Economic Evaluation of Letrozole for Early Breast Cancer in a Health Resource-Limited Setting

Systematic review of economic evaluations of aromatase inhibitors in estrogen receptor-positive breast cancer: quality evaluation

BACKGROUND

Breast cancer (BC) is a leading cause of premature death in women and the most expensive malignancy to treat. Since the introduction of targeted therapies has resulted in changes to BC therapy practices, health economic evaluations have become more important in this area. Taking generic medications, Aromatase Inhibitors (AIs), as a case study, we conducted a systematic review of the recent economic evaluations of AIs for estrogen receptor-positive breast cancer patients and evaluated the quality of these health economic studies.

OBJECTIVE

To systematically review and examine the quality of the available economic studies of AIs in estrogen receptor-positive breast cancer.

METHODS

A literature search was performed using six relevant databases (MEDLINE, Embase, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database, NHS Economic Evaluation Database, and SCOPUS) from January 2010 to July 2021. All economic studies were independently assessed by two reviewers using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist to evaluate the quality of the economic evaluations. This systematic review is registered in the PROSPERO database. To compare the different currencies used in these studies, all costs were converted to international dollars (2021).

RESULTS

A total of eight studies were included in the review; six (75%) were performed from the healthcare providers' perspective. They were conducted in seven different countries, and all were model-based analyses using Markov models. Six (75%) considered both Quality Adjusted Life Years (QALYs) and Life Years (LY) outcomes, and all costs were derived from national databases. When compared to tamoxifen, AIs were generally cost-effective in postmenopausal women. Only half of the studies addressed the increased mortality following adverse events, and none mentioned medication adherence. For the quality assessment, six studies fulfilled 85% of the CHEERS checklist requirements and are deemed good quality.

CONCLUSION

AIs are generally considered cost-effective compared to tamoxifen in estrogen receptor-positive breast cancer. The overall quality of the included studies was between high and average but characterizing heterogeneity, and distributional effects should be considered in any future economic evaluation studies of AIs. Studies should include adherence and adverse effects profiles to provide evidence to facilitate decision-making among policymakers.

Cost-effectiveness of Tamoxifen, Aromatase Inhibitor, and Switch Therapy (Adjuvant Endocrine Therapy) for Breast Cancer in Hormone Receptor Positive Postmenopausal Women in India

Background

Breast cancer is the leading cause of cancer among women in India. Treatment with hormone therapy reduces recurrence. We undertook this cost-effectiveness study to ascertain the treatment option offering the best value for money.

Methods

The lifetime costs and health outcomes of using tamoxifen, AI and switch therapy were measured in a cohort of 50-year-old women with HR-positive early stage breast cancer. A Markov model of disease was developed using a societal perspective with a lifetime study horizon. Local, contralateral, and distant recurrence were modelled along with treatment related adverse effects. Primary data collected to obtain estimates of out-of-pocket expenditure (OOPE) and utility weights. Both health system cost and OOPE were included. The future costs and consequences were discounted at 3%. A probabilistic sensitivity analysis was used.

Results

The lifetime cost of hormone therapy with tamoxifen, AI and switch therapy was to be ₹1,472,037 (I$ 68,947), ₹1,306,794 (I$ 61,208) and ₹1,281,811 (I$ 60,038). The QALYs lived per patient receiving tamoxifen, AI and switch were 13.12, 13.42 and 13.32. tamoxifen was found to be more expensive and less effective. As compared to switch therapy, AI for five years incurred an incremental cost of ₹259,792 (I$12,168) per QALY gained. At the willingness to pay equals to per capita GDP of India, there is 55% probability of AI therapy to be cost-effective compared to switch therapy.

Conclusion

In postmenopausal women with HR-positive early-stage breast cancer, switch therapy is recommended for use on the basis of cost-effectiveness.

Economic Evaluations of Breast Cancer Care in Low- and Middle-Income Countries: A Scoping Review

BACKGROUND

Understanding the cost of delivering breast cancer (BC) care in low- and middle-income countries (LMICs) is critical to guide effective care delivery strategies. This scoping review summarizes the scope of literature on the costs of BC care in LMICs and characterizes the methodological approaches of these economic evaluations.

