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Wang D, Xu X, Zhang J, Zhao Y. Ligand Promoted Olefination of Anilides for Indirectly Introducing Fluorinated Functional Groups via Palladium Catalyst. J Org Chem 2021; 86:2696-2705. [PMID: 33502195 DOI: 10.1021/acs.joc.0c02701] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We report a palladium-catalyzed, ligand promoted, C-H fluorine-containing olefination of anilides with 4-bromo-3,3,4,4-tetrafluorobutene as the fluorinated reagent, which has a potential transformation into other compounds due to its -CF2CF2Br functional group. -CF2CF2H was obtained by using the mild reducing agent sodium borohydride. Bioactive compounds such as aminoglutethimide derivative and propham were well-tolerated in this reaction, both of which highlight the synthetic importance of this method.
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Affiliation(s)
- Dongjie Wang
- College of Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou 215006, P.R. China.,Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P.R. China
| | - Xu Xu
- College of Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou 215006, P.R. China.,Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P.R. China
| | - Jingyu Zhang
- College of Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou 215006, P.R. China.,School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453000, P.R. China
| | - Yingsheng Zhao
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P.R. China.,School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453000, P.R. China
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2
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Lønning PE. The potency and clinical efficacy of aromatase inhibitors across the breast cancer continuum. Ann Oncol 2010; 22:503-514. [PMID: 20616198 PMCID: PMC3042921 DOI: 10.1093/annonc/mdq337] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The strategy of using estrogen suppression to treat breast cancer led to the development of aromatase inhibitors, including the third-generation nonsteroidal compounds anastrozole and letrozole, and the steroidal compound exemestane. Aromatase inhibitors potently inhibit aromatase activity and also suppress estrogen levels in plasma and tissue. In clinical studies in postmenopausal women with breast cancer, third-generation aromatase inhibitors were shown superior to tamoxifen for the treatment of metastatic disease. Studies of adjuvant therapy with aromatase inhibitors include (i) head-to-head studies of 5 years of the aromatase inhibitor versus 5 years of tamoxifen monotherapy; (ii) sequential therapy of 2-3 years of tamoxifen followed by an aromatase inhibitor (or the opposite sequence) versus 5 years of tamoxifen monotherapy; (iii) extended therapy with an aromatase inhibitor after 5 years of tamoxifen; and (iv) sequential therapy with an aromatase inhibitor versus aromatase inhibitor monotherapy. Recent results from the Arimidex, Tamoxifen, Alone or in Combination and Breast International Group 1-98 trials advocate using an aromatase inhibitor upfront. This article examines the clinical data with aromatase inhibitors, following a brief summary of their pharmacology.
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Affiliation(s)
- P E Lønning
- Section of Oncology, Institute of Medicine, University of Bergen, and Department of Oncology, Haukeland University Hospital, Bergen, Norway.
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Gibson L, Lawrence D, Dawson C, Bliss J. Aromatase inhibitors for treatment of advanced breast cancer in postmenopausal women. Cochrane Database Syst Rev 2009; 2009:CD003370. [PMID: 19821307 PMCID: PMC7154337 DOI: 10.1002/14651858.cd003370.pub3] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Endocrine therapy removes the influence of oestrogen on breast cancer cells and so hormonal treatments such as tamoxifen, megestrol acetate and medroxyprogesterone acetate have been in use for many years for advanced breast cancer. Aromatase inhibitors (AIs) inhibit oestrogen synthesis in the peripheral tissues and have a similar tumour-regressing effect to other endocrine treatments. Aminoglutethimide was the first AI in clinical use and now the third generation AIs, anastrozole, exemestane and letrozole, are in current use. Randomised trial evidence on response rates and side effects of these drugs is still limited. OBJECTIVES To compare AIs to other endocrine therapy in the treatment of advanced breast cancer in postmenopausal women. SEARCH STRATEGY For this update, the Cochrane Breast Cancer Group Specialised Register and the Cochrane Central Register of Controlled Trials (CENTRAL) and relevant conference proceedings were searched (to 30 June 2008). SELECTION CRITERIA Randomised controlled trials in postmenopausal women comparing the effects of any AI versus other endocrine therapy, no endocrine therapy, or a different AI in the treatment of advanced (metastatic) breast cancer. Non-English language publications, comparisons of the same AI at different doses, AIs used as neoadjuvant treatment, or outcomes not related to tumour response were excluded. DATA COLLECTION AND ANALYSIS Data from published trials were extracted independently by two review authors and cross-checked by a third. Hazard ratios (HR) were derived for analysis of time-to-event outcomes (overall and progression-free survival). Odds ratios (OR) were derived for objective response, clinical benefit, and toxicity. MAIN RESULTS Thirty-seven trials were identified, 31 of which were included in the main analysis of any AI versus any other treatment (11,403 women). No trials were excluded due to inadequate allocation concealment. The pooled estimate showed a significant survival benefit for treatment with an AI over other endocrine therapies (HR 0.90, 95% CI 0.84 to 0.97). A subgroup analysis of the three commonly prescribed AIs (anastrozole, exemestane, letrozole) also showed a similar survival benefit (HR 0.88, 95% CI 0.80 to 0.96). There were very limited data to compare one AI with a different AI, but these suggested an advantage for letrozole over anastrozole.AIs have a different toxicity profile to other endocrine therapies. For those currently prescribed, and for all AIs combined, they had similar levels of hot flushes and arthralgia; increased risks of rash, nausea, diarrhoea and vomiting; but a 71% decreased risk of vaginal bleeding and 47% decrease in thromboembolic events compared with other endocrine therapies. AUTHORS' CONCLUSIONS In women with advanced (metastatic) breast cancer, aromatase inhibitors including those in current clinical use show a survival benefit when compared to other endocrine therapy.
