Proliferative effects of combination estrogen and progesterone replacement therapy on the normal postmenopausal mammary gland in a murine model

OBJECTIVE: The aim of the study was to analyze the proliferative response of the normal mammary gland to combination hormone replacement therapy with estrogen and progesterone in a murine model of early versus late postmenopausal states. STUDY DESIGN: Ovariectomized mice were injected daily for up to 56 days with estrogen plus progesterone, starting at either 1 or 5 weeks after ovariectomy to simulate early and late menopausal periods, respectively. At various times after treatment, proliferation was analyzed by deoxyribonucleic acid histoautoradiography and whole-mount preparations. The induction of progesterone receptor by estrogen was also analyzed. To distinguish between estrogen- and progesterone-specific responses, we tested the effects of the antiprogesterone mifepristone (RU 486) and the antiestrogen ICI 182,780. RESULTS: The acute response to estrogen-progesterone therapy in the early postmenopausal period resulted in duct-end enlargement, ductal side branching, alveolar bud formation, and a 100-fold increase in epithelial cell proliferation. This was caused by the dominant effect of progesterone acting through the progesterone receptor. In the late postmenopausal period the acute response produced only duct-end enlargement; the 100-fold increase in epithelial cell proliferation resulted from the dominant effect of estrogen. After long-term treatment, both early and late postmenopausal glands exhibited similar morphologic features and a 9-fold higher steady-state proliferation rate than was found in control-treated groups. CONCLUSIONS: Starting combined estrogen and progesterone hormone replacement therapy in either early or late postmenopause produced a persistent, steady-state 9-fold increase in epithelial cell proliferation, which could be a contributing factor to increased breast cancer risk. The acute response in the late postmenopausal period mimics the hormonal response of the pubertal mammary gland, which in rodents is the stage most susceptible to carcinogen-induced mammary tumorigenesis. These observations raise questions about increased susceptibility of the late postmenopausal gland to carcinogenesis and a role for hormone replacement therapy in the promotion of tumorigenesis.     

Sequential combined transdermal and oral postmenopausal hormone replacement therapies: effects on bleeding patterns and endometrial histology

Objectives: To determine the endometrial response and bleeding patterns in postmenopausal women taking a sequential combined hormone replacement regimen either orally or transdermally. Methods: Seventy-two postmenopausal women with amenorrhea of 6 months or longer with follicle stimulating hormone and estradiol levels in the postmenopausal range and normal endometrium were included in the study. The patients randomly received sequential combined hormone replacement regimen with oral (n=37) or transdermal route (n=35). The total duration of treatment was 6 months (6 cycles of 28 d). The subjects kept daily bleeding diaries, and endometrial biopsies were taken at baseline and after 6 months of therapy. Results: The rates of adequate progestational response (secretory or atrophic) were 83.8% and 82.9% in the oral and transdermal hormone replacement groups, respectively (p>0.05). In the oral hormone replacement group, there were 16.2% of inadequate progestational response, 2.7% had endometrial hyperplasia and 13.5% proliferative endometrium. In the transdermal hormone replacement group, there were 17.1% of inadequate progestational response, 2.9% had endometrial hyperplasia and 14.3% proliferative endometrium. Cyclic bleedings occurred in 92.4% and 92% of all cycles in the oral and transdermal treatment groups, respectively. The mean duration of bleeding per cycle were 3.9±0.9 and 3.8±0.9 d in the oral and transdermal treatment groups, respectively. Conclusion: Sequential combined transdermal hormone replacement therapy is as effective as oral therapy in preventing the development of endometrial hyperplasia. Satisfactory control of bleeding is achieved with both regimens. Received: 6 June 2001 / Accepted: 12 July 2001     

