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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tamoxifen is the most widely prescribed endocrine therapy for breast cancer, with more than 7.5 million woman-years of clinical experience. Tamoxifen has both antiestrogenic and estrogenic activity. The antiestrogenic activity accounts for its efficacy against breast cancer, while the estrogenic activity is considered to be associated with positive effects on bone mineral density and lipid profiles and a proliferative effect on the endometrium in some women. Tamoxifen has a good tolerability profile and has demonstrated benefits for breast cancer patients in prolonging overall and disease-free survival and reducing the incidence of contralateral breast cancer. These known benefits of tamoxifen far outweigh the risk of endometrial cancer in tamoxifen-treated patients with breast cancer.
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PMID:Risks and benefits of tamoxifen therapy. 906 23

For nearly 20 years, tamoxifen has been successfully used in the management of breast cancer. Tamoxifen is a mixed estrogen agonist/antagonist that has a proliferative effect on the endometrium. The drug has been associated with a higher percentage of endometrial polyps and hyperplasia than in control patients as well as slightly increased risk of endometrial cancer. Although patients need to undergo annual gynecologic exams and abnormal vaginal bleeding needs to be aggressively followed up, the utility of routine gynecologic screening of tamoxifen patients has not been established and requires further study. Transvaginal sonography is a useful tool for detecting endometrial proliferation; however, an appropriate cut-off point for further intervention must be established. A cut-off point that is too low for abnormal endometrial thickness would result in a large number of unnecessary endometrial biopsies. Routine office endometrial biopsy needs further study as a screening method for breast cancer patients on tamoxifen.
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PMID:Benign and hyperplastic endometrial changes associated with tamoxifen use. 906 25

The current literature on endometrial neoplasia deals with proliferative lesions such as endometrial proliferation in early pregnancy, atypical polypoid adenomyofibromata and their possible relationship to carcinoma, and histological grading of endometrial cancer with emphasis on nuclear grading and subtypes of endometrial cancer including the newly described intestinal and hepatoid types. Recent publications dealing with p53 protein, genetic studies, and nucleolar organizer regions are of interest but have provided no striking new insight into endometrial neoplasia. Angiogenesis has appeared for the first time in the literature in connection with endometrial neoplasia. Tamoxifen continues to occupy an important place in the literature, and endometrial adenosarcoma has been identified recently as one of the myriad of lesions which patients treated with tamoxifen are prone to develop.
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PMID:Endometrial pathology. 909 Apr 83

Breast cancer tissue has been shown to contain alternatively spliced estrogen receptor (ER) mRNA variants which may result in alternate ER proteins. These ER variants lack specific functional domains and may alter breast cancer cells responses to both estrogen and antiestrogens. Specifically, ER variants might play a role in Tamoxifen resistance in breast cancer patients, as well as the development of endometrial carcinoma, an estrogen-dependent tumor, in patients taking this medication. We investigated the presence of ER variants in normal human endometrium and endometrial carcinoma. Ribonuclease protection assays (RPA) demonstrated ER mRNA variants in the DNA and hormone-binding domains. The reverse transcription-polymerase chain reaction (RT-PCR) assay was used to examine the ER complementary DNA (cDNA) from 25 patients, and generated two major products in both the exon 2 to 5 and 4 to 8 regions. Southern blot analysis of PCR products revealed exon 4 and 7 deletions in all 25 endometria without any qualitative differences in variant expression among premenopausal, postmenopausal, and adenocarcinoma samples. Cloning and sequencing of cDNA variants definitively identified exact deletions of either exon 4 or exon 7. These results demonstrate significant levels of ER mRNA splice variants as well as full-length ER mRNA in normal and neoplastic endometria.
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PMID:Estrogen receptor mRNA splice variants in pre- and postmenopausal human endometrium and endometrial carcinoma. 910 5

