PTEN、bcl-2/Bax表达预测子宫内膜增生孕激素治疗反应的研究

目的:研究孕激素治疗前后子宫内膜增生组织中PTEN基因、bcl-2/Bax的表达,结合临床治疗效果探讨其在预测孕激素治疗反应中的作用。方法:回顾分析子宫内膜增生患者56例(复杂性增生31例,非典型性增生25例),孕激素治疗3个月,留取治疗前后子宫内膜组织,取石蜡切片进行免疫组化染色,应用H-score评价孕激素治疗前后子宫内膜腺体中PTEN、bcl-2/Bax的表达。结果:(1)56例患者治疗3个月后,44例(78.57%)缓解,7例(12.50%)有效,1例(1.79%)治疗后复发,4例(7.14%)治疗无效,平均随访(33.49±9.62)个月。复杂性增生、轻度非典型性增生和中重度非典型性增生3组缓解+有效率的差异无统计学意义(P=0.245)。(2)子宫内膜增生组织中PTEN基因表达缺失率为16.07%(9/56),PTEN表达阳性组缓解+有效率为97.87%(46/47),PTEN表达阴性组缓解+有效率为55.56%(5/9),两组间比较差异有统计学意义(P<0.05)。(3)56例患者孕激素治疗前后子宫内膜腺体中bcl-2及Bax表达均阳性。缓解和有效组与复发和无效组治疗前bcl-2/Bax的H-score值无明显差异(P=0.486),两组治疗前后H-score差值亦无明显差异(P=0.368)。结论:子宫内膜增生组织中PTEN基因表达阳性组对孕激素治疗反应较好,PTEN基因表达缺失可能提示病变对孕激素抵抗,因此治疗前检测子宫内膜腺体细胞中PTEN基因的表达可以预测疗效;bcl-2/Bax不能作为预测孕激素治疗反应的指标。     

Apoptosis may be an early event of progestin therapy for endometrial hyperplasia

OBJECTIVE: The aim of this study was to investigate the role of apoptosis during progestin therapy for the treatment of endometrial hyperplasia. METHODS: Pre- and posttreatment paraffin-embedded endometrial tissue samples from 19 women with endometrial hyperplasia were examined for changes in glandular cellularity and apoptotic activity related to the administration of progestins. Twelve patients were successfully treated with progestin therapy and 7 patients failed treatment. Glandular cellularity was assessed based on calculating the average number of cells per gland obtained on histologic examination of hematoxylin and eosin stained tissue sections. Apoptotic activity was assessed on the same tissue sections by counting the average number of apoptotic cells per 10 high power fields (hpf) using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay. The effects of progesterone on apoptotic activity in a low-grade endometrial adenocarcinoma cell line (Ishikawa cells) was also examined using an ELISA cell death detection kit. RESULTS: Glandular cellularity significantly decreased with progestin therapy in both treatment outcome groups. The reduction in cells per gland was significantly greater in the group of successfully treated cases compared to the treatment failures (P = 0.005). However, within the successfully treated group, in situ detection of apoptotic cells using the TUNEL assay showed no statistical difference between pre- and posttreatment endometrial samples. Interestingly, a significant decrease in apoptosis was found in posttreatment samples of the group with persistent hyperplasia. The average number of apoptotic cells detected in 10 hpf was reduced from 7.9 prior to treatment to 3.1 after progestin therapy (P = 0.03). In the progesterone-treated Ishikawa cell line, an increase in apoptotic activity started at 24 h, reached a peak at 48 h, and continued up to 72 h of hormone treatment. At 48 h, apoptotic activity was 42.6% greater than in the untreated control (P = 0.04). By 72 h of progesterone treatment, apoptosis was 37.2% greater in the treated cells compared to the noninoculated cells (P = 0.04). CONCLUSIONS: Progestin-induced apoptosis may occur during the early period of treatment for endometrial hyperplasia. Compared to the fully responsive group, persistent endometrial hyperplasia may have intrinsically different molecular mechanisms in response to progestin therapy.     