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Affiliation(s)
- Lorna Gibson
- Cancer and Public Health Unit, London School of Hygiene and Tropical Medicine, Keppel Street, London, Greater London, UK, WC1E 7HT
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Aromatase inhibitors: past, present and future in breast cancer therapy. Med Oncol 2007; 25:113-24. [PMID: 17973095 DOI: 10.1007/s12032-007-9019-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 10/09/2007] [Indexed: 01/22/2023]
Abstract
Estrogen has been implicated in promoting breast cancer in a majority of women. Endocrine therapy controlling estrogen production has been the guiding principle in treating breast cancer for more than a century. A greater understanding of this disease at a molecular level has led to the development of molecules that inhibit estrogen production by inhibiting the aromatase enzyme, that is the primary source of estrogen in postmenopausal women. This review examines the evolution of aromatase inhibitor (AI) based therapies over the past three decades. The third generation aromatase inhibitors (anastrozole, letrozole and exemestane), which have been found to be extremely specific and effective in an adjuvant/neoadjuvant/extended adjuvant setting are discussed from a biochemical and clinical perspective. A comprehensive discussion of the past, present, and future of aromatase inhibitors is conducted in this review.
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Gibson LJ, Dawson CK, Lawrence DH, Bliss JM. Aromatase inhibitors for treatment of advanced breast cancer in postmenopausal women. Cochrane Database Syst Rev 2007:CD003370. [PMID: 17253488 DOI: 10.1002/14651858.cd003370.pub2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Hormonal treatments for advanced or metastatic breast cancer, such as tamoxifen and the progestins megestrol acetate and medroxyprogesterone acetate, have been in use for many years. Aromatase inhibitors (AIs) are a class of compounds that systemically inhibit oestrogen synthesis in the peripheral tissues. Aminoglutethimide was the first AI in clinical use (first generation) and had a similar tumour-regressing effect to other endocrine treatments, which showed the potential of this alternative type of therapy. Other AIs have since been developed and the third generation AIs anastrozole, exemestane and letrozole are in current use. Randomised evidence on response rates and side effects of these drugs is still limited. OBJECTIVES To compare aromatase inhibitors to other endocrine therapy in the treatment of advanced breast cancer in postmenopausal women. SEARCH STRATEGY The Cochrane Breast Cancer Group Specialised Register was searched on 3 December 2004 using the codes for "advanced" and "endocrine therapy". Details of the search strategy applied to create the Register and the procedure used to code references are described in the Cochrane Breast Cancer Group module on The Cochrane Library. The search was updated to 30 September 2005 and additional publications were included. Experts were consulted to determine that no relevant studies had been excluded. SELECTION CRITERIA Randomised trials comparing the effects of any aromatase inhibitor versus other endocrine therapy, no endocrine therapy or a different aromatase inhibitor in the treatment of advanced (metastatic) breast cancer. DATA COLLECTION AND ANALYSIS Data from published trials were extracted by two independent review authors. A third independent author then carried out a further cross check for accuracy and consistency. Hazard ratios (HR) were derived for analysis of time-to-event outcomes (overall and progression-free). Odds ratios (OR) were derived for objective response and clinical benefit (both analysed as dichotomous variables). Toxicity data were extracted where present and treatments were compared using odds ratios. All but one of the studies included data on one or more of the following outcomes: overall survival, progression-free survival, clinical benefit and objective response. MAIN RESULTS Thirty studies were identified, twenty five of which were included in the main analysis of any AI versus any other treatment (9416 women). The pooled estimate showed a significant survival benefit for treatment with an AI over other endocrine therapies (HR 0.89, 95%CI 0.82 to 0.96). A subgroup analysis of the three commonly prescribed AIs (anastrozole, exemestane, letrozole) also showed a similar survival benefit (HR 0.88, 95%CI 0.80 to 0.96). The results for progression-free survival, clinical benefit and objective response were not statistically significant and there was statistically significant heterogeneity across types of AI. There were very limited data to compare one AI with a different AI, but these suggested an advantage for letrozole over anastrozole. All the trials of AIs used exclusively as first-line therapy were against tamoxifen. There was an advantage to treatment with AIs in terms of progression-free survival (HR 0.78, 95% CI 0.70 to 0.86) and clinical benefit (OR 0.70, 95% CI 0.51 to 0.97) but not overall survival or objective response. There was considerable heterogeneity across studies when considering clinical benefit (P = 0.001). Use of an AI as second-line therapy showed a significant benefit in terms of overall survival (HR 0.80, 95% CI 0.66 to 0.96) but not for progression-free survival (HR 1.08, 95% CI 0.89 to 1.31), clinical benefit (OR 1.00, 95% CI 0.87 to 1.14) or objective response (OR 0.96, 95% CI 0.81 to 1.14). This is difficult to interpret due to the extreme heterogeneity across AIs for progression-free survival but not the other endpoints.AIs have a different toxicity profile to other endocrine therapies. For all AIs combined, they had similar levels of hot flushes (especially when compared to tamoxifen) and arthralgia, increased risks of nausea, diarrhoea and vomiting, but a decreased risk of vaginal bleeding and thromboembolic events compared with other endocrine therapies. A similar pattern of risks and benefits was still seen when analyses were limited to the currently most-prescribed third generation AIs. AUTHORS' CONCLUSIONS In women with advanced (metastatic) breast cancer, aromatase inhibitors including those in current clinical use show a survival benefit when compared to other endocrine therapy.