Breast cancer patients who received tamoxifen as adjuvant therapy have been reported to have more endometrial lesions such as polyps, hyperplasia, or carcinoma. We conducted a prospective study to elucidate the endometrial changes of premenopausal and postmenopausal breast cancer patients with tamoxifen. Sixty-seven symptomatic breast cancer patients who had been on tamoxifen treatment, including 34 premenopausal and 33 postmenopausal patients, and another group of 48 patients who had not been on tamoxifen, including 25 premenopausal and 23 postmenopausal patients, were recruited. Symptomatic patients were defined as having hypermenorrhea or abnormal vaginal bleeding among premenopausal patients or postmenopausal bleeding among postmenopausal patients. Endometrial thickness and uterine size determined by vaginal ultrasonography, histologic findings, and risk factors for endometrial cancer were compared. The mean endometrial thickness and uterine size showed no statistically significant difference in premenopausal patients with (n = 34) or without (n = 25) tamoxifen treatment, whereas there was a significant difference in the postmenopausal patients with (n = 33) or without (n = 23) tamoxifen treatment (12.11 +/- 12.38 mm vs 5.41 +/- 2.70 mm, P = 0.025; 234.71 +/- 76.36 cm3 vs 108.81 +/- 81.27 cm3, P = 0.0018, respectively). The frequency of endometrial histopathologic findings was 23.5% (8/34) in tamoxifen-treated women compared with 12.0% (3/25) in nontreated women (P = 0.269) in the premenopausal groups. In contrast, it was remarkably high with 66.7% (22/33) in tamoxifen-treated women compared with 30.4% (7/23) in the nontreated women in the postmenopausal groups (P = 0.025). There were four postmenopausal patients with tamoxifen, including three with atypical endometrial hyperplasia and one endometrial carcinoma, in contrast to no postmenopausal nontreated patients, although this difference did not reach statistical significance in this study (P = 0.096). There was a remarkably high prevalence of endometrial histopathologic findings in symptomatic tamoxifen-treated breast cancer patients, especially postmenopausal women. Tamoxifen might be associated with premalignant or malignant changes in postmenopausal endometrium. Thus timely, aggressive histologic assessment such as curettage or hysteroscope should be performed to detect the endometrial lesions when symptoms occur. Vaginal ultrasonography could be a useful tool to detect the endometrial lesions.
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PMID:Comparison of endometrial changes among symptomatic tamoxifen-treated and nontreated premenopausal and postmenopausal breast cancer patients. 926 68

Tamoxifen is a liver carcinogen in rats and has been shown to increase the risk of endometrial cancer in women. Recent reports of DNA adducts in leucocyte and endometrial samples from women treated with tamoxifen indicate that it may be genotoxic to humans. One of the proposed pathways for the metabolic activation of tamoxifen involves oxidation to 4-hydroxytamoxifen, which may be further oxidized to an electrophilic quinone methide. In the present study we show that 4-hydroxytamoxifen quinone methide reacts with DNA to form covalent adducts. The major products, which result from 1,8-addition of the exocyclic nitrogen of deoxyguanosine to the conjugated system of 4-hydroxytamoxifen quinone methide, are characterized as (E)- and (Z)-alpha-(deoxyguanosin-N2-yl)-4-hydroxytamoxifen.
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PMID:Identification of tamoxifen-DNA adducts formed by 4-hydroxytamoxifen quinone methide. 936 5

Tamoxifen (TAM) is widely used as adjuvant breast cancer therapy after surgery and as a chemopreventive agent in women of child-bearing age. However, TAM therapy has been shown to result in an increased incidence of endometrial carcinoma in women. The present study was designed to investigate the effects of TAM (5 mg/kg and 7.5 mg/kg body wt) given i.g. to pregnant CD-1 mice (1x/day, days 12 through 18 of gestation) on their female offspring. Progressive proliferative hyperplasia of the oviduct was frequently seen in TAM-exposed offspring, reaching 100% incidence by 52 weeks in both treatment groups. These females also developed progressive proliferative uterine lesions, including moderate/severe cystic endometrial hyperplasia (34-50%) and polypoid adenomas (27-30%) between 53 and 78 weeks. Deciduomas (15%) occurred at young ages (12 and 24 weeks) while leiomyomas (14%), a malignant leiomyosarcoma, and ovarian granulosa cell tumors (14%), were found between 72 and 78 weeks. Our findings thus suggest a strong association between transplacental TAM and reproductive tract abnormalities in female CD-1 mice.
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PMID:Proliferative lesions of oviduct and uterus in CD-1 mice exposed prenatally to tamoxifen. 936 13

