Endoscopic Surveillance for Esophageal Adenocarcinomas
Endoscopic Surveillance for Esophageal Adenocarcinomas
Background & Aims Although patients with Barrett's esophagus commonly undergo endoscopic surveillance, its effectiveness in reducing mortality from esophageal/gastroesophageal junction adenocarcinomas has not been evaluated rigorously.
Methods We performed a case-control study in a community-based setting. Among 8272 members with Barrett's esophagus, we identified 351 esophageal adenocarcinoma: 70 in persons who had a prior diagnosis of Barrett's esophagus (who were eligible for surveillance); 51 of these patients died, 38 as a result of the cancers (cases). Surveillance histories were contrasted with a sample of 101 living persons with Barrett's esophagus (controls), matched for age, sex, and duration of follow-up evaluation.
Results Surveillance within 3 years was not associated with a decreased risk of death from esophageal adenocarcinoma (adjusted odds ratio, 0.99; 95% confidence interval, 0.36–2.75). Fatal cases were nearly as likely to have received surveillance (55.3%) as were controls (60.4%). A Barrett's esophagus length longer than 3 cm and prior dysplasia each were associated with subsequent mortality, but adjustment for these did not change the main findings. Although all patients should be included in evaluations of effectiveness, excluding deaths related to cancer treatment and patients who failed to complete treatment, changed the magnitude, but not the significance, of the association (odds ratio, 0.46; 95% confidence interval, 0.13–1.64).
Conclusions Endoscopic surveillance of patients with Barrett's esophagus was not associated with a substantially decreased risk of death from esophageal adenocarcinoma. The results do not exclude a small to moderate benefit. However, if such a benefit exists, our findings indicate that it is substantially smaller than currently estimated. The effectiveness of surveillance was influenced partially by the acceptability of existing treatments and the occurrence of treatment-associated mortality.
Endoscopic surveillance of persons with Barrett's esophagus is considered a relatively safe and sensitive method for the early detection of treatable esophageal adenocarcinomas and for the detection of precancerous low- and high-grade dysplasia that may warrant closer surveillance, resection, or ablation. Although surveillance is recommended by specialty society guidelines, a national expert panel in the United States determined that no controlled studies exist to support its widespread use. In the absence of definitive data, influential cost-effectiveness analyses assume that almost all cancers detected during surveillance are resectable for potential cure. However, a national governmental review in the United Kingdom concluded that surveillance every 3 years may do more harm than good, while noting a "major gap in the evidence is the lack of…data on the effectiveness of surveillance program[s] in reducing morbidity and mortality from adenocarcinoma."
The incidence of esophageal adenocarcinoma, which has a 5-year survival of less than 15%, has increased more than 6-fold in the past 3 decades in the United States. Barrett's esophagus is a metaplastic change from the esophagus' usual squamous epithelial lining to a specialized columnar epithelium; its presence signifies a markedly increased risk of esophageal/gastroesophageal junction adenocarcinoma. Because at least 6% of asymptomatic US adults are estimated to have Barrett's esophagus, surveillance recommendations for this condition represent a substantial public health question.
Optimally, the effectiveness of surveillance would be evaluated through a randomized trial of patients with Barrett's esophagus, which would randomize patients with known Barrett's esophagus to surveillance vs no surveillance and then follow them up until an important outcome, such as death from cancer. The study then would contrast the proportions in each arm who died of cancer, using a risk ratio; however, the practicality of such a trial in the United States is challenging given current clinical practices, specialty society guidelines recommending surveillance, and the large sample sizes needed to detect a mortality benefit. Alternatively, case-control studies efficiently can evaluate the effectiveness of cancer screening interventions. The odds ratio in a case-control study of screening/surveillance is a valid estimate of the risk ratio that might be obtained from a randomized trial. Such studies contrast screening/surveillance histories of subjects who die of cancer or its treatment with those from a sample of persons at risk for cancer death. Thus, for esophageal adenocarcinoma, a case-control study of Barrett's esophagus surveillance would contrast patients with known Barrett's esophagus who subsequently die of esophageal adenocarcinoma to a sample of similar Barrett's esophagus patients who do not die of esophageal adenocarcinoma. This control group may contain some patients with nonfatal cancers. If surveillance were effective, we would expect that patients dying of cancer would be less likely to have received surveillance examinations than the average population of Barrett's esophagus patients.
This case-control study evaluated whether endoscopic surveillance of Barrett's esophagus is associated with a lower risk of death from esophageal/gastroesophageal junction adenocarcinoma. The methods were similar to those of a case-control study of screening sigmoidoscopy and death from colorectal cancer within Kaiser Permanente; the protective association shown in that study was confirmed recently by randomized trials. Its conduct in a community-based population provides an approximation of surveillance effectiveness as currently practiced in a general population.
