Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007124 (ductal carcinoma in situ)
 3,833 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In patients with hormone receptor positive DCIS tamoxifen reduces recurrence rates by almost 50%. Few data are available with aromatase inhibitors from randomised studies. In the ATAC study there were three DCIS lesions in the anastrozole arm and four in the tamoxifen arm in the women with ER positive invasive cancer. In the MA17 study which randomised patients to up to 5 years of letrozole or placebo there was only one DCIS event in the contralateral breast in patients taking letrozole and five on placebo. There were also four patients in this study who had DCIS in the conserved breast on placebo and none in the letrozole treated group. The few clinical data that are available therefore suggest the aromatase inhibitors are likely to be effective in DCIS. A histological review of a study of 206 postmenopausal women with invasive oestrogen receptor positive breast cancer who were randomised as part of a 14 day preoperative study to receive 2.5mg of letrozole or 1mg of anastrozole identified 27 patients with 28 pairs of tumours in whom there was sufficient ER positive DCIS in invasive cancer in the initial core biopsy and in the subsequent surgery specimen, to evaluate for PgR activity and proliferation. Within the DCIS both aromatase inhibitors significantly reduced PgR expression and both drugs also produced a significant fall in proliferation. There was a moderate degree of agreement between the fall in PgR in both the invasive cancer and DCIS (Kappa=0.5; p=0.0013) and between the fall in proliferation and between the invasive and in situ components (correlation coefficient=0.68; p<0.001). This study has shown significant effects of aromatase inhibitors on DCIS indicating that these agents are therapeutically active in this condition.
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PMID:DCIS and aromatase inhibitors. 1760 18

In situ estrogen synthesis is implicated in tumor cell proliferation through autocrine or paracrine mechanisms especially in postmenopausal women. Several recent studies demonstrated activity of aromatase, an enzyme that plays a critical role in estrogen synthesis in breast tumors. Proline-, glutamic acid-, and leucine-rich protein-1 (PELP1/MNAR) is an estrogen receptor (ER) coregulator, and its expression is deregulated in breast tumors. In this study, we examined whether PELP1 promotes tumor growth by promoting local estrogen synthesis using breast cancer cells (MCF7) that stably overexpress PELP1. Immunohistochemistry revealed increased aromatase expression in MCF7-PELP1-induced xenograft tumors. Real-time PCR analysis showed enhanced activation of the aromatase promoter in MCF7-PELP1 clones compared with MCF7 cells. Using a tritiated-water release assay, we demonstrated that MCF7-PELP1 clones exhibit increased aromatase activity compared with control MCF-7 cells. PELP1 deregulation uniquely up-regulated aromatase expression via activation of aromatase promoter I.3/II, and growth factor signaling enhanced PELP1 activation of aromatase. PELP1-mediated induction of aromatase requires functional Src and phosphatidylinositol-3-kinase pathways. Mechanistic studies revealed that PELP1 interactions with ER-related receptor-alpha and proline-rich nuclear receptor coregulatory protein 2 lead to activation of aromatase. Immunohistochemistry analysis of breast tumor array showed increased expression of aromatase in ductal carcinoma in situ and node-positive tumors compared with no or weak expression in normal breast tissue. Fifty-four percent (n = 79) of PELP1-overexpressing tumors also overexpressed aromatase compared with 36% (n = 47) in PELP1 low-expressing tumors. Our results suggest that PELP1 regulation of aromatase represents a novel mechanism for in situ estrogen synthesis leading to tumor proliferation by autocrine loop and open a new avenue for ablating local aromatase activity in breast tumors.
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PMID:Modulation of in situ estrogen synthesis by proline-, glutamic acid-, and leucine-rich protein-1: potential estrogen receptor autocrine signaling loop in breast cancer cells. 1807 23

