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The Cochrane Database of Systematic... Dec 2012Health care providers often tell women to wait until the next menses to begin hormonal contraception. The intent is to avoid contraceptive use during an undetected... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Health care providers often tell women to wait until the next menses to begin hormonal contraception. The intent is to avoid contraceptive use during an undetected pregnancy. An alternative is to start hormonal contraception immediately with back-up birth control for the first seven days. Immediate initiation was introduced with combined oral contraceptives (COCs), and has expanded to other hormonal contraceptives. At the time of the initial review, how immediate start compared to conventional menses-dependent start was unclear regarding effectiveness, continuation, and acceptability. The immediate-start approach may improve women's access to, and continuation of, hormonal contraception.
OBJECTIVES
This review examined randomized controlled trials (RCTs) of immediate-start hormonal contraception for differences in effectiveness, continuation, and acceptability.
SEARCH METHODS
In August 2012, we searched MEDLINE, CENTRAL, POPLINE, LILACS, ClinicalTrials.gov, and ICTRP for trials of immediate-start hormonal contraceptives. We contacted researchers to find other studies. Earlier searches also included EMBASE.
SELECTION CRITERIA
We included RCTs that compared immediate start to conventional start of hormonal contraception. Also included were trials that compared immediate start of different hormonal contraceptive methods with each other.
DATA COLLECTION AND ANALYSIS
Data were abstracted by two authors and entered into RevMan. The Peto odds ratio (OR) with 95% confidence interval (CI) was calculated.
MAIN RESULTS
Five studies were included. No new eligible studies have been found since the review was initially conducted. Method discontinuation was similar between groups in all trials. Bleeding patterns and side effects were similar in trials that compared immediate with conventional start. In a study of depot medroxyprogesterone acetate (DMPA), immediate start of DMPA showed fewer pregnancies than a 'bridge' method before DMPA (OR 0.36; 95% CI 0.16 to 0.84). Further, more women in the immediate-DMPA group were very satisfied versus those with a 'bridge' method (OR 1.99; 95% CI 1.05 to 3.77). A trial of two immediate-start methods showed the vaginal ring group had less prolonged bleeding (OR 0.42; 95% CI 0.20 to 0.89) and less frequent bleeding (OR 0.23; 95% CI 0.05 to 1.03) than COC users. The ring group also reported fewer side effects. Also, more immediate ring users were very satisfied than immediate COC users (OR 2.88; 95% CI 1.59 to 5.22).
AUTHORS' CONCLUSIONS
We found limited evidence that immediate start of hormonal contraception reduces unintended pregnancies or increases method continuation. However, the pregnancy rate was lower with immediate start of DMPA versus another method. Some differences were associated with contraceptive type rather than initiation method, i.e., immediate ring versus immediate COC. More studies are needed of immediate versus conventional start of the same hormonal contraceptive.
Topics: Contraception; Contraceptives, Oral, Hormonal; Drug Chronotherapy; Female; Humans; Intrauterine Devices; Medroxyprogesterone Acetate; Menstruation; Pregnancy; Pregnancy, Unplanned; Randomized Controlled Trials as Topic
PubMed: 23235628
DOI: 10.1002/14651858.CD006260.pub3 -
Menopause (New York, N.Y.) Oct 2011The objective of this study was to compare the effects of the levonorgestrel-releasing intrauterine system (LNG-IUS) with those of systemic progestogen in perimenopausal... (Comparative Study)
Comparative Study Meta-Analysis Review
OBJECTIVE
The objective of this study was to compare the effects of the levonorgestrel-releasing intrauterine system (LNG-IUS) with those of systemic progestogen in perimenopausal and postmenopausal women taking systemic estrogen therapy (ET).
METHODS
We searched Medline (August 8, 2009), Embase (August 8, 2009), the Cochrane Central Register of Controlled Trials on the Cochrane Library Issue 3 (2009), the MetaRegister of Controlled Trials, and the reference lists of articles for relevant trials. Randomized controlled studies of LNG-IUS versus systemic progestogen in perimenopausal and postmenopausal women taking ET were included in the review. Two reviewers abstracted the trials independently. Any disagreement was resolved through discussion with the third reviewer. For dichotomous outcomes, a Peto odds ratio was calculated. For continuous outcomes, nonskewed data from valid scales were synthesized using a weighted mean difference or a standardized mean difference.
