Abstract P3-10-14: The Prognostic Significance of mib-1 (according to St Gallen Criteria) in Patients (pts) with Early Invasive Breast Cancer (EIBC) and Its Relationship with other Biologic Parameters in a Monoinstitutional Series

• Published in: Cancer research (Chicago, Ill.) Vol. 70; no. 24_Supplement; pp. P3 - P3-10-14
• Main Authors: Ferro, A, Caldara, A, Eccher, C, Triolo, R, Aldovini, D, Cuorvo, LV, Frisinghelli, M, Fasanella, L, Berloffa, F, Barbareschi, M, Galligioni, E
• Format: Journal Article
• Language: English
• Published: 15.12.2010
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/0008-5472.SABCS10-P3-10-14

Abstract PURPOSE: To examine interactions between mib-1 and clinical-pathological markers and their impact on outcomes. PATIENTS AND METHODS: Mib-1 was identified by immunohistochemical staining in 3402 EIBC pts treated from 1995 to 2008. Mib-1 was defined as low (15%), intermediate (16%-30%) and high (>30%) value. Correlation between mib-1 and age, tumor size (T), nodal status (N), ER, PR, HER-2, grading (G) was performed by X2 test. Log-rank test and Cox regression model were performed to test mib-1 as prognostic factor for overall survival (OS) and Disease Free Survival (DFS) and its correlation with other known prognostic factors. RESULTS: Median mib-1 was 25%. Mib-1 was low in 1135, intermediate in 1094 and high in 1173 pts. Median age was 62 years. High mib-1 was significantly (P<0.001) associated with younger age, ductal type, greater size, positive N, poor G, absent or low ER and/or PR expression level, positive HER-2, triple negative subtypes, larger use of chemo±hormonotherapy. High mib-1 was a significant predictor of worse DFS and OS (P<0.001). At median follow up of 42 months DFS and OS were 83.1 and 84.8% respectively in high, 88.9 and 89.3% in intermediate, 92.7 and 93.6% respectively in low Mib-1 group. There were 401 relapses (12%): 197 (6%) in high, 121 (3.5%) in intermediate and 83 (2,5%) in low mib-1 group. BC deaths were 368 (10.8 %): 178 (5.2%) in high, 117 (3.4%) intermediate and 73 (2.2%) in low mib-1 group. High mib1 was predictive of poorer prognosis in > 40 years pts (P<0.001), small tumors (T1) (P<0.001), N+ (P<0.001) and N0 (p=0.007), G1 (p=0.02), ER+ and/or PR+ (P<0.001), negative HER-2 (p=0.007), ductal type (P<0.001) respect to intermediate and low Mib1. At Cox regression analysis Mib1 showed independent prognostic value. According to the median value, high mib-1 (>25%) resulted a prognostic factor of worse outcome (P<0.001, HR=1.81, 95% CI=1.42-2.29), along with positive lymph nodes (P<0.001, HR=2.14, 95% CI=1.67-2.74), age<40 yrs (p=0.002, HR=1.93, 95% CI=1.30-2.86), greater tumors (P<0.001, HR=3.11, 95% CI=2.21-4.39), and ER/PR positive tumors (P<0.001, HR=1.742, 95% CI=1.305-2.327). CONCLUSIONS: In our experience, Mib-1 confirms to be a significant prognostic biomarker for DFS and OS in EIBC, providing additional information besides other clinico-pathological parameters to help decision-making of treatment. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-14.