Recurrence And Survival In Early Breast Cancer In Relation To Ki-67 Expression

Background: Breast cancer (BC) is the most common malignant tumor in Mexican women. Ki-67 is a nuclear antigen related to cellular proliferation.Objective: To determine the correlation between Ki-67, recurrence and survival in early BC.Material and methods: Women > 18 years old with invasive BC, clinical stages (CS) I - IIB, ductal or lobular, underwent surgery and Ki-67 determination were included. We analyzed 4 groups regarding to Ki-67 (MiB1) expression: 1) < 5%, 2) 6%-20%, 3) 21%-50% and 4) > 51%. We performed an inferential statistical analysis to assess differences between groups and univariate and multivariate analysis for detecting association to recurrence and overall survival (OS).Results: One hundred thirty two patients analyzed. Groups 1-4 were of 23 (17.4%), 49 (37.1%), 39 (29.5%) and 21 (15.9%) patients; median age 48, 48, 51 and 48 years (p>0.05), respectively. Ki-67 correlated with tumor size > 2 cm (p=0.003), estrogen receptor + (p=0.000), p53 + (p=0.048). We detected 18 recurrences (13.6%): 0, 5, 7 and 6 cases in groups 1-4, respectively. There were 0, 2 (4%), 4 (10.2%) and 3 (14.2%) deaths, in each group. CS (odds ratio [Or]=6.69; p=0.03) and Ki-67 level (Or=2.96; p=0.017) were associated to relapse disease. Ki-67 was a factor related to OS [Or=3.3; p=0.04].Conclusions: Elevated Ki-67 (> 5%) is observed in 82% of early BC. Ki-67 expression and CS are the most important prognostic factors for recurrence in early BC.