Patient Benefit-Risk Tradeoffs for Radioactive Iodine-Refractory Differentiated Thyroid Cancer Treatments

Risk of Cancer Recurrence Exerts the Strongest Influence on Choice Between Active Surveillance and Thyroid Surgery as Initial Treatment for Low-Risk Thyroid Cancer: Results of a Discrete Choice Experiment

BACKGROUND

Treatment options for low-risk differentiated thyroid cancer (DTC) include active surveillance (AS), hemithyroidectomy (HT), or total thyroidectomy (TT). Improved understanding of patient values and preferences is required to inform shared decision-making. This study examined factors influencing patient treatment preferences and trade-offs for low-risk DTC.

METHODS

Adult participants with benign thyroid nodules or low-risk DTC completed an online discrete choice experiment (DCE). Utilizing the scenario of a 50-year-old person with a small solitary DTC, participants chose between three unlabeled treatment options (representing AS, HT, and TT). Risk profiles varied across 5 domains: voice change, thyroid hormone supplementation, hypocalcaemia, chance of future thyroid surgery, and 10-year risk of cancer recurrence. Participants self-reported demographics, disease factors, and answered a decisional regret scale. A conditional logit model was utilized.

RESULTS

The DCE was completed by 143 patients across three sites. The conditional logit model demonstrated that participants preferred AS (49%) over TT (29%) or HT (22%). All five domains influenced choices (all p < 0.001), but perceived risk of cancer recurrence exerted most influence. Cancer survivors chose AS less often than those with benign disease (46% vs. 57%), driven by perceived risks of further surgery and cancer recurrence. As the perceived risk of cancer recurrence increased, more participants preferred HT over AS.

CONCLUSION

This study demonstrates that when blinded to the actual treatment, patients prefer the trade-offs associated with AS rather than TT or HT. Perceived risk of cancer recurrence exerted the greatest influence. Accurate risk stratification for cancer recurrence is critical to shared decision-making.

Advancements in theranostic applications: exploring the role of fibroblast activation protein inhibition tracers in enhancing thyroid health assessment

BACKGROUND

The diagnostic accuracy of [18F]-fluorodeoxyglucose ([18F]-FDG) positron emission tomography imaging in accurately identifying thyroid lesions is limited, primarily due to the physiological uptake of normal head and neck tissues and inflammatory uptake in lymph nodes. Since fibroblast activating protein is highly expressed in tumors and largely unexpressed in normal tissues, quinoline-based fibroblast activating protein inhibitors (FAPI) have emerged as promising tools in the diagnosis of cancer and other medical conditions. Several studies have reported on the feasibility and value of FAPI in thyroid cancer.

MAIN BODY

In this narrative review, we summarize the current literature on state-of-the-art FAPI positron emission tomography imaging for thyroid cancer and fibroblast activating protein-targeted radionuclide therapy. We provide an overview of FAPI uptake in normal thyroid tissue, thyroid cancer and its metastases. Additionally, we highlight the difference between FAPI uptake and [18F]-FDG uptake in thyroid lesions. Furthermore, we discuss the therapeutic value of FAPI in iodine-refractory thyroid cancer.

CONCLUSION

The utilization of fibroblast activating protein inhibitors in thyroid cancer holds significant promise, offering clinicians valuable insights for more precise diagnose choices and treatments strategies in the future.

Use of Patient Preferences Data Regarding Multiple Risks to Inform Regulatory Decisions

Background and Objectives. Risk-tolerance measures from patient-preference studies typically focus on individual adverse events. We recently introduced an approach that extends maximum acceptable risk (MAR) calculations to simultaneous maximum acceptable risk thresholds (SMART) for multiple treatment-related risks. We extend these methods to include the computation and display of confidence intervals and apply the approach to 3 published discrete-choice experiments to evaluate its utility to inform regulatory decisions. Methods. We generate MAR estimates and SMART curves and compare them with trial-based benefit-risk profiles of select treatments for depression, psoriasis, and thyroid cancer. Results. In the depression study, SMART curves with 70% to 95% confidence intervals portray which combinations of 2 adverse events would be considered acceptable. In the psoriasis example, the asymmetric confidence intervals for the SMART curve indicate that relying on independent MARs versus SMART curves when there are nonlinear preferences can lead to decisions that could expose patients to greater risks than they would accept. The thyroid cancer application shows an example in which the clinical incidence of each of 3 adverse events is lower than the single-event MARs for the expected treatment benefit, yet the collective risk profile surpasses acceptable levels when considered jointly. Limitations. Nonrandom sample of studies. Conclusions. When evaluating conventional MARs in which the observed incidences are near the estimated MARs or where preferences demonstrate diminishing marginal disutility of risk, conventional MAR estimates will overstate risk acceptance, which could lead to misinformed decisions, potentially placing patients at greater risk of adverse events than they would accept. Implications. The SMART method, herein extended to include confidence intervals, provides a reproducible, transparent evidence-based approach to enable decision makers to use data from discrete-choice experiments to account for multiple adverse events.

Highlights

Estimates of maximum acceptable risk (MAR) for a defined treatment benefit can be useful to inform regulatory decisions; however, the conventional metric considers one adverse event at a time.This article applies a new approach known as SMART (simultaneous maximum acceptable risk thresholds) that accounts for multiple adverse events to 3 published discrete-choice experiments.Findings reveal that conventional MARs could lead decision makers to accept a treatment based on individual risks that would not be acceptable if multiple risks are considered simultaneously.

Patient Preferences in Targeted Pharmacotherapy for Cancers: A Systematic Review of Discrete Choice Experiments

BACKGROUND

Targeted pharmacotherapy has been increasingly applied in cancer treatment due to its breakthroughs. However, the unmet needs of cancer patients are still significant, highlighting the urgency to investigate patient preferences. It is unclear how patients deliberate their choices between different aspects of targeted therapy, including cost, efficacy, and adverse events. Since discrete choice experiments (DCEs) have been widely applied to patient preference elicitation, we reviewed DCEs on targeted therapy for different cancers. We also synthesized evidence on the factors influencing patients' choices and their willingness-to-pay (WTP) for survival when treated by targeted therapy.

METHODS

We searched databases, including PubMed, EMBASE and MEDLINE, up to August 16, 2022, supplemented by a reference screening. The attributes from the selected studies were categorized into three groups: outcomes, costs, and process. We also calculated the relative importance of attributes and WTP for survival whenever possible. The purpose, respondents, explanation, findings, significance (PREFS) checklist was used to evaluate the quality of the included DCE studies.

RESULTS

The review identified 34 eligible studies from 13 countries covering 14 cancers, such as breast, ovarian, kidney, prostate, and skin cancers. It also reveals a rising trend of DCEs on this topic, as most studies were published after 2018. We found that patients placed higher weights on the outcome (e.g., overall survival) and cost attributes than on process attributes. On average, patients were willing to pay $561 (95% confidence interval [CI]: $415-$758) and $716 (95% CI $524-$958) out-of-pocket for a 1-month increase in progression-free survival and overall survival, respectively. PREFS scores of the 34 studies ranged from 2 to 4, with a mean of 3.38 (SD: 0.65), suggesting a reasonable quality based on the checklist. However, most studies (n = 32, 94%) did not assess the impact of non-responses on the results.

CONCLUSIONS

This is the first systematic review focusing on patient preferences for targeted cancer therapy. We showcased novel approaches for evidence synthesis of DCE results, especially the attribute relative importance and WTP. The results may inform stakeholders about patient preferences toward targeted therapy and their WTP estimates. More studies with improved study design and quality are warranted to generate more robust evidence to assist decision making.

A Systematic Review of Discrete Choice Experiments in Oncology Treatments

BACKGROUND

As the number and type of cancer treatments available rises and patients live with the consequences of their disease and treatments for longer, understanding preferences for cancer care can help inform decisions about optimal treatment development, access, and care provision. Discrete choice experiments (DCEs) are commonly used as a tool to elicit stakeholder preferences; however, their implementation in oncology may be challenging if burdensome trade-offs (e.g. length of life versus quality of life) are involved and/or target populations are small.

