Dataset Information

Risk of dementia among postmenopausal breast cancer survivors treated with aromatase inhibitors versus tamoxifen: a cohort study using primary care data from the UK.

ABSTRACT:

Purpose

Among a cohort of postmenopausal breast cancer survivors, we aimed to compare the risk of dementia associated with aromatase inhibitor (AI) therapy versus tamoxifen.

Methods

Using UK primary care electronic health records, we identified 14,214 postmenopausal breast cancer survivors (aged ??54 years) with a first AI or tamoxifen prescription between January 2002 and December 2015 and no previous dementia diagnosis. Women were followed-up to identify incident cases of dementia. Cox regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) to quantify the association between AI exposure (vs. tamoxifen) and dementia, adjusted for confounders.

Results

A total of 368 incident dementia cases was identified over 57,102 person-years of follow-up. The crude incidence rate of dementia was 7.46 per 1000 person-years (95% CI 6.43-8.65) among women starting endocrine treatment on an AI, and 6.32 per 1000 person-years (95% CI 5.34-7.47) among women starting on tamoxifen. After accounting for age differences and assessing other potential confounders, there was no evidence of a difference in dementia risk between exposure groups (HR for AI vs tamoxifen 1.04, 95% CI 0.83-1.03). There was no evidence of effect modification by age.

Conclusion

There was no evidence for a difference in dementia risk between AI and tamoxifen users among postmenopausal breast cancer survivors.

Implications for cancer survivors

Our findings suggest that there is no reason for concern about a difference in dementia risk with AI vs. tamoxifen, which is relevant to postmenopausal breast cancer patients recommended these treatments.

SUBMITTER: Bromley SE

PROVIDER: S-EPMC6776493 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

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Publications

Risk of dementia among postmenopausal breast cancer survivors treated with aromatase inhibitors versus tamoxifen: a cohort study using primary care data from the UK.

Bromley Susan E SE Matthews Anthony A Smeeth Liam L Stanway Susannah S Bhaskaran Krishnan K

Journal of cancer survivorship : research and practice 20190718 4

<h4>Purpose</h4>Among a cohort of postmenopausal breast cancer survivors, we aimed to compare the risk of dementia associated with aromatase inhibitor (AI) therapy versus tamoxifen.<h4>Methods</h4>Using UK primary care electronic health records, we identified 14,214 postmenopausal breast cancer survivors (aged ≥ 54 years) with a first AI or tamoxifen prescription between January 2002 and December 2015 and no previous dementia diagnosis. Women were followed-up to identify incident cases of dement ...[more]

PMID: 31321612

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Project description:BackgroundA key priority in developing policies for providing affordable cancer care is measuring the value for money of new therapies using cost-effectiveness analyses (CEAs). For CEA to be useful it should focus on relevant outcomes and include thorough investigation of uncertainty. Randomized controlled trials (RCTs) of five years of aromatase inhibitors (AI) versus five years of tamoxifen in the treatment of post-menopausal women with early stage breast cancer, show benefit of AI in terms of disease free survival (DFS) but not overall survival (OS) and indicate higher risk of fracture with AI. Policy-relevant CEA of AI versus tamoxifen should focus on OS and include analysis of uncertainty over key assumptions.MethodsWe conducted a systematic review of published CEAs comparing an AI to tamoxifen. We searched Ovid MEDLINE, EMBASE, PsychINFO, and the Cochrane Database of Systematic Reviews without language restrictions. We selected CEAs with outcomes expressed as cost per life year or cost per quality adjusted life year (QALY). We assessed quality using the Neumann checklist. Using structured forms two abstractors collected descriptive information, sources of data, baseline assumptions on effectiveness and adverse events, and recorded approaches to assessing parameter uncertainty, methodological uncertainty, and structural uncertainty.ResultsWe identified 1,622 citations and 18 studies met inclusion criteria. All CE estimates assumed a survival benefit for aromatase inhibitors. Twelve studies performed sensitivity analysis on the risk of adverse events and 7 assumed no additional mortality risk with any adverse event. Sub-group analysis was limited; 6 studies examined older women, 2 examined women with low recurrence risk, and 1 examined women with multiple comorbidities.ConclusionPublished CEAs comparing AIs to tamoxifen assumed an OS benefit though none has been shown in RCTs, leading to an overestimate of the cost-effectiveness of AIs. Results of these CEA analyses may be suboptimal for guiding policy.

