrophic effect but sometimes may induce an estrogenic stimulation of the endometrial mucosa through the alpha and beta estrogenic receptors. Polyp is the most frequent abnormality diagnosed but endometrial cancer is significantly more frequently diagnosed than in a control population. It is well differentiated and does not modify the survival of the patient.

Distinct sets of gene alterations in endometrial carcinoma implicate alternate modes of tumorigenesis

BACKGROUND

Endometrial carcinomas seem to carry a different prognosis depending on the presence or absence of concomitant complex atypical hyperplasia (hyperplasia). The molecular genetic profile of these two pathogenetic types, based on the genes reportedly mutated in these cancers, remains to be defined. Although microsatellite inability is reported in approximately 25% of endometrial carcinomas, its relation with the 2 pathogenetic types is not investigated.

METHODS

To elucidate their underlying genetic changes, we analyzed 53 sporadic endometrial tumors, including 19 with and 34 without hyperplasia, for microsatellite instability (MSI), DNA ploidy (by flow cytometry), and for mutations in different genes.

RESULTS

Microsatellite instability was present in 21%, DNA nondiploidy in 15%, and mutations in the PTEN, KRAS, CTNNB1/beta-catenin, TP53, and CDKN2A genes were detected in 32, 11, 13, 17, and 0% of the tumors, respectively. Microsatellite instability and mutations in these genes were present in tumors both with and without complex atypical hyperplasia. All cases with complex atypical hyperplasia were early stage (I-II) endometrioid tumors and associated with long progression free disease (P = 0.0004). Furthermore, most tumors with hyperplasia had low World Health Organization or International Federation of Gynecology and Obstetrics grade, had less myometrial invasion, and showed expression of estrogen receptors. All MSI tumors were diploid and had a significantly higher rate of PTEN mutations, but similar rates of KRAS, beta-catenin, and TP53 mutations compared with microsatellite stable tumors. TP53 mutations more often were found in nondiploid tumors but never in tumors with PTEN, KRAS, or beta-catenin mutations, and all PTEN mutations occurred in diploid tumors.

CONCLUSIONS

Thus, PTEN, KRAS, beta-catenin, and TP53 mutations occurred in tumors both with and without hyperplasia, but PTEN and TP53 mutations were more common in tumors without hyperplasia. However, none of these genes seems to clearly distinguish tumors with and without hyperplasia, suggesting that other factors may be involved. Conversely, alterations in the PTEN and TP53 genes seem to define distinct subgroups of endometrial carcinoma, the former associated with diploidy and MSI, the latter with macroscopic chromosomal instability.

Association between menopausal state and prognosis of endometrial cancer

The purpose of our study was to examine the menopausal state as an independent prognostic variable of endometrial cancer and determine the conditions under which the menopausal state would be an independent prognostic variable of such cancer. We studied the clinical and pathologic variables of 255 patients with invasive endometrial cancer. In comparisons of the clinicopathologic variables between menopausal states, obesity and deep myometrial invasion were found more frequently in older patients than in younger ones. Multivariate analysis performed on 255 cases with complete pathologic data identified menopausal state, cervical invasion, pelvic lymph node metastasis, and tumor grade as prognostic variables. Univariate analysis revealed that survival of older patients with FIGO pathologic stage Ib disease was significantly poorer than in younger patients, while there was no significant difference in the analyses of stage Ic or advanced disease beyond stage II. We conclude that menopausal state was an independent prognostic variable for patients with early endometrial cancer, but not for patients with advanced disease.

beta- Catenin mutations and aberrant nuclear expression during endometrial tumorigenesis

To clarify the possible role of aberrant beta-catenin expression during endometrial tumorigenesis, a total of 199 cases of endometrial carcinomas (endometrioid type), as well as 37 cases of simple/complex and 32 of atypical hyperplasias, was consecutively investigated for immunohistochemistry, along with 141 normal endometrial samples distant from carcinomas. Of 199 carcinoma cases, 73 tumours as well as 44 normal samples were also analysed using a combination of RT-PCR and Southern blot hybridization, Western blot, and mutation gene assays. Cell membrane beta-catenin immunoreactivity showed a stepwise decrease from normal, through atypical hyperplasia, to grade 3 carcinomas. In contrast, the nuclear accumulation in atypical hyperplasias and grade 1 or 2 tumours was higher than in simple/complex hyperplasias. Mutations in exon 3 of the beta-catenin gene involving codons 33, 34, 37, 41, and 45 were observed in 16 (22.9%) of 70 endometrial carcinomas, as well as 3 (12.5%) of 24 atypical hyperplasias, the results being significantly related to low membrane and high nuclear immunoreactivity but not relative mRNA expression levels, suggesting that the gene mutations may be closely associated with changes in subcellular distribution. In addition to significant association between beta-catenin mutation and low grade histological malignancy (P = 0.048), the mutations were detected in none of 15 and 13 (26%) of 50 tumours with or without lymph node metastasis, the difference being significant (P = 0.027). These findings suggest that beta-catenin abnormalities may play an important role in a relatively early event during the endometrial hyperplasia-carcinoma sequence.