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Mauri D, Pavlidis N, Polyzos NP, Ioannidis JPA. Survival with aromatase inhibitors and inactivators versus standard hormonal therapy in advanced breast cancer: meta-analysis. J Natl Cancer Inst 2006; 98:1285-91. [PMID: 16985247 DOI: 10.1093/jnci/djj357] [Citation(s) in RCA: 175] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Aromatase inhibitors and inactivators have been extensively tested in patients with advanced breast cancer, but it is unclear whether they offer any survival benefits compared with standard hormonal treatment with tamoxifen or progestagens. We performed a meta-analysis of randomized controlled trials that compared several generations of aromatase inhibitors and inactivators with standard hormonal treatment in patients with advanced breast cancer. METHODS The endpoint that we assessed was survival. Trials were located through searches of PubMed and Cochrane Library (last update March 2006). Relative hazards (RHs) were summarized across trials through fixed- and random-effects analyses, and heterogeneity was assessed with the Q and I2 statistics. All statistical tests were two-sided. RESULTS Twenty-five different comparisons, with a total of 8504 patients, were included in the meta-analysis. We found statistically significant survival benefits with third-generation aromatase inhibitors and inactivators (vorozole, letrozole, examestane, and anastrazole) (RH = 0.87, 95% confidence interval [CI] = 0.82 to 0.93; P<.001) but not with first-generation (aminoglutethimide) or second-generation (formestane and fadrozole) agents. The difference in the summary effects between these two groups of trials was statistically significant (P = .04). The survival benefit with third-generation agents in first-line trials, in which these agents were compared with tamoxifen (11% RH reduction, 95% CI = 1% to 19%; P = .03), was identical to their benefit in second- and subsequent-line trials in which these agents were compared with other treatments (14% RH reduction, 95% CI = 6% to 21%; P<.001). CONCLUSIONS Inhibition of the aromatase system, in particular with third-generation aromatase inhibitors and inactivators, appears to be associated with statistically significant improved survival of patients with advanced breast cancer compared with standard hormonal treatments.
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Affiliation(s)
- Davide Mauri
- Department of Medical Oncology, University of Ioannina School of Medicine, Ioannina 45110, Greece
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Abstract
The development of the novel third-generation aromatase inhibitors and inactivators for breast cancer treatment is one of the most successful contemporary achievements in cancer therapy. Parallel to studies evaluating toxicity and clinical efficacy in metastatic disease, the endocrine effects of multiple compounds were evaluated, leading to the identification of the highly potent third-generation aromatase inhibitors based on estrogen deprivation and aromatase inhibition in vivo. Thus, translational studies have been of vital importance identifying the unique characteristics of these compounds. Whereas first- and second-generation aromatase inhibitors inhibit estrogen synthesis in vivo by up to 90%, the third-generation compounds anastrozole, exemestane, and letrozole were found to cause > or =98% aromatase inhibition. This article summarizes and discusses the "translational research" that provided the background for the implementation of the third-generation aromatase inhibitors and inactivators into large clinical trials. The need for future translational research exploiting the mechanisms of resistance to these compounds for future improvement of endocrine therapy is emphasized.