RESULTS
Six trials with a total of 518 participants were included. The methodological limitation was an attrition bias. In perimenopausal and postmenopausal women taking ET, the incidence of a proliferative endometrium was comparable between the use of systemic progestogen and LNG-IUS, except for sequential medroxyprogesterone acetate, which had a higher incidence of proliferative endometrium. Descriptive data synthesis showed that ET combined with either LNG-IUS or systemic progestogen effectively relieved climacteric symptoms. Vaginal bleeding and spotting were common in the LNG-IUS group for the first 3 to 6 months of use. The discontinuation rate was not different. There was insufficient evidence to draw any conclusions about the other outcomes.
CONCLUSIONS
The LNG-IUS was more effective than sequential medroxyprogesterone acetate but was comparable with other systemic progestogen regimens for endometrial protection in perimenopausal and postmenopausal women taking ET.
Topics: Adult; Climacteric; Contraceptive Agents, Female; Endometrium; Estrogens; Female; Humans; Incidence; Intrauterine Devices, Medicated; Levonorgestrel; Middle Aged; Perimenopause; Postmenopause; Progestins; Randomized Controlled Trials as Topic; Uterine Hemorrhage
PubMed: 21720280
DOI: 10.1097/gme.0b013e31821606c5 -
Contraception Aug 2009Many women want a lengthy duration of contraception but are wary of the menstrual changes from depot medroxyprogesterone acetate (DMPA). A subdermal levonorgestrel (LNG)... (Review)
Review
BACKGROUND
Many women want a lengthy duration of contraception but are wary of the menstrual changes from depot medroxyprogesterone acetate (DMPA). A subdermal levonorgestrel (LNG) implant may be a reasonable alternative. However, information on menstrual changes from these methods has not been summarized and compared in an easy-to-understand form.
STUDY DESIGN
We systematically reviewed the published literature on these contraceptives to find research that used menstrual diaries and standard World Health Organization definitions. We attempted to find information on amenorrhea, number of bleeding or spotting episodes, number of bleeding or spotting days and normal patterns, as reported in four consecutive 90-day reference periods.
RESULTS
We found 16 published articles meeting our criteria and involving diaries of up to 1600 DMPA users and 2300 LNG implant users. We were able to compare the two methods on only three outcomes. For DMPA use, the weighted prevalence of amenorrhea at successive 90-day periods was 12%, 25%, 37% and 46%. The comparable estimates for the LNG implant were 11%, 13%, 9% and 13%. Levonorgestrel implant users experienced a higher average number of bleeding or spotting days compared to DMPA users, but this average was similar to what is expected naturally. At 12 months, normal menstrual patterns were experienced by 23% of LNG implant users compared to 11% of DMPA users.
CONCLUSIONS
Like most hormonal contraception, LNG implants usually produce menstrual changes; however, the changes do not appear to deviate from normal patterns as much as the changes from DMPA. Understanding these differences and other method attributes might help women make an informed choice about which contraceptive to use.
Topics: Contraceptive Agents, Female; Drug Implants; Female; Humans; Levonorgestrel; Medication Adherence; Medroxyprogesterone Acetate; Menstruation Disturbances
PubMed: 19631785
DOI: 10.1016/j.contraception.2009.02.008 -
BMJ Sexual & Reproductive Health Jan 2020To update a 2016 systematic review on hormonal contraception use and HIV acquisition.
OBJECTIVE
To update a 2016 systematic review on hormonal contraception use and HIV acquisition.
METHODS
We searched Pubmed and Embase between 15 January 2016 and 26 June 2019 for longitudinal studies comparing incident HIV infection among women using a hormonal contraceptive method and either non-users or users of another specific hormonal contraceptive method. We extracted information from newly identified studies, assessed study quality, and updated forest plots and meta-analyses.
RESULTS
In addition to 31 previously included studies, five more were identified; three provided higher quality evidence. A randomised clinical trial (RCT) found no statistically significant differences in HIV risk among users of intramuscular depot medroxyprogesterone acetate (DMPA-IM), levonorgestrel implant (LNG implant) or the copper intrauterine device (Cu-IUD). An observational study found no statistically significant differences in HIV risk among women using DMPA, norethisterone enanthate (NET-EN), implants (type not specified) or Cu-IUD. Updated results from a previously included observational study continued to find a statistically significant increased HIV risk with oral contraceptives and DMPA compared with no contraceptive use, and found no association between LNG implant and HIV risk.
CONCLUSIONS
High-quality RCT data comparing use of DMPA, LNG implant and Cu-IUD does not support previous concerns from observational studies that DMPA-IM use increases the risk of HIV acquisition. Use of other hormonal contraceptive methods (oral contraceptives, NET-EN and implants) is not associated with an increased risk of HIV acquisition.
Topics: Adolescent; Adult; Female; HIV Infections; Hormonal Contraception; Humans
PubMed: 31919239
DOI: 10.1136/bmjsrh-2019-200509 -
AIDS (London, England) Nov 2016Some studies suggest that specific hormonal contraceptive methods [particularly depot medroxyprogesterone acetate (DMPA)] may increase women's HIV acquisition risk. We... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE AND DESIGN
Some studies suggest that specific hormonal contraceptive methods [particularly depot medroxyprogesterone acetate (DMPA)] may increase women's HIV acquisition risk. We updated a systematic review to incorporate recent epidemiological data.
METHODS
We searched for articles published between 15 January 2014 and 15 January 2016 and hand-searched reference lists. We identified longitudinal studies comparing users of a specific hormonal contraceptive method against either nonusers of hormonal contraception or users of another specific hormonal contraceptive method. We added newly identified studies to those in the previous review, assessed study quality, created forest plots to display results, and conducted a meta-analysis for data on DMPA versus non-use of hormonal contraception.
RESULTS
We identified 10 new reports of which five were considered 'unlikely to inform the primary question'. We focus on the other five reports, along with nine from the previous review, which were considered 'informative but with important limitations'. The preponderance of data for oral contraceptive pills, injectable norethisterone enanthate, and levonorgestrel implants do not suggest an association with HIV acquisition, though data for implants are limited. The new, higher quality studies on DMPA (or nondisaggregated injectables), which had mixed results in terms of statistical significance, had hazard ratios between 1.2 and 1.7, consistent with our meta-analytic estimate for all higher quality studies of hazard ratio 1.4.
CONCLUSION
Although confounding in these observational data cannot be excluded, new information increases concerns about DMPA and HIV acquisition risk in women. If the association is causal, the magnitude of effect is likely hazard ratio 1.5 or less. Data for other hormonal contraceptive methods, including norethisterone enanthate, are largely reassuring.
Topics: Contraception; Contraceptive Agents, Female; Female; HIV Infections; Humans; Risk Assessment
PubMed: 27500670
DOI: 10.1097/QAD.0000000000001228 -
The Cochrane Database of Systematic... Jul 2005Combination injectable contraceptives provide a highly effective, reversible method of preventing pregnancy, and they do not require daily administration or use at the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Combination injectable contraceptives provide a highly effective, reversible method of preventing pregnancy, and they do not require daily administration or use at the time of coitus. Although they are used in many countries, their acceptability could be limited by method characteristics, such as the need to obtain a monthly injection or bleeding pattern changes.
OBJECTIVES
To assess the contraceptive efficacy, bleeding patterns, discontinuation, user preferences, and side effects of combination injectable contraceptives.
SEARCH STRATEGY
We searched computerized databases for randomized controlled trials of combination injectable contraceptives.
SELECTION CRITERIA
Randomized controlled trials reported in any language were eligible if they compared a combination injectable with any other contraceptive method (e.g., a second combination injectable contraceptive, progestin-only injectable contraceptive, other hormonal contraceptive or barrier method) or placebo. We limited the review to currently marketed combination injectable contraceptives.
DATA COLLECTION AND ANALYSIS
The primary reviewer evaluated all titles and abstracts from the literature searches to determine their eligibility. Two reviewers independently extracted data from the eligible trials. Data on contraceptive efficacy, bleeding patterns, continuation, and side effects were entered and analyzed with RevMan 4.2.
MAIN RESULTS
Combination injectable contraceptives include depot medroxyprogesterone acetate (DMPA) 25 mg plus estradiol cypionate (E(2)C) 5 mg, as well as norethisterone enanthate (NET-EN) 50 mg plus estradiol valerate (E(2)V) 5 mg. These combination injectable contraceptives resulted in lower rates of early study discontinuation due to amenorrhea or other bleeding problems, but had higher rates of discontinuation due to other reasons than the progestin-only comparison contraceptives. Studies comparing two combination injectable contraceptives found that NET-EN 50 mg plus E(2)V 5 mg resulted in less overall early discontinuation and less discontinuation due to amenorrhea or prolonged bleeding than DMPA 25 mg plus E(2)C 5 mg. However, these differences were not detected in all trials making this comparison. The NET-EN plus E(2)V group also had more cyclical (regular) bleeding and fewer prolonged bleeding reference periods than the DMPA plus E(2)C group. The groups did not differ in their amenorrhea rates.
AUTHORS' CONCLUSIONS
While discontinuation rates can be viewed as a measure of method acceptability, the findings should be interpreted with caution since discontinuation rates are dependent on many other factors. Future research should be directed toward interventions to improve the acceptability of combination injectable contraceptives, such as providing injections in settings more convenient than clinical sites, methods for women to administer their own injections, and counseling about possible bleeding pattern changes.
Topics: Algestone; Contraception; Contraceptive Agents, Female; Drug Combinations; Estradiol; Female; Humans; Injections; Medroxyprogesterone; Megestrol Acetate; Norethindrone
PubMed: 16034938
DOI: 10.1002/14651858.CD004568.pub2 -
The Cochrane Database of Systematic... Feb 2013Uterine fibroids are the most common premenopausal benign uterine tumours. Fibroids can cause symptoms including heavy menstrual bleeding, pelvic pressure and pain.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Uterine fibroids are the most common premenopausal benign uterine tumours. Fibroids can cause symptoms including heavy menstrual bleeding, pelvic pressure and pain. Progestogens can be administered by various routes. Intramuscular injection of depot medroxyprogesterone acetate (DMPA) has dual actions (stimulatory or inhibitory) on fibroid cell growth. Progestogen-releasing intrauterine systems (IUS) decrease menstrual blood loss associated with fibroids by inducing endometrial atrophy and reduction of uterine fibroid size. Currently, their effectiveness for the treatment of uterine fibroids has not been evaluated.
OBJECTIVES
To determine the effectiveness of progestogens or progestogen-releasing intrauterine systems in treating premenopausal women with uterine fibroids.
SEARCH METHODS
We searched the Menstrual Disorders and Subfertility Group Specialised Register (inception to 17 August 2012), CENTRAL (inception to 17 August 2012) and Database of Abstracts of Reviews of Effects (DARE) in The Cochrane Library, MEDLINE (inception to 17 August 2012), Ovid EMBASE (1 January 2010 to 17 August 2012), Ovid PsycINFO (inception to 17 August 2012), CINAHL database, and trials registers for ongoing and registered trials.
SELECTION CRITERIA
All identified published or unpublished randomised controlled trials (RCTs) assessing the effect of progestogens or progestogen-releasing intrauterine systems in treating premenopausal women with uterine fibroids.
DATA COLLECTION AND ANALYSIS
We assessed all potentially eligible studies identified as a result of the search strategy. Two review authors extracted data from each included study using an agreed form and assessed the risk of bias. We resolved discrepancies through discussion.
MAIN RESULTS
This review included three studies. However, data for progestogen-releasing intrauterine systems were available from only one study that compared 29 women with a levonorgestrel (LNG)-IUS versus 29 women with a combined oral contraceptive (COC) for treating uterine fibroids. There was a significant reduction of menstrual blood loss (MBL) in women receiving the LNG-IUS compared to the COC using the alkaline hematin test (mean difference (MD) 77.5%, 95% CI 71.3% to 83.67%, 58 women) and a pictorial assessment chart (PBAC) (MD 34.5%, 95% CI 14.9% to 54.1%, 58 women). The reduction in uterine fibroid size was significantly greater in the leuprorelin group at 16 weeks compared to the progestogen lynestrenol group (MD -15.93 mm, 95% CI -18.02 to -13.84 mm, 46 women). There was no RCT evaluating the effect of DMPA on uterine fibroids.
