Cost-effectiveness analysis of bicalutamide (Casodex) for adjuvant treatment of early prostate cancer

Systematic Review of Cost-Effectiveness Models in Prostate Cancer: Exploring New Developments in Testing and Diagnosis

OBJECTIVES

Recent innovations in prostate cancer diagnosis include new biomarkers and more accurate biopsy methods. This study assesses the evidence base on cost-effectiveness of these developments (eg, Prostate Health Index and magnetic resonance imaging [MRI]-guided biopsy) and identifies areas of improvement for future cost-effectiveness models.

METHODS

A systematic review using the National Health Service Economic Evaluation Database, MEDLINE, Embase, Health Technology Assessment databases, National Institute for Health and Care Excellence guidelines, and United Kingdom National Screening Committee guidance was performed, between 2009 and 2021. Relevant data were extracted on study type, model inputs, modeling methods and cost-effectiveness conclusions, and results narratively synthesized.

RESULTS

A total of 22 model-based economic evaluations were included. A total of 11 compared the cost-effectiveness of new biomarkers to prostate-specific antigen testing alone and all found biomarkers to be cost saving. A total of 8 compared MRI-guided biopsy methods to transrectal ultrasound-guided methods and found MRI-guided methods to be most cost-effective. Newer detection methods showed a reduction in unnecessary biopsies and overtreatment. The most cost-effective follow-up strategy in men with a negative initial biopsy was uncertain. Many studies did not model for stage or grade of cancer, cancer progression, or the entire testing and treatment pathway. Few fully accounted for uncertainty.

CONCLUSIONS

This review brings together the cost-effectiveness literature for novel diagnostic methods in prostate cancer, showing that most studies have found new methods to be more cost-effective than standard of care. Several limitations of the models were identified, however, limiting the reliability of the results. Areas for further development include accurately modeling the impact of early diagnostic tests on long-term outcomes of prostate cancer and fully accounting for uncertainty.

Prostate cancer mortality and metastasis under different biopsy frequencies in North American active surveillance cohorts

BACKGROUND

Active surveillance (AS) is an accepted means of managing low-risk prostate cancer. Because of the rarity of downstream events, data from existing AS cohorts cannot yet address how differences in surveillance intensity affect metastasis and mortality. This study projected the comparative benefits of different AS schedules in men diagnosed with prostate cancer who had Gleason score (GS) ≤6 disease and risk profiles similar to those in North American AS cohorts.

METHODS

Times of GS upgrading were simulated based on AS data from the University of Toronto, Johns Hopkins University, the University of California at San Francisco, and the Canary Pass Active Surveillance Cohort. Times to metastasis and prostate cancer death, informed by models from the Scandinavian Prostate Cancer Group 4 trial, were projected under biopsy surveillance schedules ranging from watchful waiting to annual biopsies. Outcomes included the risk of metastasis, the risk of death, remaining life-years (LYs), and quality-adjusted LYs.

RESULTS

Compared with watchful waiting, AS biopsies reduced the risk of prostate cancer metastasis and prostate cancer death at 20 years by 1.4% to 3.3% and 1.0% to 2.4%, respectively; and 5-year biopsies reduced the risk of metastasis and prostate cancer death by 1.0% to 2.4% and 0.6% to 1.6%, respectively. There was little difference between annual and 5-year biopsy schedules in terms of LYs (range of differences, 0.04-0.16 LYs) and quality-adjusted LYs (range of differences, -0.02 to 0.09 quality-adjusted LYs).

CONCLUSIONS

Among men diagnosed with GS ≤6 prostate cancer, obtaining a biopsy every 3 or 4 years appears to be an acceptable alternative to more frequent biopsies. Reducing surveillance intensity for those who have a low risk of progression reduces the number of biopsies while preserving the benefit of more frequent schedules.

Health Technology Assessment Challenges in Oncology: 20 Years of Value in Health

BACKGROUND

Oncology treatments have changed from chemotherapies to targeted therapies and more recently immuno-oncology. This has posed special challenges in the field of health technology assessment (HTA): capturing quality of life (QOL) associated with toxicity due to chemotherapy, crossover upon progression in targeted therapy trials, and survival extrapolation for immuno-oncology drugs.

OBJECTIVES

To showcase 20 years of Value in Health (ViH) publications in oncology.

METHODS

A review was undertaken of oncology articles published in ViH from May 1998 to August 2018. Full-length articles published in ViH with the keywords "oncology," "cancer," "h(a)ematology," and "malignancy" were included for review. Conference abstracts were excluded.

RESULTS

Four major themes were identified: (1) QOL and the development of multiple functional assessment of cancer therapy tools and mapping instruments; (2) analysis of clinical evidence using indirect comparisons, network analyses, and adjustment for crossovers; (3) modeling, Markov models, partitioned survival models, and extrapolation methods; and (4) financial implications and how to deal with uncertainty, introduction of conditional reimbursement, managed entry, and risk share agreements.

DISCUSSION

This review article highlights the important role ViH has played in disseminating HTA research in oncology. A few key issues loom on the horizon: precision medicine, further development and practical application of new QOL measures, methods for translating clinical evidence, and exploration of modeling techniques. For a better understanding of the complex interplay between access and financial risk management, ViH will no doubt continue to promote pioneering research in HTA and oncology.

Quality-of-life effects of prostate-specific antigen screening

BACKGROUND

After 11 years of follow-up, the European Randomized Study of Screening for Prostate Cancer (ERSPC) reported a 29% reduction in prostate-cancer mortality among men who underwent screening for prostate-specific antigen (PSA) levels. However, the extent to which harms to quality of life resulting from overdiagnosis and treatment counterbalance this benefit is uncertain.

METHODS

On the basis of ERSPC follow-up data, we used Microsimulation Screening Analysis (MISCAN) to predict the number of prostate cancers, treatments, deaths, and quality-adjusted life-years (QALYs) gained after the introduction of PSA screening. Various screening strategies, efficacies, and quality-of-life assumptions were modeled.

RESULTS

Per 1000 men of all ages who were followed for their entire life span, we predicted that annual screening of men between the ages of 55 and 69 years would result in nine fewer deaths from prostate cancer (28% reduction), 14 fewer men receiving palliative therapy (35% reduction), and a total of 73 life-years gained (average, 8.4 years per prostate-cancer death avoided). The number of QALYs that were gained was 56 (range, -21 to 97), a reduction of 23% from unadjusted life-years gained. To prevent one prostate-cancer death, 98 men would need to be screened and 5 cancers would need to be detected. Screening of all men between the ages of 55 and 74 would result in more life-years gained (82) but the same number of QALYs (56).

CONCLUSIONS

The benefit of PSA screening was diminished by loss of QALYs owing to postdiagnosis long-term effects. Longer follow-up data from both the ERSPC and quality-of-life analyses are essential before universal recommendations regarding screening can be made. (Funded by the Netherlands Organization for Health Research and Development and others.).

Empirically evaluating decision-analytic models

OBJECTIVES

Model-based cost-effectiveness analyses support decision-making. To augment model credibility, evaluation via comparison to independent, empirical studies is recommended.

METHODS

We developed a structured reporting format for model evaluation and conducted a structured literature review to characterize current model evaluation recommendations and practices. As an illustration, we applied the reporting format to evaluate a microsimulation of human papillomavirus and cervical cancer. The model's outputs and uncertainty ranges were compared with multiple outcomes from a study of long-term progression from high-grade precancer (cervical intraepithelial neoplasia [CIN]) to cancer. Outcomes included 5 to 30-year cumulative cancer risk among women with and without appropriate CIN treatment. Consistency was measured by model ranges overlapping study confidence intervals.

RESULTS

The structured reporting format included: matching baseline characteristics and follow-up, reporting model and study uncertainty, and stating metrics of consistency for model and study results. Structured searches yielded 2963 articles with 67 meeting inclusion criteria and found variation in how current model evaluations are reported. Evaluation of the cervical cancer microsimulation, reported using the proposed format, showed a modeled cumulative risk of invasive cancer for inadequately treated women of 39.6% (30.9-49.7) at 30 years, compared with the study: 37.5% (28.4-48.3). For appropriately treated women, modeled risks were 1.0% (0.7-1.3) at 30 years, study: 1.5% (0.4-3.3).

CONCLUSIONS

To support external and projective validity, cost-effectiveness models should be iteratively evaluated as new studies become available, with reporting standardized to facilitate assessment. Such evaluations are particularly relevant for models used to conduct comparative effectiveness analyses.

Cost effectiveness of risk-prediction tools in selecting patients for immediate post-prostatectomy treatment

BACKGROUND AND OBJECTIVE

Ideally, tests that predict the risk of cancer recurrence should be capable of guiding treatment decisions that are both therapeutically effective and cost effective. This paper evaluates the cost effectiveness of two tools that identify patients at high risk for biochemical (prostate-specific antigen) recurrence of prostate cancer after prostatectomy, the hypothesis being that accurate classification of high-risk patients will allow more appropriate use of secondary (adjuvant/salvage) treatment and may improve on current clinical practice. These risk-prediction tools are the Kattan postoperative nomogram, which uses clinicopathologic features, and the Prostate Px test, which employs additional morphometric and immunofluorescence features of the prostate specimen to predict risk of biochemical recurrence. These tools were trained on patients treated at the Memorial Sloan-Kettering Cancer Center (996 patients for the nomogram, 342 patients for the Prostate Px test).

