[The clinical significance of P-glycoprotein, lung resistance protein and multidrug resistance related protein expressions in infiltrating breast carcinoma tissues].

OBJECTIVE: Our purpose was to explore clinical significance of three kinds of drug resistance related proteins, including P-glycoprotein (P-gp), lung resistance protein (LRP), multidrug resistance related protein (MRP) expressions in infiltrating breast carcinoma tissues. METHODS: Flow cytometry was used to analyze the expression of drug resistance related proteins in carcinoma tissues and corresponding para-carcinoma tissues from 68 primary infiltrating breast carcinoma patients. RESULTS: The relative fluorescence intensity (RFI) expressed by median (M) of P-gp, LRP and MRP in breast carcinoma tissues were 0.58, 0.51and 0.56 respectively. In corresponding para-carcinoma tissues, their expression level were 0.26, 0.33 and 0.30. Their difference were obvious (P < 0.05). There were not notable differences of drug resistance related protein expressions in different ages, different tumor sizes, different pathological types, different clinical stages, estrogen receptor or progestin receptor negative and positive patients (P > 0.05). The expressions of P-gp and MRP in lymph node metastasis positive patients were 0.61and 0.69, in lymph node metastasis negative patients they were 0.54 and 0.45. There were no notable differences of P-gp and MRP expression in lymph node metastasis negative and positive patients. The expression of LRP (M = 1.49) was higher in lymph node metastasis positive patients than that in negative patients (M = 0.50, P < 0.05). The correlation analysis showed that there was positive correlation between the expression of LRP and MRP in breast carcinoma tissues (P < 0.05). CONCLUSION: The clinical significance of three kinds of drug resistance related protein expressions had differences in infiltrating breast carcinoma tissues. The expression of LRP had related with lymph node metastasis status and had positive correlation with MRP expression. It can become a target in forecasting breast carcinoma prognosis.