Association between smoking during radiotherapy and prognosis in head and neck cancer: a follow-up study.
BACKGROUND
The study objective was to confirm a previous finding that patients with stage III/IV squamous head and neck cancer (SHNC) who smoke during radiotherapy (RT) experience reduced survival.


METHODS
An observational cohort study. Patients' smoking status was assessed weekly by questionnaire plus blood cotinine. Patients were assessed every 3 to 4 months for survival. Logistic regression and Cox proportional hazards analyses were used to detect the independent contribution of smoking on survival.


RESULTS
Of 148 patients, 113 smoked during RT. Blood cotinine and smoking questionnaire responses were highly correlated (Spearman R = .69; p < .0005). Abstainers and very light smokers experienced better survival than light, moderate, and heavy smokers (median, 42 vs 29 months; p = .07). Tumor and nodal status and years smoked were the most important prognostic factors. Smoking during RT was not an independent predictor of survival, but baseline smoking status was (p = .016).


CONCLUSIONS
Smoking status should be documented in all future trials of RT in SHNC to allow for pooled analyses with sufficient power to address this question.
Browman
George P
GP
McMaster University, Hamilton, Ontario Canada. george.browman@hrcc.on.ca
Mohide
E Ann
EA
Willan
Andrew
A
Hodson
Ian
I
Wong
Gene
G
Grimard
Laval
L
MacKenzie
Robert G
RG
El-Sayed
Samy
S
Dunn
Edward
E
Farrell
Sylvia
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D015331:Cohort Studies; D003367:Cotinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D007202:Indicators and Reagents / Q000032:analysis; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D011878:Radiotherapy / Q000009:adverse effects*; D012907:Smoking / Q000009:adverse effects* / Q000097:blood; D011795:Surveys and Questionnaires; D016019:Survival Analysis
D007202:Indicators and Reagents; D003367:Cotinine