Endometrial Histology and Biochemistry in Climacteric Women during Oestrogen and Oestrogen/Progestogen Therapy

Biology of female sex hormone action in relation to contraceptive agents and neoplasia

This article will present an overview of estrogen and progestin action at a cellular level, with emphasis on points that are relevant to neoplasia. In breast, endometrium and ovary, these two classes of hormone are clearly implicated in carcinogenesis, but their involvement with cancers of the liver, cervix and other tissues is more problematic. In the latter situations, I will highlight the major points to be considered if the hormones are involved without wishing to judge whether there actually is a causal involvement.

Bleeding patterns during continuous combined estrogen-progestogen therapy

Bleeding and climacteric symptoms were recorded in two groups of postmenopausal women receiving either continuous combined estradiol and norethisterone acetate or estradiol and cyproterone acetate. Out of a sample of 99 postmenopausal women aged 45 to 54 years, 86 completed a 2-year, double-blind, placebo-controlled study. Comparison of the bleeding patterns in the two groups revealed a statistically significant difference: More women in the estradiol-cyproterone acetate group experienced bleeding and for a longer duration. Thirteen women in the estradiol-norethisterone acetate group were amenorrheic, compared with two in the other group. The Kupperman index score in both groups declined to about 30% to 40% of initial values (p less than 0.001). The hot flushes in both treatment groups decreased to a highly significant degree (p less than 0.001), to a value below 20% of baseline values. We conclude that a continuous combination of estrogen and progestogen can produce amenorrhea and symptomatic relief. However, the progestogen components seem to differ in their ability to control bleeding.

A risk-benefit assessment of estrogen therapy in postmenopausal women

Estrogen therapy is extremely effective in relieving menopausal symptoms such as hot flushes, night sweats, urogenital atrophy and certain psychological symptoms. The short term side effects from this therapy are usually mild and self-limiting. They are more common in women who commence hormone replacement therapy some years after the menopause than in those who start treatment at about the time of the ovarian failure. Pre-existing gynaecological conditions such as fibroids and endometriosis can be worsened by estrogen therapy. The majority of published studies suggest a beneficial effect of postmenopausal estrogen therapy on cardiovascular and cerebrovascular disease. These effects may be mediated by favourable changes in lipids, but other mechanisms may also be involved. It is uncertain whether the adverse changes in lipids caused by progestogen therapy will reduce any of the benefits of estrogen therapy on the cardiovascular system. Osteoporosis is the major bone disease of the Western world; long term estrogen therapy will prevent its development in most postmenopausal women. The risk of endometrial carcinoma is increased with unopposed estrogen therapy; this increased risk appears to be abolished if a progestogen is added at an adequate dose and duration for each cycle. The risk of ovarian or cervical cancer is not increased with estrogen therapy. There may be an increased risk of breast carcinoma with long term postmenopausal estrogen use, but the studies show inconsistent results.

Sequential use of norethisterone and natural progesterone in pre-menopausal bleeding disorders

Sequential treatment with norethisterone (NET) or natural micronized progesterone (NMP) was administered randomly to 80 consecutive patients attending our clinic because of cycle disorders. The endometrial morphology indicated a need for progestogen therapy in all cases and the endometrium was hyperplastic in half of the women before therapy. Hyperplastic changes disappeared during the first three cycles of treatment with both NET and NMP, the duration of treatment being 6 months. However, the carry-over effect of both progestogens was short: three months after treatment was discontinued a proliferative or hyperplastic endometrial pattern recurred in 24% and 10% of cases, respectively. Whereas NET decreased oestradiol, follicle-stimulating hormone, luteinizing hormone and sex-hormone-binding globulin levels (P less than 0.001) no changes were seen during NMP treatment. High-density-lipoprotein cholesterol and triglyceride levels were also lowered by NET (P less than 0.001-0.02) and there was a slight decrease in phospholipids. NMP treatment induced no changes in serum lipid values and thus offers an alternative form of therapy in premenopausal bleeding disorders.

Serum placental protein 14 in pre-menopausal and post-menopausal women--dependency on oestrogen/progestogen status

In view of the increasing use of oestrogen-progestogen therapy in post-menopausal women the availability of possible biochemical marker of endometrial response to progestogen would be highly desirable. Placental protein 14 (PP14) has recently been shown to be excreted from the endometrium during the secretory phase of the menstrual cycle. In the present study we examined the concentration of serum PP14 (S-PP14) in 15 pre-menopausal women during the menstrual cycle and in 30 early post-menopausal women receiving three different doses of 17 beta-oestradiol (E2), cyclically combined with norethisterone acetate (NETA). S-PP14 levels peaked on day 1 following the onset of menstrual bleeding and on day 7 during NETA administration. It was possible to estimate the area under the S-PP14 curve reliably from one or two blood samples taken at optimal times. In the post-menopausal women, S-PP14 varied in a highly significant dose-dependent manner, i.e., the higher the E2 dose (in relation to the fixed NETA dose) the higher the S-PP14 response was found to be. We suggest that S-PP14 measurements might reflect the quantitative development of the endometrium in the secretory phase in both pre-menopausal and post-menopausal women.

The histochemistry of isocitric and oestradiol-17 beta dehydrogenases in the endometrium of postmenopausal women treated with oestrogens and progestogens

Endometrium was obtained from postmenopausal women during treatment with either oestrogen alone or on the third, sixth, tenth or twelfth day of combined therapy with oestrogens and progestogens. The activities of oestradiol-17 beta and isocitric dehydrogenases were measured in homogenates of the whole tissue and the enzymes were also located histochemically. Oestradiol dehydrogenase was located exclusively within the epithelium, whilst isocitric dehydrogenase was found in both epithelium and stroma, and also in stromal arterioles. Histochemically, oestradiol dehydrogenase was found in all the specimens which exhibited biochemical activity but in none of those from which it was absent. Isocitric dehydrogenase however, was seen in all tissue sections despite widely varying levels of biochemical activity in the homogenate. The method for measuring isocitric dehydrogenase activity was therefore nonspecific, whilst that for oestradiol dehydrogenase was reliable and low levels of enzyme activity could be detected. The latter technique may therefore be useful to predict the sensitivity of endometrial carcinomata to progestogens.

Oestrogen concentrations in plasma, endometrium, myometrium and vagina of postmenopausal women, and effects of vaginal oestriol (E3) and oestradiol (E2) applications

Oestradiol (E2), oestriol (E3) and oestrone (E1) levels were measured in plasma and endometrium, myometrium and vagina of 29 postmenopausal women who underwent hysterectomy. The influence of vaginal E3, compared to vaginal E2 therapy at a dose one-tenth that of E3 on the basal steroid levels was examined. We found (1) no correlation between basal tissue and plasma concentrations of the oestrogens in untreated postmenopausal women, however, after vaginal E3 therapy we did find a positive correlation between them, (2) E2 to be the oestrogen in the highest basal concentration in endometrium and myometrium as well as in the vagina, (3) higher basal concentrations of all three oestrogens in endometrium compared to myometrium and vagina, (4) a long term (at least 12 h) elevation of the plasma and tissue E3 concentrations after vaginal E3 therapy (0.5 mg per day), (5) no significant changes of the plasma and tissue E2 concentrations after 0.05 mg per day vaginal E2 therapy, measured 12 h after the last application and (6) no signs of a difference between vagina and uterus in uptake and retention of E3 or E2. In conclusion, there was no difference on this level of mechanism of action in vagina and uterus which can account for the supposed vaginotrophicity and non-uterotrophicity observed with E3 but not E2.

The measurement of secretory endometrial protein PP14 in serum from postmenopausal women receiving unopposed estrogen or continuously combined estrogen/progestogen

A highly sensitive radioimmunoassay was developed to measure the low serum concentrations of the endometrial secretory placenta protein 14 (PP14) in postmenopausal women. The assay was established by selecting optimum reaction conditions for radioactive labelling of PP14, combined with simple procedures for the purification of the labelled PP14. The PP14 assay was used in 2 groups of healthy, early postmenopausal women blindly receiving either estrogen monotherapy (n = 20, placebo n = 25) or continuously combined estrogen/progestogen therapy (n = 20, placebo n = 23). Neither of these regimens is believed to produce secretory endometrium. During the 12 months of estrogen monotherapy, serum PP14 (S-PP14) remained unchanged at 4.9 micrograms/l, when compared with placebo. Treatment with continuously combined estrogen/progestogen showed a small but significant increase in S-PP14 from 5.3 micrograms/l to 7.2 micrograms/l at 3 months. S-PP14 remained at this slightly elevated level throughout the treatment period of 24 months. Three months after hormone withdrawal, S-PP14 had returned to the pretreatment level. We suggest that S-PP14 might be a useful marker of secretory endometrium.