Project description:BackgroundFor women with early-stage oestrogen receptor (ER)-positive breast cancer, adjuvant tamoxifen reduces 15-year breast cancer mortality by a third. Aromatase inhibitors are more effective than tamoxifen in postmenopausal women but are ineffective in premenopausal women when used without ovarian suppression. We aimed to investigate whether premenopausal women treated with ovarian suppression benefit from aromatase inhibitors.MethodsWe did a meta-analysis of individual patient data from randomised trials comparing aromatase inhibitors (anastrozole, exemestane, or letrozole) versus tamoxifen for 3 or 5 years in premenopausal women with ER-positive breast cancer receiving ovarian suppression (goserelin or triptorelin) or ablation. We collected data on baseline characteristics, dates and sites of any breast cancer recurrence or second primary cancer, and dates and causes of death. Primary outcomes were breast cancer recurrence (distant, locoregional, or contralateral), breast cancer mortality, death without recurrence, and all-cause mortality. As distant recurrence invariably results in death from breast cancer several years after the occurrence, whereas locoregional recurrence and new contralateral breast cancer are not usually fatal, the distant recurrence analysis is shown separately. Standard intention-to-treat log-rank analyses estimated first-event rate ratios (RR) and their confidence intervals (CIs).FindingsWe obtained data from all four identified trials (ABCSG XII, SOFT, TEXT, and HOBOE trials), which included 7030 women with ER-positive tumours enrolled between June 17, 1999, and Aug 4, 2015. Median follow-up was 8·0 years (IQR 6·1-9·3). The rate of breast cancer recurrence was lower for women allocated to an aromatase inhibitor than for women assigned to tamoxifen (RR 0·79, 95% CI 0·69-0·90, p=0·0005). The main benefit was seen in years 0-4 (RR 0·68, 99% CI 0·55-0·85; p<0·0001), the period when treatments differed, with a 3·2% (95% CI 1·8-4·5) absolute reduction in 5-year recurrence risk (6·9% vs 10·1%). There was no further benefit, or loss of benefit, in years 5-9 (RR 0·98, 99% CI 0·73-1·33, p=0·89) or beyond year 10. Distant recurrence was reduced with aromatase inhibitor (RR 0·83, 95% CI 0·71-0·97; p=0·018). No significant differences were observed between treatments for breast cancer mortality (RR 1·01, 95% CI 0·82-1·24; p=0·94), death without recurrence (1·30, 0·75-2·25; p=0·34), or all-cause mortality (1·04, 0·86-1·27; p=0·68). There were more bone fractures with aromatase inhibitor than with tamoxifen (227 [6·4%] of 3528 women allocated to an aromatase inhibitor vs 180 [5·1%] of 3502 women allocated to tamoxifen; RR 1·27 [95% CI 1·04-1·54]; p=0·017). Non-breast cancer deaths (30 [0·9%] vs 24 [0·7%]; 1·30 [0·75-2·25]; p=0·36) and endometrial cancer (seven [0·2%] vs 15 [0·3%]; 0·52 [0·22-1·23]; p=0·14) were rare.InterpretationUsing an aromatase inhibitor rather than tamoxifen in premenopausal women receiving ovarian suppression reduces the risk of breast cancer recurrence. Longer follow-up is needed to assess any impact on breast cancer mortality.FundingCancer Research UK, UK Medical Research Council.

Dataset Information

Risk of dementia among postmenopausal breast cancer survivors treated with aromatase inhibitors versus tamoxifen: a cohort study using primary care data from the UK.

Purpose

Methods

Results

Conclusion

Implications for cancer survivors

Publications

Risk of dementia among postmenopausal breast cancer survivors treated with aromatase inhibitors versus tamoxifen: a cohort study using primary care data from the UK.

Similar Datasets

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