title: The prognostic relevance of the mitotic activity index in axillary lymph node-negative breast cancer.
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.
authors.affiliation: Department of Radiation Oncology, Medisch Spectrum Twente, Haaksbergerstraat 55, 7513 ER, Enschede, The Netherlands, jjjobsen@hetnet.nl.
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Jobsen
authors.forename: Job
authors.initials: J
authors.lastname: van der Palen
authors.forename: Mariël
authors.initials: M
authors.lastname: Brinkhuis
authors.forename: Johan W R
authors.initials: JW
authors.lastname: Nortier
authors.forename: Henk
authors.initials: H
authors.lastname: Struikmans
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality* / Q000601:surgery; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D008875:Middle Aged; D008940:Mitotic Index; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult