Published in:
01-01-2015 | Preclinical study
The prognostic relevance of the mitotic activity index in axillary lymph node-negative breast cancer
Authors:
Jan J. Jobsen, Job van der Palen, Mariël Brinkhuis, Johan W. R. Nortier, Henk Struikmans
Published in:
Breast Cancer Research and Treatment
|
Issue 2/2015
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Abstract
The aim of the present study is to look at the mitotic activity index (MAI) as a prognostic factor in a prospective population-based cohort of lymph node-negative invasive breast cancer patients. Analyses were based on 2,048 breast-conserving therapies in 1,971 patients, node-negative, and without any form of adjuvant systemic therapy with long-term follow-up. The 15-year distant metastases-free survival (DMFS) for women ≤55 years was 88.3 % for low MAI values (≤12) versus 73.4 % for high MAI values (>12); (HR 2.8; 95 % CI 1.8–4.4; p < 0.001). Multivariate analyses for DMFS showed significance for MAI. For MAI and Bloom–Richardson grading, by performing a likelihood ratio test, we showed the statistical significance for both. For women >55-years, the MAI was not an independent significant factor. We also confirmed the above findings for disease-specific survival. When multi-gene assays are not available, the MAI remains a robust prognostic marker in women younger than 55 years of age with early node-negative breast cancer.