OBJECTIVES

The aim of this review was to characterise DCEs relating to cancer treatments that were conducted between 1990 and March 2020.

DATA SOURCES

EMBASE, MEDLINE, and the Cochrane Database of Systematic Reviews were searched for relevant studies.

STUDY ELIGIBILITY CRITERIA

Studies were included if they implemented a DCE and reported outcomes of interest (i.e. quantitative outputs on participants' preferences for cancer treatments), but were excluded if they were not focused on pharmacological, radiological or surgical treatments (e.g. cancer screening or counselling services), were non-English, or were a secondary analysis of an included study.

ANALYSIS METHODS

Analysis followed a narrative synthesis, and quantitative data were summarised using descriptive statistics, including rankings of attribute importance.

RESULT

Seventy-nine studies were included in the review. The number of published DCEs relating to oncology grew over the review period. Studies were conducted in a range of indications (n = 19), most commonly breast (n =10, 13%) and prostate (n = 9, 11%) cancer, and most studies elicited preferences of patients (n = 59, 75%). Across reviewed studies, survival attributes were commonly ranked as most important, with overall survival (OS) and progression-free survival (PFS) ranked most important in 58% and 28% of models, respectively. Preferences varied between stakeholder groups, with patients and clinicians placing greater importance on survival outcomes, and general population samples valuing health-related quality of life (HRQoL). Despite the emphasis of guidelines on the importance of using qualitative research to inform attribute selection and DCE designs, reporting on instrument development was mixed.

LIMITATIONS

No formal assessment of bias was conducted, with the scope of the paper instead providing a descriptive characterisation. The review only included DCEs relating to cancer treatments, and no insight is provided into other health technologies such as cancer screening. Only DCEs were included.

CONCLUSIONS AND IMPLICATIONS

Although there was variation in attribute importance between responder types, survival attributes were consistently ranked as important by both patients and clinicians. Observed challenges included the risk of attribute dominance for survival outcomes, limited sample sizes in some indications, and a lack of reporting about instrument development processes.

PROTOCOL REGISTRATION

PROSPERO 2020 CRD42020184232.

Respondent Understanding in Discrete Choice Experiments: A Scoping Review

INTRODUCTION

Despite the recognised importance of participant understanding for valid and reliable discrete choice experiment (DCE) results, there has been limited assessment of whether, and how, people understand DCEs, and how 'understanding' is conceptualised in DCEs applied to a health context.

OBJECTIVES

Our aim was to identify how participant understanding is conceptualised in the DCE literature in a health context. Our research questions addressed how participant understanding is defined, measured, and used.

METHODS

Searches were conducted (June 2019) in the MEDLINE, EMBASE, PsychINFO and Econlit databases, as well as hand searching. Search terms were based on previous DCE systematic reviews, with additional understanding keywords used in a proximity-based search strategy. Eligible studies were peer-reviewed journal articles in the field of health, related to DCE or best-worst scaling type 3 (BWS3) studies, and reporting some consideration or assessment of participant understanding. A descriptive analytical approach was used to chart relevant data from each study, including publication year, country, clinical area, subject group, sample size, study design, numbers of attributes, levels and choice sets, definition of understanding, how understanding was tested, results of the understanding tests, and how the information about understanding was used. Each study was categorised based on how understanding was conceptualised and used within the study.

RESULTS

Of 306 potentially eligible articles identified, 31 were excluded based on titles and abstracts, and 200 were excluded on full-text review, resulting in 75 included studies. Three categories of study were identified: applied DCEs (n = 52), pretesting studies (n = 7) and studies of understanding (n = 16). Typically, understanding was defined in relation to either the choice context, such as attribute terminology, or the concept of choosing. Very few studies considered respondents' engagement as a component of understanding. Understanding was measured primarily through qualitative pretesting, rationality or validity tests included in the survey, and participant self-report, however reporting and use of the results of these methods was inconsistent.

