title: Can we identify the group of small invasive (T1a,b) breast cancers with minimal risk of axillary lymph node involvement? A pathohistological and DNA flow cytometric study.
abstract: The goal of this study was to identify a group of small (≤1cm) breast cancers (T1a,b) with a particularly low probability of axillary lymph node metastases, where routine axillary staging may be unnecessary. We retrospectively analyzed 152 T1a,b breast carcinomas with axillary dissection surgically removed at Clinical Hospital Center Split (Croatia) in the period from 1997 to 2006. The analysis included 40 T1a,b cancers with, and 112 T1a,b cancers without axillary lymph node metastases. The basic morphological features of cancers were investigated histologically, while hormone receptors and HER2/neu were investigated immunohistochemically with an additional CISH analysis of HER2/neu 2+ cases. The ploidy and S-phase fraction were determined by DNA flow cytometry. The association of the investigated features with the likelihood of axillary lymph node metastases was analyzed by univariate and multivariate analysis. The univariate analysis showed that lymph node metastases were associated with tumor size (T1a/T1b; p=0.026), histological type (ductal/non-ductal; p=0.014), lymphovascular invasion (p<0.001), HER2/neu expression (p=0.04), ploidy (p=0.027), and combined values of ploidy and S-phase fraction (p=0.025). The lymphovascular invasion was the only independent factor associated with axillary nodal metastases (p=0.01). In the group of T1a,b cancers without lymphovascular invasion, HER2/neu expression (p=0.021) and combined values of ploidy and S-phase fraction (p=0.016) were independent factors associated with axillary lymph node metastases. This study showed that diploid T1a,b cancers with low S-phase fraction, which are also without lymphovascular invasion and HER2/neu amplification, represented the group of cancers with a low probability of axillary lymph node metastases.
authors.affiliation: Institute of Pathology, Forensic Medicine and Cytology, Clinical Hospital Center, Split, Croatia. jbezic@mefst.hr
authors.forename: Joško
authors.initials: J
authors.lastname: Bezić
authors.forename: Ivana
authors.initials: I
authors.lastname: Samija-Projić
authors.forename: Petar
authors.initials: P
authors.lastname: Projić
authors.forename: Jelena
authors.initials: J
authors.lastname: Ljubković
authors.forename: Vesna
authors.initials: V
authors.lastname: Capkun
authors.forename: Snježana
authors.initials: S
authors.lastname: Tomić
mesh_terms: D001365:Axilla; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D004273:DNA, Neoplasm / Q000032:analysis*; D005260:Female; D005434:Flow Cytometry; D018734:Genes, erbB-2 / Q000235:genetics; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D009367:Neoplasm Staging; D011003:Ploidies; D011237:Predictive Value of Tests; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases