title: Clinical significance of CK5/6 and PTEN protein expression in patients with bilateral breast carcinoma.
abstract: OBJECTIVE
  To assess the expression of cytokeratin (CK) 5/6 in bilateral breast cancers and to assess the relationship between its expression and other prognostic variables, as well as between CK5/6 expression and patients' survival.
  
  
  RESULTS
  The expression of CK5/6, PTEN protein, oestrogen receptor, progesterone receptor, p53 and c-erbB-2 protein were evaluated by immunohistochemistry in 88 primary breast cancers diagnosed in 44 women. To assess the prognostic value of studied factors, Cox regression analysis was performed. Expression of CK5/6 was found in 23 of 88 primary breast carcinomas (23/88; 26%). The hazard ratio of development of distant metastasis in patients in whom at least one cancer was CK5/6+ was 99.8 (P=0.037) and in patients with at least one carcinoma with reduced PTEN expression it was 10.8 (P=0.044). CK5/6 expression was correlated with absence of oestrogen (P<0.0001) and progesterone receptors (P<0.0001) and very strong expression of p53 (P<0.05). Reduced PTEN expression was correlated with presence of axillary metastases (P<0.01), with very strong expression of c-erbB-2 (P<0.05) and with reduced expression of oestrogen receptor (P<0.05).
  
  
  CONCLUSIONS
  Analysis of expression of CK5/6 and PTEN protein in bilateral breast carcinomas may be of value in clinical practice and warrant further studies.
authors.affiliation: Department of Surgical Oncology, Medical University of Lodz, Poland. januszpiekar@poczta.onet.pl
authors.forename: J H
authors.initials: JH
authors.lastname: Piekarski
authors.forename: W
authors.initials: W
authors.lastname: Biernat
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D005260:Female; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000096:biosynthesis*; D008207:Lymphatic Metastasis / Q000473:pathology; D009378:Neoplasms, Multiple Primary / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis*; D011379:Prognosis; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D016019:Survival Analysis; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53
chemical_list: D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D016159:Tumor Suppressor Protein p53; D007633:Keratins; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human