CONCLUSIONS

Those conducting or using health DCEs should carefully select, justify, and report the measurement and potential impact of participant understanding in their specific choice context. There remains scope for research into the different components of participant understanding, particularly related to engagement, the impact of participant understanding on DCE validity and reliability, the best measures of understanding, and methods to maximise participant understanding.

Patient Preferences Around Extent of Surgery in Low-Risk Thyroid Cancer: A Discrete Choice Experiment

Background: Patient preferences pertaining to surgical options for thyroid cancer management are not well studied. Our aim was to conduct a discrete choice experiment (DCE) to characterize participants' views on the relative importance of various risks and benefits associated with lobectomy versus total thyroidectomy for low-risk thyroid cancer. Methods: Adult participants with low-risk thyroid cancer or a thyroid nodule requiring surgery were asked to choose between experimentally designed surgical options with varying levels of risk of nerve damage (1%, 9%, 14%), hypocalcemia (0%, 3%, 8%), risk of needing a second surgery (0%, 40%), cancer recurrence (1%, 3%, 5%), and need for daily thyroid hormone supplementation (yes, no). Their choices were analyzed using random-parameters logit regression. Results: One hundred fifty participants completed an online DCE survey. Median age was 58 years; 82% were female. Twenty-four participants (16%) had a diagnosis of thyroid cancer at the time of completing the survey, and 126 (84%) had a thyroid nodule necessitating surgery. On average, 35% of participants' choices were explained by differences in the risk of cancer recurrence; 28% by the chance of needing a second surgery; 19% by the risk of nerve damage; and 9% by differences in risks of hypocalcemia and the need for thyroid hormone supplementation. When accounting for differences in postoperative risks, the average patient favored lobectomy over total thyroidectomy as long as the chance of needing a second (i.e., completion) surgery after initial lobectomy remained below 30%. Participants would accept a 4.1% risk of cancer recurrence if the risk of a second surgery could be reduced from 40% to 10%. Conclusions: While patients with thyroid cancer may have clear preferences for extent of surgery, common themes moderating preferences for surgical interventions were identified in the DCE. Adequate preoperative evaluation to decrease the chance of a second surgery and providing patients with a good understanding of risks and benefits associated with extent of surgery can lead to better treatment decision-making.

Patient and Oncologist Preferences for the Treatment of Adults with Advanced Soft Tissue Sarcoma: A Discrete Choice Experiment

BACKGROUND

There has been no single standard-of-care treatment of patients with advanced/metastatic soft tissue sarcoma (STS). This study was designed to understand patient and oncologist preferences in the advanced/metastatic setting.

METHODS

Adult patients diagnosed with STS and oncologists treating patients with STS completed discrete choice experiment surveys. Study participants chose between pairs of hypothetical treatment profiles for advanced STS characterized by varying levels of overall survival (14, 20, or 26 months), progression-free survival (3, 5, or 7 months), objective tumor response rate (12, 18, or 26%), risk of hospitalization due to side effects (12, 30, or 46%), and days/month to administer treatment (1, 2, or 4 days). A hierarchical Bayes model was used to estimate preferences and relative importance of attributes.

RESULTS

Seventy-six patients (23.7% male, mean age 52.8 years) and 160 oncologists (73.8% male, mean 16.9 years in practice) completed the surveys. Among patients, overall survival had the highest relative importance (39.5%, standard deviation [SD] 18.2%), followed by response rate (21.2%, SD 10.4%), and hospitalization (19.8%, SD 12.5%). Among oncologists, overall survival had the highest relative importance (44.6%, SD 16.0%), followed by hospitalization (18.4%, SD 8.3%).

CONCLUSIONS

Both patients with STS and oncologists preferred a treatment that maximizes the life of patients while avoiding hospitalizations.

Care Management for Youth With Comorbid Developmental and Mental Health Conditions: A Discrete Choice Experiment Pilot Study

OBJECTIVE

Caregivers of a child with a coexisting cognitive/intellectual and an emotional/behavior/developmental disability have difficult decisions regarding care management options for their child. This study aimed to pilot and refine an instrument to elicit caregivers' preferences in managing their child's care needs.