两种激素补充治疗方案联合钙剂对绝经后妇女骨密度的影响

目的　研究利维爱 1 2 5mg d和结合雌激素 (CEE) 0 6 2 5mg +安宫黄体酮 (MPA) 2mg联合钙剂对绝经后骨质疏松和低骨量妇女骨密度的影响。方法　绝经后妇女 30人 ,分为利维爱组和CEE组。利维爱组8例为骨质疏松 ,中位年龄 6 4岁 ,中位绝经年限 1 4年 ;9例为低骨量 ,中位年龄 5 2岁 ,中位绝经年限 3年 ,均给予利维爱 1 2 5mg d、Ca -D 6 0 0mg d口服。CEE组中位年龄为 5 1岁 ,中位绝经年限为 2 5年。治疗前及治疗 1年时用DEXA方法检查前臂远端骨密度各 1次 ,做为自身对照 ,对比骨密度变化情况同时每年通过阴道B超监测子宫内膜的厚度。结果　利维爱组骨质疏松患者 ,松质骨骨密度增长中位数为 +4 0 % ,密质骨为 +2 6 % ;低骨量者 ,用利维爱者分别为 0和 - 1 0 % ,用CEE者为 +0 3%和 - 0 7%。所有患者依从性好 ,无明显副作用发生。结论　利维爱 1 2 5mg d联合钙剂能够提高绝经后骨质疏松妇女的前臂骨密度     

Long-term effects of repeated superovulation on the uterus and mammary gland in rhesus monkeys

Purpose

The aim of this study is to evaluate the effect of repeated controlled ovarian hyperstimulation (COH) on the structure and function of the uterus and mammary gland.

Methods

Three adult female rhesus monkeys were superovulated up to four times, and three spontaneously ovulating monkeys were used as controls. After a 5-year period, the uterus and mammary gland tissue samples were collected for examination of their structure and function. Further, the expression of certain tumor markers was examined to assess the cancer risk for each organ.

Results

Expression of Wnt7a (associated with the functional/developmental status of the uterus) was significantly decreased in the uterus of superovulated monkeys, and decreased expression of proliferation marker PCNA was found in uterine cells. Meanwhile, abnormal Golgi-derived secretory vesicles with an irregular shape were observed in the mammary glands of the superovulated monkeys, and decreased PCNA expression together with increased expression of caspase-3 (an apoptosis marker) was indicated in the mammary cells. The expression of tumor molecular markers of the uterus and mammary gland was not significantly different between the two groups.

Conclusions

Repeated COH affects the expression of the uterine development-related gene several years later, and uterine cells exhibited a low proliferation status. The ultrastructure of the mammary gland epithelial cells was abnormal, and the cells exhibited both low proliferation and high apoptosis status. Cancer risk for these organs was not observed. Given that primates are the closest relatives of humans, the results obtained from this study provide more intuitive information for optimization of clinical COH.

     

绝经后性激素补充治疗对心血管系统利弊的认识进展

绝经后性激素补充治疗 (ＨＲＴ)用于治疗绝经过渡期月经紊乱、血管运动不稳定症状、泌尿生殖道症状、预防绝经后骨质疏松症的效果 ,已得到证实。1998年以来 ,国际学术界对ＨＲＴ能否预防心血管疾病争议较大。国内有些媒体对此也有报道。本文介绍这方面的发展及现状 ,以求达到目前指导临床实践的共识。动脉硬化 (ＡＳ)性心血管疾病 (ＣＶＤ) ,包括冠状动脉 (冠脉 )粥样硬化性心脏病 (ＣＨＤ)、深静脉血栓 (ＤＶＴ)及脑卒中。发病的危险因素来自多个方面 ,包括年老、遗传因素、高血压、血脂异常、高纤维蛋白原血症、高同型半胱氨酸血症、胰岛…     

Effects of sequential combined transdermal and oral hormone replacement therapies on serum lipid and lipoproteins in postmenopausal women

