Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tamoxifen has become the standard of care in relation to hormonal therapy for women with hormone-sensitive tumors. However, recently completed and ongoing studies indicate that third-generation aromatase inhibitors may be more effective than tamoxifen for a wide range of patients with breast cancer. Drugs in this class currently are approved as first-line endocrine therapy for postmenopausal women with metastatic hormone-dependent breast cancer, and as second-line endocrine therapy after failure of antiestrogen therapy alone or multiple hormonal therapies. The interim results from the Arimidex, Tamoxifen Alone or in Combination Trial support the use of an aromatase inhibitor as an alternative to tamoxifen for adjuvant therapy in postmenopausal women with operable breast cancer that is hormone positive. In this trial, anastrozole had a favorable side effect profile, with fewer cases of endometrial cancer and fewer thromboembolic events than tamoxifen. Other recent studies have indicated that an aromatase inhibitor may be superior to tamoxifen as preoperative treatment for women with hormone-sensitive, primary breast cancer. Numerous clinical trials currently are comparing the efficacy of aromatase inhibitors with that of tamoxifen used as adjuvant therapy for postmenopausal women who have early-stage breast cancer. The results of these trials will provide additional information about the best ways to use these powerful agents for patients with breast cancer.
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PMID:New developments in endocrine therapy: role of adjuvant therapy for early breast cancer. 1502 6

Excessive estrogenic influence is known to be associated with initiation/promotion of endometrial cancer (EC). Allelic polymorphisms of the genes involved in steroidogenesis/steroid metabolism may contribute to EC susceptibility. It is important to know endocrine mechanisms by which such susceptibility is acquired. Here, we compared CYP19 (aromatase) and CYP17 (17alpha-hydroxylase/17,20-lyase) gene polymorphisms correspondingly in 136 and 165 EC patients and in 116 and 188 non-affected women primarily of postmenopausal age. In these expanded studies we confirmed our previous observations that genotypes with longest alleles of CYP19 (A6 or A7) are over-represented (64.7+/-4.0 vs. 49.1+/-4.6%, P = 0.04, and 11.0+/-2.7 vs. 1.7+/-1.2%, P = 0.01)) and A2/A2 CYP17 genotype is under-represented (12.1+/-2.5 vs. 25.0+/-3.2%, P = 0.001) in patients as compared to controls. Additionally, aromatase activity was studied by tritiated water release assay in tumor tissues of 32 EC patients. In carriers of A2/A2 CYP17 genotype this activity was significantly lower than in carriers of A1/A1 genotype or in combined group of A1/A1 and A1/A2 CYP17 carriers (P = 0.04 in both cases). On the other side, intratumoral aromatase activity demonstrated tendency to higher values in carriers of longest CYP19 alleles (A6A6 and A6A7) than in carriers of all other CYP19 allele variants (P = 0.066). Thus, specific set of genetic polymorphisms (carrying of CYP17 A1 allele and combination of longest A6 or A7 CYP19 alleles) may predispose to the induction of higher rate of local estrogen biosynthesis in malignant endometrium, that in its turn may support growth of the latter. Further studies are warranted to connect revealed regularities with the type I or II of EC.
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PMID:CYP17 and CYP19 genetic polymorphisms in endometrial cancer: association with intratumoral aromatase activity. 1507 28

Two-thirds of breast tumours are oestrogen-receptor positive and 60-70% of these tumours respond to interventions that reduce the effects of oestrogen. Until recently, tamoxifen was the drug of choice for the treatment of hormone-responsive early and advanced breast cancer. However, tamoxifen is associated with increased incidences of endometrial cancer and thromboembolic disease, and many tumours eventually become resistant to treatment with tamoxifen. Thus, there is a need for alternative therapies with different mechanisms of action. In postmenopausal women, aromatase inhibitors (AIs) suppress oestrogen levels by inhibiting oestrogen synthesis via the aromatase enzyme pathway. The third-generation AIs (anastrozole, letrozole and exemestane) are more potent than the earlier AIs (aminoglutethimide, formestane and fadrozole) with respect to both aromatase inhibition and oestrogen suppression. While the earlier AIs were unable to show any benefit over megestrol acetate or tamoxifen as second- and first-line therapy, respectively, in postmenopausal women with advanced breast cancer, third-generation AIs have shown significant benefits in both settings. Comparison of aromatase inhibition and oestrogen suppression between the third-generation AIs anastrozole and letrozole showed a small but significantly greater difference in the degree of suppression of oestrone and oestrone sulphate (but not oestradiol), with letrozole. In an open-label trial, there were no significant differences between letrozole and anastrozole for the clinical end points of time to progression (primary end point), time to treatment failure, overall survival, clinical benefit, duration of clinical benefit, time to response, duration of response or objective response rate in patients with confirmed hormone receptor-positive tumours. Together these data suggest that once a certain threshold of aromatase inhibition is reached, small differences in oestrogen suppression between the third-generation AIs do not lead to clinically significant differences in overall efficacy.
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PMID:Aromatase inhibition in the treatment of advanced breast cancer: is there a relationship between potency and clinical efficacy? 1577 Feb 17

