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Screening for Barrett's esophagus may not reduce morbidity and mortality due to esophageal adenocarcinoma
E TIOLOGY
Screening for Barrett’s esophagus may not reduce morbidity and mortality due to esophageal adenocarcinoma Abstracted from: Dulai G, Guha S, Kahn K, Gornbein J, Weinstein W. Preoperative prevalence of Barrett’s esophagus in esophageal adenocarcinoma: a systematic review.Gastroenterology 2002: 122; 26^33.
BACKGROUND The impact of screening and surveillance on Barrett’s-related cancers has not been quanti¢ed. OBJECTIVE To examine the prevalence of Barrett’s esophagus prior to incident adenocarcinoma undergoing resection. METHOD
Systematic review.
SEARCH STRATEGY MEDLINE and HealthSTAR were searched for English language studies published between 1966 and 2000. Observational studies of cohorts undergoing resection for high-grade dysplasia or adenocarcinoma of the gastric cardia, esophagus or gastroesophageal junction were eligible. INCLUSION/EXCLUSION/CRITERIA Seven hundred and ¢fty-two articles were identi¢ed. Studies were eligible if they reported the number of consecutive adenocarcinoma resected and the number of people with a diagnosis of Barrett’s esophagus prior to diagnosis of adenocarcinoma. Twelve studies with 1503 participants were included. OUTCOMES Prior diagnosis of Barrett’s esophagus.
144
Evidence-based Oncology (2002) 3,144 ^145 doi:10.1054/ebon.2002.0046, available online at http://www.idealibrary.com.on
ANALYSIS Two investigators screened papers and abstracted data. Pooled summary estimates of prior prevalence were calculated using ¢xed and random e¡ects models.
MAIN RESULTS About 5% of people undergoing resection for esophageal adenocarcinoma had a prior diagnosis of Barrett’s esophagus (4.772.9%).
AUTHORS’ CONCLUSIONS The prior prevalence of Barrett’s esophagus is low in people undergoing resection for esophageal adenocarcinoma. This suggests that current screening and surveillance for Barrett’s esophagus may have little impact on esophageal adenocarcinoma outcomes. Sources of funding: American Digestive Health Foundation;Veterans Administration Ambulatory Care Fellowship; STAR fellowship program at UCLA. Correspondence to: Gareth Dulai, Greater Los-Angeles Veterans Administration Healthcare System, CURE Digestive Diseases Research Centre, Building115, Room 318,11301Wilshire Boulevard, Los Angeles, CA 90073, USA
1363- 4054/02/$ - see front matter & 2002 Elsevier Science Ltd. All rights reserved
Commentary Barrett’s esophagus develops in 5% to 20% of people with chronic gastroesophageal reflux disease. It predisposes people to esophageal adenocarcinoma.1,2 Barrett’s esophagus is defined as intestinal metaplasia in which columnar epithelium with goblet cells replace the native squamous epithelium of the esophagus. Similar to colon cancer, esophageal cancer arising from Barrett’s esophagus follows a metaplasia^ dysplasia^adenocarcinoma sequence.3 Recent data suggest a rapid increase in the incidence of esophageal adenocarcinoma in North America and Western Europe. Incidence has risen almost 350 -fold since 1970.4 At diagnosis, up to 50% of people may have advanced regional or distant metastasis with little chance for cure.4 The overall 5-year survival rate is less than10%.4 The aim of endoscopic surveillance in Barrett’s esophagus is to diagnose esophageal cancer early, when it is potentially curable.2 As most people with Barrett’s esophagus do not develop adenocarcinoma of the esophagus (cancer incidence 0.3% to 0.5% per year),5 the cost-effectiveness of endoscopic surveillance is questionable. Ideally, surveillance algorithms should be based on risk stratification. There is little data to help clinicians identify which people with Barrett’s esophagus are at highest risk for the development of dysplasia and cancer. Current guidelines recommend that everyone with Barrett’s esophagus undergo surveillance at regular intervals, with the expectation that there will be a decrease in mortality from adenocarcinoma.6,7 No randomized trials have found a survival benefit in people undergoing endoscopic surveillance, however.We are not certain whether or not screening improves survival. Another challenge is that the prevalence of Barrett’s esophagus within the general population is unknown. Because of this, we are unsure whether or not most patients are discovered and enrolled into a surveillance program.This study by Dulai and colleagues focuses on this important question: the pre-operative prevalence of Barrett’s esophagus in reported cases of incident adenocarcinoma undergoing surgical resection. Ninety-five percent of people who were eligible for resection, and thus a potential cure, were unaware of the presence of Barrett’s esophagus prior to the development of cancer. Although long standing gastroesophageal reflux disease symptoms, male gender, Caucasian race and age are risk factors in the development of Barrett’s esophagus, these results suggest that it is not adequate to rely on these factors for screening eligibility.The majority of people with Barrett’s esophagus progressing to adenocarcinoma remain undetected. Could this be because most of these people have an ‘asymptomatic’ form of Barrett’s metaplasia?2 Dulai and colleagues suggest that although the incidence of adenocarcinoma has increased over a 30 year period, our ability to detect it has not improved significantly.The authors argue that effective screening strategies to identify people with Barrett’s esophagus are needed. This study addresses an important issue facing primary-care physicians, gastroenterologists, surgeons and medical oncologists. It leads us to question the current Barrett’s esophagus surveillance paradigm as a whole. More questions arise than are answered: Would screening all people with gastroesophageal reflux disease discover those missed? As with colon cancer screening, should the general population be included in screening, and if so, would this be feasible? How do we screen asymptomatic patients? Does all Barrett’s esophagus arise from gastroesophageal
reflux disease? Does all adenocarcinoma arise from Barrett’s esophagus? Is screening and surveillance making an impact on overall survival or are we seeing effects of lead-time bias? There are positive benefits of current screening,7 but this still only detects a minority of people with Barrett’s esophagus at risk for esophageal cancer. Prospective studies to evaluate the effectiveness of screening and surveillance are required. Quality assessment (scale 1 = fair, 4 = excellent) Relevance 4 Validity 3 Applicability 4 Feasibility 2* Impact 4 Knowledge context 3 *The score of 2 awarded to feasibility reflects the study design. Until cost-effective screening strategies are developed for Barrett’s esophagus, upper endoscopy remains the only feasible option for people with chronic gastroesophageal reflux disease symptoms. The surveillance interval may or may not be costeffective. Deepak V Gopal MD, FRCP(C) Division of Gastroenterology Blair A Jobe MD Department of General Surgery Oregon Health Sciences University and Portland Veterans Affairs Medical Center Portland, USA
Literature cited 1. Spechler SJ. Complications of gastroesophageal reflux disease. In Castell DO (ed). The Esophagus, 2nd edn. Boston: Little Brown,1995: 533. 2. Cameron AJ, Ott BJ, Payne WS. The incidence of adenocarcinoma in columnar-lined (Barrett’s) esophagus. N Engl J Med 1985; 313: 857. 3. Devesa SS, Blot WS, Fraumeni JF. Changing patterns in the incidence of esophageal and gastric carcinoma in the United States. Cancer 1998; 83: 2049^2053. 4. Blot WS, McLaughlin JK. The changing epidemiology of esophageal cancer. Semin Oncol 1999; 26; 2^ 8. 5. Drewitz DJ, Sampliner RE, Garewal HS. The incidence of adenocarcinoma in Barrett’s esophagus: A prospective study of 170 patients followed 4.8 years. Am J Gastroenterol 1997; 92: 212. 6. Lieberman DA, Oehlke M, Helfand M. Risk factors for Barrett’s esophagus in community-based practice. Am J Gastroenterol 1997; 92: 1293^1297. 7. Sampliner RE. Practice guidelines on the diagnosis, surveillance, and therapy of Barrett’s esophagus. The Practice Parameters Committee of the American College of Gastroenterology. Am J Gastroenterol 1998; 93: 1028. Level and Quality of Evidence: 1b
Evidence-based Oncology (2002) 3,144 ^145
145
Screening for Barrett’s esophagus may not reduce morbidity and mortality due to esophageal adenocarcinoma Abstracted from: Dulai G, Guha S, Kahn K, Gornbein J, Weinstein W. Preoperative prevalence of Barrett’s esophagus in esophageal adenocarcinoma: a systematic review.Gastroenterology 2002: 122; 26^33.