Endometrial histopathology in 700 patients treated with tamoxifen for breast cancer

OBJECTIVE

The aim of this study was the evaluation of endometrial histopathologic findings from 700 patients treated with tamoxifen (Tx) for breast cancer from two medical centers (United States and France).

METHODS

A retrospective review of data including histologic slides from 134 hysterectomies and 566 endometrial biopsies from Tx-treated patients who presented with abnormal vaginal bleeding and/or abnormal sonograms was performed. Analysis of histologic characteristics included inactive/atrophic and functional endometria, endometrial polyps, hyperplasia and metaplasia, and endometrial cancer. Duration of Tx therapy was recorded when available, and its correlation with endometrial pathology was assessed.

RESULTS

The only statistically significant difference between the data from the United States and France was the number of hysterectomies, which was almost double in France (27% vs 13.7%). Nonpathologic endometria made up 61.14% (inactive/atrophic 46%, functional 15.14%). Pathologic changes were found in 39.86% cases, of which polyps were 23.14%, glandular hyperplasia 8%, and metaplasia 3%; endometrial cancer made up 4.71% (33 cases). Nine cancers were well-differentiated endometrioid adenocarcinomas, and 24 were moderately or poorly differentiated, of which 13 had nonendometrioid components (serous, clear cell, MMMT). Fifteen cancers were found in endometrial polyps; 12 were invasive to the myometrium and 4 to blood vessels. The weight of the uteri exceeded 300 g in 15 cases, with 4 exceeding 900 g. The average age of all patients was 60.91 years and of the cancer patients alone it was 69.26 years. The shortest average duration of Tx therapy (2.5 years) was found in patients with inactive/atrophic endometria and the longest (6.8 years) in patients with endometrial cancer. Patients with endometrial polyps and cancer presented more often with abnormal vaginal bleeding than those with inactive/atrophic endometrium.

CONCLUSIONS

Most Tx-treated patients had no pathologic endometrial changes. Endometrial polyps, hyperplasia, and metaplasia, consistent with an estrogen-agonist effect of Tx, were found in roughly one-third of all patients. The endometrial cancers were often high-grade and invasive tumors. Patients with endometrial pathology were more often symptomatic than patients with inactive/atrophic endometria.

Changes in expression of estrogen receptors alpha and beta in relation to progesterone receptor and pS2 status in normal and malignant endometrium

To clarify changes in estrogen receptor (ER) alpha and ERbeta during endometrial tumorigenesis, 48 endometrial carcinomas (endometrioid type), as well as 40 samples of normal endometrial tissue, were investigated using a combination of reverse-transcription and polymerase chain reaction with Southern blot hybridization and western blot assays, and the results were compared with findings for progesterone receptor (PR) and pS2 mRNA status. In addition, 166 carcinomas were also examined for immunohistochemistry, along with 171 normal specimens. Relative amounts of ERalpha at both mRNA and protein levels were significantly greater than those for ERbeta in normal and malignant endometrial lesions. ERalpha mRNA showed a stepwise decrease from normal or grade (G) 1 through to G3 tumor lesions, in line with changes in the protein levels, in contrast to ERbeta mRNA or protein expression, which did not alter, suggesting a shift in the ratio of the two ER subtypes during endometrial tumorigenesis. PR mRNA expression was significantly correlated with ERalpha, but not ERbeta mRNA status. Although significantly higher expression of pS2 mRNA or protein was observed in carcinomas than in the normal cases, there was no apparent association with the ER status. The findings suggest that alteration in estrogen signaling pathways may occur during endometrial tumorigenesis, and provide evidence that ERalpha expression may play an important role in the regulation of PR, but not pS2 expression in normal and malignant endometrium.

