title: KIT is highly expressed in adenoid cystic carcinoma of the breast, a basal-like carcinoma associated with a favorable outcome.
abstract: Recent biological studies have classified breast carcinomas into HER2-overexpressing, estrogen receptor-positive/luminal, basal- and normal-like groups. According to this new biological classification, the objectives of our study were to assess the clinical, morphologic and immunophenotypic characteristics of adenoid cystic carcinoma of the breast in order to classify this subtype of breast carcinoma. A total of 18 cases of adenoid cystic carcinoma were identified from the Institut Curie files. Clinical information was available for 16 patients with a median follow-up of 6.5 years. Morphologically, all tumors were graded according to the system defined by Kleer and Oberman (histologic and nuclear grade). Immunophenotype was assessed with anti-ER, PR, HER-2, KIT, basal (CK5/6) and luminal cytokeratins (CK8/18) and p63 antibodies. One out of 18 tumors was nuclear grade 1 (16%), nine were nuclear grade 2 (50%) and eight were nuclear grade 3 (44%). All cases were estrogen receptor, progesterone receptor and HER-2 negative. Epithelial cells were strongly positive around glandular lumina with one or both cytokeratins, identifying the coexistence of CK5/6+ cells, CK5/6 and CK8/18+ cells, CK8/18+ cells and p63+ cells. All cases (100%) were also KIT positive. In all, 15 patients were treated by surgery. Nine of them received adjuvant radiotherapy. Follow-up was available for 16 patients. In all, 14 patients were alive. Two of them, initially treated by surgery only, presented a local recurrence. Two patients died (one of them treated by radiation therapy only died from her disease). Our study shows that adenoid cystic carcinoma of the breast is a special, estrogen receptor, progesterone receptor, HER-2 negative and highly KIT-positive, basal-like breast carcinoma, associated with an excellent prognosis. This highly specific immunophenotype could be useful to differentiate adenoid cystic carcinoma of the breast from other subtypes of breast carcinoma such as cribriform carcinoma.
authors.affiliation: Department of Pathology, Institut Curie, Paris Cedex, France.
authors.forename: Sandy
authors.initials: S
authors.lastname: Azoulay
authors.forename: Marick
authors.initials: M
authors.lastname: Laé
authors.forename: Paul
authors.initials: P
authors.lastname: Fréneaux
authors.forename: Solange
authors.initials: S
authors.lastname: Merle
authors.forename: Abir
authors.initials: A
authors.lastname: Al Ghuzlan
authors.forename: Caroline
authors.initials: C
authors.lastname: Chnecker
authors.forename: Christophe
authors.initials: C
authors.lastname: Rosty
authors.forename: Jerzy
authors.initials: J
authors.lastname: Klijanienko
authors.forename: Brigitte
authors.initials: B
authors.lastname: Sigal-Zafrani
authors.forename: Rémy
authors.initials: R
authors.lastname: Salmon
authors.forename: Alain
authors.initials: A
authors.lastname: Fourquet
authors.forename: Xavier
authors.initials: X
authors.lastname: Sastre-Garau
authors.forename: Anne
authors.initials: A
authors.lastname: Vincent-Salomon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D003528:Carcinoma, Adenoid Cystic / Q000175:diagnosis / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000378:metabolism; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D007633:Keratins; D019009:Proto-Oncogene Proteins c-kit; D018719:Erb-b2 Receptor Tyrosine Kinases