Estudio inmunohistoquimico de bcl-2 y MIB-1/KI-67 en el carcinoma de mama analisis retrospectivo en 238 casos

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 contributed to the prognosis of breast cancer. For this purpose we carried out a retrospective immunohistochemical study of 238 cases of stage I and II breast carcinomas with a follow up of at least 5 years. The study revealed that high expression of MIB-1 was associated with high nuclear and histological grades (p < 0,001 for both), negative estrogen receptor status (p = 0.009) and progesterone status (p = 0.004), and younger age (p = 0.014). High bcl-2 expression was associated with smaller 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 expression (p = 0.025). The univariate Cox regression showed a significant association 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 significant independent predictor of OS (p = 0.002) as showed by stepwise Cox regression analysis.