The association between intra-oral cancer and surrogate markers of smoking and alcohol consumption.

OBJECTIVES

1. To describe the relationships between intra-oral cancer incidence, in England and Wales and the corresponding incidence of lung cancer (a surrogate for cigarette smoking), and liver cirrhosis mortality (a surrogate for alcohol consumption). 2) To elucidate the role and relative importance of cigarette smoking and alcohol consumption in the aetiology of intra-oral cancer.

METHOD

Registration data for intra-oral cancer in males and females aged 35 years and over for the 15 regional health authorities (RHAs) in England and Wales in 1979-1983 were obtained from the Office of Population Censuses and Surveys and aggregated for the five-year period. Census-based population data enabled standardised incidence ratios (SIR) to be calculated for each RHA. Using the identical method. SIRs were also computed for lung cancer and standardised mortality ratios (SMR) for liver cirrhosis, the latter for the period 1974-1978 to reflect the shorter induction time for liver disease than for cancer. Correlation coefficients (Spearman's rho) were calculated between the surrogate measures and intra-oral cancer incidence.

RESULTS

For all three diseases a north-south gradient, favouring the more southerly RHAs was generally apparent. For males, the correlation between liver cirrhosis mortality and intra-oral cancer incidence was greater and statistically more significant (rho=0.75, P<0.01) than that between lung and intra-oral cancer incidence (rho = 0.63, P<0.05). For females, the corresponding correlation coefficients were positive but not significant.

CONCLUSION

For males at least, the association between a surrogate marker for alcohol consumption and intra-oral cancer was greater than that observed for cigarette smoking. This adds further evidence to the current view that alcohol consumption may be more important in the aetiology of intra-oral cancer than cigarette smoking.