Tobacco and Public Health - TCSC Indonesia

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SMOKING AND CERVICAL NEOPLASIA
are unclear, but could reflect a younger age group where current smoking is more
prevalent.
Seven studies report data on both CIN (cervical intraepithelial neoplasia) and invasive
cancer (Szarewski and Cuzick 1998; Hildesheim et al. 2001; Lacey et al. 2001; Zivaljevic
et al. 2001). These studies generally encompass all grades of CIN and separate odds
ratios for CIN and cancer are not given. All but one of these studies show a positive
relationship with smoking, mostly with a dose–response, with adjusted odds ratios
between 1.6 and 7.0 (Fig. 26.4).
Sixteen studies have looked at CIN only, of all grades (Kjaer et al. 1996; Sasagawa et al.
1997; Szarewski and Cuzick 1998; Derchain et al. 1999; Scholes et al. 1999). All but one of
these show a positive relationship with smoking, with adjusted odds ratios between 1.4
and 5.8 for current versus never smokers (Fig. 26.5). Six studies show a dose–response,
three studies do not, and seven do not have appropriate data for this analysis.
It is of interest that some studies which have looked separately at low and high
grades of CIN have found that the relationship with smoking tends to be stronger for
the higher grades. For example, in the study by Cuzick et al. (1990), the adjusted odds
ratio for women with CIN 1 was 1.21 (NS), whereas for CIN 3 it was 1.72 (p < 0.05).
Schiffman et al. (1993) found a significant relationship of smoking with CIN 2/3 in
HPV positive smokers (RR 2.7, 95% CI 1.1–6.5), but not in those with low- grade CIN.
Similar results were reported by Vonka et al. (1984), Morrison et al. (1991), Brisson et al.
(1994), Kjaer et al. (1996), and Derchain et al. (1999) in which the percentage of
smokers increased steadily from controls to CIN 1, to high-grade CIN or cancer.
Buckley 1981
Vonka 1984*†
Mayberry 1985
Slattery 1989
Zivaljevic 2001
All non-controlled
Hildesheim 2001
Lacey (Adeno) 2001
Lacey (CIN 3) 2001
HPV controlled
Combined
0.3 1 2.5 5 10 25
Odds ratio – log scale
Fig. 26.4 Smoking and cervical neoplasia: case–control studies—both cancer and CIN.
*Unadjusted; †Heavy exposure group.