MATERIALS AND METHODS

A systematic literature search was performed in five databases and gray literature up to March 2020. Studies were screened to identify original articles that included a cost outcome for BC diagnosis or treatment in an LMIC. Two independent reviewers assessed articles for eligibility. Data related to study characteristics and methodology were extracted. Study quality was assessed using the Drummond et al. checklist.

RESULTS

Ninety-one articles across 38 countries were included. The majority (73%) of studies were published between 2013 and 2020. Low-income countries (2%) and countries in Sub-Saharan Africa (9%) were grossly underrepresented. The majority of studies (60%) used a health care system perspective. Time horizon was not reported in 30 studies (33%). Of the 33 studies that estimated the cost of multiple steps in the BC care pathway, the majority (73%) were of high quality, but studies varied in their inclusion of nonmedical direct and indirect costs.

CONCLUSION

There has been substantial growth in the number of BC economic evaluations in LMICs in the past decade, but there remain limited data from low-income countries, especially those in Sub-Saharan Africa. BC economic evaluations should be prioritized in these countries. Use of existing frameworks for economic evaluations may help achieve comparable, transparent costing analyses.

IMPLICATIONS FOR PRACTICE

There has been substantial growth in the number of breast cancer economic evaluations in low- and middle-income countries (LMICs) in the past decade, but there remain limited data from low-income countries. Breast cancer economic evaluations should be prioritized in low-income countries and in Sub-Saharan Africa. Researchers should strive to use and report a costing perspective and time horizon that captures all costs relevant to the study objective, including those such as direct nonmedical and indirect costs. Use of existing frameworks for economic evaluations in LMICs may help achieve comparable, transparent costing analyses in order to guide breast cancer control strategies.

Cost of breast cancer care in low- and middle-income countries: a scoping review protocol

OBJECTIVE

This review will describe the scope of the literature on the cost of breast cancer care in low- and middle-income countries and summate the methodological characteristics and approaches of these economic evaluations.

INTRODUCTION

In the past decade, there has been global momentum to improve capacity for breast cancer care in low- and middle-income countries, which have higher rates of breast cancer mortality compared to high-income countries. Understanding the cost of delivering breast cancer care in low- and middle-income countries is critical to guide effective cancer care delivery strategies and policy.

INCLUSION CRITERIA

Studies that estimate the cost of breast cancer diagnosis and treatment in low- and middle-income countries will be included. Studies not available in English will be excluded.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Review guidelines will be utilized. The search strategy has been developed in consultation with a medical librarian and will be carried out on five electronic databases from their inception (MEDLINE, Embase, Web of Science, Global Health, WHO Global Index Medicus) as well as in gray literature sources. Two independent reviewers will review all abstracts and titles in the primary screen and full-text articles in the secondary screen. A third reviewer will adjudicate conflicts. One reviewer will perform data extraction. Study demographics, design, and methodological characteristics (such as costing perspective, time horizon, and included cost categories) will be summarized in narrative and tabular formats. The methodological quality of studies will be evaluated using a validated economic evaluation tool.

Cost-effectiveness of maintenance hormonal therapy in patients with advanced low grade serous ovarian cancer

OBJECTIVES

To assess the cost-effectiveness of using maintenance hormonal therapy in patients with low grade serous ovarian cancer (LGSC).

METHODS

A simulated decision analysis with a Markov decision model over a lifetime horizon was performed using the base case of a 47-year old patient with stage IIIC, LGSC following first-line treatment with primary cytoreductive surgery and adjuvant chemotherapy. Two treatment strategies were analyzed - maintenance daily letrozole until disease progression and routine observation. The analysis was from the perspective of the healthcare payer. Direct medical costs were estimated using public data sources and previous literature and were reported in adjusted 2018 Canadian dollars. The model estimated lifetime cost, quality-adjusted life years (QALY), life years (LY), median overall survival (OS), and number of recurrences with each strategy. Cost-effectiveness was compared using an incremental cost-effectiveness ratio (ICER). A strategy was considered cost-effective when the ICER was less than the willingness to pay (WTP) threshold of $50,000 CAD per QALY. Deterministic sensitivity analysis was performed to assess the impact of changing key clinical and cost variables.