Treatment of non-atypic endometrial hyperplasia using thermal balloon endometrial ablation therapy

BACKGROUND/AIM: Traditionally endometrial hyperplasias have been treated with progestins. Unfortunately, quite often hyperplasias are resistant to treatment, or they recur after therapy. The aim of the study was to compare traditional progestin administration with thermal balloon endometrial ablation in the treatment of non-atypic endometrial hyperplasia. METHODS: Women with endometrial hyperplasia (n = 34) were randomized in a 1:1 allocation ratio. Endometrial biopsy samples were taken 6 and 12 months after the treatment; if any signs of hyperplasia were detected, hysterectomy was performed. In addition, the hospital records were checked in September 2003 to observe for any later hysterectomy. Main outcome measures were recovery from hyperplasia and avoidance of hysterectomy. RESULTS: In patients treated with thermal ablation, the hyperplasias persisted at 6 or 12 months in 4 out of 17 patients, whereas the rate was 6 out of 17 patients in the progestin therapy group. According to patient records, 1 further patient treated with thermal ablation and 3 further patients treated with progestin were hysterectomized after the last visit. A total of 14 of the 34 patients (41%) have been hysterectomized so far. CONCLUSIONS: These preliminary results suggest that thermal balloon endometrial ablation therapy seems to be as effective as traditional progestin administration in the treatment of non-atypic endometrial hyperplasia. The hysterectomy rate during the follow-up period was, however, considerably high, and, therefore, hysterectomy might be considered even a first-choice treatment for endometrial hyperplasias.     

Mechanisms involved in the evolution of progestin resistance in human endometrial hyperplasia--precursor of endometrial cancer

BACKGROUND: Successful treatment of endometrial hyperplasia with progestins is commonly accompanied by the finding of an inactive or suppressed endometrium after therapy. However, approximately 30% of the endometrial hyperplasia cases do not respond to progestins and hyperplastic glands persist. The Fas/FasL system is known to play a role in tissue remodeling as a result of changes in menstrual hormone levels. The aims of this study are to examine Fas/FasL expression in endometrial hyperplasia of pre- and postprogestin treatment samples and to study the Fas/FasL regulation in vitro with Ishikawa cells after progestin stimulation. DESIGN: Pre- and posttreatment paraffin-embedded endometrial hyperplasia tissue samples from 26 women were examined by immunohistochemistry for changes in Fas/FasL expression related to the administration of progestins. Among 26 patients, 18 were successfully treated with progestins and 8 failed treatment. Fas/ FasL positivity was defined by the presence of 10% or more immunoreactive epithelial cells in each specimen. In positive cases, a percentage or an immunoscore of immunoreactive cells was given by counting 500 cells. Cell viability was evaluated by the MTT assay. The in vitro effects of progesterone on Fas/FasL expression and apoptosis in Ishikawa cells were examined by using Western blot and TUNEL assays, respectively. RESULTS: Fas immunoreactivity was present in 4/26 (15%) preprogestin cases with an average of 16% of the epithelial cells expressing Fas. FasL was expressed in 21/26 (80%) pretreatment cases with an average of 42% of the hyperplastic glandular cells being positive. In postprogestin cases, an increase of Fas expression (14/18, 77%) with an average of 47% stained cells was seen in responders (P < 0.001), while FasL was found in 16/18 (89%) responders with an average of 65% of cells positive (P = 0.587). In nonresponders, no significant changes in Fas/FasL expression were detected compared to pretreatment samples. With in vitro Ishikawa cells, a slight increase (10-20%) of Fas and FasL protein expression was detected after 24 h of progesterone treatment, but a more significant increase (220-343%) of both Fas and FasL expression was found after 48 h of withdrawing progesterone, which parallels apoptotic activity. CONCLUSIONS: The Fas/FasL system may be involved in the development of endometrial hyperplasia. Part of the molecular mechanisms of progestin therapy for endometrial hyperplasia is through upregulation of Fas/FasL expression. Dysregulation of Fas/FasL expression in hyperplastic endometrium may be part of the molecular mechanisms for nonresponders to progestin treatment. Intermittent, rather than continuous, progestin treatment may be more effective clinically for the treatment of endometrial hyperplasia.     