p53 as a significant prognostic marker in endometrial carcinoma

Although several studies have reported that p53 overexpression is associated with poor survival from endometrial cancer, this relationship might be confounded by a number of possible factors. The objective of this study was to examine the prognostic role of p53 overexpression in endometrial cancer when a panel of well-selected potential confounding factors were controlled. One hundred and twenty-five endometrial cancers were examined for p53 overexpression by immunohistochemistry (IHC). Demographic and clinical data, including age at diagnosis, race, residence, tumor grade, surgical stage, and other possible confounding factors for endometrial cancer such as diabetes, family history of cancer, hypertension, hormone replacement therapy (HRT), and obesity were collected from medical charts and pathologic reports. Survival status was determined at the end of follow-up. The Kaplan-Meier method was used to derive the survival curve, while the log-rank test was used to compare curves for two or more groups of patients. The proportional hazards regression model was used to obtain maximum likelihood estimates of relative risks (RR) and their 95% confidence intervals. Compared to the p53 nonaltered group, the presence of p53 overexpression in endometrial carcinoma was related to significantly decreased patient survival. High nuclear grade and high FIGO stage were associated with poor survival. No obvious association was found between survival and study site, race, age, and other potential risk factors of endometrial cancer. Only two variables (p53 and stage) were significantly associated with poor survival in the multivariate proportional hazards analysis. Overexpression of p53 was found to be the most significant predictor of specific survival. The relative risk for p53 overexpression was 7.46 (95% CI: 4.26-13.1) and for late stage was 4.35 (95% CI: 1.91-9.92). We conclude that p53 overexpression is the most important predictor for patient survival when a panel of well-selected potential confounding factors are taken into account. Patients with endometrial cancers who have p53 overexpression have a seven-fold higher risk of dying from disease compared to those without p53 overexpression. Whether detection of p53 alteration may serve as an indicator of high-risk patients for whom more aggressive adjuvant chemotherapy may be considered needs to be explored in the future.

Hormonal pathology of the endometrium

The endometrial tissue is a sensitive target for steroid sex hormones and is able to modify its structural characteristics with promptness and versatility. This article discusses briefly endogenous hormonal effects (cyclic changes, luteal phase defect, unopposed estrogen effect) and describes the histologic patterns encountered in the most commonly used hormone therapies: oral contraceptives, ovulation stimulation, hormone replacement therapy, and antitumoral hormone therapy. Oral contraceptives exert a predominant progestational effect on the endometrium, inducing an arrest of glandular proliferation, pseudosecretion, and stromal edema followed by decidualized stroma with granulocytes and thin sinusoidal blood vessels. Prolonged use results in progressive endometrial atrophy. Ovulation induction therapy accelerates the maturation of the stroma and is often associated with a discrepancy between early secretory glands and an edematous or decidualized stroma with spiral arterioles. Hormone replacement therapy with estrogen alone may result in continuous endometrial proliferation, hyperplasia, and neoplasia. The use of both estrogen and progesterone elicits a wide range of histologic patterns, seen in various combinations: proliferative and secretory changes, often mixed in the same tissue sample; glandular hyperplasia (in polyps or diffuse) ranging from simple to complex atypical; stromal hyperplasia and/or decidual transformation; epithelial metaplasia (eosinophilic, ciliated, mucinous); and inactive and atrophic endometrium. Progesterone therapy for endometrial hyperplasia and neoplasia induces glandular secretory changes, decidual reaction, and spiral arterioles. Glandular proliferation is usually arrested, but neoplastic changes may persist and coexist with secretory changes. Lupron therapy produces a shrinking of uterine leiomyomas by accelerating their hyaline degeneration, similar to that in postmenopausal involution. It generally produces endometrial atrophy. Tamoxifen for breast carcinoma has an estrogen agonist effect on the uterus in approximately 20% of patients, who develop endometrial polyps, glandular hyperplasia, adenomyosis, and/or leiomyomata. Both endometrioid and nonendometrioid carcinomas are seen, often in polyps. Their causal relationship to tamoxifen therapy is debatable.

Risk factors for hyperplasia-associated versus atrophy-associated endometrial carcinoma

OBJECTIVE

Endometrial cancer can be divided into atrophy-associated and hyperplasia-associated subtypes. It has been suggested that these subtypes have different pathologic features and prognoses. This preliminary study explores whether these subtypes are associated with different risk factors.

STUDY DESIGN

Hysterectomies performed in cases of endometrial carcinoma with evaluable benign endometrium on routine processing were reviewed, and clinical data were abstracted from medical records. Forty-eight subjects with atrophy-associated and 28 subjects with hyperplasia-associated cancers were studied.

RESULTS

We found younger age, higher weight, absence of cigarette smoking, and earlier menarche in subjects with hyperplasia-related cancers.

CONCLUSIONS

Our findings support the idea that hyperplasia-associated endometrial cancer is estrogen-related but also suggest that atrophy-associated cases may result from a different causal pathway. Epidemiologic studies may yield more precise and accurate measures of association if atrophy-associated and hyperplasia-associated endometrial cancers are considered separately.