AUTHORS' CONCLUSIONS
Progestogen-releasing intrauterine systems appear to reduce menstrual blood loss in premenopausal women with uterine fibroids. Oral progestogens did not reduce fibroid size or fibroid- related symptoms. However, there was a methodological limitation and the one included study with data had a small sample size. This evidence is insufficient to support the use of progestogens or progestogen-releasing intrauterine systems in treating premenopausal women with uterine fibroids.
Topics: Antineoplastic Agents, Hormonal; Female; Humans; Intrauterine Devices, Medicated; Leiomyoma; Leuprolide; Levonorgestrel; Lynestrenol; Medroxyprogesterone Acetate; Menstruation; Premenopause; Progestins; Randomized Controlled Trials as Topic; Tumor Burden; Uterine Neoplasms
PubMed: 23450594
DOI: 10.1002/14651858.CD008994.pub2 -
The Cochrane Database of Systematic... Aug 2012Reduced circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well-being of women. Hormone therapy... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Reduced circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well-being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.
OBJECTIVES
The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia or carcinoma.
SEARCH METHODS
We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2012), The Cochrane Library (Issue 1, 2012), MEDLINE (1966 to January 2012), EMBASE (1980 to January 2012), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to January 2012) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.
SELECTION CRITERIA
Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy, sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of 12 months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals owing to adverse events were also extracted.
DATA COLLECTION AND ANALYSIS
In this update, 46 studies were included. Odds ratios (ORs) were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta-analysis for many outcomes.
MAIN RESULTS
Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low-dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate (NETA) or 1.5 mg medroxyprogesterone acetate (MPA) is not significantly different from placebo at two years (1 mg NETA: OR 0.04; 95% confidence interval (CI) 0 to 2.8; 1.5 mg MPA: no hyperplasia events).
AUTHORS' CONCLUSIONS
Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.
Topics: Drug Therapy, Combination; Endometrial Hyperplasia; Endometrial Neoplasms; Estrogen Replacement Therapy; Estrogens; Female; Humans; Postmenopause; Progestins; Randomized Controlled Trials as Topic; Uterine Hemorrhage
PubMed: 22895916
DOI: 10.1002/14651858.CD000402.pub4 -
Cancer Treatment Reviews Feb 1998Adjuvant systemic treatment delays relapse and prolongs survival in patients with operable breast cancer. However, the relative wealth of available agents and the... (Review)
Review
Adjuvant systemic treatment delays relapse and prolongs survival in patients with operable breast cancer. However, the relative wealth of available agents and the heterogeneity of the target population contribute to considerable uncertainty about the optimal approach to particular patient groups. Systematic review and meta-analysis of the results of trials testing polychemotherapy have clearly established the value of such treatment. Endocrine treatment with tamoxifen was to be especially useful in patients with hormone-receptor positive tumours. Research in recent years has therefore concentrated on secondary questions, such as scheduling, dose intensity and new combinations of chemotherapeutic agents. Combined chemo-endocrine treatments, using polychemotherapy plus tamoxifen, ovarian ablation or both, have been compared with either modality alone. Other endocrine agents such as fluoxymesterone acetate, medroxyprogesterone acetate and, recently, LH-RH analogues have also received attention. The systematic review presented here suggests that combined cytotoxic and endocrine therapies might be the most effective use of available treatments for most, if not all, patients, and highlights the unresolved questions requiring further research.
Topics: Adult; Age Factors; Aged; Breast Neoplasms; Chemotherapy, Adjuvant; Combined Modality Therapy; Female; Hormones; Humans; Middle Aged; Ovariectomy; Tamoxifen
PubMed: 9606365
DOI: 10.1016/s0305-7372(98)90068-8 -
The Cochrane Database of Systematic... Oct 2009Endocrine therapy removes the influence of oestrogen on breast cancer cells and so hormonal treatments such as tamoxifen, megestrol acetate and medroxyprogesterone... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Antineoplastic Agents, Hormonal; Aromatase Inhibitors; Breast Neoplasms; Female; Humans; Neoplasms, Hormone-Dependent; Postmenopause; Randomized Controlled Trials as Topic
PubMed: 19821307
DOI: 10.1002/14651858.CD003370.pub3