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

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

The effectiveness of a levonorgestrel-releasing intrauterine system (LNG-IUS) in the treatment of endometrial hyperplasia--a long-term follow-up study

OBJECTIVES: Medical treatment of non-atypical endometrial hyperplasia with oral progestogens has limited efficacy and poor compliance. A levonorgestrel-releasing intrauterine system (LNG-IUS) has been shown to successfully treat hyperplasia in small-sized studies. Our aim was to examine the effectiveness of LNG-IUS in a larger study with long-term follow up. STUDY DESIGN: Prospective observational study of 105 women diagnosed with endometrial hyperplasia and treated with LNG-IUS between 1999 and 2004 at a University Teaching hospital. Baseline characteristics and outpatient endometrial Pipelle sampling were undertaken at 3 and 6 months post LNG-IUS insertion and 6-monthly intervals thereafter in all cases. Outcome included histological data derived from both Pipelle and uterine histologies at 1 and 2 years LNG-IUS therapy. RESULTS: LNG-IUS achieved endometrial regression in 90% (94/105) of cases by 2 years, with a significant proportion (96%, 90/94) achieving this within 1 year. Regression occurred in 88/96 (92%) of non-atypical and 6/9 (67%) of atypical hyperplasias, and in all 22 cases of endometrial hyperplasia associated with HRT. Regression rates did not differ between histological types of hyperplasia. Twenty-three women (22%) underwent hysterectomy of which 13 were indicated and 10 were performed at patient request despite regressed endometrium. Two cases of cancer (one uterine and one ovarian) were identified. CONCLUSION: LNG-IUS is highly effective in treating endometrial hyperplasia. Beneficial effects are observed by the majority within 1 year. Treatment can be reliably monitored through regular 6-montly outpatient endometrial Pipelle surveillance. LNG-IUS treatment of non-atypical hyperplasias is likely to reduce the number of hysterectomies performed in this subgroup.     

Hormonal aspects of endometrial cancer

In summary, endometrial cancer is an estrogen-related neoplasm whose precursor lesion, endometrial hyperplasia, may be successfully treated with progestational agents. Trials of adjunctive progestin therapy have failed to demonstrate benefit, even though the malignancy is sensitive to palliative therapy with progestins as well as tamoxifen. Paradoxically, chronic tamoxifen exposure in postmenopausal women may increase the risk of endometrial cancer, and such women must be followed closely. Progesterone receptor may be measured using competitive binding assays or by immunohistochemical techniques. There is tumor heterogeneity with regard to progesterone receptor. Tissues surrounding the cancer may contain progesterone receptor and produce false-positive results in biochemical assays. Last, the presence of progesterone receptor not only predicts responsiveness to progestational therapy, but also confers a survival advantage in patients with endometrial cancer.     

Molecular analysis of endometrial hyperplasia in HNPCC-suspicious patients may predict progression to endometrial carcinoma.