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Affiliation(s)
- Jürgen Geisler
- Department of Medicine, Section of Oncology, Haukeland University Hospital, Bergen, Norway
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Singh Ranger G, Sing Ranger G. Current concepts in the endocrine therapy of breast cancer: tamoxifen and aromatase inhibitors. J Clin Pharm Ther 2005; 30:313-7. [PMID: 15985044 DOI: 10.1111/j.1365-2710.2005.00655.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent results from randomized controlled trials have indicated that aromatase inhibitors have superior anticancer efficacy and toxicity profiles compared with tamoxifen in the treatment of post-menopausal women with node-negative hormone receptor positive breast cancer. This has led clinicians to question whether adjuvant tamoxifen therapy is still justified. This article discusses the evidence for the superiority of aromatase inhibitors over tamoxifen. There are limitations to the use of these drugs, and they have side effects, which require further clarification. In addition, there are certain niche advantages to the use of tamoxifen, and this drug has undergone rigorous appraisal over the last 20 years.
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Affiliation(s)
- G Singh Ranger
- Department of General Surgery, Basildon Hospital, Nethermayne, Essex, UK.
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Abstract
In few, if any, areas of cancer research has "translational research" played a role such as the one it has played in the development of endocrine therapy. Thus, much of the understanding of the mechanisms of action of different therapies has been achieved by developing novel hypotheses based on clinical observations. Ovarian ablation was developed as an empirical therapy long before characterization of oestrogen disposition or detection of the oestrogen receptor. The first-generation aromatase inhibitor, aminoglutethimide, was implemented as a strategy to achieve a 'medical adrenalectomy' and was discovered as an aromatase inhibitor subsequent to clinical observations. Currently, observations such as the lack of cross-resistance between aromatase inhibitors and inactivators and the diverse effects from combined therapy using tamoxifen in concert with hormonal suppression in pre- and post-menopausals are provoking interesting questions for further research.
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Affiliation(s)
- Per Eystein Lønning
- Department of Oncology, Institute of Medicine, University of Bergen, Haukeland University Hospital, 5021 Bergen, Norway.
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10
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Abstract
Oestrogens are heavily implicated in the risk to, and progression of, breast cancer. Therapeutic strategies targeted at the oestrogenic stimulus to the breast and hormone-sensitive breast cancers are extremely attractive measures both to prevent the disease and to treat established tumours. The present review outlines the biological rationale for such endocrine therapy and traces the evolution whereby irreversible surgical procedures have been replaced by potent and specific drugs. In particular, the development of the latest generation of agents which inhibit oestrogen biosynthesis (aromatase inhibitors) is considered by defining the central role of the aromatase enzyme, its regulation and contribution to circulating and tumour endogenous oestrogens. The nature of response and resistance which may be elicited following the use of endocrine therapy is also described as this may determine the optimal use of aromatase inhibitors and, more generally, anti-hormone therapy in the management of women at high risk to, or with, breast cancer.
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Affiliation(s)
- W R Miller
- Edinburgh Breast Unit Research Group, Western General Hospital, University of Edinburgh, Paderewski Building, Edinburgh EH4 2XU, Scotland, UK.
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11
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Affiliation(s)
- Per Lønning
- Section of Oncology, Department of Medicine, University of Bergen, Haukeland University Hospital, Bergen, Norway.
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12
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Dowsett M, Haynes BP. Hormonal effects of aromatase inhibitors: focus on premenopausal effects and interaction with tamoxifen. J Steroid Biochem Mol Biol 2003; 86:255-63. [PMID: 14623519 DOI: 10.1016/s0960-0760(03)00365-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Third generation aromatase inhibitors have excellent specificity. Some reports indicate that letrozole may have a minor effect on cortisol synthesis but these were not confirmed: valid comparisons with other aromatase inhibitors requires randomised study. The putative use of a third generation inhibitor as a single agent in premenopausal women has been investigated using YM511. It was hypothesised that in this situation site-specific suppression of estrogens in breast carcinomas, without systemic effects, may lead to a down-regulation of tumour proliferation. Plasma levels of androstenedione and testosterone were significantly increased by 2 weeks treatment with YM511. Mean plasma estrone levels were suppressed, but some plasma estradiol levels were abnormally high and others abnormally low. These differential effects of YM511 on circulating estrogens supported the concept that peripheral synthesis of estrogens might be suppressed while ovarian production remained high. However, YM511 did not demonstrate anti-proliferative effects in hormone sensitive breast carcinomas. Consideration of the pharmacology of the estrogen receptor during tamoxifen therapy indicates that tamoxifen effectively saturates the receptor (>99.94% occupancy) in postmenopausal women. The addition of an aromatase inhibitor in this situation would be very unlikely to affect the biological activity of the estrogen receptor. This provides a possible explanation why the clinical efficacy of tamoxifen combined with an aromatase inhibitor appears to be equivalent to that of tamoxifen alone.
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Affiliation(s)
- M Dowsett
- Academic Department of Biochemistry, Royal Marsden Hospital, Fulham Road, London SW3 6JJ, UK.
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Piccart M, Parker LM, Pritchard KI. Oestrogen receptor downregulation: an opportunity for extending the window of endocrine therapy in advanced breast cancer. Ann Oncol 2003; 14:1017-25. [PMID: 12853342 DOI: 10.1093/annonc/mdg290] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Advanced breast cancer is largely incurable and current treatment modalities are aimed towards restricting tumour growth, prolonging survival, palliating symptoms and maintaining quality of life (QoL). The development of breast cancer is strongly influenced by endogenous oestrogens (and other growth factors), leading to a strong focus on the development of antioestrogenic compounds for the treatment of hormone-sensitive advanced disease. DESIGN This is a review of current endocrine therapies available for postmenopausal women with advanced breast cancer, examining the likely impact of newer agents on treatment strategies. RESULTS In postmenopausal women, current treatment options include tamoxifen, aromatase inhibitors (AIs) and megestrol acetate. Fulvestrant ('Faslodex') is a new, well-tolerated, oestrogen receptor antagonist that has no known agonist effect and is at least as effective as the AI anastrozole for the treatment of postmenopausal patients with metastatic or advanced breast cancer who have progressed on prior endocrine therapy. Fulvestrant maintains QoL throughout successful treatment. CONCLUSIONS Fulvestrant represents a new treatment option for postmenopausal women with advanced disease. New agents that appear to lack cross-resistance with existing treatments may be used to extend the time period during which endocrine therapy may be employed before the need for cytotoxic chemotherapy.
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Affiliation(s)
- M Piccart
- Chemotherapy Unit, Internal Medicine and Oncology, Jules Bordet Institute, Brussels, Belgium.
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Abstract
Hormonal agents have a confirmed role in the management of postmenopausal women with receptor-positive advanced breast cancer. Until recently, tamoxifen has been the accepted agent for treating these patients. However, accumulating evidence suggests that the new antiaromatase agents will replace the antiestrogens as the preferable option in hormone-naive patients. Comparative trials indicate that the aromatase inhibitors, anastrozole and letrozole, and the aromatase inactivator, exemestane, have at least equivalent efficacy to tamoxifen with similar or superior tolerability. These agents are also more effective than the progestin, megestrol acetate, when studied in patients progressing on tamoxifen. The improved aromatase selectivity and high potency of these antiaromatase agents when compared with earlier agents have resulted in improved efficacy and tolerability. Additionally, no cross-resistance has been reported between the antiaromatase agents and tamoxifen or, in some instances, among the antiaromatase agents themselves. The role of antiaromatase agents will certainly expand in the near future to include not only treatment of metastatic breast cancer, but use in the adjuvant and neoadjuvant settings as well, and, ultimately, breast cancer prevention. The results of ongoing investigations are awaited with interest.
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Abstract
Tamoxifen has been used in the management of breast cancer for over 30 years. Since its introduction for the treatment of advanced breast cancer, its indications have increased to include the treatment of early breast cancer, ductal carcinoma in situ, and more recently for breast cancer chemoprevention. Tamoxifen has a good tolerability profile and moreover, unlike many other endocrine therapies, it is efficacious in both pre- and postmenopausal women. It is the combination of efficacy and tolerability that allows tamoxifen to maintain its position as the hormonal treatment of choice for most patients with oestrogen-receptor positive breast cancer. Ongoing studies will provide further information about the optimal duration of tamoxifen therapy and how it compares with the newer aromatase inhibitors.
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Affiliation(s)
- M Clemons
- Division of Medical Oncology, Toronto-Sunnybrook Regional Cancer Centre, 2075 Bayview Avenue, Toronto, Ontario, Canada M4N 3M5.
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Boeddinghaus I, Dowsett M. Recent Developments in the Hormonal Treatment of Breast Cancer. Breast Cancer 2002. [DOI: 10.1201/b14039-13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
PURPOSE The purpose of this article is to provide an overview of the current clinical status and possible future applications of aromatase inhibitors in breast cancer. METHODS A review of the literature on the third-generation aromatase inhibitors was conducted. Some data that have been presented but not published are included. In addition, the designs of ongoing trials with aromatase inhibitors are outlined and the implications of possible results discussed. RESULTS All of the third-generation oral aromatase inhibitors--letrozole, anastrozole, and vorozole (nonsteroidal, type II) and exemestane (steroidal, type I)--have now been tested in phase III trials as second-line treatment of postmenopausal hormone-dependent breast cancer. They have shown clear superiority compared with the conventional therapies and are therefore considered established second-line hormonal agents. Currently, they are being tested as first-line therapy in the metastatic, adjuvant, and neoadjuvant settings. Preliminary results suggest that the inhibitors might displace tamoxifen as first-line treatment, but further studies are needed to determine this. CONCLUSION The role of aromatase inhibitors in premenopausal breast cancer and in combination with chemotherapy and other anticancer treatments are areas of future exploration. The ongoing adjuvant trials will provide important data on the long-term safety of aromatase inhibitors, which will help to determine their suitability for use as chemopreventives in healthy women at risk of developing breast cancer.
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Affiliation(s)
- P E Goss
- Division of Hematology/Oncology, Princess Margaret Hospital, Toronto, Ontario, Canada.