It is well known that sex steroids play important roles in the development of invasive ductal carcinoma (IDC) of the human breast. However, biological significance of sex steroids remains largely unclear in ductal carcinoma in situ (DCIS), regarded as a precursor lesion of IDC, which is partly due to the fact that the intratumoral concentration of sex steroids has not been examined in DCIS. Therefore, in this study, we first examined the intratumoral concentrations of estradiol and 5alpha-dihydrotestosterone (DHT) using liquid chromatography/electrospray tandem mass spectrometry in DCIS. Intratumoral concentrations of both estradiol and DHT were threefold higher in DCIS than non-neoplastic breast tissues and estrogen-producing enzymes (aromatase, steroid sulfatase, and 17beta-hydroxysteroid dehydrogenase type 1 (17betaHSD1)), and androgen-producing enzymes (17betaHSD5 and 5alpha-reductase type 1 (5alphaRed1)) were abundantly expressed in DCIS by real-time PCR and immunohistochemical analyses. The intratumoral concentration of DHT was significantly lower in IDC than DCIS, while the expression of aromatase mRNA in carcinoma cells and intratumoral stromal cells was significantly higher in IDC than those in DCIS. Immunohistochemistry for sex steroid-producing enzymes in DCIS demonstrated that 5alphaRed1 immunoreactivity was positively correlated with Ki-67 labeling index and histological grade and was also associated with an increased risk of recurrence in patients with DCIS examined. Results of our study suggest that intratumoral concentrations of estradiol and DHT are increased in DCIS, which is possibly due to intratumoral production of these steroids. Therefore, estradiol and DHT may play important roles in the development of DCIS of the human breast.
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PMID:Intratumoral concentration of sex steroids and expression of sex steroid-producing enzymes in ductal carcinoma in situ of human breast. 1831 Feb 80

Breast-conserving surgery (BCS) followed by radiotherapy (RT) has become the standard of care for the treatment of early-stage (St. I-II) invasive breast carcinoma. However, controversy exists regarding the value of RT in the conservative treatment of ductal carcinoma in situ (DCIS). In this article we review the role of RT in the management of DCIS. Retrospective and prospective trials and meta-analyses published between 1975 and 2007 in the MEDLINE database, and recent issues of relevant journals/handbooks relating to DCIS, BCS and RT were searched for. In retrospective series (10,194 patients) the 10-year rate of local recurrence (LR) with and without RT was reported in the range of 9-28% and 22-54%, respectively. In four large randomised controlled trials (NSABP-B-17, EORTC-10853, UKCCCR, SweDCIS; 4,568 patients) 50 Gy whole-breast RT significantly decreased the 5-year LR rate from 16-22% (annual LR rate: 2.6-5.0%) to 7-10% (annual LR rate: 1.3-1.9%). In a recent meta-analysis of randomised trials the addition of RT to BCS resulted in a 60% risk reduction of both invasive and in situ recurrences. In a multicentre retrospective study, an additional dose of 10 Gy to the tumour bed yielded a further 55% risk reduction compared to RT without boost. To date, no subgroups have been reliably identified that do not benefit from RT after BCS. In the NSABP-B-24 trial, the addition of tamoxifen (TAM) to RT reduced ipsilateral (11.1% vs. 7.7%) and contralateral (4.9% vs. 2.3%) breast events significantly. In contrast, in the UKCCCR study, TAM produced no significant reduction in all breast events. Based on available evidence obtained from retrospective and prospective trials, all patients with DCIS have potential benefit from RT after BCS. Further prospective studies are warranted to identify subgroups of low-risk patients with DCIS for whom RT can be safely omitted. Until long-term results of ongoing studies on outcomes of patients treated with BCS alone (with or without TAM or aromatase inhibitors) are available, RT should be routinely recommended after BCS for all patients except those with contraindication.
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PMID:The role of radiotherapy in the conservative treatment of ductal carcinoma in situ of the breast. 1843 23

Ductal carcinoma in situ (DCIS) is commonly diagnosed today, mainly due to widespread use of screening mammography. Despite a better understanding of its biological behavior, many issues regarding its optimal management remain controversial. The biological behavior of DCIS has been associated with distinct molecular and histological features (such as expression of COX2, Ki67, c-erbB2, p53 mutation, presence or absence of comedonecrosis, nuclear grade, hormone receptor status, etc.). Recent advances in the diagnosis of DCIS include using magnetic resonance imaging, and the use of stereotactic-guided directional vacuum-assisted biopsy (DVAB). Ductoscopy and ductal lavage have a limited role in the management of DCIS. Surgical treatment of DCIS includes simple local excision to various forms of wider excision (segmental resection or quadrantectomy), or even mastectomy (either simple or skin-sparing). Radiotherapy following breast-conserving surgery significantly reduces local recurrence rates. Axillary lymph node dissection is not required for the management of DCIS; however, during the last decade, sentinel lymph node biopsy is increasingly used to exclude the presence of axillary metastases (when invasive disease is present within the DCIS). This approach has many advantages (including the avoidance of a second surgery if invasive disease is diagnosed within the DCIS) and should be considered when there is an increased probability for the presence of invasive breast cancer within the DCIS. The role of other minimally invasive methods (such as the "therapeutic" application of the DVAB technique, radiofrequency ablation, laser therapy, cryotherapy and brachytherapy) in the management of small DCIS remains unproven. Tamoxifen should be considered in the management of selected patients with DCIS, such as patients with hormone receptor positive DCIS, young patients, and patients without risk factors for potential side effects. Additionally, and controversial, there is evidence that aromatase inhibitors may be better than tamoxifen in the management of DCIS.
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PMID:Recent advances and current controversies in the management of DCIS of the breast. 1849 Jan 11

