Cessation of alcohol drinking, tobacco smoking and the reversal of head and neck cancer risk.
BACKGROUND
Quitting tobacco or alcohol use has been reported to reduce the head and neck cancer risk in previous studies. However, it is unclear how many years must pass following cessation of these habits before the risk is reduced, and whether the risk ultimately declines to the level of never smokers or never drinkers.


METHODS
We pooled individual-level data from case-control studies in the International Head and Neck Cancer Epidemiology Consortium. Data were available from 13 studies on drinking cessation (9167 cases and 12 593 controls), and from 17 studies on smoking cessation (12 040 cases and 16 884 controls). We estimated the effect of quitting smoking and drinking on the risk of head and neck cancer and its subsites, by calculating odds ratios (ORs) using logistic regression models.


RESULTS
Quitting tobacco smoking for 1-4 years resulted in a head and neck cancer risk reduction [OR 0.70, confidence interval (CI) 0.61-0.81 compared with current smoking], with the risk reduction due to smoking cessation after > or =20 years (OR 0.23, CI 0.18-0.31), reaching the level of never smokers. For alcohol use, a beneficial effect on the risk of head and neck cancer was only observed after > or =20 years of quitting (OR 0.60, CI 0.40-0.89 compared with current drinking), reaching the level of never drinkers.


CONCLUSIONS
Our results support that cessation of tobacco smoking and cessation of alcohol drinking protect against the development of head and neck cancer.
Marron
Manuela
M
International Agency for Research on Cancer, Lyon, France.
Boffetta
Paolo
P
Zhang
Zuo-Feng
ZF
Zaridze
David
D
Wünsch-Filho
Victor
V
Winn
Deborah M
DM
Wei
Qingyi
Q
Talamini
Renato
R
Szeszenia-Dabrowska
Neonila
N
Sturgis
Erich M
EM
Smith
Elaine
E
Schwartz
Stephen M
SM
Rudnai
Peter
P
Purdue
Mark P
MP
Olshan
Andrew F
AF
Eluf-Neto
Jose
J
Muscat
Joshua
J
Morgenstern
Hal
H
Menezes
Ana
A
McClean
Michael
M
Matos
Elena
E
Mates
Ioan Nicolae
IN
Lissowska
Jolanta
J
Levi
Fabio
F
Lazarus
Philip
P
La Vecchia
Carlo
C
Koifman
Sergio
S
Kelsey
Karl
K
Herrero
Rolando
R
Hayes
Richard B
RB
Franceschi
Silvia
S
Fernandez
Leticia
L
Fabianova
Eleonora
E
Daudt
Alexander W
AW
Dal Maso
Luigino
L
Curado
Maria Paula
MP
Cadoni
Gabriella
G
Chen
Chu
C
Castellsague
Xavier
X
Boccia
Stefania
S
Benhamou
Simone
S
Ferro
Gilles
G
Berthiller
Julien
J
Brennan
Paul
P
Møller
Henrik
H
Hashibe
Mia
M
D000328:Adult; D000367:Age Factors; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology*; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D040242:Risk Reduction Behavior; D012737:Sex Factors; D016540:Smoking Cessation / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D013997:Time Factors