Expression of steroid receptors, Ki-67, and epidermal growth factor receptor in tamoxifen-treated endometrium.

Endometrial specimens of 34 (25 premenopausal and 9 postmenopausal) breast cancer patients receiving tamoxifen were immunohistochemically examined using estrogen receptor (ER), progesterone receptor (PR), Ki-67, and epidermal growth factor receptor (EGFR) antibodies. Proliferative (n = 6), secretory (n = 9), and postmenopausal (n = 6) endometria served as controls. The ER and PR expressions of the glandular cells in tamoxifen-treated patients did not differ from those of the glandular cells in the control women regardless of menopausal status. The Ki-67 index of glandular cells in tamoxifen-induced amenorrheic women was found to be lower than that of the proliferative glandular cells in the control women (p < 0.03), whereas the Ki-67 index of glandular cells in the tamoxifen-treated postmenopausal patients was higher than that of the glandular cells in the control women (p < 0.02). No EGFR overexpression was found in the glandular cells of the tamoxifen-treated premenopausal patients, but expression of EGFR was high in glandular cells of the tamoxifen-treated postmenopausal patients associated with a high Ki-67 index. In competition with ovarian estrogen secretion, tamoxifen may have an antiestrogenic effect on the endometrium, but tamoxifen probably has an estrogenic effect in the absence of ovarian estrogen secretion. This estrogenic effect of tamoxifen may be associated with an EGFR autocrine system.     

绝经期乳腺癌妇女服用他莫昔芬后Ki-67及Bcl-2在子宫内膜中的表达

目的:评估绝经期乳腺癌妇女服用他莫昔芬(tamoxifen,TAM)后Ki-67及Bcl-2在子宫内膜中的表达。方法:46例绝经后因乳腺癌服用TAM超过6个月妇女的子宫内膜为研究组,行宫腔镜检查及内膜活检。18例因子宫脱垂行子宫切除的绝经后妇女的萎缩型子宫内膜为对照组。用免疫组化法测定Ki-67及Bcl-2在子宫内膜中的表达。结果:与对照组比较,Ki-67在TAM相关内膜腺上皮细胞呈显著高表达(15.41±4.83vs9.05±5.52,P=0.009);Bcl-2在TAM相关内膜腺上皮细胞呈较高表达,但与对照组比较无统计学差异(0.50±0.17vs0.43±0.11,P=0.077)。结论:绝经后乳腺癌妇女服用TAM能引起子宫内膜细胞增殖,但并不代偿性促进细胞凋亡,诱导细胞增殖是TAM对绝经后子宫内膜作用机理的一部分。     

Endometrial patterns and endocrinologic characteristics of asymptomatic menopausal women

The endometrial histology and endocrinologic and demographic characteristics of 556 asymptomatic postmenopausal women ,who attended the menopause outpatient clinic at Ankara Numune Education and Research Hospital were studied before initiating estrogen replacement therapy. Of these women ,486 (87.4%) had atrophic endometrium ,37 (6.65%) had proliferative endometrium ,27 (4.86%) had endometrial hyperplasia without atypia ,three (0.54%) had endometrial hyperplasia with atypia and three (0.54%) had endometrial adenocarcinoma on their biopsy specimens. When demographic characteristics of the patients were considered, we found that the patients with endometrial adenocarcinoma and endometrial hyperplasia with atypia had potential risk factors for endometrial pathology such as chronic anovulation ,diabetes or hypertension. This study confirms that routine endometrial sampling in asymptomatic postmenopausal women is not warranted ,but patients with associated risk factors should be screened for endometrial pathology before starting estrogen replacement therapy.     

Endometrial patterns and endocrinologic characteristics of asymptomatic menopausal women.

The endometrial histology and endocrinologic and demographic characteristics of 556 asymptomatic postmenopausal women, who attended the menopause outpatient clinic at Ankara Numune Education and Research Hospital were studied before initiating estrogen replacement therapy. Of these women, 486 (87.4%) had atrophic endometrium, 37 (6.65%) had proliferative endometrium, 27 (4.86%) had endometrial hyperplasia without atypia, three (0.54%) had endometrial hyperplasia with atypia and three (0.54%) had endometrial adenocarcinoma on their biopsy specimens. When demographic characteristics of the patients were considered, we found that the patients with endometrial adenocarcinoma and endometrial hyperplasia with atypia had potential risk factors for endometrial pathology such as chronic anovulation, diabetes or hypertension. This study confirms that routine endometrial sampling in asymptomatic postmenopausal women is not warranted, but patients with associated risk factors should be screened for endometrial pathology before starting estrogen replacement therapy.     

Ultrastructural effects of estrogen replacement on postmenopausal endometrium

Endometrial adenocarcinoma occurs almost exclusively in postmenopausal women, and excessive or unopposed estrogen stimulation is suspect as a causative factor in its pathogenesis. Furthermore, the incidence of endometrial adenocarcinoma has increased in women undergoing estrogen replacement therapy. In the present study, the cellular response of premenopausal and postmenopausal endometrium to estrogenic stimulation was compared with endometrial adenocarcinoma by the electron microscope. Tissues were obtained at hysterectomy, endometrial biopsy, or endometrial curettage and were processed routinely for light and electron microscopy. Ultrastructurally the endometrium from postmenopausal patients undergoing estrogen replacement therapy was similar to normal cyclic endometrium in the late proliferative phase. At least three features of the estrogen-treated postmenopausal tissue resembled those observed in adenocarcinoma of the endometrium: accumulation of lipid droplets, irregular nuclei, and perinuclear whorls of microfibrils.     

Heparanase expression increases throughout the endometrial hyperplasia-cancer sequence.

OBJECTIVE: To assess the expression of heparanase in the different stages leading to endometrial cancer. METHODS: The 38 examined specimens included adenocarcinoma, hyperplasia, and normal endometrium specimens. Heparanase, estrogen, and progesterone receptor expressions were analyzed immunohistochemically and the intensity was scored. RESULTS: Secretory normal endometrium and simple hyperplasia specimens expressed the lowest mean values of expression (1.00 and 0.63, respectively); the complex hyperplasia specimens and G2 endometrioid adenocarcinoma showed the highest values of expression (2.33 and 2.71, respectively). A linear trend (P=0.005) of heparanase expression was observed when comparing the normal endometrium and simple hyperplasia group with the complex hyperplasia+G1 carcinoma group and the G2+G3 carcinoma group. Evaluation of atrophic and inactive endometrium compared with papillary serous carcinomas yielded no significant differences. We found no significant correlation between heparanase expression and estrogen receptor or progesterone receptor expression. CONCLUSION: Heparanase expression was tightly regulated in endometrial tumorigenesis.     

Comparison of endometrial pathologies collected by hysteroscopy and hysterectomy in postmenopausal breast cancer tamoxifen-treated patients

PURPOSE OF INVESTIGATION: 1) To assess whether endometrial specimens obtained from removed uteri might show an increase in endometrial pathologies which had been previously diagnosed by hysteroscopy in postmenopausal breast cancer tamoxifen-treated patients. 2) To assess whether hysteroscopy is an efficient method of detecting endometrial pathologies in such patients. METHODS: The findings of two consecutive pathological evaluations in 18 postmenopausal breast cancer tamoxifen-treated patients, performed 11.2+/-11.2 months apart, were compared. The first specimen was collected by hysteroscopy and the second was obtained following hysterectomy. RESULTS: The most significant changes observed were three new cancers diagnosed at hysterectomy, one of which was poorly-differentiated. In the first (hysteroscopy) samplings, one patient had atrophic endometrium, a second patient had endometrial proliferation and a third patient had a benign endometrial polyp. Overall, 55.6% of the study patients had various endometrial pathologies in the first sampling, while 83.3% had endometrial pathologies in the second sampling. However, this difference was not statistically significant. CONCLUSION: 1) Endometrial histologic evaluations, performed on removed uteri 11.2+/-11.2 months following previous endometrial samplings of postmenopausal breast cancer tamoxifen-treated patients, showed a non-significant risk of developing overall endometrial pathologies. 2) Hysteroscopy may have missed some endometrial pathologies which were diagnosed later on in specimens obtained by hysterectomy.     