The selective estrogen receptor modulators (SERMs) tamoxifen and raloxifene exert their estrogen agonist and antagonist actions depending on the target organ and individual circumstances. For instance, tamoxifen increases bone mineral density in postmenopausal patients, but decreases it in premenopausal patients when it is used as the adjuvant therapy for breast cancer in both populations. Due to positive results from recent large clinical trials for early breast cancer, the aromatase inhibitors (AIs) are the agent of first choice for postmenopausal patients. However, the veteran SERM tamoxifen is still the primary drug for premenopausal breast cancer patients, patients with ductal carcinoma in situ and subset of postmenopausal women. Recent accumulated data suggest that both raloxifene and tamoxifen could be useful in chemoprevention. Further investigation should be made into the development of a systematic strategy for application to a suitable target population, i.e., one more likely to develop hormone receptor-positive breast cancer. Unlike the AIs, SERMs have a distinct function that does not directly relate to hormone receptors when used in higher pharmacological concentration. The attempt to overcome chemo-drug resistance using high-dose SERMs would be one approach to developing such a strategy. There were several reports showing the antiproliferative effect of SERMs for estrogen receptor-negative cells, such as glioma. There are still numerous possible applications for SERMs when their intrinsic nature is utilized.
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PMID:Application of selective estrogen receptor modulators for breast cancer treatment according to their intrinsic nature. 1865 29

Tamoxifen is the most common endocrine therapy administered worldwide to women with hormone receptor-positive metastatic breast cancer or as adjuvant therapy for early stages of the disease. Tamoxifen may also be prescribed to women with ductal carcinoma in situ or to decrease the risk of breast cancer in women at high risk of developing the disease. While the use of aromatase inhibitors is increasing in the postmenopausal treatment setting, tamoxifen remains the drug of choice for premenopausal women. Several factors may contribute to reduced benefit from tamoxifen. It has been increasingly recognized in recent years that pharmacogenetics may play a role in tamoxifen's metabolism, efficacy, and safety. Cytochrome P450 (CYP) 2D6 encodes for a liver enzyme that is responsible for the conversion of tamoxifen into its active metabolite, endoxifen. Variant alleles in CYP2D6 or the use of medications that inhibit the enzyme clearly influence tamoxifen's metabolism into endoxifen. In addition, several retrospective studies suggest that variants in CYP2D6 may influence long term outcomes. In this review, we will summarize recent data that examined associations between CYP2D6 activity and effects on tamoxifen's metabolism and efficacy.
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PMID:Tamoxifen metabolism and its effect on endocrine treatment of breast cancer. 1939 43

Ductal carcinoma in situ or DCIS belongs to intraductal proliferative lesions, which are a group of cytologically and architecturally diverse ductal proliferations, typically originating from the terminal duct-lobular units. In these intraductal proliferative diseases, estrogens are considered to be involved in the progression of the disease especially from ductal non-neoplastic hyperplasia to DCIS and possibly development of invasive carcinoma from DCIS. Estrogen receptor (ER) alpha is abundantly expressed in atypical ductal hyperplasia and low grade DCIS. Suppression of estrogenic actions using tamoxifen resulted in inhibition of recurrence of DCIS and/or of progression into invasive carcinoma. Intratumoral estrogen concentration in DCIS determined by liquid chromatography/electrospray tandem mass spectrometry is significantly higher than that in non-neoplastic breast tissues with statistically not lower than that in invasive carcinoma. Aromatase mRNA expression in both stromal and parenchymal cells of DCIS determined by quantitative RT-PCR following laser capture microdissection was also much higher than that in non-neoplastic breast, although lower than that in invasive carcinoma. Immunohistochemistry of aromatase also revealed the similar patterns of immunolocalization as in invasive carcinoma. Aromatase is overexpressed in noninvasive breast malignancies including DCIS and results in elevated concentrations of intratumoral estradiol. These findings could provide the scientific rationale as to employing aromatase inhibitors in the management of ER positive DCIS patients.
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PMID:Aromatase and in situ estrogen production in DCIS (ductal carcinoma in situ) of human breast. 1978 35