RESULTS

Maintenance letrozole was the preferred strategy with an associated lifetime cost of $69,985 CAD ($52,620 USD) and an observed improvement of 0.91 QALYs and 1.55 LYs. The ICER for letrozole maintenance therapy was an additional $11,037 CAD ($8298 USD) per QALY. The modeled median OS was 150 months with maintenance letrozole and 126 months in the observation strategy. The maintenance letrozole strategy resulted in 34% and 17% fewer first recurrences at 5-year and 10-year follow-up, respectively.

CONCLUSION

Maintenance letrozole is a cost-effective treatment strategy in patients with advanced LGSC resulting in clinically-relevant improvement in QALYs, LYs, and fewer disease recurrences.

Cost-effectiveness analyses of breast cancer medications use in developing countries: a systematic review

BACKGROUND

Pharmacoeconomic evaluation is important for breast-cancer medications due to their high costs. To our knowledge, no systematic literature reviews of pharmacoeconomic studies for breast-cancer medication use are present in developing-countries.

OBJECTIVES

To systematically review the existing cost-effectiveness evaluations of breast-cancer medication in developing-countries.

METHODOLOGY

A systematic literature search was performed in PubMed, EMBASE, SCOPUS, and EconLit. Two researchers determined the final articles, extracted data, and evaluated their quality using the Quality of Health-Economic Studies (QHES) tool. The interclass-correlation-coefficient (ICC) was calculated to assess interrater-reliability. Data were summarized descriptively.

RESULTS

Fourteen pharmacoeconomic studies published from 2009 to 2019 were included. Thirteen used patient-life-years as their effectiveness unit, of which 10 used quality-adjusted life-years. Most of the evaluations focused on trastuzumab as a single agent or on regimens containing trastuzumab (n = 10). The conclusion of cost-effectiveness analysis varied among the studies. All the studies were of high quality (QHES score >75). Interrater reliability between the two reviewers was high (ICC = 0.76).

CONCLUSION

In many studies included in the review, the use of breast-cancer drugs in developing countries was not cost-effective. Yet, more pharmacoeconomic evaluations for the use of recently approved agents in different disease stages are needed in developing countries.

A Case-Control Study of the Association Between the SPP1 Gene SNPs and the Susceptibility to Breast Cancer in Guangxi, China

Secreted phosphoprotein-1 (SPP1) has been reported to be involved in the pathogenesis of breast cancer (BRC), but the influence of SPP1 single nucleotide polymorphisms on the BRC susceptibility has been rarely reported. In this study, we explored the association between rs11730582, rs2853750, and rs35893069 in the SPP1 gene and the BRC susceptibility. We used Snapshot assay to detect SPP1 single nucleotide polymorphisms in 471 BRC patients and 471 controls. The plasma SPP1 level was measured by ELISA. We found that the CC genotype and C allele of rs11730582 were associated with a significantly decreased BRC risk compared with the TT genotype and T allele, respectively [CC vs. TT: odds ratio (OR) = 0.59, 95% CI = 0.37–0.94, P = 0.026; C vs. T: OR = 0.79, 95% CI = 0.65–0.96, P = 0.022]. In addition, BRC patients and controls with the rs11730582 CC genotype had a lower plasma SPP1 level than did BRC patients and controls with TT genotype (P = 0.007 and P = 0.011, respectively). Moreover, the proportions of rs11730582 CC genotype and C allele were decreased in BRC patients with clinical stages I–III compared with those with clinical stage IV (P = 0.012 and P = 0.003, respectively). Besides, the C-G-T haplotype was associated with a significantly decreased BRC risk compared with the T-A-T haplotype (OR = 0.69, 95% CI = 0.52–0.93, P = 0.015). However, there was no significant association between rs2853750 or rs35893069 and the BRC risk. In summary, our study found the association between rs11730582 and the risk of BRC and suggested that rs11730582 may promote the occurrence and development of BRC by regulating SPP1 expression.