(Build Pharmacoeconomics Evaluation Model Of Gastric Cancer Fitted China Based On Markov Model)

Objectives1.From the perspective of the Chinese health-care system,a cost-effectiveness analysis of adjuvant chemotherapy with capecitabine and oxaliplatin (XELOX) after a gastrectomy with extended (D2) lymph-node dissection for patients with stage Ⅱ-ⅢB gastric cancer was performed on the basis of CLASSIC trial.The aims of this study were to provide objective basis for Chinese patients with gastric cancer selecting adjuvant chemotherapy with XELOX, to provide data analysis for Chinese health policy makers,and to provide methodology reference for building pharmacoeconomics evaluation model of two remedies in gastric cancer-like illness.2.One aim of the present study was to establish a method of evaluating the cost-effectiveness for more than two remedies in gastric cancer-like illness of China, through comparing the cost-effectiveness of adjuvant chemotherapy with XELOX, with S-1and no treatment after a D2gastrectomy among patients with stage Ⅱ-ⅢB gastric cancer.3.The methods of evaluating cost-effectiveness for more than two and two remedies in Chinese gastric cancer had been established. We analyzed the feasibility of performing pharmacoeconomics evaluation for strategies in Chinese NCCN Clinical Practice Guidelines in Oncology: Gastric Cancer.Methods1.Based on data from the CLASSIC trial,a Markov model was created to determine economic and clinical data for patients in the chemotherapy and surgery group (CSG) and the surgery-only group (SOG).The costs, presented in2010US dollars and estimated from the perspective of Chinese healthcare system, were obtained from the published literatures and the local health system.The utilities were based on published literature.Costs,life-years gained (LYG),quality-adjusted life-years (QALYs),and incremental cost-effectiveness ratios (ICER) were estimated. A lifetime horizon and a3%annual discount rate were used. One-way and probabilistic sensitivity analyses were performed.2.A Markov model,based on data from two clinical phase III trials, was developed to analyse the cost-effectiveness of patients in the XELOX group, S-1group and surgery only (SO) group.The costs were estimated from the perspective of Chinese healthcare system. The utilities were assumed on the basis of previously published reports.Costs,QALYs and ICER were calculated with a lifetime horizon.One-way and probabilistic sensitivity analyses were performed.3.According to the results acquired from above, to perform an analysis on evidences of remedies recommended by Chinese NCCN Clinical Practice Guidelines in Oncology:Gastric Cancer taking phase3trials and K-M survival curves as a standard.Results1.For the base case, the CSG compared with SOG would increase LYs and QALYs in a3-,5-,10-or30-year time horizon (except the QALYs in3or5years).In the short run (such as in3or5years), the medical costs would increase owing to adjuvant chemotherapy of capecitabine plus oxaliplatin after D2gastrectomy, but in the long run the costs would decline.The ICERs suggested that the SOG was dominant in3or5years and the CSG was dominant in10or30years.The one-way sensitivity analysis showed that the utility of disease-free survival for1-10years for the SOG and the cost of oxaliplatin were the most influential parameters.The probabilistic sensitivity analysis predicted a98.6%likelihood that the ICER for the CSG would be less than US$13,527/QALY (three times the per capita gross domestic product in China).2.For the base case, XELOX had the lowest total cost ($44,568) and cost-effectiveness ratio($7,360/QALY).The relative scenario analyses showed that SO was dominated by XELOX and the ICERs of S-1was$58,843/QALY compared with XELOX.The one-way sensitivity analysis showed that the most influential parameter was the utility of disease-free survival.The probabilistic sensitivity analysis predicted a75.8% likelihood that the ICER for XELOX would be less than$13,527compared with S-1.When ICER was more than$38,000,the likelihood of cost-effectiveness achieved by S-1group was greater than50%.3.In Chinese NCCN Clinical Practice Guidelines in Oncology: Gastric Cancer,11strategies including preoperative treatments (cisplatin+fluoropyrimidine, oxaliplatin+fluoropyrimidine),postoperative treatments (5-FU+LV, LV+5-FU after5-FU, LV+5FU after capecitabine), and treatments for definitive chemotherapy for metastatic or locally advanced cancer (Trastuzumab with chemotherapy, DCF, ECF, cisplatin+fluoropyrimidine,5-FU+irinotecan, capecitabine or tegafur) can be performed pharmacoeconomics evaluation using Markov model.Conclusions1.For patients in China with resectable disease, our results suggest that adjuvant chemotherapy with capecitabine plus oxaliplatin after a D2gastrectomy is cost-saving and dominant in the long run based on a current clinical trial,compared with treatment with a D2gastrectomy alone.Improving the quality of life with chemotherapy after a D2gastrectomy and decreasing the price of oxaliplatin are potential ways to meet the treatment demands of Chinese patients.Markov model can be used in the pharmacoeconomics evaluation of two remedies for Chinese gastric cancer patients.Cost and utilities can be obtained from the published literatures and the local health system.The transition probabilities can be estimated from K-M curves and WHO life table.2.Our results suggest that for patients in China with resectable disease, first-line adjuvant chemotherapy with XELOX after a D2gastrectomy is a best option comparing with S-1and SO in view of our current study. In addition, S-1might be a better choice, especially with a higher value of willingness-to-pay threshold.Markov model can be used in the pharmacoeconomics evaluation of more than two remedies for Chinese gastric cancer patients.Cost and utilities can be obtained from the published literatures and the local health system.The estimation of transition probabilities is the critical question in whole evaluation.3.In Chinese NCCN Clinical Practice Guidelines in Oncology: Gastric Cancer, the strategies who have category1or phase3randomized controlled trials can be, while who have category3can’t be performed pharmacoeconomics evaluation using Markov model.