Objectives: To measure the multidrug resistance gene (MDR1) messenger RNA (mRNA) content of ovarian carcinoma and to investigate the clinical significance of MDR1 expression in ovarian carcinoma.
Methods: A sensitive assay based on the polymerase chain reaction (PCR) was used to measure MDR1 mRNA in biopsy samples of 35 ovarian carcinoma, 20 ovarian benign tumors and 17 normal controls. Pathological diagnosis was made from these samples.
Results: (1) The expression rate of MDR1 in ovarian carcinomas was 57.1%, but there was no expression in benign ovarian tumors and in the normal controls. (2) 40.9% of patients given primary treatments and 84.6% of patients previously treated but with relapses had over expression of MDR1 gene. (3) The positive expression rate of MDR1 in cancer lesion, its adjacent sites and metastasis was 52.9%, 11.8% and 70.6% respectively. (4) The response rate to chemotherapy was lower in patients with overexpression of MDR1 gene than in patients without such expression. (5) No significant correlation was observed when the positive rate of expression of MDR1 in cancer tissues was analyzed against clinical stages and pathological types.
Conclusions: The overexpression of MDR1 was correlated with acquired drug-resistance in patients with ovarian caracinoma. Measurement of the expression of MDR1 in a patient's tumor may be of value clinically in detecting drug-sensitivity and in predicting prognosis.