Women predisposed to hereditary nonpolyposis colorectal cancer are at high risk of developing endometrial carcinoma at a young age. Hereditary nonpolyposis colorectal cancer-associated endometrial carcinomas are of the endometrioid type, usually arise from complex atypical hyperplasia, and often show microsatellite instability. To identify occult hereditary nonpolyposis colorectal cancer individuals among endometrial carcinoma patients, we examined complex atypical hyperplasias and endometrial carcinomas of 60 women < or =50 years of age (mean age: 35.7 years) using microsatellite instability, immunohistochemistry, and DNA sequence analysis. Three patient groups were recruited: group 1, patients with complex atypical hyperplasia exclusively (n = 27); group 2, patients with complex atypical hyperplasia and synchronous or metachronous endometrial carcinoma (n = 15); group 3, patients with endometrial carcinoma only (n = 18). Overall, 13 of 33 endometrial carcinomas (39%) displayed high-level microsatellite instability. None of the complex atypical hyperplasias in group 1 had high-level microsatellite instability or loss of hMLH1/hMSH2 protein expression. In group 2 patients, 33% of complex atypical hyperplasias and 53% of endometrial carcinomas had high-level microsatellite instability. Loss of hMSH2 protein expression was found in six endometrial carcinoma patients, five of them with verified hMSH2 germline mutations, including four patients with high-level microsatellite instability in complex atypical hyperplasia. Among group 3 patients, 28% of endometrial carcinomas displayed high-level microsatellite instability; three of those five endometrial carcinomas were from patients with multiple extrauterine hereditary nonpolyposis colorectal cancer-associated tumors. We conclude that young women (< or =50 years of age) with concurrent complex atypical hyperplasia and multiple hereditary nonpolyposis colorectal cancer-associated carcinomas are at risk of developing high-level microsatellite instability endometrial carcinoma. Combined microsatellite instability and immunohistochemistry analysis allows the identification of a high proportion of hereditary nonpolyposis colorectal cancer patients among young women with endometrial carcinoma and complex atypical hyperplasia. All complex atypical hyperplasias with high-level microsatellite instability progressed to endometrial carcinoma. Only one third of the complex atypical hyperplasias with microsatellite stability progressed to high-level microsatellite instability endometrial carcinoma, while seven complex atypical hyperplasias progressed to microsatellite stability endometrial carcinoma. Microsatellite analysis of complex atypical hyperplasia in young patients may therefore be a useful prognostic marker for predicting possible progression to high-level microsatellite instability endometrial carcinomas.     

Fas-mediated pathway and apoptosis in normal, hyperplastic, and neoplastic endometrium

OBJECTIVES: Abnormalities in the control of cell proliferation and apoptosis have been suggested to contribute to the development and progression of neoplasia. There are at least two pathways that activate apoptosis. The first is a mitochondria-dependent route governed by bcl-2 family proteins. The second is a parallel mechanism which involves the activation of a group of tumor necrosis factor (TNF) receptors, such as Fas. METHODS: The aim of this study was to examine the distribution and interrelation between the expression patterns of apoptosis-related proteins such as Fas, caspase-3 (CPP32), and M30, and to investigate the role of Fas-mediated apoptosis in the pathogenesis and progression of endometrial neoplasms. RESULTS: Using specific antibodies for Fas, caspase-3, and M30, we examined protein expressions in 29 endometrial carcinomas, 30 endometrial hyperplasias, and 21 normal cyclic endometria. The results of immunostaining for Fas and caspase-3 were analyzed semiquantitatively by using an immunohistochemical scoring system (HSCORE) that incorporated both the intensity and the distribution of specific staining. For M30, positive staining cells and extracellular particles were analyzed semiquantitatively per 10 high-power fields.HSCOREs of Fas and caspase-3 were slightly higher in the secretory endometria than in the proliferative endometria. Similarly, M30 reactivity seemed to increase in the late secretory phase of the cycle. HSCOREs of Fas and caspase-3 and the reactivity of M30 were significantly higher in the carcinoma group than in the simple hyperplasia group (P < 0.05). Complex hyperplasias, however, expressed quite similar HSCOREs of Fas and caspase-3 as carcinomas. M30 reactivity was also significantly higher in complex hyperplasias than in simple hyperplasias, and in carcinomas positivity increased significantly (P < 0.05) as the grade progressed. CONCLUSIONS: The significant increase observed in Fas, caspase-3, and M30 expression in carcinomas as compared with simple hyperplasias may suggest that the Fas-related apoptotic pathway is also involved in the regulation of apoptosis in the endometrial tissue and promotes the development and progression of endometrial neoplasia.     