Expression of fos and jun proto-oncogenes in benign versus malignant human uterine tissue

OBJECTIVE: The objective of this study was to evaluate expression of fos and jun proto-oncogenes in benign human uterine tissue compared with malignant uterine tissue. METHODS: Forty-two endometrial tissue specimens were obtained at the time of hysterectomy. Tissue samples from different phases of the menstrual cycle and from postmenopausal patients were stained using immunohistochemical methods to detect Fos and Jun proteins, estrogen and progesterone receptor status, and Ki67 (detects a nuclear antigen associated with proliferating cells). Tissue was examined microscopically for nuclear staining in endometrial epithelium and stroma. The endometrium was based on the patient's last menstrual period, pathologic dating, and proliferative versus nonproliferative status as determined by Ki67. Benign and malignant specimens were subjected to Northern blot analysis to evaluate levels of expression of c-fos, c-jun, and jun-B mRNA. The pattern of c-fos mRNA expression in malignant samples was further evaluated using in situ hybridization. RESULTS: In proliferative, secretory, postmenopausal, and progesterone-influenced, uterine specimens immunohistochemically stained and examined, the endometrial and stromal nuclei stained for both Fos and Jun in varying intensities. However, no pattern was found in the variation of intensity according to the phase of the endometrium. Similarly, in malignant and benign endometrial tissue examined by Northern blot and in situ hybridization analyses, expression of proto-oncogene mRNAs was readily detectable, but no statistical correlation between type of tissue examined, grade of adenocarcinoma, and stage of endometrial cancer was found in this study. CONCLUSIONS: In rodent models, control of uterine cell proliferation is related to change in expression of fos and jun proto-oncogenes. Our results indicate that hormonal control is likely to be different in human endometrium and probably involves genes other than the proto-oncogenes under study. Expression of Fos and Jun do not correlate with endometrial cancer stage and grade.     

Sonographic, hysteroscopic, and histologic evaluation of the endometrium in postmenopausal women with breast cancer receiving tamoxifen

STUDY OBJECTIVE: To evaluate the estrogenic effects of tamoxifen on the endometrium in postmenopausal women with breast cancer. DESIGN: Consecutive study (Canadian Task Force classification II-2). SETTING: University-affiliated hospital. PATIENTS: Thirty-three women. Interventions. All patients underwent transvaginal sonography (TVS) and color flow Doppler of endometrial vessels, hysteroscopy, and, if necessary, endometrial biopsy or other operative hysteroscopic procedures. MEASUREMENTS AND MAIN RESULTS: In four women the endometrium was thin on TVS and atrophic at hysteroscopic assessment. In 29 women with thick endometrium on TVS, hysteroscopy and endometrial biopsy showed atrophy (11 patients), hyperplasia (5), polyps (11), and well-differentiated adenocarcinoma (2). The two endometrial cancers were present in women with uterine bleeding. In women with positive histologic findings, the endometrium was significantly thicker (p = 0.04) and duration of tamoxifen therapy longer than in those with negative findings, although this was not statistically significant (p = 0.067). CONCLUSION: We believe regular assessment of the endometrium by TVS should be performed in postmenopausal patients at the start of the tamoxifen therapy, and hysteroscopy in women with a thick endometrium or postmenopausal bleeding. We believe that patients with thin endometrium on TVS at the beginning of tamoxifen therapy, who have no abnormal uterine bleeding should be screened with these examinations for 2 years.     

The differential expression of oestrogen receptors, progesterone receptors, Bcl-2 and Ki67 in endometrial polyps

Objective To obtain a greater understanding of the pathogenesis of endometrial polyps and to gain insight into which factors play a pivotal role in their growth.
Design Retrospective analysis of archived paraffin-embedded specimens.
Setting St James's University Hospital.
Sample Thirty secretory phase endometrial samples, 10 secretory phase endometrial polyps, 8 proliferative phase endometrial samples and 10 proliferative phase endometrial polyps.
Methods Immunohistochemistry was used to characterise the expression of oestrogen and progesterone receptors, Bcl-2 and Ki67 in cycling endometrium and phase-matched endometrial polyps. Patterns of expression were compared between the polyps and the endometrium.
Main outcome measure The expression of oestrogen receptors, progesterone receptors, Bcl-2 and Ki67.
Results Three significant differences were found between the endometrium and the polyps. Polyps taken from the proliferative phase of the cycle displayed significantly elevated expression of Bcl-2 and weak or no expression of progesterone receptors. Secretory phase polyps displayed an elevated expression of oestrogen receptors.
Conclusion A localised increase in Bcl-2 expression and consequential decline or cessation of apoptosis is an important mechanism underlying the pathogenesis of endometrial polyps. Elevated Bcl-2 expression results in failure of the polyp tissue from undergoing normal cyclical apoptosis during the late secretory phase. This may mean the polyp is not shed along with the rest of the endometrium during menstruation.     

Tamoxifen increases plasma estrogen-binding equivalents and has an estradiol agonistic effect on histologically normal premenopausal and postmenopausal endometrium.

