Cost-effectiveness of adjuvant chemotherapy with uracil-tegafur for curatively resected stage III rectal cancer.Br J Cancer. 2008;99:1232-1238. [PMID: 18797469 DOI: 10.1038/sj.bjc.6604666]

A Systematic Review of Methods to Incorporate External Evidence into Trial-Based Survival Extrapolations for Health Technology Assessment

BACKGROUND

External evidence is commonly used to inform survival modeling for health technology assessment (HTA). While there are a range of methodological approaches that have been proposed, it is unclear which methods could be used and how they compare.

PURPOSE

This review aims to identify, describe, and categorize established methods to incorporate external evidence into survival extrapolation for HTA.

DATA SOURCES

Embase, MEDLINE, EconLit, and Web of Science databases were searched to identify published methodological studies, supplemented by hand searching and citation tracking.

STUDY SELECTION

Eligible studies were required to present a novel extrapolation approach incorporating external evidence (i.e., data or information) within survival model estimation.

DATA EXTRACTION

Studies were classified according to how the external evidence was integrated as a part of model fitting. Information was extracted concerning the model-fitting process, key requirements, assumptions, software, application contexts, and presentation of comparisons with, or validation against, other methods.

DATA SYNTHESIS

Across 18 methods identified from 22 studies, themes included use of informative prior(s) (n = 5), piecewise (n = 7), and general population adjustment (n = 9), plus a variety of "other" (n = 8) approaches. Most methods were applied in cancer populations (n = 13). No studies compared or validated their method against another method that also incorporated external evidence.

LIMITATIONS

As only studies with a specific methodological objective were included, methods proposed as part of another study type (e.g., an economic evaluation) were excluded from this review.

CONCLUSIONS

Several methods were identified in this review, with common themes based on typical data sources and analytical approaches. Of note, no evidence was found comparing the identified methods to one another, and so an assessment of different methods would be a useful area for further research.HighlightsThis review aims to identify methods that have been used to incorporate external evidence into survival extrapolations, focusing on those that may be used to inform health technology assessment.We found a range of different approaches, including piecewise methods, Bayesian methods using informative priors, and general population adjustment methods, as well as a variety of "other" approaches.No studies attempted to compare the performance of alternative methods for incorporating external evidence with respect to the accuracy of survival predictions. Further research investigating this would be valuable.

Evaluating the benefit of adjuvant chemotherapy in patients with ypT0–1 rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND

Adjuvant chemotherapy (ACTx) is recommended in rectal cancer patients after preoperative chemoradiotherapy (PCRT), but its efficacy in patients in the early post-surgical stage who have a favorable prognosis is controversial.

AIM

To evaluate the long-term survival benefit of ACTx in patients with ypT0–1 rectal cancer after PCRT and surgical resection.

METHODS

We identified rectal cancer patients who underwent PCRT followed by surgical resection at the Asan Medical Center from 2005 to 2014. Patients with ypT0–1 disease and those who received ACTx were included. The 5-year overall survival (OS) and 5-year recurrence-free survival (RFS) were analyzed according to the status of the ACTx.

RESULTS

Of 520 included patients, 413 received ACTx (ACTx group) and 107 did not (no ACTx group). No significant difference was observed in 5-year RFS (ACTx group, 87.9% vs no ACTx group, 91.4%, P = 0.457) and 5-year OS (ACTx group, 90.5% vs no ACTx group, 86.2%, P = 0.304) between the groups. cT stage was associated with RFS and OS in multivariate analysis [hazard ratio (HR): 2.57, 95% confidence interval (CI): 1.07–6.16, P = 0.04 and HR: 2.27, 95%CI: 1.09–4.74, P = 0.03, respectively]. Furthermore, ypN stage was associated with RFS and OS (HR: 4.74, 95%CI: 2.39–9.42, P < 0.00 and HR: 4.33, 95%CI: 2.20–8.53, P < 0.00, respectively), but only in the radical resection group.

CONCLUSION

Oncological outcomes of patients with ypT0–1 rectal cancer who received ACTx after PCRT showed no improvement, regardless of the radicality of resection. Further trials are needed to evaluate the efficacy of ACTx in these group of patients.

Comparison of Parametric Survival Extrapolation Approaches Incorporating General Population Mortality for Adequate Health Technology Assessment of New Oncology Drugs

OBJECTIVES

Survival extrapolation of trial outcomes is required for health economic evaluation. Generally, all-cause mortality (ACM) is modeled using standard parametric distributions, often without distinguishing disease-specific/excess mortality and general population background mortality (GPM). Recent National Institute for Health and Care Excellence guidance (Technical Support Document 21) recommends adding GPM hazards to disease-specific/excess mortality hazards in the log-likelihood function ("internal additive hazards"). This article compares alternative extrapolation approaches with and without GPM adjustment.

METHODS

Survival extrapolations using the internal additive hazards approach (1) are compared to no GPM adjustment (2), applying GPM hazards once ACM hazards drop below GPM hazards (3), adding GPM hazards to ACM hazards (4), and proportional hazards for ACM versus GPM hazards (5). The fit, face validity, mean predicted life-years, and corresponding uncertainty measures are assessed for the active versus control arms of immature and mature (30- and 75-month follow-up) multiple myeloma data and mature (64-month follow-up) breast cancer data.

RESULTS

The 5 approaches yielded considerably different outcomes. Incremental mean predicted life-years vary most in the immature multiple myeloma data set. The lognormal distribution (best statistical fit for approaches 1-4) produces survival increments of 3.5 (95% credible interval: 1.4-5.3), 8.5 (3.1-13.0), 3.5 (1.3-5.4), 2.9 (1.1-4.5), and 1.6 (0.4-2.8) years for approaches 1 to 5, respectively. Approach 1 had the highest face validity for all data sets. Uncertainty over parametric distributions was comparable for GPM-adjusted approaches 1, 3, and 4, and much larger for approach 2.

CONCLUSION

This study highlights the importance of GPM adjustment, and particularly of incorporating GPM hazards in the log-likelihood function of standard parametric distributions.

Adjuvant Chemotherapy Does Not Improve Recurrence-Free Survival in Patients With Stage 2 or Stage 3 Rectal Cancer After Neoadjuvant Chemoradiotherapy and Total Mesorectal Excision

BACKGROUND

Current guidelines for locally advanced stage 2/3 rectal cancer recommend neoadjuvant chemoradiotherapy followed by total mesorectal excision and adjuvant chemotherapy. The oncologic benefit of adjuvant chemotherapy has not been consistently demonstrated.

OBJECTIVE

The purpose of this study was to evaluate disease recurrence and survival in patients with rectal cancer who received adjuvant chemotherapy after chemoradiotherapy and total mesorectal excision.

DESIGN

This was a retrospective review of patients with stage 2/3 rectal cancer after chemoradiotherapy and surgery, based on receipt of adjuvant chemotherapy.

SETTINGS

The study was conducted at the Kaiser Permanente Southern California system of 14 hospitals and associated clinics.

PATIENTS

A total of 862 patients with stage 2/3 rectal cancer diagnosed and treated between January 1, 2005, and December 31, 2016, were included in this study.

INTERVENTIONS

The study involved neoadjuvant chemoradiotherapy followed by total mesorectal excision with or without adjuvant chemotherapy.

MAIN OUTCOME MEASURES

The primary end point was recurrence-free survival.

RESULTS

A total of 348 stage 2 and 514 stage 3 patients were included; 660 patients (76.6%) underwent adjuvant chemotherapy. Mean patient follow-up after surgery was 63.0 months (range, 3-160). Multivariable analysis showed that yp stage (HR for yp stage 2 = 4.74; yp stage 3 = 8.83) and en bloc resection (HR = 1.76) were the only variables that significantly predicted disease recurrence. Neither pretreatment tumor stage nor receipt of adjuvant chemotherapy was significantly associated with recurrence-free survival. Log-rank testing failed to demonstrate significant recurrence-free survival improvement after receipt of adjuvant chemotherapy in any patient subgroup.

LIMITATIONS

The study was limited by selection bias attributed to the nature of a retrospective study without patient randomization or predefined treatment protocol.

CONCLUSIONS

In stage 2/3 rectal cancer treated with chemoradiotherapy and surgery, the addition of adjuvant chemotherapy was not associated with decreased recurrence-free survival in the entire cohort or in any subgroup, whereas tumor response to chemoradiotherapy is closely associated with disease recurrence. These findings have important consequences for treatment and surveillance decisions for patients with rectal cancer. Presurgical efforts that maximize tumor downstaging, such as total neoadjuvant therapy, may produce better oncologic outcomes than traditional adjuvant chemotherapy. See Video Abstract at http://links.lww.com/DCR/B134. LA QUIMIOTERAPIA ADYUVANTE NO MEJORA LA SOBREVIDA LIBRE DE RECURRENCIA EN PACIENTES CON CÁNCER DE RECTO ESTADÍOS II O III DESPUÉS DE RADIO-QUIMIOTERAPIA NEOADYUVANTE Y ESCISIÓN TOTAL DEL MESORRECTO: Las guías actuales para el tratamiento de cáncer rectal en estadio II-III localmente avanzado, recomiendan la radio-quimioterapia neoadyuvante con escisión total del mesorrecto seguidas de quimioterapia adyuvante. El beneficio oncológico de la quimioterapia adyuvante no ha sido demostrado de manera fehaciente.Evaluar la recurrencia y sobrevida a la enfermedad en pacientes con cáncer rectal que recibieron quimioterapia adyuvante después de radio-quimioterapia y escisión total del mesorrecto.Revisión retrospectiva de pacientes con cáncer rectal en estadios II-III después de radio-quimioterapia y cirugía, basada en la recepción de quimioterapia adyuvante.Sistema Permanente de Kaiser Sur-Californiano de 14 hospitales y clínicas asociadas.862 pacientes con cáncer rectal en estadio II-III diagnosticados y tratados entre el 1 de Enero 2005 y el 31 de Diciembre 2016.Radio-quimioterapia neoadyuvante seguida de escisión total del mesorrecto +/- quimioterapia adyuvante.El objetivo primario fue la sobrevida libre de recurrencia.Fueron incluidos 348 pacientes en estadio II y 514 en estadio III. 660 pacientes (76,6%) se sometieron a quimioterapia adyuvante. El seguimiento medio de cada paciente después de la cirugía fué de 63.0 meses (rango, 3-160). El análisis multivariable mostró que la etapa yp (Cociente de riesgo para estadío yp II = 4.74 y estadío yp III = 8.83) y la resección en bloque (Cociente de riesgo = 1.76) fueron las únicas variables que predijeron significativamente la recurrencia de la enfermedad. Ni el estadío tumoral previo al tratamiento ni la recepción de quimioterapia adyuvante se asociaron significativamente con la sobrevida libre de recurrencia. Las pruebas de rango logarítmico no pudieron demostrar una mejoría significativa de la sobrevida libre de recurrencia después de recibir quimioterapia adyuvante en cualquier subgrupo de pacientes.Sesgo de selección, debido al estudio retrospectivo sin aleatorización de los pacientes o protocolo de tratamiento predefinido.En casos de cáncer de recto estadíos II-III tratados con radio-quimioterapia y cirugía, la adición de quimioterapia adyuvante no se asoció con una disminución de la sobrevida libre de recurrencia en toda la cohorte o en ningún subgrupo, mientras que la respuesta tumoral a la radio-quimioterapia está estrechamente asociada con la recurrencia de la enfermedad. Estos hallazgos tienen consecuencias importantes en la decisión del tratamiento y la vigilancia en pacientes con cáncer de recto. Los esfuerzos pre-quirúrgicos que maximizan la reducción del tamaño del tumor, como la terapia neoadyuvante total, pueden producir mejores resultados oncológicos que la quimioterapia adyuvante tradicional. Consulte Video Resumen en http://links.lww.com/DCR/B134.

Pharmacoeconomics Evaluations of Oral Anticancer Agents: Systematic Review of Characteristics, Methodological Trends, and Reporting Quality

OBJECTIVES

To review literature characteristics, describe methodological trends, and assess the reporting quality of the economic evaluations of oral anticancer drugs (OACDs).

METHODS

The review included comparative economic evaluations of OACDs. The search was conducted via PubMed, Embase, EconLit, and Economic Evaluation Database, and studies till December 2017 were included. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist, literature inclusion and data extraction were performed in duplicate by separate investigators. Outcome measures were literature characteristics, gaps and methodological trends, and reporting quality using the Consolidated Health Economic Evaluation Reporting Standards checklist. Data were summarized on the basis of methodological themes of interest. Descriptive statistics and tabulations were used for result presentation.