The effects of the addition of nomegestrol acetate to post-menopausal oestrogen therapy

Progestogens are added to the oestrogen treatment for 10-12 days each cycle in order to prevent endometrial abnormalities. However, concern has been expressed about the safety of certain of the currently available progestogens because of the potential adverse metabolic effects. We have evaluated the effects of nomegestrol acetate - non-androgenic progestogen - for administration to post-menopausal oestrogen users. Thirty-six (36) women receiving 50 mg oestradiol implants at regular intervals also took nomegestrol acetate for 12 days each calendar month at doses of 0.5 mg, 1.0 mg and 2.5 mg daily. Allocation to one of the dose regimens was random. Physical and psychological side-effects were recorded and all vaginal bleeding was noted: an endometrial biopsy was performed on the sixth day of progestogen addition for histological, ultrastructural and biochemical evaluation. Adverse side-effects were responsible for a dose-dependent drop out rates of 17%. All patients experienced a regular, progestogen-induced withdrawal bleed each month; and histological, ultrastructural and biochemical changes were induced within the endometrium by all 3 doses. Nomegestrol acetate is a potent progestogen and further studies are required to determine its lowest effective dose.

Endometrial and vaginal response to three different oestrogen preparations administered by the transdermal and oral routes

In a randomized, cross-over study endometrial and vaginal response to transdermal 17 beta-oestradiol (TTS-oestradiol 50 micrograms) and two forms of oral oestrogen replacement therapy (conjugated oestrogens 1.25 mg and oestradiol valerate 2 mg) were studied in 13 peri-menopausal and post-menopausal women. Five (5) of the women exhibited periodic ovarian function as evidenced by peripheral oestradiol and progesterone levels and were considered to be peri-menopausal. In the post-menopausal group of 8 women the bleeding pattern was more regular than among the peri-menopausal women. In the case of the post-menopausal group the number of days on which spotting and bleeding occurred was significantly lower during the administration of TTS-oestradiol than during treatment with conjugated oestrogens. This finding was paralleled by a significantly higher karyopyknotic index in the vaginal epithelium and significantly increased deoxyribonucleic acid (DNA) synthesis in the endometrial cells during treatment with equine oestrogens. No significant difference was seen in these indices when the effect of TTS-oestradiol was compared with that of oestradiol valerate. The study results in the post-menopausal group suggested a relationship between the intensity of the oestrogen treatment and not only the proliferation and maturation of the oestrogen target-organ cells but also the number of days on which bleeding occurred. It was concluded that a clear distinction needs to be made between peri-menopausal and post-menopausal women. In the present study the irregular ovarian activity among the peri-menopausal subjects precluded an unbiased assessment of the exogenous oestrogens. It is also likely that exogenous oestrogens exert a cumulative action with oestrogen secreted endogenously, interfere with the physiological events at the target organ level and induce uncontrollable endometrial bleeding. The complete cessation of ovarian activity may therefore have to be established before exogenous oestrogens are administered to climacteric patients.

Basement membrane components in normal hyperplastic and neoplastic endometrium

The major basement membrane (BM) components, laminin and type IV collagen, were studied by immunochemistry in normal, hyperplastic, and neoplastic endometrium. By immunoperoxidase technique, proliferative and secretive endometrium showed capillary and epithelial cell basement membranes with linear staining with antibodies to both laminin and type IV collagen. Immunostaining of laminin and type IV collagen showed that capillaries were surrounded by a continuous perivascular sheath of these matrices in specimens of adenomatous hyperplasia and in nearly all specimens of endometrial adenocarcinoma. Laminin and type IV collagen were found to accumulate around glandular epithelial cells of adenomatous hyperplastic endometrium, but in several specimens these linear surrounding formations were defective and discontinuous. In several areas of well-differentiated endometrial adenocarcinomas BM-like structures were found around glandular epithelial cells as shadows without staining for laminin and type IV collagen. These basement membrane components accumulate around stromal cells to encircle each cell with a gradual, progressive, and cyclic process depending on the phase of the menstrual cycle. Laminin and type IV collagen were clearly detected around stromal cells at days 20 to 22 of the menstrual cycle and more thickly at days 26 to 28. The accumulation of these matrices around stromal cells is a progesterone/progestin-related process. In the well-differentiated adenocarcinoma a mid-term treatment with progestin (Danatrol Maggioni-Winthrop, SPA, Milan, Italy) was found to be effective on laminin and type IV collagen accumulation around stromal cells.