The aim of this study was to compare the effects of sequential combined transdermal and oral postmenopausal hormone replacement therapies on serum lipid-lipoprotein profiles risk markers for cardiovascular disease. A prospective randomize study was designed: Ninety-six healthy nonhysterectomised postmenopausal women were randomized to receive either transdermal continuous 17β-estradiol, 0.05 mg/d (Estraderm TTS, Novartis, Basel, Switzerland), with transdermal sequential norethisterone acetate, 0.25 mg/d (Estragest TTS, Novartis, Basel, Switzerland), or oral continuous conjugated equine estrogens, 0.625 mg/d (Premarin 0.625 mg, Wyeth, Philadelphia, U.S.A.), with oral sequential medroxyprogesterone acetate, 10 mg/d (Farlutal 5 mg, Deva, Istanbul, Turkey). 84 women completed the trial, 42 in oral and 42 in the transdermal group. The serum levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apolipoproteins AI and apolipoproteins B at 6 months after starting treatment were compared with baseline values for both therapies. Both oral and transdermal therapies significantly reduced serum levels of total cholesterol (208– 190 mg/dL and 216–199 mg/dL, respectively, p=0.0001) and LDL-cholesterol (128–112 mg/dL and 140– 127 mg/dL, respectively, p=0.001). The serum levels of triglycerides did not show any significant change with oral therapy, whereas this lipid fell (128–101 mg/dL, p=0.0001) significantly with transdermal therapy. We found significant decrease in HDL-cholesterol with transdermal therapy while there was no significant change with oral therapy. Apolipoproteins AI, the major protein component of HDL₂ subfraction, was increased by oral therapy and lowered by transdermal therapy. As a conclusion, we have found that serum total cholesterol and LDL-cholesterol were lowered by both therapies, with no significant differences between treatments, whereas there were significant differences between treatments according to effects on serum triglycerides and apolipoproteins AI. Received: 15 May 2001 / Accepted: 20 July 2001     

Effects of hormone replacement therapy on glucose and lipid profiles and on cardiovascular risk parameters in postmenopausal women

Objectives  

The aim of this study was to evaluate the effects of hormone replacement therapy (HRT) on carbohydrate and lipid metabolisms and cardiovascular risk parameters in healthy postmenopausal women.     

Long-term effects of hormone replacement therapy: cardiovascular disease

Even though mortality from coronary heart disease (CHD) has declined since the 1960s, CHD is still the leading cause of death in western countries. Evidence has accumulated to suggest that postmenopausal hormone replacement therapy (HRT) protects against cardiovascular disease (CVD). In the US, HRT predominantly consists of conjugated oestrogens in combination with medroxy progesterone acetate (MPA). The European HRT tradition is based on 17-β-oestradiol and 19-norethisterone derivate norethisteron-acetate (NETA) or other progestogens. These different regimens must be considered when interpreting the epidemiological data. Meta-analysis of observational studies indicates a 30–50% risk reduction for CHD among women taking HRT compared to never users. Biological evidence supports the notion of a causal relationship between HRT and decreased incidence of CVD.There is a two- to three-fold increased risk of venous thromboembolic disease among current users of HRT, both unopposed and opposed with progestogen, compared to never users. Most epidemiologic data suggests that HRT has no influence on the risk of stroke, however, the latest follow-up from the Nurses Health Study questions this.The conclusion on studies on secondary preventive effect of HRT is that it might prevent CHD but cannot be recommended as secondary prevention of CHD for women with pre-existing CHD.Identifying women who especially will benefit from HRT is a complex medical decision, which demands counselling based on the pros and cons for the individual women.     

Body composition modulates the effects of hormone replacement therapy on growth hormone and insulin-like growth factor-I levels in postmenopausal women

OBJECTIVE: To examine the relationships of body composition with basal serum estrone, estradiol, androstenedione, cortisol, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels in 73 postmenopausal women. DESIGN: Cross-sectional study of hormone levels and body composition determined by dual-energy X-ray absorptiometry and anthropometry in women who were not taking oral hormone replacement therapy (HRT) and women taking HRT. Because high adiposity may modify hormone levels, subjects were grouped by fatness into obese (BMI >25 kg/m(2) and waist circumference >80 cm) and lean groups, as well as by HRT use. RESULTS: Total levels of estrone, estradiol, GH and cortisol were significantly higher and IGF-1 was lower in HRT users. In HRT users, estradiol levels were higher and GH levels were lower in obese than lean women. IGF-1 levels were lower in obese HRT users than lean nonusers. Total cortisol levels were significantly higher in lean HRT users than lean nonusers and obese users. GH and IGF-1 were significantly inversely correlated with trunk fat and percent body fat. Multiple regression revealed that only trunk fat was a significant (negative) determinant of GH and IGF-1 levels, whereas HRT use positively and negatively predicted GH and IGF-1, respectively. Percent body fat significantly predicted estradiol levels. Body composition did not differ by HRT use. CONCLUSIONS: Our results suggest that trunk fat attenuates the HRT-induced increase on GH levels. In addition, trunk fat is a significant determinant of low IGF-1 levels in postmenopausal women, and IGF-1 levels decline more with HRT use.     