To elucidate potential mechanisms involved in the increased incidence of endometrial carcinomas in tamoxifen-treated patients, we examined the in-vitro effects of tamoxifen on endometrial cancer cells. The effects of tamoxifen, alone and in combination with oestradiol, on cell proliferation, plasminogen activator (PA) activity, glycogen synthase and phosphorylase activities, p53 protein concentration, and collagenase expression were assessed in two human adenocarcinoma cell lines. These lines were the oestrogen receptor-positive (Ishikawa) cells, representing a well-differentiated endometrial adenocarcinoma, and oestrogen receptor-negative (HEC-1A) cells, derived from a poorly differentiated endometrial adenocarcinoma. Tamoxifen or oestradiol alone and their combination significantly enhanced cellular proliferation of Ishikawa but not of HEC-1A cells. Both lines produced appreciable PA activity, most of which was of the urokinase type. Tamoxifen and oestradiol stimulated this activity in Ishikawa cells but not in HEC-1A cells. The effect of oestradiol was dose-dependent in a linear fashion, while tamoxifen produced a stimulation peaking at 10(-8) M and declining at higher concentrations. Tamoxifen in combination with oestradiol exhibited a synergistic effect on proliferation and on PA activity. The response of PA extended beyond the increase in proliferation, leading to higher specific activity of PA in the tamoxifen-treated cultures. In Ishikawa cells, oestradiol also increased glycogen synthase and glycogen phosphorylase activities, while tamoxifen markedly suppressed these enzymes. Oestradiol, tamoxifen, and their combination had no apparent effect on the expression of protein p53 in Ishikawa cells, or on gelatinase activity in either Ishikawa or HEC-1A cells. The present findings imply that tamoxifen produces oestrogen-agonistic effects on cell proliferation and PA activity, and oestrogen antagonistic effects on glycogen synthase and glycogen phosphorylase activities, but fails to regulate p53 and gelatinase expression. The tamoxifen-responsive systems were only observed in oestrogen-responsive adenocarcinoma cells. Thus, only certain potential oncogenic effects of tamoxifen can be simulated in vitro, and when present, these effects are enhanced in the presence of oestradiol.
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PMID:Tamoxifen exerts oestrogen-agonistic effects on proliferation and plasminogen activation, but not on gelatinase activity, glycogen metabolism and p53 protein expression, in cultures of oestrogen-responsive human endometrial adenocarcinoma cells. 946 46

Long-term tamoxifen therapy is associated with increased risk of uterine endometrial cancer and benign alterations. Tamoxifen is metabolized to reactive intermediates by endometrial tissue, and tamoxifen therapy-induced DNA adducts have been found in human endometrium. Since metabolic activation is often catalyzed by cytochrome P450 (CYP) enzymes, the expression profile of individual xenobiotic-metabolizing CYP genes was studied in human uterine endometrium by reverse transcriptase-polymerase chain reaction. The following CYP mRNAs were detected: CYP2B6, CYP2C, CYP2E1, CYP3A4, CYP3A5, CYP4B1, and CYP11A. Amplification of CYP1A1, CYP1A2, CYP2A6, CYP2D6, CYP2F1, CYP3A7, and CYP19 was not found. CYP3A5 and CYP4B1 transcripts were found only in samples from premenopausal women. These data suggest that the human endometrial epithelium has the potential of producing CYP enzymes known to generate genotoxic intermediates from tamoxifen and metabolites that affect oestrogen receptors.
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PMID:Expression of cytochrome P450 genes encoding enzymes active in the metabolism of tamoxifen in human uterine endometrium. 949 38

Tamoxifen has been shown to decrease the recurrence rate of breast cancer. Evidence that tamoxifen use may be associated with an increased risk of endometrial cancer has caused investigators to recommend routine invasive sampling. We have assessed a minimally invasive alternative for endometrial surveillance of tamoxifen-treated patients utilizing transvaginal ultrasound and saline infusion sonohysterography. Asymptomatic women (n = 44) with breast cancer on postoperative tamoxifen treatment were referred to our gynecological ultrasound unit. Initially, the endometrial echo was measured with unenhanced transvaginal ultrasound. If a distinct echo measured < or = 5 mm, no further procedure was performed. For thickened or inadequately visualized echoes, sonohysterography was performed. If a thin echo was noted on sonohysterography, no further procedure was performed. If focal changes were detected, hysteroscopy/dilatation and curettage (D&C) was performed. For generalized symmetrically thickened echoes, a blind biopsy was done. If sonohysterography was unsuccessful, hysteroscopy/D&C was performed. Eleven (25%) patients had thin unenhanced echoes of < or = 5 mm. Twenty-five (57%) patients had thickened endometrial echoes. Three (7%) had naturally occurring endometrial fluid outlining a polyp. An endometrial echo could not be visualized in five (11%) patients. Sonohysterography was successfully performed in 21 out of 30 (70%) patients with either thickened or non-visualized unenhanced echoes. Of these, two patients had thin endometria with coexisting myomas; seven had thin endometria with typical tamoxifen-induced subendometrial changes: and seven had focal polypoid thickening confirmed by hysteroscopy/D&C. Histology revealed carcinoma associated with two, proliferation in one and four polyps. Five patients had thickened unenhanced echoes with symmetrically thickened single-layer measurements on sonohysterography. Histology revealed that three were proliferative, one was inactive and one was hyperplastic. In the nine patients with unsuccessful sonohysterography, hysteroscopy/D&C revealed inactive endometria in six, and three polyps. Our paradigm of evaluating the endometrial response to tamoxifen is concluded to overcome the shortcomings of either unenhanced transvaginal ultrasound or blind biopsy alone while it kept the number of invasive sampling procedures to 55% (24 out of 44).
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PMID:The use of transvaginal ultrasound and saline infusion sonohysterography for the evaluation of asymptomatic postmenopausal breast cancer patients on tamoxifen. 951 Nov 96


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