The strategy of therapy and prognosis of reproductive system neoplasia generally depend on the steroid receptor status of tumor. The causes of formation of steroid receptor-free tumors are to be investigated. The genetic polymorphism of CYP19 (aromatase), CYP17 (17-hydroxylase; 17,20-lyase), CYP1B1 (4-estrogen hydroxylase) and COMT (catechol-O-methyl transferase) was studied in a total of 254 patients with breast and endometrial cancer, with particular reference to the association of certain polymorphisms and receptor status of tumor. It was found that the lack of estrogen receptor (ER) in breast tumor was due to a deficit in the A3A6 allele (p(0.01), while the absence of progesterone receptors was associated with a lower incidence of the A1A1 and A1A2 variants (p = 0.022) of tetranucleotide repeats in the CYP19 gene. In the same patients, receptor-negative tumors occurred more often (p = 0.032) than in combinations of higher level of 4-hydroxylase estradiol of S-allele in position 48 (Gly/Arg) of the CYP1B1 gene. Moreover, endometrial carcinoma patients tended to reveal (p = 0.058) an increased ratio of A6A7-CYP19 to allele A1-containing variant. No other distinctions between R(+) and R(-) tumors were identified. It is suggested that peculiar polymorphisms of steroidogenic enzymes may moderately influence the genesis of R(-) neoplasms which may be associated with either the rate of estrogen biosynthesis or, as in the case of CYP1B1, with formation of genotoxic derivatives of estrogens. The latter point is to be investigated further.
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PMID:[Genetic polymorphism of steroidogenic enzymes and steroid receptor level in tumors of the reproductive system]. 1517 18

Hormonal therapies have been used in the adjuvant therapy of breast cancer for decades. Tamoxifen, a selective estrogen receptor modulator, is the current standard therapy. It reduces the risk of recurrence by about one half Only recently, new aromatase inhibitors (anastrozole, letrozole, exemestane) have been competing with tamoxifen; these drugs are superior to tamoxifen in advanced breast cancer. Two recent trials are discussed: Anastrozole reduced the short-term risk of recurrent disease more efficiently than tamoxifen. The use of letrozole after five years of adjuvant tamoxifen treatment further reduced the risk of recurrence. Numerous side-effects, notably endometrial cancer and thromboembolic disease, were less frequent with aromatase inhibitors whereas the risk of osteoporotic fractures increased substantially. The positive preliminary results of these and other trials are discussed: At present, the use of aromatase inhibitors is not yet recommended on a routine basis. Future trial results will allow a more complete assessment of the efficacy and toxicity of aromatase inhibitors.
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PMID:[Aromatase inhibitors in the adjuvant therapy of breast carcinomas]. 1525 60

Adjuvant hormonal therapy in the treatment of women with early-stage, hormone receptor (HR)-positive breast cancer is now considered the standard of care. Adjuvant tamoxifen decreases the risk of breast cancer recurrence and death in women with early-stage breast cancer when taken for 5 years. The benefits of tamoxifen are counterbalanced by toxicities including an increased risk of endometrial cancer and thromboembolic events. The selective aromatase inhibitors (AIs)--including anastrozole, letrozole, and exemestane--are challenging the role of tamoxifen as the adjuvant hormonal therapy of choice in postmenopausal women. Results of the Arimidex and Tamoxifen Alone or in Combination trial favor the use of anastrozole over tamoxifen as initial adjuvant hormonal therapy, with improvement in disease-free survival (DFS) and a favorable toxicity profile. The results of 2 large adjuvant trials using AIs sequentially with tamoxifen in postmenopausal women with early-stage, HR-positive breast cancer have been reported. The MA-17 study randomized women to placebo or letrozole for 5 years after completion of 4.5-6 years of initial tamoxifen. The Intergroup Exemestane Study (IES) randomized women following 2-3 years of adjuvant tamoxifen to continue to receive tamoxifen or switch to exemestane for a total of 5 years of adjuvant hormonal therapy. The MA-17 and IES trials demonstrated superior DFS with the AI and corroborated the smaller GROCTA-4B and Italian Tamoxifen Arimidex trials, which studied sequential therapy with aminoglutethamide or anastrozole. There is now substantial medical evidence supporting the use of AIs in postmenopausal women with early-stage, HR-positive breast cancer.
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PMID:Adjuvant aromatase inhibitors following tamoxifen for early-stage breast cancer in postmenopausal women: what do we really know? 1534 35

The new anti-estrogens, including the selective estrogen receptor modulators (e.g., toremifene, droloxifene, idoxifene, raloxifene and arzoxifene), the selective estrogen receptor downregulators (e.g., fulvestrant), and the new steroidal (e.g., exemestane) and non-steroidal (anastrozole and letrozole) aromatase inhibitors have been investigated in the treatment of breast cancer and hormonally sensitive tumors of the uterine body. In postmenopausal women, anastrozole, letrozole and exemestane appear to have superior efficacy and an improved toxicity profile than tamoxifen, and fulvestrant seems to be at least as effective as anastrozole in patients in whom tumors have progressed after prior endocrine treatment. Preliminary data showed a high response rate and a favorable toxicity profile for arzoxifene in endometrial cancer, whereas letrozole could represent a new interesting therapeutic tool for endometrial cancer as well as for low-grade endometrial stromal sarcoma.
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PMID:Use of estrogen antagonists and aromatase inhibitors in breast cancer and hormonally sensitive tumors of the uterine body. 1553 24