Sequential use of conjugated estrogens and medroxyprogesterone in the climacteric syndrome: clinical and histological findings

Seventy-four symptomatic postmenopausal women received conjugated equine estrogens, 0.625 mg daily, alternating 3 wk of treatment with 1 wk free. Medroxyprogesterone acetate, 10 mg daily, was added from day 12 to day 21 of the estrogen therapy. The length of treatment ranged between 36 and 50 mth (media 42.8). This sequential treatment appears to be an effective medication for menopausal women as 86.4% of patients showed a complete regression of symptoms. Its acceptability may be considered good since few side effects and low incidence of abandons (12.2%) were registered. Medroxyprogesterone seems to be a useful agent to counteract the possible cocarcinogenetic effect of conjugated estrogens on account of the high incidence of induced secretory endometrium obtained (92.2%), the reversal of six pretreatment endometrial hyperplasias and the absence of any premalignant endometrial lesion after at least 3 yr of this sequential treatment. The only case of endometrial cancer registered does not jeopardize this conclusion as was observed in a women who took medroxyprogesterone very irregularly.

Dose-response effects on serum lipids and lipoproteins following combined oestrogen-progestogen therapy in post-menopausal women

The dose-response effects on serum lipids and lipoproteins were studied in 87 healthy post-menopausal women treated for 1 yr with three different doses of sequential oestrogen/progestogen (4 mg, 2 mg and 1 mg 17 beta-oestradiol cyclically combined with 1 mg norethisterone acetate) or placebo. Total serum cholesterol levels were significantly reduced by 4-10% (P less than 0.05-P less than 0.001) in a dose-related way in the hormone groups. This was mainly caused by a similar reduction in low-density-lipoprotein (LDL) cholesterol, whereas the changes in high-density-lipoprotein (HDL) cholesterol were not significantly different from those observed in the placebo group. It is concluded that treatment with sequentially combined oestrogen and progestogen, using norethisterone acetate in combination with 17 beta-oestradiol in clinically relevant doses, does not produce any adverse effects on serum lipids or lipoproteins.

Climacteric symptoms after oral and percutaneous hormone replacement therapy

One hundred and ten (110) healthy early post-menopausal women with mild subjective vasomotor symptoms (mean Kupperman index score 11) participated in a long-term, double-blind, placebo-controlled therapeutic trial. The effects of 2 hormone regimens were evaluated. Group I received percutaneous oestrogen therapy for 2 yr, opposed by oral micronized progesterone (200 mg) during the second year, while Group II received oral 17 beta-oestradiol valerate together with cyproterone acetate (CPA). The serum oestrogen concentrations differed markedly in the 2 treatment groups. In Group I the serum/oestrone/oestradiol ratio was 1 (comparable to the pre-menopausal value), but in group II the ratio was greater than 5. Despite the difference in the serum oestradiol and oestrone concentrations, the mean symptom scores were rapidly and similarly reduced in both treatment groups (P less than 0.001). They remained low throughout the study and were not significantly different from pre-menopausal values.

Postmenopausal osteoporosis--intervention and prophylaxis. A review

Postmenopausal osteoporosis is a common disorder associated with significant morbidity and mortality through fractures of the femoral neck, vertebrae and distal forearm. The national cost of this illness is measured in billions of dollars annually. Although the etiology of postmenopausal osteoporosis is unclear, specific effective therapies are available if initiated early in the course of the disease. A large body of information concerning this illness has been generated but many questions remain. The epidemiology, etiology, diagnosis and therapy of postmenopausal osteoporosis are discussed in this review with emphasis on prophylactic and interventional therapy as related to subpopulations of women at risk for osteoporosis.

