title: Intratumoral Heterogeneity for Ki-67 Index in Invasive Breast Carcinoma: A Study on 131 Consecutive Cases.
abstract: In addition to conventional histopathologic parameters, the assessment of proliferation is a major factor in treatment decision in breast carcinoma patients. The aim of this study was to assess whether Ki-67 heterogeneity in invasive breast carcinomas could have an impact over treatment decision.
  
  
  
  Immunohistochemistry for Ki-67 was evaluated in resection specimens of 131 consecutive invasive breast carcinomas. Heterogeneity was defined as the presence of a low (<17%) and high (>35%) proliferative activity within the same tumor in the same histologic section. The rest of the cases were defined as homogenous. Clinical-pathologic features were also analyzed.
  
  
  
  A total of 107 (81.67%) of the cases were homogenous and 24 of 131 cases (18.32%) showed heterogeneity as defined above. Among these, 10 (41.6%) cases showed a gradient of increasing staining toward the tumor edge and 14 (58.4%) cases showed hot spots. In general, the proliferative activity varied from 1% to 90% in different areas of the tumor. A higher incidence of breast carcinoma was observed after menopause in both groups (83.33% in heterogeneous cases and 79.43% in homogeneous cases) (P=0.783). These groups were similar as far as the most frequent histologic types were concerned: no special type (95.83% vs. 56.07%) (P=0.0001). Tumor histologic grade, T and N stage were similar in both groups. We noted a higher proportion of stage N3 cases in the heterogeneous tumor group (54.16% vs. 34.57%) (P=0.14). Prognostic markers analysis in the heterogeneous cases revealed 100% positivity for hormone receptors (compared with 94.65%) and a much higher proportion of HER2-negative cases (87.5% vs. 73.83%) (P=0.19).
  
  
  
  As Ki-67 heterogeneity can be encountered in breast carcinomas and Ki-67 value could have an impact on clinical decisions, it is mandatory to evaluate the whole specimen and not only the core biopsy specimen and to correlate it with mitotic count.
authors.affiliation: *Department of Pathology, County Emergency Clinical Hospital, Oradea Departments of †Pathology ‡Histology §Cardiology ∥Surgery, University of Medicine and Pharmacy of Tirgu Mures, Tirgu Mures, Romania.
authors.forename: Monica
authors.initials: M
authors.lastname: Boros
authors.forename: Denisa
authors.initials: D
authors.lastname: Moncea
authors.forename: Cosmin
authors.initials: C
authors.lastname: Moldovan
authors.forename: Cristian
authors.initials: C
authors.lastname: Podoleanu
authors.forename: Rares
authors.initials: R
authors.lastname: Georgescu
authors.forename: Simona
authors.initials: S
authors.lastname: Stolnicu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged
chemical_list: D019394:Ki-67 Antigen