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Rose C, Kamby C, Mouridsen HT, Andersson M, Bastholt L, Møller KA, Andersen J, Munkholm P, Dombernowsky P, Christensen IJ. Combined endocrine treatment of elderly postmenopausal patients with metastatic breast cancer. A randomized trial of tamoxifen vs. tamoxifen + aminoglutethimide and hydrocortisone and tamoxifen + fluoxymesterone in women above 65 years of age. Breast Cancer Res Treat 2000; 61:103-10. [PMID: 10942095 DOI: 10.1023/a:1006460925986] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The efficacy of combined endocrine therapy with tamoxifen (TAM), aminoglutethimide (AG), and hydrocortisone (H) or tamoxifen and fluoxymesterone (FLU) was evaluated against treatment with tamoxifen alone in 311 patients above 65 years of age with a first recurrence of a metastatic breast cancer. A total of 279 patients were eligible. The response rates were assessed for 258 fully evaluable patients and were the following for the TAM (N = 94), the TAM+AG+H (N = 83), and the TAM+FLU (N = 81) groups, respectively, PR: 14, 18, and 21%, and CR: 20, 11, and 23%. The overall response rates are not statistically different (p = 0.30). The 95% CL of difference in response rates for TAM vs. TAM+AG+H are -9-19% and for TAM vs. TAM+FLU -4-25%. Time to treatment failure was comparable with median values of 9.2, 7.7, and 9.2 months in the TAM, TAM+AG+H, and TAM + FLU group, respectively (p = 0.17). The corresponding figures for survival are median times of 22.0, 24.1, and 21.1 months with a p-value of 0.62. Toxicity was more pronounced in both the combined treatment groups, and could in most instances be attributed to treatment with either AG+H or FLU. Currently, new specific aromatase inhibitors with lesser toxicity than AG are being evaluated in combination with TAM for treatment of primary and metastatic breast cancer. In conclusion, the simultaneous use of TAM and AG +H or FLU does not seem to improve the therapeutic efficacy in elderly postmenopausal patients with metastatic disease. So far, combined endocrine therapy in this group of patients should only be used in the context of clinical trials.
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Affiliation(s)
- C Rose
- Department of Oncology, Odense University Hospital, Denmark.
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Michaud LB, Buzdar AU. Complete estrogen blockade for the treatment of metastatic and early stage breast cancer. Drugs Aging 2000; 16:261-71. [PMID: 10874521 DOI: 10.2165/00002512-200016040-00002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Complete estrogen blockade has long been sought as a more effective means of controlling breast cancer compared with single agent endocrine therapy. This approach may be accomplished through the use of agents which reduce estrogen production combined with agents that prevent the activity of estrogen at the cellular level. For prostate cancer, another hormonally responsive malignancy, this approach has not been successful at improving survival compared with that achieved with single agent therapy. Preclinical information is contradictory for many promising combinations and may not reflect the true nature of in vivo interaction between agents. For premenopausal patients with metastatic breast cancer, the combination of a luteinising hormone-releasing hormone (LHRH) agonist and tamoxifen is clearly effective, but whether the combination is more effective than either single agent is still controversial. Similar response rates and overall survival were reported with goserelin or goserelin plus tamoxifen by Jonat et al. in 1 randomised, prospective study, but the addition of tamoxifen improved time to progression. A second trial comparing buserelin plus tamoxifen with either single agent reported superior efficacy in terms of response rates, disease-free survival and overall survival with combination therapy. A meta-analysis of 4 randomised trials making similar comparisons, demonstrated significant improvement in median overall survival, progression-free survival, response rate, and duration of response with the combination of a LHRH agonist (goserelin or buserelin) and tamoxifen in premenopausal breast cancer patients with metastatic disease. For postmenopausal women with metastatic breast cancer, the addition of an aromatase inhibitor to tamoxifen has yet to be prospectively compared to single agent therapy. Use of endocrine combinations in the treatment of early stage breast cancer is under investigation. Preliminary results of some of the ongoing adjuvant therapy trials indicate that the combination of a LHRH agonist and tamoxifen may have similar efficacy to cyclophosphamide, methotrexate, and fluorouracil chemotherapy in premenopausal women with estrogen receptor-positive tumour. Addition of LHRH agonist therapy in premenopausal patients with estrogen receptor-positive tumour who had maintained the ovarian function following chemotherapy [cyclophosphamide, doxorubicin (adriamycin), fluorouracil, and tamoxifen], also led to a reduction in the risk of recurrence. These studies have identified a sub-population of patients who may benefit from the addition of combination endocrine therapy. Overall, the issue is quite complex and the data from many ongoing trials are still awaited with anticipation to further delineate the role of complete estrogen deprivation in this disease.