Long-term effects of percutaneous estrogens and oral progesterone on serum lipoproteins in postmenopausal women

Serum lipids and lipoproteins were examined in a group of 45 healthy postmenopausal women who were treated for 2 years with either 3 mg of percutaneous estradiol (n = 20) or placebo (n = 25). Percutaneous estradiol was given alone during the first year of treatment and in combination with oral micronized progesterone (200 mg) for 12 days of each cycle during the second year. The women were examined every 3 months throughout the 2 years. Percutaneous estrogen therapy significantly reduced total serum cholesterol and low-density lipoprotein cholesterol, whereas no significant differences were observed in serum triglycerides and high-density lipoprotein cholesterol. Addition of oral progesterone during the second year of treatment did not produce any significant alterations in serum total cholesterol or low-density lipoprotein cholesterol, both of which remained significantly reduced. Serum triglycerides remained virtually unchanged, whereas a slight but significant increase (p less than 0.05) was observed in high-density lipoprotein cholesterol levels at the end of the study period. We conclude that percutaneous estrogen administration produces changes in total serum cholesterol and low-density lipoprotein cholesterol levels similar to those observed after oral estrogen administration. However, the magnitude and time course of the response seem to be modulated by the route of administration. Addition of oral micronized progesterone does not influence the beneficial estrogenic actions on serum lipids and lipoproteins and seems to be a proper "progestogen" in percutaneous estrogen therapy.

A simple method for determining the optimal dosage of progestin in postmenopausal women receiving estrogens

Progestin is often added to regimens of estrogen therapy in postmenopausal women to reduce the risk of endometrial hyperstimulation, but it may cause undesirable metabolic effects. Therefore, a low dosage is recommended. At present, the only way to determine whether the dosage of progestin is causing the desired secretory transformation of the endometrium is by endometrial sampling, which is invasive. We studied 102 postmenopausal women undergoing estrogen therapy who also took a progestin for 12 days each month, and we correlated the day of onset of bleeding with the endometrial histology over a three-month period. A bleeding pattern suitable for interpretation was observed in 96 women. Regardless of the preparation and dosage of the estrogen and progestin used, wholly or predominantly proliferative endometrium was always associated with bleeding on or before day 10 after the addition of progestin; wholly or predominantly secretory endometrium, or a lack of endometrial tissue, was associated with bleeding on day 11 or later. We conclude that the bleeding pattern reflected the histologic condition of the endometrium and that adjustment of the dosage of progestin so that regular bleeding is induced on or after day 11 may obviate the need for endometrial biopsy.

Psychological effects of progestogens in the post-menopausal years

Progestogens are increasingly being advocated as a necessary and integral part of hormone replacement therapy. Yet few studies have measured the acceptability of these regimes. One factor profoundly affecting acceptability, and thus patient compliance, is the presence of adverse psychological effects of progestogens. There have been few double-blind trials which have evaluated such effects of progestogens and compared them with the effects of oestrogen administration alone. There is some evidence of less favourable effects when certain progestogens are added to oestrogen or used alone. Whilst the literature is limited there is an indication that adverse effects of progestogens may relate to dosage, type of progestogen and individual sensitivity of women to hormone provocation of symptoms. Further studies are needed to test these hypotheses.

Reliability of endometrial cancer diagnoses in a Swedish Cancer Registry--with special reference to classification bias related to exogenous estrogens

In this study, various qualitative aspects of endometrial cancer diagnoses were critically evaluated regarding cases included in the Swedish Cancer Registry from the Uppsala Health Care Region. By comparing the number of such cases in the registry with cases reported directly from the departments of pathology and of gynecological oncology in the same region, it was found that approximately 5% of all incident cases had not been notified to the registry. An independent histopathological review of the original specimens showed that almost 9% of the cases did not represent an endometrial neoplastic lesion, the majority of these being reclassified as uterine sarcoma. The review also revealed the problem of a diagnostic bias that might arise in connection with estrogen exposure, in that a significantly higher proportion of the cases observed in a cohort of women who had received estrogen prescriptions were reclassified as a premalignant endometrial lesion than of the cases from the background population without estrogen exposure (33% versus 10%). Additional independent reviews of cases showing discordant diagnoses in the primary review indicated variability in diagnostic criteria among pathologists. It is concluded that when cancer registry data are employed in epidemiological studies of endometrial cancer, the use of additional sources of case recruitment is desirable in order to obtain a complete material; also that an independent histopathological review is necessary to standardize diagnostic criteria and thereby to avoid a classification bias.

