Tobacco and Public Health - TCSC Indonesia

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TOBACCO USE AND RISK OF ORAL CANCER
Descriptive epidemiology
Cancers of the oral cavity and pharynx combined is the sixth most common cancer
site for both sexes (reviewed in Boyle et al. 1990a, 1995; La Vecchia et al. 1997;
Franceschi et al. 2000). Combined these cancers account for approximately 220 000
new cases per year in men and 90 000 in women worldwide. Their incidence rates vary
approximately 20-fold in both sexes across the world. At present, high incidence rates
are found in southern India, Pakistan, northern France, and a few areas of central and
eastern Europe, with the highest rate recorded in Bas Rhin, France (49.4/100 000 men)
(Franceschi et al. 2000).
Men are more likely to be diagnosed with oral cancer than women. Male-to-female
ratios for oral and pharyngeal cancers ranged between 4 and 20 in southern, central,
and eastern Europe (Franceschi et al. 2000). In the United States, the rates for men
are 2.5–4 times higher than those for women (Weller et al. 1993). Based on the SEER
program, in the US, African-Americans have an overall incidence of oral cancer
13.2/100 000, 65% higher than Whites of 8.0/100 000 (Weller et al. 1993). The majority
of these racial and gender differences in the US is attributable to the effects of tobacco
and alcohol (Day 1993).
In many parts of the world (such as India, Puerto Rico, and Colombia), a steady
decline in oral cancer incidence in both sexes has been observed while a stable
incidence rate was observed in the USA (Franceschi et al. 2000). There are, however,
reports that oral cancer is increasing, particularly amongst younger persons in
the Nordic countries and Europe with the reasons unknown (Boyle et al. 1990b;
Macfarlane et al. 1994).
Tobacco use and risk of oral cancer
Cigarette smoking
Oral cancer and smoking has been investigated for many years. The early studies were
restricted by the methodologies of their time and have been the subject of numerous
other reviews (Boyle et al. 1995). Accordingly, this review will focus on more recent
studies using newer epidemiological methods. In fact, a large number of studies have
explored the relationship of cigarette smoking and oral cancer risk over the past
two decades. The methods have varied but largely consist of hospital-based case–
control studies, population-based case–control studies, and prospective follow-up studies.
The major findings using each method are discussed below (also see Table 23.1) with a
brief presentation of the strengths and limitations of each method.
Hospital-based case–control studies:
A number of hospital-based case–control studies have been conducted and have clearly
shown a strong relationship between oral cancer and cigarette smoking. In interpreting
the results from these hospital-based case–control studies, a major concern is whether