BACKGROUND The impact of screening and surveillance on Barrett’s-related cancers has not been quanti¢ed. OBJECTIVE To examine the prevalence of Barrett’s esophagus prior to incident adenocarcinoma undergoing resection. METHOD
Systematic review.
SEARCH STRATEGY MEDLINE and HealthSTAR were searched for English language studies published between 1966 and 2000. Observational studies of cohorts undergoing resection for high-grade dysplasia or adenocarcinoma of the gastric cardia, esophagus or gastroesophageal junction were eligible. INCLUSION/EXCLUSION/CRITERIA Seven hundred and ¢fty-two articles were identi¢ed. Studies were eligible if they reported the number of consecutive adenocarcinoma resected and the number of people with a diagnosis of Barrett’s esophagus prior to diagnosis of adenocarcinoma. Twelve studies with 1503 participants were included. OUTCOMES Prior diagnosis of Barrett’s esophagus.
144
Evidence-based Oncology (2002) 3,144 ^145 doi:10.1054/ebon.2002.0046, available online at http://www.idealibrary.com.on
ANALYSIS Two investigators screened papers and abstracted data. Pooled summary estimates of prior prevalence were calculated using ¢xed and random e¡ects models.
MAIN RESULTS About 5% of people undergoing resection for esophageal adenocarcinoma had a prior diagnosis of Barrett’s esophagus (4.772.9%).
AUTHORS’ CONCLUSIONS The prior prevalence of Barrett’s esophagus is low in people undergoing resection for esophageal adenocarcinoma. This suggests that current screening and surveillance for Barrett’s esophagus may have little impact on esophageal adenocarcinoma outcomes. Sources of funding: American Digestive Health Foundation;Veterans Administration Ambulatory Care Fellowship; STAR fellowship program at UCLA. Correspondence to: Gareth Dulai, Greater Los-Angeles Veterans Administration Healthcare System, CURE Digestive Diseases Research Centre, Building115, Room 318,11301Wilshire Boulevard, Los Angeles, CA 90073, USA
1363- 4054/02/$ - see front matter & 2002 Elsevier Science Ltd. All rights reserved
Commentary Barrett’s esophagus develops in 5% to 20% of people with chronic gastroesophageal reflux disease. It predisposes people to esophageal adenocarcinoma.1,2 Barrett’s esophagus is defined as intestinal metaplasia in which columnar epithelium with goblet cells replace the native squamous epithelium of the esophagus. Similar to colon cancer, esophageal cancer arising from Barrett’s esophagus follows a metaplasia^ dysplasia^adenocarcinoma sequence.3 Recent data suggest a rapid increase in the incidence of esophageal adenocarcinoma in North America and Western Europe. Incidence has risen almost 350 -fold since 1970.4 At diagnosis, up to 50% of people may have advanced regional or distant metastasis with little chance for cure.4 The overall 5-year survival rate is less than10%.4 The aim of endoscopic surveillance in Barrett’s esophagus is to diagnose esophageal cancer early, when it is potentially curable.2 As most people with Barrett’s esophagus do not develop adenocarcinoma of the esophagus (cancer incidence 0.3% to 0.5% per year),5 the cost-effectiveness of endoscopic surveillance is questionable. Ideally, surveillance algorithms should be based on risk stratification. There is little data to help clinicians identify which people with Barrett’s esophagus are at highest risk for the development of dysplasia and cancer. Current guidelines recommend that everyone with Barrett’s esophagus undergo surveillance at regular intervals, with the expectation that there will be a decrease in mortality from adenocarcinoma.6,7 No randomized trials have found a survival benefit in people undergoing endoscopic surveillance, however.We are not certain whether or not screening improves survival. Another challenge is that the prevalence of Barrett’s esophagus within the general population is unknown. Because of this, we are unsure whether or not most patients are discovered and enrolled into a