The cost-effectiveness of routine esophageal cancer screening by endoscope for oral cancer patients in Taiwan: a Markov decision analysis approach

Background: The incidence of oral cancer in Taiwan has increased in the past decade. Oral cancer is the 4th leading cause of cancer deaths for males. The median age of death is 55-years of age, at least 10 years younger than those with lung cancer. Treatment and prognosis of oral cancer remain favorable. Patients with stages one through to four have a 5-year survival rate of 75%, 65.5% , 49% and 30% respectively. Although the results of treatment have improved, however, since most of the patients were exposed to the carcinogens such as alcohol, smoking and betel quid, they have a higher incidence of developing secondary cancers. According to the Taiwan Cancer Registry, the most common one being cancer of the esophagus. Between 10- 20 % of patients with oral cancer develop squamous cell carcinoma of the esophagus synchronously or metachronously. Since esophagogastroduodenoscopic (EGD) screening for esophageal cancer is not routinely performed for the follow-up of patients with oral cancer, the diagnosis is usually made only after the symptom of dysphagia occurred. This results in the late diagnosis and consequent poorer prognosis for these patients.
Purpose: The objective of the study is to evaluate the effect and cost-effectiveness of including endoscopic screening of esophageal cancer for patients who received curative treatment for their oral cancer. The authors shall assess whether early detection of esophageal cancer lowers its mortality, and thus improves overall survival rate of oral cancer.
Methods: We developed a Markov decision model, in which Markov cohort simulation was used to assess the economic value of this intervention. In this model, 1000 patients with oral cancer aged 50 years of age were enrolled. All patients completed curative treatment and were at the state of remission. In the control group, all patients received postoperative surveillance every 6 months, according to national guidelines, until 60 years of age, or until they die. Esophagogastroduodenoscopy was arranged only when symptoms occur. In the experimental group, 2 different interventional strategies were used. This included screening by EGD (magnified narrow-band imaging endoscope) for esophageal cancer. In group A, EGD was performed every 6 months, and in group B, EGD was performed every year. The primary outcome was the survival difference, difference of quality-adjusted life year (QALY) gained, and incremental cost-effectiveness ratio (ICER). The threshold used to determine the cost-effectiveness was $20336 per QALY. One way sensitivity analysis is done for the important parameters.
Results: The number of survivors after 10 years of follow-up was 515 in the control group, and 534 in both experimental groups A (screening every 6 months) and B (screening every year). The number of esophageal cancer related deaths was highest (44) in the control group, 19 in group A, and 20 in group B. respectively. The esophageal cancer related death decreased more than 50% in both EGD screening groups. The mean cost was ($18447, $18885, $18770) respectively. The ICER is $6620 per QALY for the group B, and $4955 per QALY for the group C. Both follow-up strategies were dominant as compared to current strategy.
Conclusions: Routine esophagogastroduodenoscopy screening of esophageal cancer in addition to the current postoperative surveillance among patients with oral cancer seem to improve overall survival and is cost-effective.