IMMUNOHISTOCHEMICAL DETECTION OF BCL-2 AN D MIB-1 KI-67 IN BREAST-CANCER - RETROSPECTIVE ANALYSIS OF 238 CASES/

We considered of interest to determine the possible interrelationship between the proliferation-related marker MIB-1/Ki-67 and the bcl-2, a protein involved in the blockage of apoptosis, and whether they contri buted to the prognosis of breast cancer. For this purpose we carried o ut a retrospective immunohistochemical study of 238 cases of stage I a nd II breast carcinomas with a follow up of at least 5 years. The stud y revealed that high expression of MIB-1 was associated with high nucl ear and histological grades (p < 0.001 for both), negative estrogen re ceptor status (p = 0.009) and progesterone status (p = 0.004), and you nger age (p = 0.014). High bcl-2 expression was associated with smalle r tumor size (p = 0.001); positive estrogen and progesterone receptors (p < 0.001 for both); low nuclear grade (p < 0.001), low histological grade (p < 0.002), stage I disease (p = 0.01) and low MIB-1 expressio n (p = 0.025). The univariate Cox regression showed a significant asso ciation of high MIB-1 expression (p = 0.002) and low bcl-2 expression (p = 0.04) with shorter OS. Furthermore, MIB-1 expression was a signif icant independent predictor of OS (p = 0.002) as showed by stepwise Co x regression analysis.