OBJECTIVE: To determine the effects of single dose tamoxifen on plasma estrogen (E)-binding equivalents and endometrial estradiol (E2) and progesterone (P) receptors. DESIGN: Controlled clinical study. SETTING: Normal human volunteers were studied in an academic research environment. PATIENTS: Premenopausal and postmenopausal women with histologically normal endometrium undergoing curettage or hysterectomy were selected. INTERVENTIONS: Tamoxifen was administered orally; blood and endometrial samples were collected 4 to 96 hours after tamoxifen administration. MAIN OUTCOME MEASURES: Plasma E-binding equivalents, endometrial cytosolic and nuclear E2 and P receptors. RESULTS: (1) Plasma E-binding equivalents increased eightfold at 4 to 24 hours of tamoxifen administration and declined exponentially thereafter, reaching control levels at 73 to 96 hours. Plasma E-binding equivalents were not affected by endogenous E2 levels. (2) Endometrial total E2 and P receptor levels increased in all women 2.9 to 19.2-fold after tamoxifen. (3) Tamoxifen resulted in an increase in the fraction of the E2 receptor measured in the nuclear extract 2.1 to 7.5-fold in midcycle, secretory, and menopausal endometria but not in proliferative endometrium. CONCLUSIONS: (1) Tamoxifen has an E2 agonistic effect on histologically normal human endometrium. (2) Irrespective of the total level of the endometrial E2 receptor, the nuclear capacity of that receptor in vivo is limited (approximately 75% to 80% of the total level).     

Subsequent endometrial carcinoma with adjuvant tamoxifen treatment in Japanese breast cancer patients

Abstract. Nishimura N, Hachisuga T, Saito T, Kawarabayashi T. Subsequent endometrial carcinoma with adjuvant tamoxifen treatment in Japanese breast cancer patients.
This study aimed to detail the clinicopathologic features of endometrial carcinomas that developed in Japanese patients receiving adjuvant tamoxifen treatment for breast cancer patients. Ten endometrial carcinomas in tamoxifen-treated breast cancer patients were collected from two medical centers. The endometrial carcinomas included two stage Ia, four stage Ib, two stage Ic and two stage IIIc. Three tumors were Grade 1, six were Grade 2, and one was Grade 3. The tumor was limited to the endometrium in two cases. Myometrial invasion was limited to the inner half of the myometrium in five cases and involved the outer half in three. A mild degree of lymphovascular space invasion was identified in five cases. Deep cervical invasion was recognized in one case. The cell types comprised nine endometrioid adenocarcinomas and one serous carcinoma. Five of eight postmenopausal endometrial carcinomas were associated with polypoid endometrial lesions composed of cystically dilated atrophic and proliferative glands widely separated by fibrotic stroma. Two patients with retroperitoneal lymph node metastases died of endometrial cancer. One patient developed a contralateral breast cancer during tamoxifen treatment. No patient died of breast cancer. We did not demonstrate a higher frequency of either high-grade tumors or unfavorable histologic subtypes in tamoxifen-treated Japanese breast cancer patients.     

Discrepancy between ultrasonography and hysteroscopy and histology of endometrium in postmenopausal breast cancer patients using tamoxifen

BACKGROUND: The increased risk of endometrial carcinoma following the use of tamoxifen has stimulated studies on endometrial diagnostic screening methods. In tamoxifen users the endometrial thickening observed with transvaginal ultrasonography (TVU) frequently cannot be confirmed by hysteroscopy or histology. OBJECTIVE: The aim was to investigate the relationship between TVU and hysteroscopic and histologic endometrial findings in postmenopausal patients using tamoxifen. METHODS: Fifty-three asymptomatic postmenopausal tamoxifen-using breast cancer patients underwent a gynecological examination combined with TVU. Patients with an endometrial thickness of >5 mm were offered hysteroscopy and endometrial biopsy. FINDINGS: Thirty-one patients (58%) had an endometrial thickness of >5 mm with enhanced, inhomogeneous echogenicity. Hysteroscopy was performed in 22 patients and 3 underwent hysterectomy. Seven of 22 patients had endometrial polyps, histologically characterized by cystically dilated glands lined with atrophic epithelium and periglandular stromal condensation. Histology of the three hysterectomy specimens showed a similar picture of atrophic luminal epithelium, covering dilated glands lined with atrophic epithelium and surrounded by dense stroma, which resembled the histology of the endometrial polyps. In all three specimens the histologically measured endometrial thickness corresponded with that on TVU. INTERPRETATION: Tamoxifen can induce specific endometrial changes consisting of cystically dilated glands with periglandular stromal condensation while the overlying epithelium remains atrophic. The changes occur either in the endometrium itself or as a protrusion of the endometrium, i.e., as endometrial polyps. These findings explain the discrepancy between ultrasound, hysteroscopy, and histology. Due to the high number of false-positive findings, TVU is not an effective screening instrument in these patients.     

