title: Basal-like grade III invasive ductal carcinoma of the breast: patterns of metastasis and long-term survival.
abstract: BACKGROUND
  Cytokeratin (CK) 14, one of several markers expressed in normal myoepithelial/basal cells, is also expressed in a proportion of breast carcinomas. Previous studies have suggested that expression of such 'basal' markers predicts different biological behaviour, with more frequent lung and brain metastases and poorer prognosis than other carcinomas.
  
  
  METHODS
  We performed CK14 immunohistochemistry on 443 grade III invasive ductal carcinomas with extended clinical follow-up (mean 116 months), and we correlated CK14 immunopositivity (basal-like phenotype) with clinicopathological criteria.
  
  
  RESULTS
  Eighty-eight of 443 (20%) tumours showed CK14 expression. CK14-positive tumours were more likely to be oestrogen receptor-negative (p < 0.0001) and axillary node-negative (p = 0.001) than were CK14-negative cases. CK14-positive cases developed less bone and liver metastases (hazard ratio [HR] 0.49, p = 0.01, and HR 0.53, p = 0.035, respectively) but more frequent brain metastases (HR 1.92, p = 0.051). In patients without metastatic disease, disease-free survival in CK14-positive cases was significantly better than in CK14-negative cases (HR 0.65, p = 0.005). In patients with metastatic disease, however, CK14 positivity was associated with a poorer prognosis (HR 1.84, p = 0.001). The overall survival in CK14-positive and -negative patients was similar at 5 years (60% and 59%, respectively), but the long-term survival was better in CK14-positive patients (HR 0.69, p = 0.02).
  
  
  CONCLUSIONS
  These results demonstrate that basal-like tumours differ in their biological behaviour from other tumours, with a distinct pattern of metastatic spread. Compared to other grade III tumours, basal-like tumours appear to have a relatively good long-term survival but survival after metastases is poor.
authors.affiliation: Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, Fulham Road, London, SW3 6JB, UK. laura.work@gmail.com
authors.forename: Laura G
authors.initials: LG
authors.lastname: Fulford
authors.forename: Jorge S
authors.initials: JS
authors.lastname: Reis-Filho
authors.forename: Ken
authors.initials: K
authors.lastname: Ryder
authors.forename: Chris
authors.initials: C
authors.lastname: Jones
authors.forename: Cheryl E
authors.initials: CE
authors.lastname: Gillett
authors.forename: Andrew
authors.initials: A
authors.lastname: Hanby
authors.forename: Douglas
authors.initials: D
authors.lastname: Easton
authors.forename: Sunil R
authors.initials: SR
authors.lastname: Lakhani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053547:Keratin-14 / Q000032:analysis / Q000378:metabolism; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis; D016019:Survival Analysis
chemical_list: D053547:Keratin-14