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Affiliation(s)
- L B Michaud
- Department of Breast Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston, USA
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20
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Abstract
This review reassesses the role of hormonal therapy in breast cancer specifically the sequential or concurrent use of endocrine therapy and the combined use of chemotherapy with endocrine therapy. In advanced disease the sequential use of hormone therapies is generally recommended rather than the combined use of various hormonal agents, though combination hormonal therapy offers advantages in certain subsets of patients. The efficacy of combined chemo-endocrine therapy is questionable. Chemotherapy with estrogenic recruitment is an attractive but still experimental concept. However, in an adjuvant setting there is evidence that combined chemo-endocrine therapy causes a significant increase in disease-free and/or overall survival, particularly in postmenopausal patients with estrogen receptor(ER)-positive tumors. While hormonal treatment strategies have clearly benefitted from randomized studies, data regarding optimal endocrine therapy are still insufficient.
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21
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Affiliation(s)
- G Y Locker
- Evanston Northwestern Healthcare, Northwestern University, IL, USA
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22
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Affiliation(s)
- W R Miller
- Breast Unit, Western General Hospital, Edinburgh, U.K
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23
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Abstract
Endocrine treatment plays an important role in the therapy of breast cancer. While the basic mechanisms are understood, additional mechanisms may be of importance to their action and they may also contribute to the mechanism(s) of acquired resistance. Currently, several novel drugs are entering into clinical trials. Observations of the absence or presence of cross resistance to novel 'pure' steroidal antiestrogens and the non-steroidal tamoxifen may add important information to our understanding of the mechanisms of action of both classes of drugs. Similarly, exploration of different aromatase inhibitors in sequence or concert, as well as the combining of different endocrine treatment options may be warranted. Additionally, alterations in different biochemical parameters such as growth factors should not only be carefully explored in relation to treatment options but should also be followed during the course of treatment to asess alterations over time and in relation to the development of drug resistance.
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MESH Headings
- Adrenal Cortex/drug effects
- Adrenal Cortex/physiopathology
- Adult
- Aged
- Animals
- Antineoplastic Agents, Hormonal/classification
- Antineoplastic Agents, Hormonal/pharmacology
- Antineoplastic Agents, Hormonal/therapeutic use
- Aromatase Inhibitors
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/physiopathology
- Breast Neoplasms/therapy
- Chemotherapy, Adjuvant
- Combined Modality Therapy
- Drug Resistance, Multiple
- Enzyme Inhibitors/pharmacology
- Enzyme Inhibitors/therapeutic use
- Estrogen Antagonists/adverse effects
- Estrogen Antagonists/pharmacology
- Estrogen Antagonists/therapeutic use
- Estrogens/blood
- Estrogens/physiology
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Gonadotropin-Releasing Hormone/agonists
- Humans
- Insulin-Like Growth Factor I/antagonists & inhibitors
- Insulin-Like Growth Factor I/physiology
- Mammary Neoplasms, Experimental/drug therapy
- Mammary Neoplasms, Experimental/physiopathology
- Menopause
- Mice
- Middle Aged
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasms, Hormone-Dependent/drug therapy
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/physiopathology
- Neoplasms, Hormone-Dependent/therapy
- Progesterone/antagonists & inhibitors
- Progesterone/physiology
- Progestins/antagonists & inhibitors
- Progestins/pharmacology
- Progestins/therapeutic use
- Receptors, Estrogen/drug effects
- Receptors, Estrogen/physiology
- Signal Transduction/drug effects
- Steroids/metabolism
- Tamoxifen/adverse effects
- Tamoxifen/pharmacology
- Tamoxifen/therapeutic use
- Tumor Cells, Cultured/drug effects
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Affiliation(s)
- E Lønning
- Department of Oncology, Haukeland University Hospital, Bergen, Norway
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24
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Cocconi G. First generation aromatase inhibitors--aminoglutethimide and testololactone. Breast Cancer Res Treat 1994; 30:57-80. [PMID: 7949205 DOI: 10.1007/bf00682741] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aminoglutethimide and testololactone may be considered the first generation aromatase inhibitors for the endocrine treatment of breast carcinoma. Initially, both of these agents were designed and used clinically based on different concepts of their mechanisms of action. Only later were they both demonstrated to inhibit aromatase. Curiously, testololactone was earlier and more widely used than aminoglutethimide in treating advanced breast carcinoma. The discovery of the peripheral aromatase inhibition as the proper mechanism of action was delayed for both the agents but was relatively more timely for aminoglutethimide. Paradoxically, the clinical use of testololactone has become already obsolete since its true mechanism of action was discovered. Aminoglutethimide is still the most widely used aromatase inhibitor in treating advanced breast carcinoma. Due to the initial misinterpretation of its mechanism of action, aminoglutethimide was used for a long time at a relative high daily dose, always combined with hydrocortisone. Subsequent phase II and then randomized phase III studies demonstrated an equivalent efficacy using half (500 mg) of the previous conventional daily dose (1000 mg), with hydrocortisone. Very recently, a randomized clinical trial demonstrated that administering this lower dose without hydrocortisone did not significantly decrease the clinical efficacy. By decreasing the dose of aminoglutethimide, the incidence of side effects has been reduced. So, the last paradoxical aspect of the aminoglutethimide story is that this agent seemed initially very toxic but finally, with the new schedules, shows a very low toxicity profile, especially after the first few weeks of treatment.