RESULTS

Out of 241 found articles, 21 were included. There is a recent increasing interest in the economics of OACDs, whereby the cost per quality-adjusted life-year, via cost-utility analysis, is the most used for decision making. Most of the studies were from the payer perspective, and the primary sources of data were clinical trials, expert panels, and medical charts. The dominance status (higher effect, lower cost) was a commonly reported outcome. Decision-analytic modeling was used in most of the studies, mostly including Markov modeling. Studies were highly heterogeneous in methodological aspects, and the included studies did not meet most of the reporting quality criteria.

CONCLUSIONS

High heterogeneity in methods in studies may limit the robustness and transferability of results, potentially misleading decision makers toward wrong decisions on OACDs. The transferability and generalizability of results are further limited by a "less than ideal" adherence to current reporting standards.

Cost-minimization analysis of adjuvant chemotherapy regimens given to patients with colorectal cancer in Japan

Background

Consideration of medical costs as well as effectiveness and adverse events is rapidly been becoming an important factor in the selection of chemotherapy regimens. However, practical data on the costs of chemotherapy are scarce. We clinically estimated the medical costs of 6 adjuvant chemotherapy regimens for colorectal cancer on the basis of clinical and cost-related data and compared their cost-effectiveness by cost-minimization analyses.

Methods

All patients who received adjuvant chemotherapy for colorectal cancer between April 2012 and May 2015 at four hospitals affiliated with Showa University were studied retrospectively. Clinical and cost data related to adjuvant chemotherapy were collected from medical records and medical fee receipt data, respectively. Six adjuvant chemotherapy regimens were studied: capecitabine and oxaliplatin (CapeOX); 5-fluorouracil (5-FU), ℓ-leucovorin (LV), and oxaliplatin (modified FOLFOX6 [mFOLFOX6]); 5-FU and LV (5-FU/LV); tegafur and uracil (UFT), and LV (UFT/LV); capecitabine; and tegafur, gimeracil and oteracil (S-1). The regimens were divided into 2 groups according to whether or not they contained oxaliplatin because of the difference in effectiveness. Cost-minimization analyses, where relative costs of regimens showing equivalent effectiveness were simply compared, were performed to evaluate the cost-effectiveness of the regimens in each group.

Results

A total of 154 patients with colorectal cancer received adjuvant chemotherapy during the study period. Fifty-seven patients were treated with CapeOX, 10 with mFOLFOX6, 38 with UFT/LV, 20 with capecitabine, and 29 with S-1. No patient received 5-FU/LV. The total costs of oxaliplatin-containing regimens were significantly higher than those of oxaliplatin non-containing regimens. The high cost of oxaliplatin, but not the costs of drugs or various tests for the treatment of adverse events, was the primary reason for the higher costs of the oxaliplatin-containing regimens. The cost-effectiveness of the oxaliplatin-containing regimens CapeOX and mFOLFOX6 were comparable. Among the oxaliplatin non-containing regimens, the cost-effectiveness of S-1 and capecitabine was superior to that of UFT/LV.

Conclusion

Thus, we provided the cost-effectiveness data of 5 adjuvant chemotherapy regimens for colorectal cancer based on practical clinical and cost data from Japanese patients. The results can be included as a factor in regimen selection because these results would represent the real world.

Trial registration

This study is a retrospective observational study and does not include any health care interventions. Therefore, we did not register the protocol of this study.

Extrapolating Survival from Randomized Trials Using External Data: A Review of Methods

This article describes methods used to estimate parameters governing long-term survival, or times to other events, for health economic models. Specifically, the focus is on methods that combine shorter-term individual-level survival data from randomized trials with longer-term external data, thus using the longer-term data to aid extrapolation of the short-term data. This requires assumptions about how trends in survival for each treatment arm will continue after the follow-up period of the trial. Furthermore, using external data requires assumptions about how survival differs between the populations represented by the trial and external data. Study reports from a national health technology assessment program in the United Kingdom were searched, and the findings were combined with “pearl-growing” searches of the academic literature. We categorized the methods that have been used according to the assumptions they made about how the hazards of death vary between the external and internal data and through time, and we discuss the appropriateness of the assumptions in different circumstances. Modeling choices, parameter estimation, and characterization of uncertainty are discussed, and some suggestions for future research priorities in this area are given.

Economic studies in colorectal cancer: challenges in measuring and comparing costs

Estimates of the costs associated with cancer care are essential both for assessing burden of disease at the population level and for conducting economic evaluations of interventions to prevent, detect, or treat cancer. Comparisons of cancer costs between health systems and across countries can improve understanding of the economic consequences of different health-care policies and programs. We conducted a structured review of the published literature on colorectal cancer (CRC) costs, including direct medical, direct nonmedical (ie, patient and caregiver time, travel), and productivity losses. We used MEDLINE to identify English language articles published between 2000 and 2010 and found 55 studies. The majority were conducted in the United States (52.7%), followed by France (12.7%), Canada (10.9%), the United Kingdom (9.1%), and other countries (9.1%). Almost 90% of studies estimated direct medical costs, but few studies estimated patient or caregiver time costs or productivity losses associated with CRC. Within a country, we found significant heterogeneity across the studies in populations examined, health-care delivery settings, methods for identifying incident and prevalent patients, types of medical services included, and analyses. Consequently, findings from studies with seemingly the same objective (eg, costs of chemotherapy in year following CRC diagnosis) are difficult to compare. Across countries, aggregate and patient-level estimates vary in so many respects that they are almost impossible to compare. Our findings suggest that valid cost comparisons should be based on studies with explicit standardization of populations, services, measures of costs, and methods with the goal of comparability within or between health systems or countries. Expected increases in CRC prevalence and costs in the future highlight the importance of such studies for informing health-care policy and program planning.

Prognostic significance of response to preoperative radiotherapy, lymph node metastasis, and CEA level in patients undergoing total mesorectal excision of rectal cancer

PURPOSE

The aim of this study was to investigate the prognostic significance of the response of primary rectal lesions to preoperative radiotherapy, pathological nodal status, and carcinoembryonic antigen (CEA) levels before and after radiotherapy in rectal cancer patients treated with a total mesorectal excision.

METHODS

We investigated the prognostic significance of the clinical and pathological factors in 97 patients treated with preoperative radiotherapy (50-50.4 Gy over 5-6 weeks) followed by curative resections.

RESULTS

A high CEA level (>5 ng/mL) after radiotherapy (hazard ratio, 2.849; 95% confidence interval, 1.061-7.651; p = 0.0377) and pathological lymph node metastasis (hazard ratio, 0.350; 95% confidence interval, 0.154-0.797; p = 0.0124) were independently associated with postoperative recurrence. Although the CEA level before radiotherapy was associated with disease-free survival in a univariate analysis, it lost its statistical significance in a multivariate analysis. The response of the primary rectal lesions, evaluated pathologically by T stage and the degree of regression, was not associated with disease-free survival. In patients without lymph node metastasis, the 5-year disease-free survival of those with a high CEA level after radiotherapy was significantly worse than those with low CEA after radiotherapy (61.6% vs. 89.0%, respectively, p = 0.0234).

CONCLUSIONS

Pathological lymph node metastasis and a high CEA level after radiotherapy were independent predictors of a poor outcome in rectal cancer patients treated with preoperative radiotherapy. The CEA level after radiotherapy was capable of discriminating patients with a high risk of recurrence among pathologically node-negative patients.

Protective effects of water-soluble low-molecular-weight β-(1,3-1,6)D-glucan purified from Aureobasidium pullulans GM-NH-1A1 against UFT toxicity in mice

Objectives

5-Fluorouracil and its derivatives are widely used in the treatment of a variety of tumours. However, their use is associated with gastrointestinal toxicity, myelotoxicity and immune toxicity. In this study, we examined the protective effects of low-molecular-weight β-glucan isolated from Aureobasidium pullulans GM-NH-1A1 against toxicity of UFT (combination of tegafur (1-(2-tetrahydrofuryl)-5-fluorouracil) and uracil) in mice bearing colon 26 tumours.

Methods

UFT was administered orally at 50 mg/kg once daily for 14 days alone or with orally administered low-molecular-weight β-glucan, 25, 50 and 100 mg/kg twice daily.

Key findings

Tumour growth was inhibited equally in all treatment groups. Onset of diarrhoea, which started on day 9 of UFT administration, was delayed by concomitant administration of the β-glucan (50 and 100 mg/kg twice daily). Histological analysis showed that damage to small-intestine villi by UFT was inhibited by the orally administered β-glucan.

Conclusions

Oral administration of low-molecular-weight β-glucan prevents gastrointestinal mucositis associated with UFT therapy without interfering with its anti-tumour activity.