title: The effect of smoking on tumour oxygenation and treatment outcome in cervical cancer.
abstract: OBJECTIVE
  Tumour hypoxia is associated with an increased risk of cervical tumour recurrence and death. Because smoking is a modifiable behaviour, it is important to establish the importance of smoking as a prognostic factor. We hypothesized that there is an association between smoking and tumour hypoxia, and that smoking adversely affects radiation response and survival.
  
  
  METHODS
  A smoking history was obtained from 100 of 115 patients with cervical cancer entered into a prospective study of tumour oxygenation. Eighty-seven of these had clinically evident disease and radiation therapy alone was the planned treatment. Patients who smoked within 2 weeks of commencing radiation therapy were considered smokers, and the amount that they smoked was recorded in packs per day. Patients who had never smoked or quit at least 2 weeks prior to radiation therapy were considered non-smokers. Tumour oxygenation was determined using the Eppendorf polarographic oxygen electrode and tumour oxygenation is represented by the hypoxic proportion HP5 (% of pO2 measurements <5 mmHg).
  
  
  RESULTS
  There was no significant association between smoking and tumour hypoxia (P=0.3), haemoglobin (P=0.6) nor tumour size (P=0.1). Progression-free survival at 3 years was 56% for non-smokers and 44% for smokers (P=0.23). In both univariate and multivariate analysis, neither smoking status nor amount smoked were significant predictors of progression-free survival or local control.
  
  
  CONCLUSIONS
  There was no significant association between smoking and tumour hypoxia, treatment response or survival in this study of patients with cervix cancer.
authors.affiliation: Department of Radiation Oncology, Ontario Cancer Institute/Princess Margaret Hospital, University of Toronto, 610 University Avenue, Toronto, Ontario, Canada M5G 2M9. anthony.fyles@rmp.uhn.on.ca
authors.forename: A
authors.initials: A
authors.lastname: Fyles
authors.forename: D
authors.initials: D
authors.lastname: Voduc
authors.forename: A
authors.initials: A
authors.lastname: Syed
authors.forename: M
authors.initials: M
authors.lastname: Milosevic
authors.forename: M
authors.initials: M
authors.lastname: Pintilie
authors.forename: R
authors.initials: R
authors.lastname: Hill
mesh_terms: D000328:Adult; D018572:Disease-Free Survival; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D000860:Hypoxia / Q000209:etiology* / Q000473:pathology; D008487:Medical History Taking; D009367:Neoplasm Staging; D010100:Oxygen / Q000032:analysis; D011379:Prognosis; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000473:pathology* / Q000628:therapy
chemical_list: D006454:Hemoglobins; D010100:Oxygen