AbstractIntroduction: Dietary questionnaire studies have suggested that patients with oesophageal adenocarcinoma are deficient in antioxidants. It is unknown whether the same holds true for patients with the precursor lesion, Barrett's oesophagus. The current study considered the hypothesis that patients with Barrett's oesophagus were deficient in antioxidants compared to reflux patients without evidence of Barrett's oesophagus.Bcl-2 is an inhibitor of apoptosis or programmed cell death and bax is a promoter. p53 is a protein regulating these. Studies have shown a bcl-2/bax ratio favouring bax expression to be predictive of a good response to neoadjuvant chemoradiotherapy; that expression of mutated p53 is predictive of a poor response.The current study considered the hypothesis that the ratio ofbcl-2/bax and the expression of p53 in oesophageal tumours could be used to predict the response to chemoradiotherapy.
Methods: Serum antioxidant profiles (copper, selenium, zinc, vitamins A, C & E, the carotenoids, and xanthophyll) were determined for patients with: Barrett's oesophagus (n=36), erosive oesophagitis (n=32) and patient controls (n=35).The expression of bcl-2, bax and p53 in oesophageal tumour biopsies were ascertained by means of immunohistocytochemistry, and compared with the patients' known response to chemoradiotherapy.
Results: Patients with Barrett's oesophagus had significantly lower levels of selenium, vitamin C and j3-cryptoxanthine compared to the other patient groups.There was no difference demonstrated in the expression ofbcl-2, bax, and p53 between two groups of patients, those responding well, and those responding poorly to chemoradiotherapy.
Conclusion: This study confirmed the hypothesis that patients with Barrett's oesophagus are deficient in certain antioxidants. It is speculated that antioxidant supplementation may play a role in the prevention of this condition and progression to neoplasia.
|Date of Award||2007|