Estrogen and progesterone receptors and cyclooxygenase-2 expression in endometrial cancer, endometrial hyperplasia, and normal endometrium

OBJECTIVES: To determine whether cyclooxygenase-2 (COX-2) expression is seen in endometrial cancer, endometrial hyperplasia, and normal endometria and whether it correlates with expression of estrogen and progesterone receptors. METHODS: The study was a retrospective, IRB-approved analysis of biopsy samples from 14 patients with endometrial adenocarcinoma, 19 with endometrial hyperplasias, and 10 with normal endometrium. Excluded were samples from women with a history of pelvic radiation, NSAID use, or treatment with hormones during previous year. Immunohistochemical analyses were performed on formalin-fixed, paraffin-embedded tissues. Expression of COX-2, estrogen and progesterone receptors were scored according to the proportion of positive-staining cells: 1(+), <10%; 2(+), 10-50%; and 3(+), >50%. A score > or =2(+) was considered positive. Fisher's exact test and analysis of variance were used to compare proportions and continuous variables, respectively. RESULTS: Overexpression of COX-2 was seen in 4 (29%) of the endometrial cancers, 6 (32%) of the endometrial hyperplasia, and 4 (20%) of the normal endometria. These differences were not statistically significant (P = 0.90). No COX-2 expression was found in stromal tissue. Of 14 endometrial cancers, 7 (50%) expressed any COX-2, with 4 (29%) having an expression score of > or =2(+). Of 19 endometrial hyperplasias, 11 (58%) expressed any COX-2; with 6 (32%) having a score of > or =2(+). All 10 normal endometria showed only 1(+) expression. No significant differences were detected in COX-2 expression by grade or stage of cancer. Although 100% and 95% of both hyperplasia and normal endometrium samples expressed in estrogen and progesterone receptors, respectively, only 71% and 79% of endometrial cancers expressed estrogen and progesterone receptors (P = 0.01). A nonparametric trend was performed to detect a relationship, between COX-2 and estrogen receptor or progesterone receptor expression; no significant trend was found. CONCLUSIONS: In this study, the immunohistochemical analysis showed a trend toward increased COX-2 expression in endometrial cancer and hyperplasia compared to normal endometria. A larger sample size is needed to confirm these results. The increased COX-2 expression in hyperplasia may signify an early step in carcinogenesis. These findings may represent an important treatment opportunity for synergism in the hormonal therapy of endometrial cancer.     

Hormonal treatment of endometrial cancer: past, present and future

The concept that hormonal therapy may be useful in the treatment of endometrial cancer antedated the pharmaceutical availability of progestational compounds. By 1959, initial studies demonstrated the ability of progestins to reverse endometrial hyperplasias. Thereafter, progestins and other hormonal agents have been used in various roles as treatment for endometrial cancers. This chapter reviews the use of hormonal agents for the treatment of primary and metastatic/recurrent endometrial cancer, as well as such treatment in an adjuvant setting. Major problems in enhancing the efficacy of endocrine therapy of cancers arising from hormonally responsive tissues are also considered. The regulations of steroid-hormone receptor expression in endometrial and breast cancers continues to be an active area of research interest.     

bcl-2 Expression in Endometrial Hyperplasia and Carcinoma

The bcl-2 gene codes for a protein which functions to inhibit apoptotic cell death. bcl-2 overexpression was originally described in follicular lymphoma, but more recently bcl-2 expression has been observed in a variety of other human neoplasms. In this study we used immunohistochemistry to examine bcl-2 protein expression in endometrial hyperplasia and carcinoma. bcl-2 protein was observed in 4/4 cases of complex hyperplasia, 1/4 cases of complex atypical hyperplasia, and 10/29 cases of carcinoma. The staining observed in the cases of complex atypical hyperplasia and carcinoma was focal and less intense than the reactivity of normal proliferative endometrium. We conclude that bcl-2 protein is seldom overexpressed in complex atypical hyperplasia or carcinoma of the endometrium. Rather, in many cases of endometrial carcinoma bcl-2 expression appears to be decreased.     

The effect of long-term use of progesterone therapy on proliferation and apoptosis in simple endometrial hyperplasia without atypia

The aim of this study was to evaluate the effect of long-term use of progesterone treatment on proliferation and apoptosis in simple endometrial hyperplasia without atypia. In this prospective control study, endometrial tissue samples of 19 patients with simple endometrial hyperplasia without atypia (group 1), posttreatment biopsy materials of the patients after 3 months of cyclic progesterone treatment with noretisterone for 10 days (group 2), and 18 endometrial biopsy materials of the control group (group 3) were examined for proliferative and apoptotic activities. There was a statistically significant difference between the median values of the proliferative index of the three groups (P = 0.000). The proliferative index was significantly higher in the endometrial hyperplasia group than in posttreatment group (P = 0.000). But there was no significant difference between posttreatment group and control group. The median value of apoptotic activity was significantly different between three groups (P = 0.000). Apoptotic index was highest in hyperplasia group. A significant decrease in apoptosis was observed after the progesterone treatment (P = 0.002). The lowest apoptotic activity was detected in the control group. In conclusion, 3 months of cyclic progesterone treatment reduces both proliferative and apoptotic activities in endometrial tissue with simple hyperplasia.     

Atypical hyperplasias of the endometrium

A review of the literature concerning atypical hyperplasias of the endometrium is presented. The new pathological classifications differentiate structural abnormalities from cellular abnormalities. For atypical hyperplasias with cellular abnormalities, similar classifications to that of Richard for the cervix have been proposed: Intra Endometrial Neoplasia (IEN) grades I to III. Evolution of these lesions toward endometrial adenocarcinoma must guide the treatment. In prospective studies, atypical hyperplasias with structural abnormalities evolve into adenocarcinoma in 1.6 to 22 per cent of the cases. In atypical hyperplasia with cellular abnormalities, they evolve into adenocarcinoma in 23 to 57 per cent of the cases, according to the authors. Total hysterectomy is the treatment which is the most suitable for atypical hyperplasias with cellular abnormalities. Continuous progestational medications before menopause and the same given intermittently before menopause, represent the possible medical treatments.     

The patterns of expression of an apoptosis-related CK18 neoepitope, the bcl-2 proto-oncogene, and the Ki67 proliferation marker in normal, hyperplastic, and malignant endometrium.

Expression of a neoepitope on cytokeratin 18, recognized by the monoclonal antibody M30, is an early indicator of apoptosis in epithelial cells. The aim of this study was to determine the equilibrium between apoptosis (M30), anti-apoptosis (bcl-2), and proliferation (Ki-67) in different endometrial conditions. Paraffin-embedded samples (n = 107), representing proliferative endometrium (18), secretory endometrium (19), postmenopausal endometrium (15), disordered proliferative endometrium (6), simple hyperplasia (12), complex hyperplasia (8), and endometrial adenocarcinoma (29), were evaluated immunohistochemically. The indirect streptavidin-biotin-horseradish peroxidase technique, with 3-amino-9-ethylcarbazole as the chromogen, was used to visualize the reactions. Proliferative endometrium showed high bcl-2 and Ki-67 expression levels with no M30. In the secretory phase, the balance was tipped in favor of M30 with a decrease of bcl-2 and Ki-67. Postmenopausal endometrium revealed high Ki-67 and bcl-2 expression levels and no M30. In complex hyperplasia, M30, bcl-2, and Ki-67 showed increased expression. In endometrial carcinoma, an increasing reactivity for M30 and Ki-67 was seen as the grade progressed. bcl-2 reacted weakly and only in grade 1 cancer. Immunohistochemistry facilitates the study of the expression of proteins related to cyclic endometrial activity. Interruption of these cyclic events is associated with specific disturbances in the expression patterns of these proteins.     

Apoptosis, bcl-2 expression, and proliferation in benign and malignant endometrial epithelium: An approach using multiparameter flow cytometry

OBJECTIVE: Disturbances in the regulation of cell proliferation and differentiation play an important role in the formation of neoplastic lesions. Consequently, abnormalities in apoptosis regulation may contribute to this process. Expression of a neoepitope on cytokeratin 18, unmasked by an early caspase cleavage event and recognized by the novel monoclonal antibody M30, is an indicator of early epithelial cell apoptosis. The purpose of this study was to evaluate the quantitative relation among apoptosis (M30), cell persistence (bcl-2), and proliferation (S-phase fraction; SPF) in malignant and benign endometrium. METHODS: Using multiparameter DNA flow cytometry on 54 formalin-fixed paraffin-embedded samples from benign (proliferative, secretory, inactive, and hyperplastic endometrium) and malignant (grades 1-3 endometrial adenocarcinoma) endometrial tissue, bcl-2 expression and M30 reactivity were assessed together with the SPF in the cytokeratin-positive epithelial cells. RESULTS: Benign cyclic endometrium showed a relatively high bcl-2 expression and low M30 reactivity in the proliferative phase whereas in the secretory phase this relation was inverse. In endometrial hyperplasia the expression of bcl-2 was increased compared to that in secretory and postmenopausal endometrium, but still below the level of proliferative samples. The expression of M30 also increased compared to normal proliferative endometrium but did not reach the level of endometrium in the secretory phase of the menstrual cycle. In cancer the expression of bcl-2 decreased with the progression of differentiation grade. For M30 expression this relation was inverse. Overall there was a significant increase of M30 reactivity in cancerous compared to hyperplasia and normal cyclic endometrium. CONCLUSION: Transition of endometrial epithelium from hyperplasia to cancer seems to involve both increased apoptosis and decreased bcl-2 expression. Flow cytometric evaluation of M30 and bcl-2 expression levels, with the SPF, in currettage specimens from postmenopausal patients complaining of bleeding provides a quantitative assessment of endometrial apoptosis, anti-apoptosis, and proliferation. Further studies are needed to determine the relationship among these three processes as indicators of the biological behavior of gynecological tumors.     

Histopathologic behavior of endometrial hyperplasia during tamoxifen therapy for breast cancer

OBJECTIVE: The purpose of the present study is to prospectively evaluate the effects of tamoxifen on the pathological behavior of endometrial hyperplasias without atypia, diagnosed before the start of adjuvant endocrine therapy, in menopausal patients suffering from breast cancer. METHODS: Twenty-six patients suffering from estrogen-receptor positive breast cancer and candidate to receive adjuvant tamoxifen, were found to be affected by endometrial hyperplasias before the start of endocrine therapy. All women showed a baseline endometrial stripe, measured by transvaginal ultrasonography, thicker than 4 mm and the diagnosis of endometrial hyperplasia was made by hysteroscopy and endometrial biopsy. Two patients showing complex atypical hyperplasia underwent vaginal hysterectomy, whereas the remaining 24 patients, suffering from endometrial hyperplasia without atypia, were followed on a yearly basis during the period of tamoxifen intake, by hysteroscopy and endometrial biopsy. RESULTS: Baseline histopathology showed simple and complex hyperplasia in 20 and in 4 patients, respectively. The median follow-up period was 38 months; in particular, all patients underwent endometrial assessment after 12 months, while 22, 16, 10 and 4 patients were followed-up after 24, 36, 48 and 60 months of tamoxifen therapy, respectively. Progression from complex hyperplasia to complex atypical hyperplasia (1 patient) and from complex and simple hyperplasia to adenocarcinomas (2 patients) was found within 24 months of tamoxifen intake in 3 patients (12.5%). In 2 patients (8.3%), a progression from simple to complex hyperplasia was detected within 36 months of tamoxifen treatment. In 13 patients (54.1%), stable histology of simple or complex hyperplasia was found, whereas 6 patients (25.0%), with focal hyperplasia harbored in an endometrial polyp, showed a normalization of endometrial histology after polyp resection. CONCLUSIONS: Endometrial hyperplasias without atypia diagnosed before endocrine therapy for breast cancer in menopausal patients show an early and high progression-rate to atypical lesions under tamoxifen influence.     

