title: Biologic markers in axillary node-negative breast cancer: differential expression in invasive ductal carcinoma versus invasive lobular carcinoma.
abstract: OBJECTIVE
  The objective of this study was to compare the differential expression of established histopathologic and biologic markers of proliferation, apoptosis, and angiogenesis in invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) in a group of axillary node-negative breast cancers.
  
  
  METHODS
  Two hundred twenty patients with axillary node-negative ILC and IDC who underwent surgery at the University of Texas M. D. Anderson Cancer Center between 1978 and 1995 had tissue available for analysis. Of these, 206 (94%) had IDC and 14 (6%) had ILC. Estrogen receptors, progesterone receptors, tumor and stromal expression of vascular endothelial growth factor receptor 2, CD44, laminin-5, E-cadherin, and topoisomerase-2 were evaluated by immunohistochemical analysis. HER2/neu and alpha6beta4 integrin were evaluated by in situ hybridization. The Fisher exact test was used to calculate significant differences between ILC and IDC. Median age was 59 years.
  
  
  RESULTS
  Invasive lobular carcinoma was more likely to occur in patients aged > 50 years. Invasive lobular carcinoma tended to be > 2 cm (50% vs. 39%), have a nuclear grade of 1/2 (100% vs. 72%), be estrogen receptor positive (93% vs. 70%), HER2/neu negative (92% vs. 68%), have high CD44 expression (31% vs. 16%), low stromal vascular endothelial growth factor receptor 2 expression (36% vs. 47%), no E-cadherin expression (0 vs. 90%), and low laminin-5 expression (15% vs. 25%), compared with IDC.
  
  
  CONCLUSIONS
  Invasive lobular carcinoma and IDC might be distinct histologic types of breast cancer with different expression of biologic markers. These differences, not all being statistically significant in this small study, might generate hypotheses to develop tailored options for future systemic therapy.
authors.affiliation: Department of Breast Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA. agonzalez@mdanderson.org
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Gonzalez-Angulo
authors.forename: Aysegul
authors.initials: A
authors.lastname: Sahin
authors.forename: Savitry
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Shu-Wan
authors.initials: SW
authors.lastname: Kau
authors.forename: Gabriel N
authors.initials: GN
authors.lastname: Hortobagyi
authors.forename: Massimo
authors.initials: M
authors.lastname: Cristofanilli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D044584:Carcinoma, Ductal / Q000378:metabolism*; D018275:Carcinoma, Lobular / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000378:metabolism; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D039503:Integrin alpha6 / Q000378:metabolism; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011987:Receptors, Steroid / Q000032:analysis; D012189:Retrospective Studies; D000097794:Kalinin
chemical_list: D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; D018960:Hyaluronan Receptors; D039503:Integrin alpha6; D011987:Receptors, Steroid; D000097794:Kalinin