A 1-year comparison of the efficacy and clinical tolerance in postmenopausal women of two hormone replacement therapies containing estradiol in combination with either norgestrel or trimegestone

This double-blind ,randomized ,multi-center study compared the efficacy and clinical tolerance of a combined formulation containing 2 mg estradiol (E2) and 0.5 mg trimegestone (TMG) with a standard hormone replacement therapy containing estradiol valerate (E2V) and norgestrel (NG) in the treatment of climacteric symptoms. The study was conducted over 13 cycles ,each of 28 days ,and involved 634 subjects, of whom 481 completed the study. The primary efficacy variable was the percentage of subjects who showed at least a 50% reduction from baseline in the mean daily number of hot flushes in cycle 3. This was observed in 98.5% of the subjects in the E2 + TMG group and 93.3% of the subjects in the E2V + NG group (95% confidence interval of the difference ,8.6 ,1.9). Significant differences in favor of the E2 + TMG combination were observed in the reduction in the mean daily number and severity of hot flushes ,and in the percentage of subjects who had hot flushes at baseline but no hot flushes during treatment. There were no significant differences between the treatments in the Kupperman index and in urogenital signs or symptoms. Treatment with the E2 + TMG combination was well tolerated and the incidences of adverse events were similar in the two treatment groups. Breast pain was the main adverse event ,possibly related to treatment that resulted in discontinuation. The mean number of bleeding days per cycle was significantly lower with the E2 + TMG combination than with the E2V + NG combination. The incidences of endometrial hyperplasia were low and comparable in both treatment groups. It was concluded that the E2 + TMG combination was either equivalent or superior to the E2V + NG combination in the treatment of hot flushes and other climacteric symptoms ,and that its bleeding profile was favorable.     

Uterine effects of raloxifene in comparison with continuous-combined hormone replacement therapy in postmenopausal women

OBJECTIVE: We sought to compare the uterine effects of raloxifene with those of continuous-combined hormone replacement therapy. STUDY DESIGN: This randomized, double-blind 24-month study involved 136 postmenopausal women who received raloxifene 150 mg/d or conjugated equine estrogens 0.625 mg/d with medroxyprogesterone acetate 2.5 mg/d. After baseline evaluations, endometrial biopsy specimens were obtained, and endometrial thickness was measured annually by means of transvaginal ultrasonography. Statistical analyses were performed with an intention-to-treat approach. RESULTS: In the raloxifene group at the end point of the study 94.4% of biopsy specimens showed normal benign postmenopausal endometrium and 5.6% were classified as benign stimulatory endometrium. In the continuous-combined hormone replacement therapy group at the end point of the study 78.7% of biopsy specimens showed normal benign postmenopausal endometrium, 19. 1% were classified as benign stimulatory endometrium, and 2.1% showed benign abnormal postmenopausal endometrium. Mean endometrial thickness was unchanged from baseline with raloxifene and was increased significantly by 0.5 mm at 12 months with continuous-combined hormone replacement therapy. CONCLUSION: Raloxifene 150 mg/d did not increase endometrial thickness or cause endometrial proliferation in healthy postmenopausal women.     

A 1-year comparison of the efficacy and clinical tolerance in postmenopausal women of two hormone replacement therapies containing estradiol in combination with either norgestrel or trimegestone.

This double-blind, randomized, multi-center study compared the efficacy and clinical tolerance of a combined formulation containing 2 mg estradiol (E2) and 0.5 mg trimegestone (TMG) with a standard hormone replacement therapy containing estradiol valerate (E2V) and norgestrel (NG) in the treatment of climacteric symptoms. The study was conducted over 13 cycles, each of 28 days, and involved 634 subjects, of whom 481 completed the study. The primary efficacy variable was the percentage of subjects who showed at least a 50% reduction from baseline in the mean daily number of hot flushes in cycle 3. This was observed in 98.5% of the subjects in the E2 + TMG group and 93.3% of the subjects in the E2V + NG group (95% confidence interval of the difference, -8.6, -1.9). Significant differences in favor of the E2 + TMG combination were observed in the reduction in the mean daily number and severity of hot flushes, and in the percentage of subjects who had hot flushes at baseline but no hot flushes during treatment. There were no significant differences between the treatments in the Kupperman index and in urogenital signs or symptoms. Treatment with the E2 + TMG combination was well tolerated and the incidences of adverse events were similar in the two treatment groups. Breast pain was the main adverse event, possibly related to treatment that resulted in discontinuation. The mean number of bleeding days per cycle was significantly lower with the E2 + TMG combination than with the E2V + NG combination. The incidences of endometrial hyperplasia were low and comparable in both treatment groups. It was concluded that the E2 + TMG combination was either equivalent or superior to the E2V + NG combination in the treatment of hot flushes and other climacteric symptoms, and that its bleeding profile was favorable.     

Effects of two different regimens of continuous hormone replacement therapy on endometrial histopathology and postmenopausal uterine bleeding

Objective: To compare the effects of frequently used two different regimens of combined continuous hormone replacement therapy; 0.625 mg conjugated equine estrogen (CEE) + 2.5 mg medroxyprogesterone acetate (MPA) and 1 mg 17β estradiol (E2) + 0.5 mg norethindrone acetate (NETA), on endometrial histopathology and postmenopausal uterine bleeding. Materials and methods: Two hundred and forty-six outpatient subjects aged 41–57 years were enrolled in the study conducted at the menopause clinic between November 2003 and November 2004. One hundred and thirty-nine patients were assigned to receive 0.625 mg conjugated equine estrogen + 2.5 mg medroxyprogesterone acetate (CEE/MPA), whereas 107 patients were to receive 17β estradiol + 0.5 mg norethindrone acetate (E2/NETA). Inclusion criteria of the study were: normal values of endometrial thickness at basal evaluation, women with intact uterus, at least 12 months of amenorrhea, normal vaginal smear, bilateral mammography and biochemical blood parameters. All women were questioned every 3 months for vaginal bleeding/spotting. Endometrial sampling was performed by Pipelle catheter in the 12th month of therapy. Results: For the first 3 months, vaginal bleeding/spotting rate for the CEE/MPA group was 38.7%, whereas it was higher (45%) in the E2/NETA group. For the second 3-month period, vaginal bleeding/spotting frequencies were 41.1 and 37.8%, respectively. In the third 3-month period 30.6 and 29.6%, and in the fourth 3-month period, 18.5 and 12.5% of the patients reported vaginal bleeding or spotting. None of the results of endometrial sampling have shown findings of cancer histopathology. Conclusion: Compared to CEE/MPA regimen, E2/NETA therapy has not shown more favorable effects on postmenopausal bleeding abnormalities. Irregular endometrial proliferation was seen more with the E2/NETA regimen.     

Assessment of the metabolic tolerance in postmenopausal women over a 1-year period of two hormone replacement therapies containing estradiol in combination with either norgestrel or trimegestone

This double-blind, randomized, multi-center study compared the metabolic tolerance of a combined formulation containing estradiol (E2) and trimegestone (TMG) with a standard hormone replacement therapy (HRT) containing estradiol valerate (EV) and norgestrel (NG). Blood lipids, glucose and fibrinogen concentrations were measured in the study which was conducted over 13 cycles, each of 28 days, and included 634 subjects in two randomized groups. A total of 481 subjects completed the study. The circulating concentrations of high density lipoprotein (HDL), HDL2, HDL3 cholesterol and apolipoprotein A1 were increased in the E2 + TMG group and reduced in the EV + NG group. Total cholesterol, low density lipoprotein (LDL) cholesterol, apolipoprotein B and lipoprotein(a) concentrations were decreased in both treatment groups; however, the reduction in LDL cholesterol was greater in the E2 + TMG group. Similar lipid findings were found in a subgroup that excluded subjects who had less than 3 months washout from a previous HRT, who provided a blood sample outside the day 17-28 window, or who were taking beta-blockers or thiazide diuretics. Blood glucose concentrations were reduced slightly in both treatment groups. A significant reduction in fibrinogen was also seen in both groups over the course of the study. The changes in lipid profile, especially HDL cholesterol, were more beneficial in the E2 + TMG group in comparison with the EV + NG group. This reflects the lack of androgenic action of trimegestone in comparison with norgestrel, which exhibits an androgenic effect and prevents the estrogen-induced increase in HDL cholesterol. The results of the study suggest that the use of trimegestone in combination with E2 may be preferable to norgestrel because of the more favorable lipid profile.     