A multicentric European study testing the reproducibility of the WHO classification of endometrial hyperplasia with a proposal of a simplified working classification for biopsy and curettage specimens

This study was designed to assess intraobserver and interobserver agreement in the diagnosis of 56 endometrial specimens by five European expert gynecologic pathologists using the WHO classification and to establish which histologic features are significantly associated with each classification category. The seven categories were simple hyperplasia, complex hyperplasia, atypical hyperplasia, well-differentiated adenocarcinoma, proliferative endometria, secretory endometria, and other. Slides were reviewed twice for diagnosis, with accompanying evaluation of a checklist of histologic features. These seven categories were eventually reduced to four and three for the purposes of data analysis. The four modified diagnostic categories consisted of hyperplasia (previously simple hyperplasia and complex hyperplasia), atypical hyperplasia, well-differentiated adenocarcinoma, and cyclical endometrium (previously proliferative, secretory, and other). The three diagnostic categories consisted of hyperplasia, endometrioid neoplasia (previously atypical hyperplasia and well-differentiated adenocarcinoma), and cyclical endometrium. Intraobserver and interobserver agreement was assessed using the percentage agreement and kappa statistics. The associations among the various histologic features and diagnoses was analyzed using multiple logistic regression to identify those features that were useful for distinguishing diagnostic categories. When using seven categories, kappa values ranged from 0.53 to 0.74 (percentage agreement, 61-79%) and from 0.33 to 0.59 (percentage agreement, 43-63%) for intraobserver and interobserver agreement, respectively. When using four categories, kappa values ranged from 0.68 to 0.73 (percentage agreement, 77-80%) and from 0.39 to 0.64 (percentage agreement, 54-73%) for intraobserver and interobserver agreement, respectively. When using three categories, kappa values ranged from 0.70 to 0.83 (percentage agreement, 80-89%) and from 0.55 to 0.73 (percentage agreement, 70-82%) for intraobserver and interobserver agreement, respectively. Data were analyzed in each diagnostic category. When using four or three diagnostic categories, the mean intraobserver and interobserver agreements varied less between categories and achieved higher values, with smaller 95% confidence intervals. The mean percentage agreement was lowest for complex hyperplasia and for atypical hyperplasia. For distinguishing cyclical endometrium versus hyperplasia, the useful histologic feature was glandular crowding. For hyperplasia versus atypical hyperplasia and for hyperplasia versus endometrioid neoplasia, the useful features were nuclear enlargement, nuclear pleomorphism, vesicular chromatin, and nucleoli, but of these, only nuclear pleomorphism achieved substantial mean intraobserver and interobserver agreements. For discriminating atypical hyperplasia from well-differentiated adenocarcinoma, the only useful feature was stromal alterations, which achieved only fair mean intraobserver and interobserver agreements. In summary, in endometrial biopsy or curettage specimens, the lack of agreement in the diagnoses of complex hyperplasia and atypical hyperplasia and the lack of reproducibility in the recognition of the histologic feature of stromal alterations to differentiate atypical hyperplasia from well-differentiated adenocarcinoma suggest that the histologic classification should be simplified by including a combined category for simple and complex hyperplasia, called hyperplasia, and a combined category for atypical hyperplasia and well-differentiated adenocarcinoma, called endometrioid neoplasia. Diagnoses of hyperplasia and endometrioid neoplasia are highly reproducible between observers from different institutions. Glandular crowding is the best histologic feature to differentiate cyclical endometrium from hyperplasia, whereas nuclear pleomorphism is the reproducible cytologic feature to differentiate hyperplasia from endometrioid neoplasia.

The distribution of alpha inhibin and alpha glutathione S-transferase (delta4-5 isomerase) in the ovaries of patients with endometrial carcinoma

Estrogen is to thought to play a role in the pathogenesis of low grade but not high grade endometrial carcinomas. The dominant circulating estrogen in post menopausal women is estrone which is formed by aromatization of androstenedione. delta4-5 isomerase, active in the conversion of dehydroepiandrosterone to androstenedione, may be demonstrated immunohistochemically by the antibody to alpha glutathione S-transferase (alphaGST). Inhibin, normally acting to suppress FSH secretion, also has an LH-dependent paracrine stimulatory effect on ovarian stromal cells to produce androstenedione. The purpose of this study was to compare the distributions of alphaGST and alpha inhibin in the ovaries of patients with low grade and high grade endometrial carcinomas. The results show a statistically significant increase in intracytoplasmic alphaGST staining in patients with low grade endometrioid adenocarcinomas compared to high grade carcinomas. There was also a statistically significant correlation between the distribution of alphaGST and alpha inhibin. These findings lend some support to the hypothesis that estrogen plays a role in the pathogenesis of low grade carcinomas; that the increase in estrone is partly due to increased production of androstenedione by the ovary and that this increased production could be the consequence of increased inhibin paracrine activity.