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Affiliation(s)
- G Cocconi
- Medical Oncology Division, University Hospital, Parma, Italy
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25
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Abstract
Drug resistance is the main reason for therapeutic failure and death in breast cancer. In vitro investigations have identified some mechanisms that may be responsible for resistance to chemotherapeutic agents in breast cancer, but we know little about the mechanisms responsible for resistance to endocrine treatment in receptor-positive tumors. Accordingly, a major task for future studies is to explore the mechanisms of both primary and acquired resistance to endocrine treatment as well as to chemotherapy in breast cancer. Drug resistance may be related to alterations in endocrine as well as paracrine delivery of certain growth factors or hormones, but it may also be caused by alterations in drug disposition. Primary resistance may be evaluated by comparing the response to drug treatment with the expression of different biochemical parameters in the tumor before treatment. To explore the mechanisms of acquired drug resistance requires study of the changes in biological parameters developing over time during drug therapy. Also, it may be of interest to use certain drugs (like a 'classical' anti-estrogen and a steroidal anti-estrogen) in a particular sequence to explore the possibility of cross-resistance (or lack of it) between particular treatment modalities. Possible implications for the design of future trials in breast cancer treatment are discussed.
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Affiliation(s)
- E Lønning
- Department of Oncology, University of Bergen, Haukeland Hospital, Norway
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26
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Wolf DM, Jordan VC. Gynecologic complications associated with long-term adjuvant tamoxifen therapy for breast cancer. Gynecol Oncol 1992; 45:118-28. [PMID: 1592278 DOI: 10.1016/0090-8258(92)90273-l] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The antiestrogen tamoxifen was originally introduced as a therapy for advanced breast cancer. Today, tamoxifen is used to treat selected patients with all stages of breast cancer, and trials are underway to evaluate its effectiveness as a potential breast cancer preventive. When tamoxifen is used as an adjuvant or preventive, extended patient survival times can be expected, and concerns about iatrogenic complications arising from long-term treatment become important. This review discusses currently available laboratory and clinical data regarding the toxicology of tamoxifen and focuses in particular on the gynecologic complications potentially associated with long-term tamoxifen administration.
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Affiliation(s)
- D M Wolf
- Department of Human Oncology, University of Wisconsin Comprehensive Cancer Center, Madison 53792
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27
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28
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Buckley MM, Goa KL. Tamoxifen. A reappraisal of its pharmacodynamic and pharmacokinetic properties, and therapeutic use. Drugs 1989; 37:451-90. [PMID: 2661195 DOI: 10.2165/00003495-198937040-00004] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Tamoxifen, a non-steroidal antioestrogen, represents a significant advance in treatment of female breast cancer. In trials of tamoxifen as postsurgical adjuvant treatment of early breast cancer, disease-free survival is consistently prolonged, representing an enhanced quality of life in association with tamoxifen's favourable adverse effect profile. Moreover, overview analysis indicates a survival benefit of approximately 20% at 5 years for all women, most clearly evident in women over 50 years, while a survival benefit independent of menopausal, nodal or oestrogen receptor status has been demonstrated in some individual trials. Thus, for postmenopausal women, tamoxifen is clearly optimal adjuvant treatment, although the relative benefit of adjuvant chemotherapy in node-negative patients requires clarification. A survival benefit for women under 50 has not been clearly demonstrated in overview analysis, but is not precluded by these rather limited data, and adjuvant treatment of premenopausal women with tamoxifen may also warrant serious consideration. Response rates to tamoxifen in advanced breast cancer are around 30 to 35%, increasing with patient selection for oestrogen receptor positivity. Tamoxifen must be regarded as first-line endocrine treatment in postmenopausal women, and may represent an alternative to first-line ovarian ablation in premenopausal women. An emergent role in primary therapy of elderly and frail patients with operable disease is apparent. Tamoxifen is also of benefit following surgery in male breast cancer, and may have a role as first-line endocrine treatment. Tamoxifen also has a potential role in other hormone-sensitive malignancies such as pancreatic carcinoma, and in treatment of benign breast disease. Finally, tamoxifen has a place in treatment of male and female infertility. because of adverse effects is rarely necessary. The most frequent adverse effects are related to the drug's anti-oestrogenic activity, and include hot flushes, nausea and/or vomiting, vaginal bleeding or discharge, and menstrual disturbances in premenopausal patients. Thus, tamoxifen continues to play a major role in management of female breast cancer in both early and advanced stages of disease, with a place also in treatment of male breast cancer and of infertility.
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Affiliation(s)
- M M Buckley
- ADIS Drug Information Services, Auckland, New Zealand
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