Dissociated expression of Bcl-2 and Ki-67 in endometrial lesions: diagnostic and histogenetic implications.

The objective of the present study was to analyze the expression of the proliferation marker, Ki-67, and the anti-apoptotic protein, bcl-2, in various endometrial lesions. Ki-67 and bcl-2 expressions were studied in 194 specimens of endometrial hyperplasia, polyps, carcinomas, and cyclic endometrium from a defined geographic area. Results were statistically analyzed with respect to marker expression, localization to the stromal or glandular component, and intraglandular topography. The lowest glandular Ki-67 expression was seen in secretory endometrium, in polyps, and in atypical hyperplasia. The Ki-67 score was significantly higher and less heterogeneous in endometrial carcinomas than in hyperplasia (p<0.001). Endometrial hyperplasia of all types was characterized by a markedly heterogeneous glandular expression of Ki-67. The glandular expression of bcl-2 was highest in proliferative endometrium and polyps. Bcl-2 expression was significantly lower in adenocarcinomas than in hyperplastic lesions (p=0.002). Ki-67 and bcl-2 expression showed a significant association in proliferative endometrium (p=0.003). Endometrial polyps demonstrated a unique pattern of very low expression of Ki-67 and high bcl-2 expression in both stroma and glands. Our findings indicate that an imbalance between proliferation and apoptosis may be an important factor in the development of different endometrial lesions, benign as well as malignant. The specific finding of inter- and intraglandular Ki-67 heterogeneity may be valuable as an adjunct to morphology in the differential diagnosis of endometrial hyperplasia.     

Clinical and pathological responses of progestin therapy for non-atypical endometrial hyperplasia: a prospective study

AIMS: To evaluate the clinical and pathological responses and factors predicting non-responders to various progestins currently prescribed for the treatment of non-atypical endometrial hyperplasia. METHODS: A prospective observational study was conducted in the Gynecologic Endocrinology Unit, Faculty of Medicine, Siriraj Hospital, Thailand, from 1998 to 2003. A 6-month course of progestin therapy was offered to all patients. The clinical response was evaluated from the vaginal bleeding pattern during the first 4 months of treatment. The pathological response was evaluated from the histopathology of the endometrium after completion of the 6-month therapy. RESULTS: Of 250 registered patients, the number of cases qualified for the evaluation of the clinical and pathological response were 198 and 134 cases, respectively, revealing the overall clinical and pathological response rates of 93.4% and 92.5%, respectively. Among 13 clinical non-responders, 84.6% might have associated pelvic pathology. Among 10 pathological non-responders, three had surgical treatment, and progressive disease was found in one case. Significant factors predicting clinical non-responders included a history of prior bleeding (odds ratio [OR] = 8.79, 95% confidence interval [CI] = 1.63, 47.53), the presence of associated pelvic pathology (OR = 25.52, 95% CI = 3.21, 203.01), and treatment using progestins other than medroxyprogesterone acetate. Factors predicting pathological non-responders were not statistically significant. CONCLUSIONS: The current regimens of progestin therapy for non-atypical endometrial hyperplasia have high response rates. Patients who fail to have a clinical response should be evaluated for associated pelvic pathology. Follow-up endometrial biopsy should be offered to the patients, because 7.5% have persistent or progressive lesions, necessitating aggressive treatment.