Endometrial carcinoma associated with hyperplasia--immunohistochemical study of angiogenesis and p53 expression

OBJECTIVE

To clarify the hypothesis that there are two pathways of endometrial carcinogenesis we compared the frequency of abnormal p53 protein expression and angiogenesis in endometrial carcinomas with and without hyperplasia.

METHODS

Specimens obtained from 70 patients with stage I-IV endometrial carcinomas were available for this immunohistochemical study. Immunohistochemical staining for factor VIII-related and p53 antigens was performed using a standard immunoperoxidase technique (Histofine SAB-PO Kit, Nichirei Co., Tokyo, Japan). Microvessels were highlighted by staining endothelial cells for factor VIII-related antigen, and microvessel density (MVD) was counted in a x200 field (0.785 mm2 per field) in the area of most active neovascularization. p53 protein was detected with monoclonal anti-p53 antibodies (clone DO-7, Dako, Santa Barbara, CA).

RESULTS

Twenty-six of 73 (37%) patients had hyperplasia in the endometrium adjacent to the carcinoma. Significantly more patients with low MVD (less than 60) had carcinoma with hyperplasia than those with carcinoma without hyperplasia (P = 0.0053). p53 expression was noted in a carcinomatous area in 8 of 26 patients (30. 8%) with hyperplasia compared to 26 of 44 (59.1%) without hyperplasia, and the difference was statistically significant (P = 0. 0220).

CONCLUSION

The presence or absence of hyperplasia is a different pathogenesis and important in assessing the biological behavior of endometrial carcinoma, especially concerning angiogenesis and p53 expression.

p53 immunostaining as a significant adjunct diagnostic method for uterine surface carcinoma: precursor of uterine papillary serous carcinoma

Uterine papillary serous carcinoma (UPSC) is a biologically aggressive carcinoma that causes a disproportionate number of endometrial cancer deaths because of its dismal clinical outcome. Although the precursor lesion of UPSC has been suggested both morphologically and molecularly, diagnosis continues to represent a challenge to surgical pathologists, particularly in biopsy specimens, largely in part because of its multiple histologic patterns and many benign morphologic mimics. In this study, we used p53 immunohistochemical staining as an adjunct test to correctly identify six cases of uterine surface carcinoma (USC) prospectively and three cases retrospectively. Both sensitivity and specificity for this immunostaining method approached 100% when the cutoff score of p53 overexpression was 7 or higher. The precision estimated by receiving operating characteristic curve was 100%, indicating that the diagnostic value of the score for p53 overexpression was very high. p53 immunohistochemical staining was considered a significant adjunct diagnostic method for the probable precursor lesion of UPSC. The probable precursor lesion of UPSC, previously referred to as endometrial intraepithelial carcinoma or endometrial carcinoma in situ, appears to represent the early phase of UPSC. However, unlike its names would suggest, this lesion is often multicentric and behaves in a more aggressive fashion than regular in situ carcinomas. For this reason, we prefer the term uterine surface carcinoma, a term that is more descriptive and less restrictive, to emphasize the unique aggressive nature of the UPSC precursor lesion. The reason we postulate using the term uterine surface carcinoma rather than endometrial intraepithelial carcinoma or endometrial carcinoma in situ is that the latter terms would seem define a neoplastic process confined to the endometrial epithelium without potential for metastasis. In reality, the precursor lesion of UPSC has a tendency to stromal and vascular space involvement as seen by the presence of stromal and vascular invasion in one of the prospectively identified USC cases. Therefore, the term uterine surface carcinoma is selected to alert clinicians that this early carcinoma has features of carcinoma in situ, but still carries a potential for metastasis.

Recent advances in the histopathology and molecular pathology of carcinoma of the endometrium

Endometrial carcinoma is the commonest malignancy of the female genital tract. The pathogenesis is complex and at least three pathogenetic subtypes exist with different prognostic implications. The molecular events involved remain poorly defined but several genes are involved and mutations of tp53, WAF1/CIP1, PTEN, bcl-2 and c-erbB-2 have been implicated. Although care is needed in interpreting the results, the majority of these mutations can be detected immunohistochemically and therefore have the potential to aid the pathologist and surgeon in assessing the prognosis of a tumour. However, for the time being, no molecular marker is as valuable in determining prognosis as conventional parameters such as tumour type, grade and vascular space involvement.

Concomitant endometrial hyperplasia in patients with endometrial carcinoma

OBJECTIVES

The aim of this study was to compare the histopathologic features and prognosis of patients with endometrial carcinoma with and without concomitant hyperplasia.

METHODS

Histologic slides of the surgical specimens of 214 consecutive patients who underwent surgery as primary treatment for endometrial carcinoma from 1985 through 1991 were reviewed.

RESULTS

Ninety-two of the 214 patients (43%) with endometrial carcinoma had concomitant endometrial hyperplasia. Patients with endometrial carcinoma with hyperplasia were significantly younger than those without hyperplasia (mean age 62 +/- 10 vs 65 +/- 9 years, P < 0.05). Carcinomas associated with hyperplasia were better differentiated and of lower surgical stage. By univariate analysis the frequency of recurrence was significantly lower (4% vs 17%, P < 0.004) and the estimated 5-year survival rate significantly higher (96% vs 85%, P < 0.01) in patients with endometrial carcinoma with concomitant hyperplasia. However, in multivariate analysis the presence of endometrial hyperplasia was not an independent prognostic factor and the 5-year survival rates of patients with or without hyperplasia did not differ significantly in any surgical stage.

CONCLUSION

The presence or absence of concomitant endometrial hyperplasia is strongly correlated with the surgical stage of endometrial carcinoma.

CD44 expression in normal, hyperplastic, and malignant endometrium

A total of 140 endometrial carcinomas (endometrioid type), as well as 72 hyperplasias (41 of simple or complex and 31 of atypical type) and 141 normal endometria (35 in the proliferative and 106 in the secretory phase), were immunohistochemically investigated for expression of the standard and variant-3 and -6 isoforms of CD44, and the results compared with several known prognostic factors. A combination of the reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot hybridization (SBH) for CD44 mRNA levels was also carried out on 27 endometrial carcinomas. In normal endometrium, the expression of standard and variant CD44 forms was remarkably higher in the secretory than in the proliferative phase, with immunoreactivity scores being inversely correlated with numbers of oestrogen and progesterone receptors. Significantly elevated levels of CD44 expression in endometrial carcinomas compared with the proliferative phase and hyperplasia were also revealed by both the immunohistochemical and the RT-PCR/SBH assays, while no association was noted with any prognostic factors. The results indicate that CD44 expression in the normal menstrual cycle is closely related to the secretory differentiation of the glandular epithelium. Moreover, detection of aberrant expression may be useful for the early diagnosis of endometrial carcinoma, but not as an indicator of tumour progression.

Office procedures. Endometrial biopsy

Endometrial biopsy is a relatively safe, efficient, and well-tolerated procedure. Indications include evaluation of abnormal uterine bleeding and infertility. Excluding the presence of endometrial cancer and precursors is of primary concern. Use of the popular narrow polyethylene sampling devices results in a sensitivity approaching 95% for the diagnosis of endometrial cancer. Inadequate samples are more common in postmenopausal than premenopausal women, primarily because of atrophy of the endometrium.

The behavior of endometrial hyperplasia: a prospective study. Endometrial Hyperplasia Study Group

OBJECTIVE

To clarify the behavior of endometrial hyperplasia in a prospective study.

METHOD

Fifty-one patients with endometrial hyperplasia were followed up for 6 months. Samples of endometrial tissues were taken by uterine endometrial biopsy every 4 weeks during the first 3 months and at the end of follow-up.

RESULTS

In 69% (35/51) of the patients histological picture of the endometrium became normal during the observation period. The lesions persisted in 17% (6/35) of the patients with simple hyperplasia, in 25% (1/4) of those with complex hyperplasia, in 14% (1/7) of those with simple atypical hyperplasia, and in 80% (4/5) of the patients with complex atypical hyperplasia. In the remaining 3 patients with simple hyperplasia, the lesions progressed to complex atypical hyperplasia by the end of follow-up, after showing a normal endometrium.

CONCLUSION

Most cases of endometrial hyperplasia, except for complex atypical hyperplasia, disappeared spontaneously within a short period of time.

Treatment of endometrial hyperplasias with gonadotropin-releasing hormone agonists: pathological, clinical, morphometric, and DNA-cytometric data

On the basis of the recently reported observation that gonadotropin-releasing hormone agonists (GnRH-a) can affect endometrial cell proliferation, both indirectly, through the hormonal axis, and directly, by acting on the GnRH-a receptors, we investigated how far GnRH-a can be used as a new treatment mode for endometrial hyperplasias. Forty-two women, aged 28-60 years, with histologically confirmed simple (n = 30) or complex (n = 12, 2 with atypias) hyperplasia of the endometrium were involved in the study. According to the protocol they were treated for 6 months with GnRH-a (leuprolide acetate or triptorelin), and each patient underwent uterine curettage in the third and the sixth month of treatment, and 6 and at least 12 months after cessation of the treatment, for histological examination and morphometric and DNA-cytometric evaluation of the endometrium (mean pathological follow-up, 19.2 months; mean clinical follow-up, 30.7 months). During treatment, most of the women first revealed endometrial atrophy, and, after cessation of the treatment, again an atrophic or mainly functional endometrium; in 7 women, all with initial diagnosis of simple hyperplasia, the endometrial hyperplasia reappeared, which led in all 7 cases to hysterectomy. The mean values of almost all morphometric and DNA-cytometric parameters during and after treatment showed statistically significant changes in relation to pretreatment values, indicating a decrease in the proliferative activity of the endometrial cells; the GnRH-a antiproliferative effect was still active for a long time after cessation of the therapy. Our results, based for the first time not only on histological but also on serial nuclear morphometric and DNA-cytometric examinations of the endometrial cells and on the longest follow-up time, support the view that in cases of endometrial hyperplasia, especially of complex type, the use of GnRH agonists, which decrease the proliferative tendency of endometrial cells, could represent an alternative conservative therapeutic approach, which, however, requires close monitoring of the endometrium.

Bcl-2 expression is correlated with a low apoptotic index and associated with progesterone receptor immunoreactivity in endometrial carcinomas

A total of 103 endometrial carcinomas (endometrioid type), as well as 15 samples of normal (atrophic or proliferative phase) and 26 of hyperplastic endometrium, were immunohistochemically investigated for expression of Bcl-2, and oestrogen and progesterone receptors (ER and PR), and the results compared with findings for apoptosis and cell proliferation. Carcinoma cases were subdivided into tubular and solid components on the basis of tumour growth patterns. Immunopositivity for Bcl-2, ER, and PR in tubular components was significantly higher than in the solid category, being negatively associated with histological grading. Immunoreactivity scores revealed that Bcl-2 in the tubular group was positively correlated with PR but not ER, while its expression in normal and hyperplastic endometrium was closely linked with both. Apoptotic and mitotic indices (AI and MI) were both significantly lower in tubular than in solid areas. In the tubular areas, AI, values were significantly lower in the subgroup with a high level of Bcl-2 expression than in either low-level or negative groups. These results indicate that Bcl-2 expression may play a central role in the inhibition of apoptosis in endometrial carcinoma, in particular those cases with tubular components, possibly being associated with PR rather than ER. Changes in the propensity for apoptosis may be related to alterations of tumour growth pattern and of features of differentiation.

Effects of age on endometrial carcinogenesis induced by concurrent oral administration of ethylenethiourea and sodium nitrite in mice

Aging effects on the susceptibility to chemical endometrial carcinogenesis were investigated in ICR female mice. The animals were divided into 3 groups of different ages: 1 month (young), 6 months (middle), and 12 months (old) at initiation of treatment. They received weekly oral administration of mixture of ETU (100 mg/kg body weight) and sodium nitrite (70 mg/kg body weight) for 6 months followed by a withdrawal period of 3 months. All animals were subjected to histopathology. The incidence of endometrial adenocarcinomas was highest in the middle age group (8/20), secondary in the old age group (4/20), and lowest in the young group (1/20). The incidence of atypical glandular hyperplasia, a precursor lesion of the tumor, was also higher in the middle age group. The endometrial adenocarcinomas showed morphological similarities among all age groups and the nuclei of tumor cells lost almost all staining reactivity to estrogen receptors. The labeling indices with bromodeoxyuridine (BrdU) were notably higher in the old age group than in the young and middle age groups. A further investigation on the aging process of female genital organs in control mice revealed that their senility seemed to be preceded by the formation of ovarian cysts which first appeared at 6 months of age with a concomitant elevation of plasma 17 beta-estradiol level. These results indicate that the susceptibility of the mouse endometrium to the carcinogenic effects of N-nitroso ETU could be closely linked with the stage of aging process of the genital organs and it appears to be most susceptible when initiated at around 6 months of age. However, the mitotic activity of neoplastic endometrial glandular cells seems to be higher in older mice than younger ones.

Endometrial cancer. Management of high risk and recurrence including the tamoxifen controversy

Risk factors for endometrial cancer include obesity, nulligravidity, late menopause, and anovulatory states. Although diabetes is highly associated with endometrial cancer, hypertension is not an independent variable when correction is made for other factors. Exogenous estrogen increases the risk by at least four times, and smoking is a significant factor. Screening of asymptomatic women may be useful among high risk patients. In addition, racial influence on virulence has recently been identified. Most recurrences of endometrial cancer are identified within 3 years of initial diagnosis. Predictors include ploidy, histologic grade, histologic type, receptor status, and stage. Treatment of recurrence is individualized based on tumor location and receptor status and may involve surgery, radiation therapy, hormonal therapy, or cytotoxic chemotherapy. Tamoxifen has been shown to improve survival among subsets of patients with breast cancer in all stages. A comprehensive literature review and meta-analyses, however, verified an increased risk of endometrial cancer among tamoxifen-treated patients compared with control subjects that may equal the cancer risk from exogenous estrogen exposure. Screening techniques include sonographic assessment of endometrial thickening and vascular patterns, hysteroscopy, and endometrial sampling. A subendometrial cystic proliferation can confuse radiographic evaluation of endometrium, leading to unindicated curettage. A disproportionate incidence of high grade lesions has been reported; however, tamoxifen should not be withheld from patients with breast cancer.

