title: HSP-90 expression as a predictor of response to radiotherapy in head and neck cancer patients.
abstract: OBJECTIVE
  HSP-90 is an intracellular protein that protects the cell from environmental stress situations. The overexpression of HSP-90 isoforms could serve as a mechanism of resistance to radiotherapy for tumour cells. We studied this effect in a sample of head and neck tumours.
  
  
  METHODS
  We included 87 patients diagnosed with oral cavity, oropharynx, larynx and hypopharynx tumours. We studied the expression of the HSP-90 isoforms by real-time PCR on pre-treatment biopsy samples. We analysed the relationship between HSP-90 expression levels and local relapse of the tumour with CRT decision trees.
  
  
  RESULTS
  The expression levels of the inducible citosolic isoform (HSP90AA) allowed the definition of 2 groups of patients with different rates of local relapse. The group with a low expression level showed a 2.9% local relapse rate, while the group with a high expression level showed a 38.2% rate. Survival curves showed differences in time to local relapse for both groups of patients. These differences did not reach statistical significance.
  
  
  CONCLUSIONS
  Radiotherapy response was related to expression levels of HSP-90 in a sample of head and neck cancer patients. This result could prove useful in the selection of treatments for this group of patients.
authors: Servicio de Otorrinolaringología, Hospital de la Santa Creu i Sant Pau, Barcelona, España. Electronic address: jgarcial@santpau.cat.
authors: Jacinto
authors: J
authors: García Lorenzo
authors: Servicio de Otorrinolaringología, Hospital de la Santa Creu i Sant Pau, Barcelona, España.
authors: Xavier
authors: X
authors: León Vintró
authors: Laboratorio de Angiología, Biología Vascular e Inflamación. Instituto de Investigación Biomédica Sant Pau, Barcelona, España.
authors: Mercedes
authors: M
authors: Camacho Pérez de Madrid
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D018841:HSP90 Heat-Shock Proteins / Q000032:analysis* / Q000235:genetics; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis* / Q000235:genetics; D009364:Neoplasm Recurrence, Local / Q000737:chemistry*; D009959:Oropharyngeal Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D020033:Protein Isoforms / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics; D011836:Radiation Tolerance
chemical_list: D018841:HSP90 Heat-Shock Proteins; D009363:Neoplasm Proteins; D020033:Protein Isoforms; D012334:RNA, Neoplasm
keywords: HSP90 Heat-Shock Proteins; Head and Neck Neoplasms; Local Neoplasm Recurrence; Neoplasias de cabeza y cuello; Radioterapia; Radiotherapy; Recidiva local