Presenting Features of Breast Cancer Differ by Molecular Subtype

• Published in: Annals of surgical oncology 2009-10, Vol.16 (10), p.2705-2710
• Main Authors: Wiechmann, Lisa, Sampson, Michelle, Stempel, Michelle, Jacks, Lindsay M., Patil, Sujata M., King, Tari, Morrow, Monica
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Breast cancer; Breast Neoplasms - diagnosis; Breast Neoplasms - metabolism; Breast Oncology; Female; Humans; Lymph Nodes - pathology; Lymphatic Metastasis; Medicine; Medicine & Public Health; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Neoplasms, Basal Cell - diagnosis; Neoplasms, Basal Cell - metabolism; Oncology; Prognosis; Receptor, ErbB-2 - metabolism; Receptors, Estrogen - metabolism; Receptors, Progesterone - metabolism; Surgery; Surgical Oncology; Young Adult
• ISSN: 1068-9265; 1534-4681
• DOI: 10.1245/s10434-009-0606-2

Background Gene expression profiling of breast cancers identifies distinct molecular subtypes that affect prognosis. Our goal was to determine whether presenting features of tumors differ among molecular subtypes. Methods Subtypes were classified by immunohistochemical surrogates as luminal A (estrogen receptor [ER] and/or progesterone receptor [PR] positive, HER-2 −), luminal B (ER and/or PR+, HER-2 +), HER-2 (ER and PR−, HER-2 +), or basal (ER, PR, HER-2 −). Data were obtained from an established, registered database of patients with invasive breast cancer treated at our institution between January 1998 and June 2007. A total of 6,072 tumors were classifiable into molecular subtypes. The χ 2 test, analysis of variance, and multivariate logistic regression analysis were used to determine associations between subtype and clinicopathologic variables. Results The distribution of subtypes was luminal A, 71%; luminal B, 8%; HER-2 , 6%; and basal, 15%. Marked differences in age, tumor size, extent of lymph node involvement, nuclear grade, multicentric/multifocal disease, lymphovascular invasion (LVI), and extensive intraductal component were observed among subtypes. When compared with luminal A tumors, those overexpressing HER-2 (luminal B, HER-2 ) were significantly more likely to manifest nodal involvement, multifocal, extensive intraductal component, and LVI ( P