Abstract
The resistance of malignant tumors to chemotherapy is often associated with overexpression of the multidrug resistance gene MDR. Its gene product, P-glycoprotein, acts as a drug efflux pump for chemotherapeutic agents. The authors studied MDR expression in 28 adenocarcinomas arising in Barrett's esophagus (EAs) using a monoclonal antibody directed against this gene product. The results were compared with MDR expression in 27 gastric adenocarcinomas (GAs). P-glycoprotein was detected in both tumor and normal mucosa in 7 of 27 GAs and in 6 of 10 EAs that were resected without prior chemotherapy. Chemotherapy was given before surgical resection in 18 of the EAs studied. Five patients had a partial response to chemotherapy, and one had a complete eradication of his carcinoma; all of these tumors were negative for P-glycoprotein. of 12 patients without chemotherapy response, 6 had tumors that expressed P-glycoprotein. The authors conclude that P-glycoprotein is present in EAs and GAs before exposure to chemotherapy. The presence of P-glycoprotein in tumors usually correlates with its presence in the adjacent mucosa. Its presence in tumor cells may be an indicator of lack of sensitivity to chemotherapy.
Original language | English (US) |
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Pages (from-to) | 1-7 |
Number of pages | 7 |
Journal | American journal of clinical pathology |
Volume | 93 |
Issue number | 1 |
DOIs | |
State | Published - 1990 |
Keywords
- Barrett's esophagus
- MDR1
- P-glycoprotein
- esophageal adenocarcinoma
- multidrug resistance
ASJC Scopus subject areas
- Pathology and Forensic Medicine