[Relationship of mdr1 gene expression and multidrug resistance of primary lung cancer].

OBJECTIVE

To evaluate the expression of mdr1 gene in various type of primary lung cancer.

METHOD

A serious of 48 resected primary lung cancer tissues from 5 post-chemotherapy and 43 untreated patients and 33 adjacent normal lung tissues were analyzed for mdr1 gene by RT-PCR method.

RESULTS

Fifteen of 48 tumor tissues were found to have overexpression of mdr1 gene, comprising 6 of 12 adenocarcinomas, 7 of 22 squamous cell carcinomas, 1 of 2 sarcocarcinomas, 1 of 12 small cell carcinomas. Of 5 post-chemotherapy specimens, only one case showed positive. In addition, 3 of 33 adjacent normal tissues also showed mdr1-positive. Overexpression of mdr1 gene did not be associated with tumor size, metastasis and stage of lung cancer. The relapse rate with mdr1-positive cases was higher (80%) than that with mdr1-negative (58%) by one year follow-up of these patients.

CONCLUSION

Overexpression of mdr1 gene can be detected in untreated primary lung cancer, specially in non-small cell lung cancer and may be regarded as one poorly prognostic marker.