Roux-en-Y gastric bypass is a gastric reduction duodenal switch with a combination of restrictive and malabsorptive procedures. It is the most common gastric bypass procedure performed in the United States. Malabsorption causing nutritional deficiencies does occur, yet a PubMed literature search (1955-2009) returned no reports of malabsorption of anticancer agents after gastric bypass. To our knowledge, this is the first report of three cases of malabsorption of the anticancer agent tamoxifen after this procedure. The first patient was a 58-year-old woman who underwent Roux-en-Y bypass for morbid obesity. Two years later, she developed estrogen receptor-positive ductal carcinoma in situ of the breast, underwent lumpectomy and irradiation, and tamoxifen was started. Two years after that, she presented with concerns of potential malabsorption of the drug. Her plasma tamoxifen level was 28 ng/ml, which was below the lower limit of the therapeutic range (77-274 ng/ml for 10-30-mg/day regimens). The second patient was a 51-year-old woman who sought medical advice on risk reduction for breast cancer after receiving a diagnosis of atypical ductal hyperplasia of the breast. She also had a history of morbid obesity and underwent Roux-en-Y bypass. Tamoxifen was started to reduce her risk of breast cancer; her plasma tamoxifen level was subtherapeutic at 14 ng/ml. The third patient was a 53-year-old woman with estrogen receptor-positive breast cancer who underwent lumpectomy and was prescribed anastrozole, an aromatase inhibitor. She also underwent Roux-en-Y bypass for morbid obesity. As she experienced adverse effects while receiving anastrozole, the drug was discontinued, and tamoxifen 20 mg/day was started. Her tamoxifen plasma level was 52 ng/ml. Therefore, her tamoxifen dosage was increased to 20 mg twice/day. Six weeks later, her tamoxifen level was 120 ng/ml (therapeutic range 95-520 ng/ml for the increased dosage). These three cases suggest that steady-state serum tamoxifen levels should be evaluated in patients who have undergone Roux-en-Y gastric bypass. Until adequate data suggest otherwise, parenteral anticancer alternatives should be considered when systemic therapy is needed in a patient with malabsorption.
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PMID:Tamoxifen malabsorption after Roux-en-Y gastric bypass surgery: case series and review of the literature. 2009 95

EPIDEMIOLOGY OF BREAST CANCER: The incidence and mortality of breast cancer are lower in Asia than in the West, particularly in post-menopausal women, but they are increasing. The age patterns of the incidence of breast cancer in Asia differ from in the West: in most Asian countries the peak incidence of breast cancer is at about age 45-50, whereas in western countries the incidence continues to increase even at older ages. Mortality is decreasing in western countries, whereas it is still increasing in Asian nations. There are many epidemiological factors involved in breast cancer, and important known risk factors include diet, obesity and diabetes. Asian studies found that high intake of isoflavones reduced the risk of breast cancer. PATHOLOGY OF BREAST CANCER: With regard to the pathology of breast cancer, for the molecular subtype, luminal A and luminal B are being used, while HER2 expression and rapid proliferation are also employed. Study results showed a somewhat higher prevalence of luminal A in Japanese compared with Americans. Ductal carcinoma in situ breast cancer is less frequent in Asian breast cancer patients than in Americans. The Working Group resolved to establish an international committee for pathological assessment of breast cancer in Asia. TREATMENT OF BREAST CANCER: Pharmacokinetics-pharmacodynamics studies are needed between ethnic backgrounds, investigating aromatase inhibitors and tamoxifen (endoxifen), as well as the effects of demographic factors such as diet, medical care, body mass index, etc. Correlations between adverse events and the clinical outcome also need to be studied.
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PMID:The Breast Cancer Working Group presentation was divided into three sections: the epidemiology, pathology and treatment of breast cancer. 2087 Sep 14


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