Abstract and Introduction
Abstract
Background & Aims Although patients with Barrett's esophagus commonly undergo endoscopic surveillance, its effectiveness in reducing mortality from esophageal/gastroesophageal junction adenocarcinomas has not been evaluated rigorously.
Methods We performed a case-control study in a community-based setting. Among 8272 members with Barrett's esophagus, we identified 351 esophageal adenocarcinoma: 70 in persons who had a prior diagnosis of Barrett's esophagus (who were eligible for surveillance); 51 of these patients died, 38 as a result of the cancers (cases). Surveillance histories were contrasted with a sample of 101 living persons with Barrett's esophagus (controls), matched for age, sex, and duration of follow-up evaluation.
Results Surveillance within 3 years was not associated with a decreased risk of death from esophageal adenocarcinoma (adjusted odds ratio, 0.99; 95% confidence interval, 0.36–2.75). Fatal cases were nearly as likely to have received surveillance (55.3%) as were controls (60.4%). A Barrett's esophagus length longer than 3 cm and prior dysplasia each were associated with subsequent mortality, but adjustment for these did not change the main findings. Although all patients should be included in evaluations of effectiveness, excluding deaths related to cancer treatment and patients who failed to complete treatment, changed the magnitude, but not the significance, of the association (odds ratio, 0.46; 95% confidence interval, 0.13–1.64).
Conclusions Endoscopic surveillance of patients with Barrett's esophagus was not associated with a substantially decreased risk of death from esophageal adenocarcinoma. The results do not exclude a small to moderate benefit. However, if such a benefit exists, our findings indicate that it is substantially smaller than currently estimated. The effectiveness of surveillance was influenced partially by the acceptability of existing treatments and the occurrence of treatment-associated mortality.
Introduction
Endoscopic surveillance of persons with Barrett's esophagus is considered a relatively safe and sensitive method for the early detection of treatable esophageal adenocarcinomas and for the detection of precancerous low- and high-grade dysplasia that may warrant closer surveillance, resection, or ablation. Although surveillance is recommended by specialty society guidelines, a national expert panel in the United States determined that no controlled studies exist to support its widespread use. In the absence of definitive data, influential cost-effectiveness analyses assume that almost all cancers detected during surveillance are resectable for potential cure. However, a national governmental review in the United Kingdom concluded that surveillance every 3 years may do more harm than good, while noting a "major gap in the evidence is the lack of…data on the effectiveness of surveillance program[s] in reducing morbidity and mortality from adenocarcinoma."
The incidence of esophageal adenocarcinoma, which has a 5-year survival of less than 15%, has increased more than 6-fold in the past 3 decades in the United States. Barrett's esophagus is a metaplastic change from the esophagus' usual squamous epithelial lining to a specialized columnar epithelium; its presence signifies a markedly increased risk of esophageal/gastroesophageal junction adenocarcinoma. Because at least 6% of asymptomatic US adults are estimated to have Barrett's esophagus, surveillance recommendations for this condition represent a substantial public health question.
Optimally, the effectiveness of surveillance would be evaluated through a randomized trial of patients with Barrett's esophagus, which would randomize patients with known Barrett's esophagus to surveillance vs no surveillance and then follow them up until an important outcome, such as death from cancer. The study then would contrast the proportions in each arm who died of cancer, using a risk ratio; however, the practicality of such a trial in the United States is challenging given current clinical practices, specialty society guidelines recommending surveillance, and the large sample sizes needed to detect a mortality benefit. Alternatively, case-control studies efficiently can evaluate the effectiveness of cancer screening interventions. The odds ratio in a case-control study of screening/surveillance is a valid estimate of the risk ratio that might be obtained from a randomized trial. Such studies contrast screening/surveillance histories of subjects who die of cancer or its treatment with those from a sample of persons at risk for cancer death. Thus, for esophageal adenocarcinoma, a case-control study of Barrett's esophagus surveillance would contrast patients with known Barrett's esophagus who subsequently die of esophageal adenocarcinoma to a sample of similar Barrett's esophagus patients who do not die of esophageal adenocarcinoma. This control group may contain some patients with nonfatal cancers. If surveillance were effective, we would expect that patients dying of cancer would be less likely to have received surveillance examinations than the average population of Barrett's esophagus patients.
This case-control study evaluated whether endoscopic surveillance of Barrett's esophagus is associated with a lower risk of death from esophageal/gastroesophageal junction adenocarcinoma. The methods were similar to those of a case-control study of screening sigmoidoscopy and death from colorectal cancer within Kaiser Permanente; the protective association shown in that study was confirmed recently by randomized trials. Its conduct in a community-based population provides an approximation of surveillance effectiveness as currently practiced in a general population.
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