surveillance program.This study by Dulai and colleagues focuses on this important question: the pre-operative prevalence of Barrett’s esophagus in reported cases of incident adenocarcinoma undergoing surgical resection. Ninety-five percent of people who were eligible for resection, and thus a potential cure, were unaware of the presence of Barrett’s esophagus prior to the development of cancer. Although long standing gastroesophageal reflux disease symptoms, male gender, Caucasian race and age are risk factors in the development of Barrett’s esophagus, these results suggest that it is not adequate to rely on these factors for screening eligibility.The majority of people with Barrett’s esophagus progressing to adenocarcinoma remain undetected. Could this be because most of these people have an ‘asymptomatic’ form of Barrett’s metaplasia?2 Dulai and colleagues suggest that although the incidence of adenocarcinoma has increased over a 30 year period, our ability to detect it has not improved significantly.The authors argue that effective screening strategies to identify people with Barrett’s esophagus are needed. This study addresses an important issue facing primary-care physicians, gastroenterologists, surgeons and medical oncologists. It leads us to question the current Barrett’s esophagus surveillance paradigm as a whole. More questions arise than are answered: Would screening all people with gastroesophageal reflux disease discover those missed? As with colon cancer screening, should the general population be included in screening, and if so, would this be feasible? How do we screen asymptomatic patients? Does all Barrett’s esophagus arise from gastroesophageal
reflux disease? Does all adenocarcinoma arise from Barrett’s esophagus? Is screening and surveillance making an impact on overall survival or are we seeing effects of lead-time bias? There are positive benefits of current screening,7 but this still only detects a minority of people with Barrett’s esophagus at risk for esophageal cancer. Prospective studies to evaluate the effectiveness of screening and surveillance are required. Quality assessment (scale 1 = fair, 4 = excellent) Relevance 4 Validity 3 Applicability 4 Feasibility 2* Impact 4 Knowledge context 3 *The score of 2 awarded to feasibility reflects the study design. Until cost-effective screening strategies are developed for Barrett’s esophagus, upper endoscopy remains the only feasible option for people with chronic gastroesophageal reflux disease symptoms. The surveillance interval may or may not be costeffective. Deepak V Gopal MD, FRCP(C) Division of Gastroenterology Blair A Jobe MD Department of General Surgery Oregon Health Sciences University and Portland Veterans Affairs Medical Center Portland, USA
Literature cited 1. Spechler SJ. Complications of gastroesophageal reflux disease. In Castell DO (ed). The Esophagus, 2nd edn. Boston: Little Brown,1995: 533. 2. Cameron AJ, Ott BJ, Payne WS. The incidence of adenocarcinoma in columnar-lined (Barrett’s) esophagus. N Engl J Med 1985; 313: 857. 3. Devesa SS, Blot WS, Fraumeni JF. Changing patterns in the incidence of esophageal and gastric carcinoma in the United States. Cancer 1998; 83: 2049^2053. 4. Blot WS, McLaughlin JK. The changing epidemiology of esophageal cancer. Semin Oncol 1999; 26; 2^ 8. 5. Drewitz DJ, Sampliner RE, Garewal HS. The incidence of adenocarcinoma in Barrett’s esophagus: A prospective study of 170 patients followed 4.8 years. Am J Gastroenterol 1997; 92: 212. 6. Lieberman DA, Oehlke M, Helfand M. Risk factors for Barrett’s esophagus in community-based practice. Am J Gastroenterol 1997; 92: 1293^1297. 7. Sampliner RE. Practice guidelines on the diagnosis, surveillance, and therapy of Barrett’s esophagus. The Practice Parameters Committee of the American College of Gastroenterology. Am J Gastroenterol 1998; 93: 1028. Level and Quality of Evidence: 1b
Evidence-based Oncology (2002) 3,144 ^145
145