Endogenous oestrogens play a crucial role in endometrial cancer pathogenesis, with most endometrial cancer risk factors causing an increase in oestrogens. Adipose tissue, where androgens are converted to oestrogens by the enzyme aromatase, is an important source of endogenous oestrogen production in the postmenopausal woman. The peroxisome proliferator-activated receptor-gamma (PPARgamma), a key transcriptional regulator of adipogenesis, may also play a role in the regulation of aromatase expression in adipose tissue. We hypothesized that the functional PPARgamma ProAla polymorphism may alter aromatase expression, ultimately affecting endometrial cancer susceptibility. We genotyped the PPARgamma ProAla polymorphism in a study of invasive endometrial cancer cases (n = 222) and matched controls (n = 666) nested within the Nurses' Health Study Cohort. We found little or no evidence of an association between the Ala allele of the PPARgamma codon 12 polymorphism and endometrial cancer risk (adjusted odds ratio = 1.18, 95% confidence interval = 0.80-1.76). Furthermore, we found no association with the PPARgamma ProAla polymorphism and the ratio of oestrone to androstenedione or oestradiol to testosterone plasma hormone levels, measures of aromatase activity. Consistent with previous findings for breast cancer, these results suggest that the PPARgamma ProAla polymorphism does not play a major role in mediating circulating oestrogen levels or endometrial cancer susceptibility.
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PMID:No evidence of a role for PPARgamma Pro12Ala polymorphism in endometrial cancer susceptibility. 1560 64

Estrogen plays an important role in the skeletal health of all women. Many therapies used in the treatment of breast cancer reduce estrogen levels and have the potential to affect bone negatively by increasing the risk of osteoporosis and associated bone fractures. The long-term effects of systemic endocrine therapy on bone, therefore, are an important consideration in the adjuvant setting. Tamoxifen has been shown to have a moderate protective effect on postmenopausal bone due to its partial estrogen agonist activity; however, its long-term use is potentially associated with negative side effects, such as an increased risk of thromboembolic disease and endometrial cancer. Newer agents, the third-generation aromatase inhibitors (AIs), anastrozole, letrozole and exemestane, for example, do not possess estrogen agonist effects and have improved breast cancer outcomes when compared to the standard 5 years of tamoxifen. However, patients treated with adjuvant AIs have been shown to have an increased incidence of osteoporosis and osteoporotic fractures. In order to select the optimal adjuvant therapy for each patient, it is important to assess the overall risk:benefit ratio for each endocrine strategy. All postmenopausal women should follow published guidelines to assess the risk of osteoporosis and, where appropriate, they should receive bone mineral density monitoring. Postmenopausal women with breast cancer who are at increased risk of osteoporotic fracture should be identified and managed with appropriate nonpharmacologic and pharmacologic measures.
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PMID:Skeletal health in postmenopausal survivors of early breast cancer. 1564 35

The incidence of newly diagnosed breast cancer cases world-wide is expected to double by 2020. Risk-reducing strategies for breast cancer include lifestyle modifications, chemoprevention and surgery (bilateral mastectomy and/or oophorectomy). Lifestyle modifications include avoidance of postmenopausal obesity and hormone replacement therapy (HRT), regular physical activity, and restriction of alcohol and animal fat intake. Tamoxifen is a selective estrogen receptor modulator (SERM) shown in randomized controlled trials to reduce the incidence of estrogen receptor (ER)-positive breast cancer in high-risk healthy women. However, its routine use cannot be recommended for breast cancer prevention in healthy women due to its significant adverse effects, specifically in terms of endometrial carcinoma and thromboembolism. On the other hand, tamoxifen may be used for chemoprevention in women at high risk of developing ER-positive breast cancer and at low risk of developing complications. Raloxifene, another SERM, also appears to be effective in reducing breast cancer risk, and lacks the unwanted stimulatory effect on the uterus. Other promising chemopreventive agents currently under investigation include cyclo-oxygenase 2 (COX-2) inhibitors, fenretinide, aromatase inhibitors, and goserelin. Prophylactic mastectomy can reduce breast cancer risk by 90% in high-risk women. Bilateral oophorectomy has the potential of reducing the risk of both breast and gynecologic cancer in women carrying BRCA-1 or BRCA-2 mutations. Further research is required to identify novel strategies to prevent ER-negative breast cancer, minimize the adverse effects of tamoxifen and other SERMs, and evaluate the role of mammary ductal lavage and ductoscopy in guiding risk-reducing strategies.
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PMID:Risk-reducing strategies for breast cancer--a review of recent literature. 1564 97


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