Endometrial intraepithelial carcinoma: a distinctive lesion specifically associated with tumors displaying serous differentiation

Endometrial intraepithelial carcinoma (EIC) is a recently described lesion characterized by replacement of endometrial surface epithelium or glands by malignant cells resembling high-grade invasive endometrial carcinoma. EIC has been identified in a high proportion of uteri containing serous carcinoma, but its association with other endometrial tumors is unknown. To determine the strength and specificity of the association of EIC with tumors displaying serous differentiation, the appearance of the endometrium in 38 uteri with serous carcinoma, 113 with endometrioid carcinoma, and 34 with malignant mixed mesodermal tumor (MMMT) were compared. EIC was present in 34 (98%) uteri with serous carcinoma compared with 7 (6%) uteri removed for endometrioid carcinoma (P = .0001). Hyperplasia without atypia was found in only 2 (5%) of 38 serous carcinomas compared with 38 (34%) of 113 endometrioid carcinomas. Similarly, atypical hyperplasia was not found in any uterus with serous carcinoma, but was present in 14 (12%) uteri with endometrioid carcinoma (P = .02). The endometrium was inactive or atrophic in 29 (76%) patients with serous carcinoma compared with 33 (29%) with endometrioid carcinoma (P = .0001). EIC was found in five (56%) of nine MMMTs with a serous epithelial component (serous-MMMT) compared with one (4%) of 25 MMMTs woth an endometrioid epithelial component (endometrioid-MMMT). As with endometrioid and serous carcinomas, hyperplasia with and without atypia was more common with endometrioid-MMMTs as compared with serous-MMMTs. Hyperplasia was found in 25 (100%) and atypical hyperplasia in 8 (32%) of 25 endometrioid-MMMTs, but in none of the nine serous-MMMTs. This study shows that EIC is frequently and specifically associated with uterine tumors displaying serous differentiation. The findings suggest that EIC represents a form of intraepithelial tumor growth characteristic of serous carcinoma and serous MMMT and that EIC is the likely precursor of these neoplasms. In addition, the findings provide further evidence supporting the view that MMMTs represent variants of carcinoma not sarcoma.

Endometrial cancer: stage at diagnosis and associated factors in black and white patients

OBJECTIVE

This study examined the relationship of clinicopathologic, health status, medical system, and socioeconomic factors to differences in stage at diagnosis of endometrial cancer in black and white patients.

STUDY DESIGN

A population-based study of 130 black and 329 white patients with invasive endometrial cancer was conducted as part of the National Cancer Institute's Black/White Cancer Survival Study. Logistic regression was used to determine the relative importance of factors thought to be related to stage at diagnosis after age and geographic location were adjusted for.

RESULTS

High-grade (poorly differentiated) lesions increased the risk for stage III or IV disease (odds ratio 8.3, 95% confidence interval 3.4 to 20.3), as did serous histologic subtype (odds ratio 3.5, 95% confidence interval 1.4 to 8.8) and no usual source of care (odds ratio 5.5, 95% confidence interval 1.4 to 20.9). In the final statistical model these three factors also accounted for the majority of the excess risk of advanced stage for blacks.

CONCLUSIONS

Black-white racial disparities in stage at diagnosis appear to be related to higher-grade lesions and more aggressive histologic subtypes occurring more frequently in black patients with endometrial cancer.

Endometrial cancer chemoprevention: implications of diverse pathways of carcinogenesis

Endometrial cancers may be divided into two groups, reflecting differences in clinical behavior and pathogenesis. Endometrioid adenocarcinoma, which accounts for the majority of endometrial cancers, typifies the group of endometrial carcinomas that develop from atypical endometrial hyperplasia in the setting of excess estrogenic stimulation. In contrast, serous carcinomas are representative of endometrial tumors that occur in older women who have endometrial atrophy and lack the typical endometrial cancer risk factors reflecting unopposed estrogen exposure. Serous carcinomas are frequently associated with p53 abnormalities and appear to develop from a surface lesion termed endometrial intraepithelial carcinoma. Although serous carcinomas are rare, these highly aggressive tumors account for a disproportionate number of endometrial cancer deaths. Further delineation of the estrogen-dependent and estrogen-independent pathways of endometrial carcinogenesis may be useful in developing comprehensive chemopreventive approaches for endometrial cancer.