PCNA CYCLIN AND P-GLYCOPROTEIN AS PROGNOSTIC FACTORS IN LOCALLY ADVANCED BREAST-CANCER - AN IMMUNOHISTOCHEMICAL, RETROSPECTIVE STUDY

Aims and Background: The alm of the present study was to determine, re trospectively, whether the immunohistochemical expression of two biolo gic markers of aggressivity, P-glycoprotein (P-gp) and PCNA/cyclin (PC NA), could be related to response to chemotherapy and prognosis in loc ally advanced breast cancer. Methods: PC 10 Mab was used to determine the proliferation index (PCNA) and C-219 Mab to determine P-gp in 25 l ocally advanced breast carcinomas subjected to preoperative chemothera py with MDR-related drugs. Results: P-gp and PCNA were expressed in 76 % and 100 % of the tumors, respectively. No case of high P-gp express ion was associated with good chemosensitivity, and all P-gp-negative c ases showed the best chemotherapeutic response. P-gp and PCNA were bot h highly expressed in patients who developed local-regional or distant metastases. No recurrence was associated with a negative or low P-gp score. Conclusions: Statistical analysis showed that high P-gp express ion was related to a poor response to chemotherapy and a short disease -free survival. A high PCNA score was not found to be significant for predicting chemosensitivity or survival.