METHODS

Subjects were 38 caregivers of a child aged 21 and younger with a coexisting cognitive/intellectual and an emotional/behavior/developmental disability. A mixed-methods design was used to develop and pilot a discrete choice experiment (DCE) to elicit care management preferences for their child. Six attributes of care management decisions were tested in the DCE: medication use, parental custody, time cost, social interactions, medication effects, and school placement. Subjects completed a paper-and-pencil survey after which a debriefing discussion was held to obtain feedback that would aid in refining the attribute descriptions. Conditional logistic regression generated mean scores for each attribute. Comments from the debriefing sessions were audio-recorded and used to modify the attribute descriptions.

RESULTS

The majority (84%) of subjects were aged 40 years or older and a female caregiver. Common diagnoses of the children were autism spectrum disorder (55%) and attention-deficit/hyperactivity disorder (76%). Subjects preferred using fewer medications and maintaining decision-making authority as opposed to delegating authority to a third party. Medication effects on the child's mood were more important than effects on personality or body weight.

CONCLUSIONS

The DCE was sensitive to caregivers' preferences for managing their child's coexisting cognitive/intellectual and emotional/behavior/developmental disability. Findings may help providers gauge treatment in a broader context of health outcomes.

Discrete Choice Experiments in Health Economics: Past, Present and Future

OBJECTIVES

Discrete choice experiments (DCEs) are increasingly advocated as a way to quantify preferences for health. However, increasing support does not necessarily result in increasing quality. Although specific reviews have been conducted in certain contexts, there exists no recent description of the general state of the science of health-related DCEs. The aim of this paper was to update prior reviews (1990-2012), to identify all health-related DCEs and to provide a description of trends, current practice and future challenges.

METHODS

A systematic literature review was conducted to identify health-related empirical DCEs published between 2013 and 2017. The search strategy and data extraction replicated prior reviews to allow the reporting of trends, although additional extraction fields were incorporated.

RESULTS

Of the 7877 abstracts generated, 301 studies met the inclusion criteria and underwent data extraction. In general, the total number of DCEs per year continued to increase, with broader areas of application and increased geographic scope. Studies reported using more sophisticated designs (e.g. D-efficient) with associated software (e.g. Ngene). The trend towards using more sophisticated econometric models also continued. However, many studies presented sophisticated methods with insufficient detail. Qualitative research methods continued to be a popular approach for identifying attributes and levels.

CONCLUSIONS

The use of empirical DCEs in health economics continues to grow. However, inadequate reporting of methodological details inhibits quality assessment. This may reduce decision-makers' confidence in results and their ability to act on the findings. How and when to integrate health-related DCE outcomes into decision-making remains an important area for future research.

Patients' Preferences for Outcome, Process and Cost Attributes in Cancer Treatment: A Systematic Review of Discrete Choice Experiments

INTRODUCTION

As several studies have been conducted to elicit patients' preferences for cancer treatment, it is important to provide an overview and synthesis of these studies. This study aimed to systematically review discrete choice experiments (DCEs) about patients' preferences for cancer treatment and assessed the relative importance of outcome, process and cost attributes.

METHODS

A systematic literature review was conducted using PubMed and EMBASE to identify all DCEs investigating patients' preferences for cancer treatment between January 2010 and April 2016. Data were extracted using a predefined extraction sheet, and a reporting quality assessment was applied to all studies. Attributes were classified into outcome, process and cost attributes, and their relative importance was assessed.

RESULTS

A total of 28 DCEs were identified. More than half of the studies (56%) received an aggregate score lower than 4 on the PREFS (Purpose, Respondents, Explanation, Findings, Significance) 5-point scale. Most attributes were related to outcome (70%), followed by process (25%) and cost (5%). Outcome attributes were most often significant (81%), followed by process (73%) and cost (67%). The relative importance of outcome attributes was ranked highest in 82% of the cases where it was included, followed by cost (43%) and process (12%).