Cytosol and nuclear estrogen and progestin receptors and 17 beta-hydroxysteroid dehydrogenase activity in normal and carcinomatous endometrium

Endometrial estrogen and progestin receptors were quantitatively measured in the cytosol (ERc, PRc) and nuclear (ERn, PRn) fractions, the activity of 17 beta-hydroxysteroid dehydrogenase measured in 13 normal women in the late proliferative phase of the cycle (control group), in 33 patients with adenocarcinoma, and in 6 patients with other malignancies of the endometrium. The parameters measured had relatively small variations in the control group, whereas the opposite was true for the malignant endometrium. ERc and PRc were present in significantly higher concentrations in normal endometrial tissue (167 and 1697 fmol/mg cytosol protein, respectively) than in malignant endometrial tissue (45 and 116 fmol/mg cytosol protein, respectively), and the ratios of ERc/ERn and PRc/PRn were higher (P much less than .001 in both cases) in the normal group. The activities of 17 beta-hydroxysteroid dehydrogenase were identical in normal and adenocarcinoma tissue and correlated with PRc in carcinomatous endometrium. The present results support previous findings that the great majority of endometrial adenocarcinoma specimens have significant concentrations of ERc and PRc and that these concentrations are lower than in normal endometrium. In addition, they demonstrate that nuclear location of the female sex steroid receptors is favored in the malignant tissue. Despite these differences, the 17 beta-hydroxysteroid dehydrogenase activities were identical in proliferative endometrium and in endometrial adenocarcinoma.     

Endometrial pathology of 104 postmenopausal breast cancer patients treated with tamoxifen

OBJECTIVE: To investigate the effects of tamoxifen on the endometrium in postmenopausal breast cancer patients. METHODS: Endometrial thickness was measured by transvaginal sonography and endometrial biopsies were done in 104 postmenopausal breast cancer cases who were treated with tamoxifen. Histopathologic findings were discussed. RESULTS: Mean endometrial thickness was 11.7+/-5.9 mm and duration of tamoxifen administration was 35.3 months. Four endometrial cancers, 17 endometrial hyperplasias, 25 proliferative endometrium, 5 endometrial polyps in the endometrial biopsies. We observed atrophic endometrium in 53 of the cases. Only one case with endometrial polyps was observed as a premalignant lesion when the endometrium was less than 5 mm, 51% of the cases had thicker endometrium (more than 10 mm) and 32% of these cases had malignant and premalignant endometrium. We found a significant correlation with the duration of tamoxifen and age (p<0.05). One hundred and two of our cases were asymptomatic; only 2 out of 4 endometrial cancer cases had vaginal spotting. A significant relation was noticed between endometrial thickness and duration of tamoxifen treatment (p=0.025). CONCLUSION: It was concluded that positive endometrial findings and endometrial thickness were due to continuous unopposed tamoxifen treatment and our findings support the hypothesis that tamoxifen increases the risk of endometrial carcinoma and premalignant changes.     

Global gene expression profiling of proliferative phase endometrium reveals distinct functional subdivisions

The human endometrium follows a predictable pattern of development during the proliferative phase. Endometrial thickness increases after day 3 and then plateaus at days 9 to 10 of the menstrual cycle despite continued high serum levels of estrogen. We hypothesized that proliferative phase endometrium undergoes more than simple estrogen responsive growth, rather it is characterized by complex time-dependent functional activities reflected in differential gene expression. Nine endometrial RNA samples from healthy participants were subjected to microarray analysis and 15 samples were used for quantitative real-time polymerase chain reaction. The samples were divided into early, mid, or late proliferative phase. The early proliferative phase showed higher expression of genes including transforming growth factor β2, chemokine (C-C motif) ligand 18 (CCL18), and metallothionein 2A. The mid-proliferative phase was characterized by higher expression of heat shock proteins and implantation-associated genes including Indian hedgehog, secreted frizzled protein 4, and progesterone receptor. In the late proliferative phase, we identified increased angiotensin II receptor, type 2 and large decrease in expression of genes related to natural killer (NK) cell function. We demonstrate a unique gene expression signature at distinct time points within the proliferative phase. The early proliferative phase is characterized by tissue remodeling, angiogenesis, and modulation of inflammation; the mid-proliferative phase is characterized not only by proliferation in response to estrogens but also marks the onset of expression of genes required for endometrial receptivity and a dampening of estrogen responsiveness. In the late proliferative phase, changes in immune function and NK cells predominate. The proliferative phase is not simply a uniform period of estrogen responsive endometrial growth that can be considered as a single experimental time point when evaluating endometrial development; rather the proliferative phase is complex with differing functions and patterns of gene expression.     