绝经后妇女激素补充治疗后同型半胱氨酸及超声心动图改变的初步观察

目的　观察绝经后妇女激素补充治疗 (HRT)后血浆总同型半胱氨酸 [H(e) ]及超声心动图的改变。方法　将受试者分为 4组。Ⅰ组、Ⅱ组为自然绝经妇女 ,各 30例 ,其中Ⅰ组给予HRT(结合雌激素 0 6 2 5mg d ,安宫黄体酮 2mg d ,或者每月后 14d加安宫黄体酮 4mg d) 3个月 ;Ⅱ组不给予HRT ,为对照 ;Ⅲ组 2 0例 ,为已接受HRT1 5年的绝经后妇女 ;Ⅳ组 2 0例 ,为从未应用HRT的绝经后妇女。Ⅰ组、Ⅱ组受试者于接受HRT前及接受HRT 3个月后测定H(e) ;Ⅲ组、Ⅳ组受试者测定H(e) ,并行超声心动图检查。结果　Ⅰ组、Ⅱ组接受HRT 3个月前后H(e)无明显变化 ,Ⅰ组接受HRT前为(9 3± 2 5 ) μmol L ,Ⅱ组为 (9 4± 2 9) μmol L ;Ⅰ组接受HRT后H(e)为 (9 1± 2 8) μmol L ,Ⅱ组为(9 8± 3 6 ) μmol L。两组比较 ,差异无显著性 (P >0 0 5 )。Ⅲ组H(e)明显低于Ⅳ组 ,分别为 (8 0±1 3) μmol L及 (10 3± 3 2 ) μmol L。两组比较 ,差异有显著性 (P <0 0 5 )。Ⅲ组、Ⅳ组的超声心动图检查结果无明显改变。结论　短期应用HRT对H(e)无明显改善 ,长期应用HRT可降低H(e)水平。绝经后妇女应用HRT 1 5年 ,未见超声心动图有明显变化。     

Transient increase in the levels of T-helper 1 cytokines in postmenopausal women and the effects of hormone replacement therapy

The aim of this study was to determine, at least in part, T-cell function in postmenopausal women and the effects of hormone replacement therapy (HRT). Levels of T-helper 1 (Th1) cytokines (IL-2 and IFN-gamma) and T-helper 2 (Th2) cytokines (IL-4 and IL-10) produced by phytohemagglutinin-stimulated whole blood cells from 72 untreated and 44 HRT-treated women were measured by ELISA. Thirteen of the 44 HRT-treated women were examined before and during HRT. The production of IL-2 increased gradually with advance of the postmenopausal period. The levels of IL-2 in women in the early (< or =10 years) and mid (>10 and <30 years) postmenopausal stages were significantly higher than those in women in their second, third and fourth decades. The level in women in the late (> or =30 years) postmenopausal stage, however, was significantly lower than those in women in the early and mid postmenopausal stages. The level of IFN-gamma was highest in women in the mid postmenopausal stage. On the other hand, the levels of Th2 cytokines did not change with age or after menopause until the mid postmenopausal period but were significantly lower in women in the late postmenopausal stage. IFN-gamma levels in women on HRT were significantly lower than those in untreated postmenopausal women at all postmenopausal stages. HRT induced a significant decrease in the production of IL-2 and IL-4. In conclusion, production of Th1 cytokines is augmented in women after menopause. HRT prevents this increase, thereby improving the aberration of Th1/Th2 balance that is implicated in an inadequate immune response and pathological conditions.     

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.