Dose dependent effects of oral progesterone on the oestrogenised postmenopausal endometrium

Oral progesterone 100, 200, or 300 mg daily was given for the first 10 days of each calendar month to postmenopausal women also receiving conjugated oestrogens 1.25 mg daily continuously. Endometrial biopsy specimens were taken on the sixth day of the third or subsequent cycle of combined treatment for histological, ultrastructural, and biochemical evaluation. Secretory histological changes were induced within the endometrium in a dose dependent manner, as were progesterone sensitive ultrastructural features such as nucleolar channel systems, giant mitochondria, and subnuclear accumulations of glycogen. Dose response relations were also observed for suppression of DNA synthesis and nuclear oestrogen receptor, and for induction of the activities of oestradiol and isocitric dehydrogenases. Progesterone administered by mouth clearly provokes an end organ response within the endometrium. Suboptimal effects were observed with the lower doses but progesterone 300 mg daily achieved responses approaching and within the physiological range. This dose may therefore be effective as an alternative to synthetic progestogens for therapeutic purposes.

Actions of progestins on the morphology and biochemistry of the endometrium of postmenopausal women receiving low-dose estrogen therapy

Endometrial biopsies were obtained from postmenopausal women receiving 0.625 mg Premarin daily and either 2.5 or 5 mg norethindrone daily or 150 or 500 microgram dl-norgestrel daily for 10 days each month. Sample were taken during the estrogen-only phase of treatment and on the sixth day of combined estrogen/progestin administration. Progestin exposure caused marked morphologic and biochemical changes as well as features comparable with the premenopausal luteal phase. Thus, progestins oppose the stimulation of premarin to the postmenopausal endometrium. However, the currently recommended dosage of norethindrone and dl-norgestrel greatly exceed those necessary to suppress endometrial proliferation effectively. The recommended daily dosage may be lowered without losing protective effect. This reduction will probably minimize the risk of dose-dependent progestin side effects.

Endometrial hyperplasia in women on cyclic or continuous estrogen regimens

Twenty-five symptomatic postmenopausal women with an intact uterus were assigned in random double-blind fashion to receive 0.625 mg of conjugated estrogens on either a cyclic (3 weeks on, 1 week off) or continuous (daily) basis. The incidence of endometrial hyperplasia as demonstrated by screening biopsies at 6 and 12 months of therapy was 4.5 per 100 woman-months in the cyclic group and 3.7 per 100 woman-months in the continuous group (a difference not statistically significant). Thus, in this study, cyclic therapy was found to offer no advantage over continuous therapy. In our opinion, the rate of hyperplasia development in both groups unacceptably high, and efforts must be directed at reducing its incidence primarily.

Effects of estrogens and progestins on the biochemistry and morphology of the postmenopausal endometrium

To study the effects of exogenous estrogens on the postmenopausal endometrium, and to determine the time course and minimum dosage of added progestins necessary to oppose estrogen stimulation, we obtained endometrial specimens from symptomatic postmenopausal women being treated with various preparations of estrogens and progestins. Morphologic changes were assessed with light and electron microscopy, and biochemical effects through measurement of DNA synthesis, estradiol and progesterone receptors, and isocitric and estradiol dehydrogenase activity. For comparison, identical studies were carried out on specimens from premenopausal women in the proliferative and secretory phases of their cycle. All the estrogens exerted stimulatory effects in the postmenopausal specimens that were comparable to those observed in the premenopausal proliferative-phase specimens. Estropipate, subcutaneous estradiol, and conjugated estrogens had some hyperphysiologic effects. Maximal progestational effects occurred in the postmenopausal specimens only after norethindrone was administered for six days, and a constant level of activity equal to that in premenopausal secretory-phase specimens was then observed until the 10th day of exposure. Similar maximal effects occurred after six days of treatment with D/L-norgestrel (150 and 5 mg daily [10 mg daily produced less complete changes]). We conclude that many estrogen preparations subject the endometrium to a potent stimulus. Norethindrone and norgestrel are protective because they counteract the proliferative effects of estrogens, but the currently recommended daily dosages of these progestins can be greatly reduced without loss of response.