Role of alcohol and tobacco in the aetiology of head and neck cancer: a case-control study in the Doubs region of France.

A case-control study conducted from 1986 to 1989 using the Doubs Cancer Registry included 299 cases of head and neck cancer and 645 controls from the general population. The results provide an indicator of the respective roles of alcohol and tobacco in all these cancers and on the tumour site. The people who smoked more than one packet of cigarettes a day have a risk that is 13 times higher than that of non-smokers and those who drink more than one and a half litres of wine per day have a risk that is 34 times higher of developing head and neck cancer. The combined exposure of alcohol and tobacco is characterised by a high risk and can be described by a multiplicative model without interaction. The age at onset (below 18 years of age) and the duration of smoking (over 35 years) are high risk factors. The risk decreases after stopping smoking, but only casual smokers (less than 7 cigarettes per day) can hope to have the same risk as non-smokers within a period of 15 years. Subjects smoking only non-filter cigarettes have a higher risk (OR = 1.98) than those who smoke filter cigarettes. The same applies to those who roll their own cigarettes (OR = 1.93) or inhale the smoke (OR = 1.51).