OBJECTIVE: To evaluate the relationship between smoking and uterine my
omas requiring surgery. STUDY DESIGN: We conducted a case-control stud
y in Milan between 1986 and 1992. Cases were 476 patients under 55 yea
rs of age with histologically confirmed myomas. Controls were 1,283 wo
men admitted to the hospital for a spectrum of-acute, other-than-gynec
ologic, hormonal or neoplastic conditions (30% trauma, 25% nontraumati
c orthopedic conditions, 25% surgical, 20% other miscellaneous).RESULT
S: Cases were less frequently current smokers (22%) than controls (32%
). In comparison with never smokers, the multivariate relative risk (R
R) for myomas was 0.5 (95% confidence interval [CI], 0.4-0.7) in smoke
rs. Ex-smokers were 10% of cases versus 7% of controls (RR 1.2, 95% CI
0.9-1.8). No clear trend in risk was observed with the number of ciga
rettes smoked per day or duration of smoking and risk of fibroids. The
estimated RRs were largely consistent when separate analyses were per
formed in strata of body weight. CONCLUSION: Current smoking seems to
reduce the risk of myomas.