title: Different expression of thymidylate synthase in primary tumour and metastatic nodes in breast cancer patients.
abstract: BACKGROUND
  To date an accurate evaluation of predictive markers in breast cancer is mainly conducted at the primary site, although the main goal of the adjuvant therapy is the control of micrometastases. Adjuvant therapy drugs need a high proliferative cell rate to be effective. The proliferating activity can be evaluated by the Ki-67 marker and even by thymidylate synthase (TS), a cell cycle enzyme present in proliferating cells. In this study the TS levels in primary tumours were compared to those of their metastases.
  
  
  METHODS
  The TS expression and Ki-67 were evaluated by means of immunohistochemistry in 80 primary breast tumours (PTs) and in their matched axillary metastatic lymph-nodes (ALNs).
  
  
  RESULTS
  In 16% of patients, malignant cells of involved nodes showed a lower TS expression than the PTs. In the same group, we also found a lower number of Ki-67 immunoreactive cells in lymph node metastases when compared with primary tumours.
  
  
  CONCLUSIONS
  The group of patients with lower TS and Ki-67 expression in lymph node metastatic cells may be less sensitive to 5-fluorouracil and high dose methotrexate requiring them to be treated with other drug combinations.
authors: Dipartimento di Patologia Umana, Via del Vespro 129, 90100 Palermo, Italy.
authors: Daniela
authors: D
authors: Cabibi
authors: Anna
authors: A
authors: Calascibetta
authors: Anna
authors: A
authors: Martorana
authors: Maria
authors: M
authors: Campione
authors: Elisabetta
authors: E
authors: Barresi
authors: Luciano
authors: L
authors: Rausa
authors: Federico
authors: F
authors: Aragona
authors: Rosario
authors: R
authors: Sanguedolce
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology*; D048708:Cell Growth Processes / Q000502:physiology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008207:Lymphatic Metastasis; D009367:Neoplasm Staging; D013940:Thymidylate Synthase / Q000096:biosynthesis*
chemical_list: D019394:Ki-67 Antigen; D013940:Thymidylate Synthase