The risk of cancer in Barrett's oesophagus
June 21st 2011
Barrett’s oesophagus is associated with a common form of cancer of the oesophagus, but the magnitude of the risk is not clearly known. The progress of the disease is through changes in the lining of the oesophagus, initially with specialised intestinal metaplasia (SIM), followed in a small proportion of patients by increasingly severe grades of pre-cancerous changes in the cells, called dysplasia, and eventually to cancer. This process usually takes many years.
A study recently reported in the Journal of The National Cancer Institute using data from the Northern Ireland Barrett's Oesophagus Register (NIBR) clarifies the risk and offers some comfort to Barrett’s sufferers. NIBR is one of the largest population-based registries of BO worldwide, and includes every adult diagnosed with Barrett’s oesophagus in Northern Ireland between 1993 and 2005.
The study followed more than 8,500 patients diagnosed with Barrett's oesophagus. During a follow-up period averaging seven years, 79 of the patients were diagnosed with oesophageal cancer. 16 patients were diagnosed with cancer of the gastric cardia (the junction of the oesophagus and stomach), and 36 patients developed high-grade dysplasia (abnormality of the cells immediately preceding the development of cancer).
The incidence rate for these three conditions together was 0.22% percent per year (about 1/500 patients per year). This is much less than the approximately 1% annual rates of cancer reported in some previous studies. This may be because this study is population-based, and includes all patients diagnosed with Barrett’s oesophagus.
Comparing those patients with and without SIM, the risk in men with SIM was 7 times greater than in those without, and the cancer risk in women was slightly more than doubled, so if there is no SIM in your biopsies, your risk of cancer is very low.
In contrast, the risk of cancer in patients with low grade dysplasia (LGD) was 1.4% per year, compared with 0.17% in patients without LGD.
All studies have their faults, but this large population-based and inclusive epidemiologic study in a UK population clarifies the risk and offers comfort that it is lower than at first thought. It also offers support for the current policy of stratified frequency of endoscopy. Patients without SIM on biopsy may not need endoscopy. Regular but infrequent endoscopy with biopsy is indicated for patients with SIM, but more frequent examinations are necessary for patients with dysplasia. The study was not intended to contain any information about treatments; further information will be posted as it becomes available.
Risk of Malignant Progression in Barrett's Esophagus Patients: Results from a Large Population-Based Study
S Bhat et al JNCI J Natl Cancer Inst (2011). First published online: June 16, 2011