Malignant endometrial polyps in postmenopausal breast cancer tamoxifen-treated patients.

BACKGROUND: Endometrial polyps are the most common endometrial pathology described in association with postmenopausal tamoxifen exposure. It is generally accepted that the occurrence of malignancy in endometrial polyps among healthy women is up to 0.5%. However, no one has yet described the incidence of this malignant transformation among postmenopausal breast cancer tamoxifen-treated patients. Objective. The aim of this study was to study the exact rate of malignant changes in endometrial polyps recovered from postmenopausal breast cancer tamoxifen-treated patients. METHODS: We reviewed the pathological results and medical records of all postmenopausal breast cancer patients in whom endometrial polyps were recovered following at least 6 months of tamoxifen treatment in our institute. We also looked for the rate of malignant changes in polyps recovered from all healthy postmenopausal controls with endometrial polyps in our institute during the period of the study. RESULTS: Two (3.0%) of 67 endometrial polyps recovered from postmenopausal breast cancer tamoxifen-treated patients revealed malignant features. None of the clinical variables tested, including risk factors for endometrial cancer, was significantly different between the groups. In the controls only 5 (0.48%) of 1034 polyps were malignant. CONCLUSION: Up to 3.0% of endometrial polyps recovered from postmenopausal breast cancer tamoxifen-treated patients may show malignant changes. This rate is higher than that found in our controls as well as that reported in the general female population.     

长期应用小剂量米非司酮对子宫内膜形态和雌、孕激素受体的影响

本文利用HE染色和免疫组化方法结合计算机辅助图象分析技术观察了长期服用小剂量米非司酮对子宫内膜形态和雌、孕激素受体（ER、PR）的影响，15例子宫肌瘤患者于早卵泡期服用来非司酮（10例，10mg／日；5例，20mg／日）治疗，1～3个月后取内膜，另10例肌瘤患者取内膜作对照。结果：用药后所有的患者均闭经，内膜变薄，发育不良，无周期性改变，大部分基质致密，基质与腺体发育不同步，同时相间存在增殖与分泌期样改变，以增殖期样改变为主，腺体以分泌期样改变为主，腺体大小形态不一，但分泌不良。免疫组化显示内膜ER、PR明显分布不均，图象分析结果表明用药后内膜ER、PR相当于对照组增殖早中期水平。结果表明每日10mg米非司酮可明显抑制排卵并影响内膜成熟，在无孕激素存在的情况下，米非司酮有微弱的孕激素样作用。     

An immunohistochemical study of estrogen and progesterone receptors in adenocarcinoma of the endometrium and in the adjacent mucosa

The immunoperoxidase stain for estrogen and progesterone receptor content in endometrial adenocarcinoma was correlated with the grade and stage, level of myometrial invasion, age and survival of the patients. Anti-estrogen and anti-progesteone receptor monoclonal antibodies were applied to paraffin-embedded tissue from hysterectomy specimens of 100 patients with adenocarcinoma of the endometrium. In 34 of the cases the receptors were studied in the endometrium adjacent to the tumor and compared to the nuclear receptor content in the carcinoma. There was a high inverse correlation between the estrogen receptor status and the grade of tumor ( R = − 0.45, P = 0.006). The estrogen receptor measured in the endometrium near the tumor showed a negative correlation with the grade of the tumor ( R = −0.42, P = 0.013). The estrogen, but not the progesterone, receptor content, was positively related to the age of the patient ( P < 0.05). No significant correlation of the receptor status with the depth of myometrial invasion was found, despite the obvious interdependence between the grade and myometrial invasion. The progesterone receptor staining index appeared to be a distinct independent prognostic factor in endometrial cancer. The immunohistochemical analysis of the steroid hormone status in endometrial cancer therefore offers an alternative to the quantitative ligand-binding assay.