CONCLUSION

This systematic review suggests that attributes related to cancer treatment outcomes are the most important for patients. Process and cost attributes were less often included in studies but were still (but less) important to patients in most studies. Clinicians and decision makers should be aware that attribute importance might be influenced by level selection for that attribute.

Inhibiting β-catenin expression promotes efficiency of radioiodine treatment in aggressive follicular thyroid cancer cells probably through mediating NIS localization

The present study investigated whether the efficacy of radioiodine therapy towards aggressive thyroid cancer cells was affected by β-catenin activity and associated with sodium/iodine symporter (NIS) localization. Human thyroid cancer cell line follicular thyroid carcinoma (FTC) 133 was endowed with aggressiveness by HIF-1α or β-catenin overexpression. The protein amount and subcellular localization of NIS, and the radioiodine uptake capacity were detected in the cells, as well as in cells subsequently undergoing β-catenin knockdown. Xenograft experiments were conducted to compare the tumor growth ability and responsiveness to radioactive treatment among HIF-1α and β-catenin overexpressing FTC cells, respectively with or without β-catenin knockdown. β-catenin increased upon HIF-1α overexpression, but not vice versa. This signal axis would prompt metastatic propensity in FTC cells, and translocate NIS from cytomembrane to cytoplasm. Consistently the radioiodine uptake capacity in the cells decreased obviously. Knockdown of β-catenin reversed all these changes. Furthermore, the xenograft experiments showed that radioiodine treatment could thoroughly suppress tumor growth ability of aggressive FTC cells only if the HIF-1α-induced β-catenin activation was disrupted by β-catenin knockdown. β-catenin nuclear translocation in tumor cells was accompanied by abnormal subcellular localization of NIS. Moreover, we found that only after inhibiting β-catenin expression, can the radioiodine treatment promote apoptosis other than repress proliferation and survival in xenograft tumor cells. In conclusion, aggressive FTC cells overexpressing HIF-1α will be fully cracked down by radioiodine therapy once β-catenin expression is inhibited, and regulated localization of NIS may account for underlying mechanisms.

Evaluation of Rumex hastatus D. Don for cytotoxic potential against HeLa and NIH/3T3 cell lines: chemical characterization of chloroform fraction and identification of bioactive compounds

Background

The importance of Rumex genus and the renowned ethnopharmacological and biological potentials of Rumex hastatus is evident from the previous reports. Recently the R. hastatus has been evaluated for anticancer potential against HepG2, MCF7 or LNCaP cell lines with considerable cytotoxicity. We also reported the anti-tumor and anti-angiogenic potentials of R. hastatus. The current study has been arranged to evaluate cytotoxic potential of this plant against HeLa and NIH/3T3 cell lines and sort out the most active fraction of R. hastatus along with the identification of bioactive compounds responsible for cytotoxicity.

Methods

The cytotoxic potential of methanolic extract and sub-fractions of R. hastatus was performed following (3-[4, 5-dimethylthiazole-2-yl]-2, 5-diphenyl-tetrazolium bromide) MTT calorimetric assay. Four concentrations (500, 250, 125 and 62.5 μg/ml) of each sample were used against both cell lines. Two cell lines i.e. HeLa and NIH/3T3 were used in the assay. Furthermore, chemical characterization of chloroform fraction was performed by GC-MS analysis.

Results

The current investigational study demonstrates that all the solvent fractions of R. hastatus were active against HeLa and NIH/3T3 cell lines. Among all the fractions, chloroform fraction was dominant in activity against both cell lines. The observed IC₅₀ values of chloroform fraction were 151.52 and 53.37 μg/ml against HeLa and NIH/3T3 respectively. The GC-MS analysis of chloroform fraction revealed the identification of 78 compounds with the identification of bioactive ones like ar-tumerone, phytol, dihydrojasmone, sitostenone etc.

Conclusion

It can be concluded from our results that Rumex hastatus D. Don possess strong cytotoxic potential. Moreover, the observed IC₅₀ values and GC-MS analysis of chloroform fraction reveal that most of the bioactive compounds are in chloroform fraction. It can be further deduce that the chloroform fraction is a suitable target for the isolation of compounds having potential role in cancer therapy.