METHODS

The cost effectiveness of the Prostate Px test, the Kattan postoperative nomogram, and current clinical practice were compared using a decision analytic model. The modeled treatment for low-risk patients was watchful waiting. The modeled treatments for high-risk patients were local radiation, hormonal therapy, and watchful waiting. Costs, utilities, and transition probabilities were obtained from the literature. Costs and effects were discounted at 3% per year. The time span modeled was 10 years after prostatectomy. Monte Carlo simulation was performed to estimate cost and effectiveness; sensitivity analysis was performed to examine the impact of uncertainty in the parameter values.

RESULTS

The expected quality-adjusted life years (QALYs) for the Prostate Px test, nomogram, and current practice were 8.11, 7.39, and 6.47, respectively. The expected costs were $US17 549, $US14 162, and $US14 104, respectively. The incremental cost-effectiveness ratio of the Prostate Px was $US4704/QALY compared with the nomogram, and $US2100/QALY compared with current practice. The incremental cost-effectiveness ratio of the nomogram was $US63/QALY compared with current practice. These ratios are well below the common willingness-to-pay limit of $US50 000/QALY. Expected effectiveness was highest for the Prostate Px test, followed by the nomogram. Expected cost was slightly higher for Prostate Px than for either alternative; nevertheless, the Prostate Px was cost effective compared with both the nomogram and current practice. The nomogram was cost effective compared with current practice. The acceptable cost effectiveness of the Prostate Px test and the nomogram compared with current practice were not sensitive to changes in the values used to inform the model within clinically plausible ranges. The superior performance of both Prostate Px test and nomogram over current practice resulted from identifying high-risk patients likely to benefit from adjuvant treatment, while sparing the low-risk patients the added cost and toxicity of treatment.

CONCLUSION

Incorporation of risk-prediction tools in the initial management of patients after prostatectomy resulted in increased QALYs at an acceptable increase in cost relative to current practice.

Bicalutamide 150mg

Bicalutamide (Casodex) is a competitive androgen receptor antagonist that inactivates androgen-regulated prostate cell growth and function, leading to cell apoptosis and inhibition of prostate cancer growth. It is administered orally as a once-daily dose. In the EU and a number of other countries, bicalutamide 150 mg/day is approved in men with locally advanced nonmetastatic prostate cancer as immediate therapy either as an adjuvant to active treatment or as monotherapy as an alternative to surgical or medical castration. Combined analysis of the three trials that comprise the bicalutamide Early Prostate Cancer (EPC) programme showed that bicalutamide administered in conjunction with standard care in men with locally advanced prostate cancer offers disease-free survival benefits over standard care alone and is generally well tolerated. Overall survival was improved to a greater extent in the subgroup of patients who received bicalutamide plus radiation therapy compared with radiation therapy alone. Men with localised prostate cancer do not benefit from the addition of bicalutamide to standard care. Combined analysis of two other studies in men with locally advanced prostate cancer show that bicalutamide monotherapy offers better tolerability and higher health-related quality-of-life (HR-QOL) scores for sexual interest and physical capacity compared with surgical or medical castration, while achieving disease-free and overall survival durations that were not significantly different. Thus, when treatment options are being evaluated, bicalutamide as adjuvant therapy or monotherapy should be considered as an alternative to other available hormonal therapies in men with locally advanced prostate cancer, especially in those who wish to maintain an active lifestyle.

Bicalutamide (‘Casodex’) 150 mg in addition to standard care in patients with nonmetastatic prostate cancer: updated results from a randomised double-blind phase III study (median follow-up 5.1 y) in the early prostate cancer programme

Trial 24 is one of three placebo-controlled trials within the ongoing bicalutamide ('Casodex') Early Prostate Cancer (EPC) programme evaluating bicalutamide 150 mg/day in addition to radical prostatectomy, radiotherapy or watchful waiting for T1b-4, any N, M0 prostate cancer. In Trial 24, at 5.1 y median follow-up, the addition of bicalutamide significantly (P < 0.0001) improved objective progression-free survival (PFS) and prostate-specific antigen PFS compared with standard care alone. There was no significant difference in overall survival (P = 0.746). In the context of the whole EPC programme, long-term bicalutamide is not appropriate for localised disease, yet provides advantages in delaying disease progression in patients with locally advanced prostate cancer.